From 0722db015c246204044299eae3b02d18d3ca4faf Mon Sep 17 00:00:00 2001 From: "K.Prasad" Date: Mon, 1 Jun 2009 23:46:40 +0530 Subject: hw-breakpoints: ftrace plugin for kernel symbol tracing using HW Breakpoint interfaces This patch adds an ftrace plugin to detect and profile memory access over kernel variables. It uses HW Breakpoint interfaces to 'watch memory addresses. Signed-off-by: K.Prasad Signed-off-by: Frederic Weisbecker --- kernel/trace/trace.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 6e735d4771f..7d5cc37b8fc 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -15,6 +15,10 @@ #include #include +#ifdef CONFIG_KSYM_TRACER +#include +#endif + enum trace_type { __TRACE_FIRST_TYPE = 0, @@ -40,6 +44,7 @@ enum trace_type { TRACE_KMEM_FREE, TRACE_POWER, TRACE_BLK, + TRACE_KSYM, __TRACE_LAST_TYPE, }; @@ -207,6 +212,21 @@ struct syscall_trace_exit { unsigned long ret; }; +#define KSYM_SELFTEST_ENTRY "ksym_selftest_dummy" +extern int process_new_ksym_entry(char *ksymname, int op, unsigned long addr); + +struct trace_ksym { + struct trace_entry ent; + struct hw_breakpoint *ksym_hbp; + unsigned long ksym_addr; + unsigned long ip; +#ifdef CONFIG_PROFILE_KSYM_TRACER + unsigned long counter; +#endif + struct hlist_node ksym_hlist; + char ksym_name[KSYM_NAME_LEN]; + char p_name[TASK_COMM_LEN]; +}; /* * trace_flag_type is an enumeration that holds different @@ -323,6 +343,7 @@ extern void __ftrace_bad_type(void); TRACE_SYSCALL_ENTER); \ IF_ASSIGN(var, ent, struct syscall_trace_exit, \ TRACE_SYSCALL_EXIT); \ + IF_ASSIGN(var, ent, struct trace_ksym, TRACE_KSYM); \ __ftrace_bad_type(); \ } while (0) @@ -540,6 +561,8 @@ extern int trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr); extern int trace_selftest_startup_hw_branches(struct tracer *trace, struct trace_array *tr); +extern int trace_selftest_startup_ksym(struct tracer *trace, + struct trace_array *tr); #endif /* CONFIG_FTRACE_STARTUP_TEST */ extern void *head_page(struct trace_array_cpu *data); -- cgit v1.2.3-70-g09d2 From db59504d89db1462a5281fb55b1d962cb74a398f Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Tue, 7 Jul 2009 13:52:36 +0800 Subject: ksym_tracer: Extract trace entry from struct trace_ksym struct trace_ksym is used as an entry in hbp list, and is also used as trace_entry stored in ring buffer. This is not necessary and is a waste of memory in ring buffer. There is also a bug that dereferencing field->ksym_hbp in ksym_trace_output() can be invalid. Signed-off-by: Li Zefan Acked-by: Frederic Weisbecker Cc: "K.Prasad" Cc: Alan Stern Cc: Steven Rostedt LKML-Reference: <4A52E2A4.4050007@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace.h | 13 ++++--------- kernel/trace/trace_ksym.c | 26 ++++++++++++++++++-------- 2 files changed, 22 insertions(+), 17 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 7d5cc37b8fc..ff1ef411a17 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -215,17 +215,12 @@ struct syscall_trace_exit { #define KSYM_SELFTEST_ENTRY "ksym_selftest_dummy" extern int process_new_ksym_entry(char *ksymname, int op, unsigned long addr); -struct trace_ksym { +struct ksym_trace_entry { struct trace_entry ent; - struct hw_breakpoint *ksym_hbp; - unsigned long ksym_addr; unsigned long ip; -#ifdef CONFIG_PROFILE_KSYM_TRACER - unsigned long counter; -#endif - struct hlist_node ksym_hlist; + unsigned char type; char ksym_name[KSYM_NAME_LEN]; - char p_name[TASK_COMM_LEN]; + char cmd[TASK_COMM_LEN]; }; /* @@ -343,7 +338,7 @@ extern void __ftrace_bad_type(void); TRACE_SYSCALL_ENTER); \ IF_ASSIGN(var, ent, struct syscall_trace_exit, \ TRACE_SYSCALL_EXIT); \ - IF_ASSIGN(var, ent, struct trace_ksym, TRACE_KSYM); \ + IF_ASSIGN(var, ent, struct ksym_trace_entry, TRACE_KSYM);\ __ftrace_bad_type(); \ } while (0) diff --git a/kernel/trace/trace_ksym.c b/kernel/trace/trace_ksym.c index eef97e7c8db..085ff055fdf 100644 --- a/kernel/trace/trace_ksym.c +++ b/kernel/trace/trace_ksym.c @@ -37,6 +37,15 @@ #define KSYM_TRACER_OP_LEN 3 /* rw- */ #define KSYM_FILTER_ENTRY_LEN (KSYM_NAME_LEN + KSYM_TRACER_OP_LEN + 1) +struct trace_ksym { + struct hw_breakpoint *ksym_hbp; + unsigned long ksym_addr; +#ifdef CONFIG_PROFILE_KSYM_TRACER + unsigned long counter; +#endif + struct hlist_node ksym_hlist; +}; + static struct trace_array *ksym_trace_array; static unsigned int ksym_filter_entry_count; @@ -71,7 +80,7 @@ void ksym_hbp_handler(struct hw_breakpoint *hbp, struct pt_regs *regs) { struct ring_buffer_event *event; struct trace_array *tr; - struct trace_ksym *entry; + struct ksym_trace_entry *entry; int pc; if (!ksym_tracing_enabled) @@ -85,11 +94,12 @@ void ksym_hbp_handler(struct hw_breakpoint *hbp, struct pt_regs *regs) if (!event) return; - entry = ring_buffer_event_data(event); + entry = ring_buffer_event_data(event); + entry->ip = instruction_pointer(regs); + entry->type = hbp->info.type; strlcpy(entry->ksym_name, hbp->info.name, KSYM_SYMBOL_LEN); - entry->ksym_hbp = hbp; - entry->ip = instruction_pointer(regs); - strlcpy(entry->p_name, current->comm, TASK_COMM_LEN); + strlcpy(entry->cmd, current->comm, TASK_COMM_LEN); + #ifdef CONFIG_PROFILE_KSYM_TRACER ksym_collect_stats(hbp->info.address); #endif /* CONFIG_PROFILE_KSYM_TRACER */ @@ -380,7 +390,7 @@ static enum print_line_t ksym_trace_output(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; struct trace_seq *s = &iter->seq; - struct trace_ksym *field; + struct ksym_trace_entry *field; char str[KSYM_SYMBOL_LEN]; int ret; @@ -389,12 +399,12 @@ static enum print_line_t ksym_trace_output(struct trace_iterator *iter) trace_assign_type(field, entry); - ret = trace_seq_printf(s, "%-15s %-5d %-3d %-20s ", field->p_name, + ret = trace_seq_printf(s, "%-15s %-5d %-3d %-20s ", field->cmd, entry->pid, iter->cpu, field->ksym_name); if (!ret) return TRACE_TYPE_PARTIAL_LINE; - switch (field->ksym_hbp->info.type) { + switch (field->type) { case HW_BREAKPOINT_WRITE: ret = trace_seq_printf(s, " W "); break; -- cgit v1.2.3-70-g09d2 From 413d37d1eb69c1765b9ace0a612dac9b6c990e66 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 13 Aug 2009 16:35:11 -0400 Subject: tracing: Add kprobe-based event tracer MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add kprobes-based event tracer on ftrace. This tracer is similar to the events tracer which is based on Tracepoint infrastructure. Instead of Tracepoint, this tracer is based on kprobes (kprobe and kretprobe). It probes anywhere where kprobes can probe(this means, all functions body except for __kprobes functions). Similar to the events tracer, this tracer doesn't need to be activated via current_tracer, instead of that, just set probe points via /sys/kernel/debug/tracing/kprobe_events. And you can set filters on each probe events via /sys/kernel/debug/tracing/events/kprobes//filter. This tracer supports following probe arguments for each probe. %REG : Fetch register REG sN : Fetch Nth entry of stack (N >= 0) sa : Fetch stack address. @ADDR : Fetch memory at ADDR (ADDR should be in kernel) @SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol) aN : Fetch function argument. (N >= 0) rv : Fetch return value. ra : Fetch return address. +|-offs(FETCHARG) : fetch memory at FETCHARG +|- offs address. See Documentation/trace/kprobetrace.txt in the next patch for details. Changes from v13: - Support 'sa' for stack address. - Use call->data instead of container_of() macro. [fweisbec@gmail.com: Fixed conflict against latest tracing/core] Signed-off-by: Masami Hiramatsu Acked-by: Ananth N Mavinakayanahalli Cc: Avi Kivity Cc: Andi Kleen Cc: Christoph Hellwig Cc: Frank Ch. Eigler Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Jason Baron Cc: Jim Keniston Cc: K.Prasad Cc: Lai Jiangshan Cc: Li Zefan Cc: Przemysław Pawełczyk Cc: Roland McGrath Cc: Sam Ravnborg Cc: Srikar Dronamraju Cc: Steven Rostedt Cc: Tom Zanussi Cc: Vegard Nossum LKML-Reference: <20090813203510.31965.29123.stgit@localhost.localdomain> Signed-off-by: Frederic Weisbecker --- kernel/trace/Kconfig | 12 + kernel/trace/Makefile | 1 + kernel/trace/trace.h | 30 + kernel/trace/trace_event_types.h | 18 + kernel/trace/trace_kprobe.c | 1202 ++++++++++++++++++++++++++++++++++++++ 5 files changed, 1263 insertions(+) create mode 100644 kernel/trace/trace_kprobe.c (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 06be85a7ef8..fb5fbf75f27 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -411,6 +411,18 @@ config BLK_DEV_IO_TRACE If unsure, say N. +config KPROBE_TRACER + depends on KPROBES + depends on X86 + bool "Trace kprobes" + select TRACING + select GENERIC_TRACER + help + This tracer probes everywhere where kprobes can probe it, and + records various registers and memories specified by user. + This also allows you to trace kprobe probe points as a dynamic + defined events. It provides per-probe event filtering interface. + config DYNAMIC_FTRACE bool "enable/disable ftrace tracepoints dynamically" depends on FUNCTION_TRACER diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 844164dca90..7c00a1ec149 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -54,5 +54,6 @@ obj-$(CONFIG_EVENT_TRACING) += trace_export.o obj-$(CONFIG_FTRACE_SYSCALLS) += trace_syscalls.o obj-$(CONFIG_EVENT_PROFILE) += trace_event_profile.o obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o +obj-$(CONFIG_KPROBE_TRACER) += trace_kprobe.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 654fd657bd0..667f832d16b 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -38,6 +38,8 @@ enum trace_type { TRACE_KMEM_FREE, TRACE_POWER, TRACE_BLK, + TRACE_KPROBE, + TRACE_KRETPROBE, __TRACE_LAST_TYPE, }; @@ -205,6 +207,30 @@ struct syscall_trace_exit { unsigned long ret; }; +struct kprobe_trace_entry { + struct trace_entry ent; + unsigned long ip; + int nargs; + unsigned long args[]; +}; + +#define SIZEOF_KPROBE_TRACE_ENTRY(n) \ + (offsetof(struct kprobe_trace_entry, args) + \ + (sizeof(unsigned long) * (n))) + +struct kretprobe_trace_entry { + struct trace_entry ent; + unsigned long func; + unsigned long ret_ip; + int nargs; + unsigned long args[]; +}; + +#define SIZEOF_KRETPROBE_TRACE_ENTRY(n) \ + (offsetof(struct kretprobe_trace_entry, args) + \ + (sizeof(unsigned long) * (n))) + + /* * trace_flag_type is an enumeration that holds different @@ -317,6 +343,10 @@ extern void __ftrace_bad_type(void); TRACE_KMEM_ALLOC); \ IF_ASSIGN(var, ent, struct kmemtrace_free_entry, \ TRACE_KMEM_FREE); \ + IF_ASSIGN(var, ent, struct kprobe_trace_entry, \ + TRACE_KPROBE); \ + IF_ASSIGN(var, ent, struct kretprobe_trace_entry, \ + TRACE_KRETPROBE); \ __ftrace_bad_type(); \ } while (0) diff --git a/kernel/trace/trace_event_types.h b/kernel/trace/trace_event_types.h index e74f0906ab1..186b598a1f1 100644 --- a/kernel/trace/trace_event_types.h +++ b/kernel/trace/trace_event_types.h @@ -175,4 +175,22 @@ TRACE_EVENT_FORMAT(kmem_free, TRACE_KMEM_FREE, kmemtrace_free_entry, ignore, TP_RAW_FMT("type:%u call_site:%lx ptr:%p") ); +TRACE_EVENT_FORMAT(kprobe, TRACE_KPROBE, kprobe_trace_entry, ignore, + TRACE_STRUCT( + TRACE_FIELD(unsigned long, ip, ip) + TRACE_FIELD(int, nargs, nargs) + TRACE_FIELD_ZERO(unsigned long, args) + ), + TP_RAW_FMT("%08lx: args:0x%lx ...") +); + +TRACE_EVENT_FORMAT(kretprobe, TRACE_KRETPROBE, kretprobe_trace_entry, ignore, + TRACE_STRUCT( + TRACE_FIELD(unsigned long, func, func) + TRACE_FIELD(unsigned long, ret_ip, ret_ip) + TRACE_FIELD(int, nargs, nargs) + TRACE_FIELD_ZERO(unsigned long, args) + ), + TP_RAW_FMT("%08lx <- %08lx: args:0x%lx ...") +); #undef TRACE_SYSTEM diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c new file mode 100644 index 00000000000..0c4f00aafb9 --- /dev/null +++ b/kernel/trace/trace_kprobe.c @@ -0,0 +1,1202 @@ +/* + * kprobe based kernel tracer + * + * Created by Masami Hiramatsu + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "trace.h" +#include "trace_output.h" + +#define TRACE_KPROBE_ARGS 6 +#define MAX_ARGSTR_LEN 63 + +/* currently, trace_kprobe only supports X86. */ + +struct fetch_func { + unsigned long (*func)(struct pt_regs *, void *); + void *data; +}; + +static __kprobes unsigned long call_fetch(struct fetch_func *f, + struct pt_regs *regs) +{ + return f->func(regs, f->data); +} + +/* fetch handlers */ +static __kprobes unsigned long fetch_register(struct pt_regs *regs, + void *offset) +{ + return regs_get_register(regs, (unsigned int)((unsigned long)offset)); +} + +static __kprobes unsigned long fetch_stack(struct pt_regs *regs, + void *num) +{ + return regs_get_kernel_stack_nth(regs, + (unsigned int)((unsigned long)num)); +} + +static __kprobes unsigned long fetch_memory(struct pt_regs *regs, void *addr) +{ + unsigned long retval; + + if (probe_kernel_address(addr, retval)) + return 0; + return retval; +} + +static __kprobes unsigned long fetch_argument(struct pt_regs *regs, void *num) +{ + return regs_get_argument_nth(regs, (unsigned int)((unsigned long)num)); +} + +static __kprobes unsigned long fetch_retvalue(struct pt_regs *regs, + void *dummy) +{ + return regs_return_value(regs); +} + +static __kprobes unsigned long fetch_ip(struct pt_regs *regs, void *dummy) +{ + return instruction_pointer(regs); +} + +static __kprobes unsigned long fetch_stack_address(struct pt_regs *regs, + void *dummy) +{ + return kernel_stack_pointer(regs); +} + +/* Memory fetching by symbol */ +struct symbol_cache { + char *symbol; + long offset; + unsigned long addr; +}; + +static unsigned long update_symbol_cache(struct symbol_cache *sc) +{ + sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); + if (sc->addr) + sc->addr += sc->offset; + return sc->addr; +} + +static void free_symbol_cache(struct symbol_cache *sc) +{ + kfree(sc->symbol); + kfree(sc); +} + +static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) +{ + struct symbol_cache *sc; + + if (!sym || strlen(sym) == 0) + return NULL; + sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); + if (!sc) + return NULL; + + sc->symbol = kstrdup(sym, GFP_KERNEL); + if (!sc->symbol) { + kfree(sc); + return NULL; + } + sc->offset = offset; + + update_symbol_cache(sc); + return sc; +} + +static __kprobes unsigned long fetch_symbol(struct pt_regs *regs, void *data) +{ + struct symbol_cache *sc = data; + + if (sc->addr) + return fetch_memory(regs, (void *)sc->addr); + else + return 0; +} + +/* Special indirect memory access interface */ +struct indirect_fetch_data { + struct fetch_func orig; + long offset; +}; + +static __kprobes unsigned long fetch_indirect(struct pt_regs *regs, void *data) +{ + struct indirect_fetch_data *ind = data; + unsigned long addr; + + addr = call_fetch(&ind->orig, regs); + if (addr) { + addr += ind->offset; + return fetch_memory(regs, (void *)addr); + } else + return 0; +} + +static __kprobes void free_indirect_fetch_data(struct indirect_fetch_data *data) +{ + if (data->orig.func == fetch_indirect) + free_indirect_fetch_data(data->orig.data); + else if (data->orig.func == fetch_symbol) + free_symbol_cache(data->orig.data); + kfree(data); +} + +/** + * kprobe_trace_core + */ + +struct trace_probe { + struct list_head list; + union { + struct kprobe kp; + struct kretprobe rp; + }; + const char *symbol; /* symbol name */ + unsigned int nr_args; + struct fetch_func args[TRACE_KPROBE_ARGS]; + struct ftrace_event_call call; +}; + +static int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs); +static int kretprobe_trace_func(struct kretprobe_instance *ri, + struct pt_regs *regs); + +static __kprobes int probe_is_return(struct trace_probe *tp) +{ + return (tp->rp.handler == kretprobe_trace_func); +} + +static __kprobes const char *probe_symbol(struct trace_probe *tp) +{ + return tp->symbol ? tp->symbol : "unknown"; +} + +static __kprobes long probe_offset(struct trace_probe *tp) +{ + return (probe_is_return(tp)) ? tp->rp.kp.offset : tp->kp.offset; +} + +static __kprobes void *probe_address(struct trace_probe *tp) +{ + return (probe_is_return(tp)) ? tp->rp.kp.addr : tp->kp.addr; +} + +static int trace_arg_string(char *buf, size_t n, struct fetch_func *ff) +{ + int ret = -EINVAL; + + if (ff->func == fetch_argument) + ret = snprintf(buf, n, "a%lu", (unsigned long)ff->data); + else if (ff->func == fetch_register) { + const char *name; + name = regs_query_register_name((unsigned int)((long)ff->data)); + ret = snprintf(buf, n, "%%%s", name); + } else if (ff->func == fetch_stack) + ret = snprintf(buf, n, "s%lu", (unsigned long)ff->data); + else if (ff->func == fetch_memory) + ret = snprintf(buf, n, "@0x%p", ff->data); + else if (ff->func == fetch_symbol) { + struct symbol_cache *sc = ff->data; + ret = snprintf(buf, n, "@%s%+ld", sc->symbol, sc->offset); + } else if (ff->func == fetch_retvalue) + ret = snprintf(buf, n, "rv"); + else if (ff->func == fetch_ip) + ret = snprintf(buf, n, "ra"); + else if (ff->func == fetch_stack_address) + ret = snprintf(buf, n, "sa"); + else if (ff->func == fetch_indirect) { + struct indirect_fetch_data *id = ff->data; + size_t l = 0; + ret = snprintf(buf, n, "%+ld(", id->offset); + if (ret >= n) + goto end; + l += ret; + ret = trace_arg_string(buf + l, n - l, &id->orig); + if (ret < 0) + goto end; + l += ret; + ret = snprintf(buf + l, n - l, ")"); + ret += l; + } +end: + if (ret >= n) + return -ENOSPC; + return ret; +} + +static int register_probe_event(struct trace_probe *tp); +static void unregister_probe_event(struct trace_probe *tp); + +static DEFINE_MUTEX(probe_lock); +static LIST_HEAD(probe_list); + +static struct trace_probe *alloc_trace_probe(const char *symbol, + const char *event) +{ + struct trace_probe *tp; + + tp = kzalloc(sizeof(struct trace_probe), GFP_KERNEL); + if (!tp) + return ERR_PTR(-ENOMEM); + + if (symbol) { + tp->symbol = kstrdup(symbol, GFP_KERNEL); + if (!tp->symbol) + goto error; + } + if (event) { + tp->call.name = kstrdup(event, GFP_KERNEL); + if (!tp->call.name) + goto error; + } + + INIT_LIST_HEAD(&tp->list); + return tp; +error: + kfree(tp->symbol); + kfree(tp); + return ERR_PTR(-ENOMEM); +} + +static void free_trace_probe(struct trace_probe *tp) +{ + int i; + + for (i = 0; i < tp->nr_args; i++) + if (tp->args[i].func == fetch_symbol) + free_symbol_cache(tp->args[i].data); + else if (tp->args[i].func == fetch_indirect) + free_indirect_fetch_data(tp->args[i].data); + + kfree(tp->call.name); + kfree(tp->symbol); + kfree(tp); +} + +static struct trace_probe *find_probe_event(const char *event) +{ + struct trace_probe *tp; + + list_for_each_entry(tp, &probe_list, list) + if (tp->call.name && !strcmp(tp->call.name, event)) + return tp; + return NULL; +} + +static void __unregister_trace_probe(struct trace_probe *tp) +{ + if (probe_is_return(tp)) + unregister_kretprobe(&tp->rp); + else + unregister_kprobe(&tp->kp); +} + +/* Unregister a trace_probe and probe_event: call with locking probe_lock */ +static void unregister_trace_probe(struct trace_probe *tp) +{ + if (tp->call.name) + unregister_probe_event(tp); + __unregister_trace_probe(tp); + list_del(&tp->list); +} + +/* Register a trace_probe and probe_event */ +static int register_trace_probe(struct trace_probe *tp) +{ + struct trace_probe *old_tp; + int ret; + + mutex_lock(&probe_lock); + + if (probe_is_return(tp)) + ret = register_kretprobe(&tp->rp); + else + ret = register_kprobe(&tp->kp); + + if (ret) { + pr_warning("Could not insert probe(%d)\n", ret); + if (ret == -EILSEQ) { + pr_warning("Probing address(0x%p) is not an " + "instruction boundary.\n", + probe_address(tp)); + ret = -EINVAL; + } + goto end; + } + /* register as an event */ + if (tp->call.name) { + old_tp = find_probe_event(tp->call.name); + if (old_tp) { + /* delete old event */ + unregister_trace_probe(old_tp); + free_trace_probe(old_tp); + } + ret = register_probe_event(tp); + if (ret) { + pr_warning("Faild to register probe event(%d)\n", ret); + __unregister_trace_probe(tp); + } + } + list_add_tail(&tp->list, &probe_list); +end: + mutex_unlock(&probe_lock); + return ret; +} + +/* Split symbol and offset. */ +static int split_symbol_offset(char *symbol, long *offset) +{ + char *tmp; + int ret; + + if (!offset) + return -EINVAL; + + tmp = strchr(symbol, '+'); + if (!tmp) + tmp = strchr(symbol, '-'); + + if (tmp) { + /* skip sign because strict_strtol doesn't accept '+' */ + ret = strict_strtol(tmp + 1, 0, offset); + if (ret) + return ret; + if (*tmp == '-') + *offset = -(*offset); + *tmp = '\0'; + } else + *offset = 0; + return 0; +} + +#define PARAM_MAX_ARGS 16 +#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) + +static int parse_trace_arg(char *arg, struct fetch_func *ff, int is_return) +{ + int ret = 0; + unsigned long param; + long offset; + char *tmp; + + switch (arg[0]) { + case 'a': /* argument */ + ret = strict_strtoul(arg + 1, 10, ¶m); + if (ret || param > PARAM_MAX_ARGS) + ret = -EINVAL; + else { + ff->func = fetch_argument; + ff->data = (void *)param; + } + break; + case 'r': /* retval or retaddr */ + if (is_return && arg[1] == 'v') { + ff->func = fetch_retvalue; + ff->data = NULL; + } else if (is_return && arg[1] == 'a') { + ff->func = fetch_ip; + ff->data = NULL; + } else + ret = -EINVAL; + break; + case '%': /* named register */ + ret = regs_query_register_offset(arg + 1); + if (ret >= 0) { + ff->func = fetch_register; + ff->data = (void *)(unsigned long)ret; + ret = 0; + } + break; + case 's': /* stack */ + if (arg[1] == 'a') { + ff->func = fetch_stack_address; + ff->data = NULL; + } else { + ret = strict_strtoul(arg + 1, 10, ¶m); + if (ret || param > PARAM_MAX_STACK) + ret = -EINVAL; + else { + ff->func = fetch_stack; + ff->data = (void *)param; + } + } + break; + case '@': /* memory or symbol */ + if (isdigit(arg[1])) { + ret = strict_strtoul(arg + 1, 0, ¶m); + if (ret) + break; + ff->func = fetch_memory; + ff->data = (void *)param; + } else { + ret = split_symbol_offset(arg + 1, &offset); + if (ret) + break; + ff->data = alloc_symbol_cache(arg + 1, + offset); + if (ff->data) + ff->func = fetch_symbol; + else + ret = -EINVAL; + } + break; + case '+': /* indirect memory */ + case '-': + tmp = strchr(arg, '('); + if (!tmp) { + ret = -EINVAL; + break; + } + *tmp = '\0'; + ret = strict_strtol(arg + 1, 0, &offset); + if (ret) + break; + if (arg[0] == '-') + offset = -offset; + arg = tmp + 1; + tmp = strrchr(arg, ')'); + if (tmp) { + struct indirect_fetch_data *id; + *tmp = '\0'; + id = kzalloc(sizeof(struct indirect_fetch_data), + GFP_KERNEL); + if (!id) + return -ENOMEM; + id->offset = offset; + ret = parse_trace_arg(arg, &id->orig, is_return); + if (ret) + kfree(id); + else { + ff->func = fetch_indirect; + ff->data = (void *)id; + } + } else + ret = -EINVAL; + break; + default: + /* TODO: support custom handler */ + ret = -EINVAL; + } + return ret; +} + +static int create_trace_probe(int argc, char **argv) +{ + /* + * Argument syntax: + * - Add kprobe: p[:EVENT] SYMBOL[+OFFS|-OFFS]|ADDRESS [FETCHARGS] + * - Add kretprobe: r[:EVENT] SYMBOL[+0] [FETCHARGS] + * Fetch args: + * aN : fetch Nth of function argument. (N:0-) + * rv : fetch return value + * ra : fetch return address + * sa : fetch stack address + * sN : fetch Nth of stack (N:0-) + * @ADDR : fetch memory at ADDR (ADDR should be in kernel) + * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) + * %REG : fetch register REG + * Indirect memory fetch: + * +|-offs(ARG) : fetch memory at ARG +|- offs address. + */ + struct trace_probe *tp; + struct kprobe *kp; + int i, ret = 0; + int is_return = 0; + char *symbol = NULL, *event = NULL; + long offset = 0; + void *addr = NULL; + + if (argc < 2) + return -EINVAL; + + if (argv[0][0] == 'p') + is_return = 0; + else if (argv[0][0] == 'r') + is_return = 1; + else + return -EINVAL; + + if (argv[0][1] == ':') { + event = &argv[0][2]; + if (strlen(event) == 0) { + pr_info("Event name is not specifiled\n"); + return -EINVAL; + } + } + + if (isdigit(argv[1][0])) { + if (is_return) + return -EINVAL; + /* an address specified */ + ret = strict_strtoul(&argv[0][2], 0, (unsigned long *)&addr); + if (ret) + return ret; + } else { + /* a symbol specified */ + symbol = argv[1]; + /* TODO: support .init module functions */ + ret = split_symbol_offset(symbol, &offset); + if (ret) + return ret; + if (offset && is_return) + return -EINVAL; + } + + /* setup a probe */ + tp = alloc_trace_probe(symbol, event); + if (IS_ERR(tp)) + return PTR_ERR(tp); + + if (is_return) { + kp = &tp->rp.kp; + tp->rp.handler = kretprobe_trace_func; + } else { + kp = &tp->kp; + tp->kp.pre_handler = kprobe_trace_func; + } + + if (tp->symbol) { + kp->symbol_name = tp->symbol; + kp->offset = offset; + } else + kp->addr = addr; + + /* parse arguments */ + argc -= 2; argv += 2; ret = 0; + for (i = 0; i < argc && i < TRACE_KPROBE_ARGS; i++) { + if (strlen(argv[i]) > MAX_ARGSTR_LEN) { + pr_info("Argument%d(%s) is too long.\n", i, argv[i]); + ret = -ENOSPC; + goto error; + } + ret = parse_trace_arg(argv[i], &tp->args[i], is_return); + if (ret) + goto error; + } + tp->nr_args = i; + + ret = register_trace_probe(tp); + if (ret) + goto error; + return 0; + +error: + free_trace_probe(tp); + return ret; +} + +static void cleanup_all_probes(void) +{ + struct trace_probe *tp; + + mutex_lock(&probe_lock); + /* TODO: Use batch unregistration */ + while (!list_empty(&probe_list)) { + tp = list_entry(probe_list.next, struct trace_probe, list); + unregister_trace_probe(tp); + free_trace_probe(tp); + } + mutex_unlock(&probe_lock); +} + + +/* Probes listing interfaces */ +static void *probes_seq_start(struct seq_file *m, loff_t *pos) +{ + mutex_lock(&probe_lock); + return seq_list_start(&probe_list, *pos); +} + +static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + return seq_list_next(v, &probe_list, pos); +} + +static void probes_seq_stop(struct seq_file *m, void *v) +{ + mutex_unlock(&probe_lock); +} + +static int probes_seq_show(struct seq_file *m, void *v) +{ + struct trace_probe *tp = v; + int i, ret; + char buf[MAX_ARGSTR_LEN + 1]; + + seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p'); + if (tp->call.name) + seq_printf(m, ":%s", tp->call.name); + + if (tp->symbol) + seq_printf(m, " %s%+ld", probe_symbol(tp), probe_offset(tp)); + else + seq_printf(m, " 0x%p", probe_address(tp)); + + for (i = 0; i < tp->nr_args; i++) { + ret = trace_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]); + if (ret < 0) { + pr_warning("Argument%d decoding error(%d).\n", i, ret); + return ret; + } + seq_printf(m, " %s", buf); + } + seq_printf(m, "\n"); + return 0; +} + +static const struct seq_operations probes_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_seq_show +}; + +static int probes_open(struct inode *inode, struct file *file) +{ + if ((file->f_mode & FMODE_WRITE) && + (file->f_flags & O_TRUNC)) + cleanup_all_probes(); + + return seq_open(file, &probes_seq_op); +} + +static int command_trace_probe(const char *buf) +{ + char **argv; + int argc = 0, ret = 0; + + argv = argv_split(GFP_KERNEL, buf, &argc); + if (!argv) + return -ENOMEM; + + if (argc) + ret = create_trace_probe(argc, argv); + + argv_free(argv); + return ret; +} + +#define WRITE_BUFSIZE 128 + +static ssize_t probes_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos) +{ + char *kbuf, *tmp; + int ret; + size_t done; + size_t size; + + kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + ret = done = 0; + while (done < count) { + size = count - done; + if (size >= WRITE_BUFSIZE) + size = WRITE_BUFSIZE - 1; + if (copy_from_user(kbuf, buffer + done, size)) { + ret = -EFAULT; + goto out; + } + kbuf[size] = '\0'; + tmp = strchr(kbuf, '\n'); + if (tmp) { + *tmp = '\0'; + size = tmp - kbuf + 1; + } else if (done + size < count) { + pr_warning("Line length is too long: " + "Should be less than %d.", WRITE_BUFSIZE); + ret = -EINVAL; + goto out; + } + done += size; + /* Remove comments */ + tmp = strchr(kbuf, '#'); + if (tmp) + *tmp = '\0'; + + ret = command_trace_probe(kbuf); + if (ret) + goto out; + } + ret = done; +out: + kfree(kbuf); + return ret; +} + +static const struct file_operations kprobe_events_ops = { + .owner = THIS_MODULE, + .open = probes_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, + .write = probes_write, +}; + +/* Kprobe handler */ +static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs) +{ + struct trace_probe *tp = container_of(kp, struct trace_probe, kp); + struct kprobe_trace_entry *entry; + struct ring_buffer_event *event; + int size, i, pc; + unsigned long irq_flags; + struct ftrace_event_call *call = &event_kprobe; + + if (&tp->call.name) + call = &tp->call; + + local_save_flags(irq_flags); + pc = preempt_count(); + + size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args); + + event = trace_current_buffer_lock_reserve(TRACE_KPROBE, size, + irq_flags, pc); + if (!event) + return 0; + + entry = ring_buffer_event_data(event); + entry->nargs = tp->nr_args; + entry->ip = (unsigned long)kp->addr; + for (i = 0; i < tp->nr_args; i++) + entry->args[i] = call_fetch(&tp->args[i], regs); + + if (!filter_current_check_discard(call, entry, event)) + trace_nowake_buffer_unlock_commit(event, irq_flags, pc); + return 0; +} + +/* Kretprobe handler */ +static __kprobes int kretprobe_trace_func(struct kretprobe_instance *ri, + struct pt_regs *regs) +{ + struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); + struct kretprobe_trace_entry *entry; + struct ring_buffer_event *event; + int size, i, pc; + unsigned long irq_flags; + struct ftrace_event_call *call = &event_kretprobe; + + if (&tp->call.name) + call = &tp->call; + + local_save_flags(irq_flags); + pc = preempt_count(); + + size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args); + + event = trace_current_buffer_lock_reserve(TRACE_KRETPROBE, size, + irq_flags, pc); + if (!event) + return 0; + + entry = ring_buffer_event_data(event); + entry->nargs = tp->nr_args; + entry->func = (unsigned long)probe_address(tp); + entry->ret_ip = (unsigned long)ri->ret_addr; + for (i = 0; i < tp->nr_args; i++) + entry->args[i] = call_fetch(&tp->args[i], regs); + + if (!filter_current_check_discard(call, entry, event)) + trace_nowake_buffer_unlock_commit(event, irq_flags, pc); + + return 0; +} + +/* Event entry printers */ +enum print_line_t +print_kprobe_event(struct trace_iterator *iter, int flags) +{ + struct kprobe_trace_entry *field; + struct trace_seq *s = &iter->seq; + int i; + + trace_assign_type(field, iter->ent); + + if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) + goto partial; + + if (!trace_seq_puts(s, ":")) + goto partial; + + for (i = 0; i < field->nargs; i++) + if (!trace_seq_printf(s, " 0x%lx", field->args[i])) + goto partial; + + if (!trace_seq_puts(s, "\n")) + goto partial; + + return TRACE_TYPE_HANDLED; +partial: + return TRACE_TYPE_PARTIAL_LINE; +} + +enum print_line_t +print_kretprobe_event(struct trace_iterator *iter, int flags) +{ + struct kretprobe_trace_entry *field; + struct trace_seq *s = &iter->seq; + int i; + + trace_assign_type(field, iter->ent); + + if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) + goto partial; + + if (!trace_seq_puts(s, " <- ")) + goto partial; + + if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) + goto partial; + + if (!trace_seq_puts(s, ":")) + goto partial; + + for (i = 0; i < field->nargs; i++) + if (!trace_seq_printf(s, " 0x%lx", field->args[i])) + goto partial; + + if (!trace_seq_puts(s, "\n")) + goto partial; + + return TRACE_TYPE_HANDLED; +partial: + return TRACE_TYPE_PARTIAL_LINE; +} + +static struct trace_event kprobe_trace_event = { + .type = TRACE_KPROBE, + .trace = print_kprobe_event, +}; + +static struct trace_event kretprobe_trace_event = { + .type = TRACE_KRETPROBE, + .trace = print_kretprobe_event, +}; + +static int probe_event_enable(struct ftrace_event_call *call) +{ + struct trace_probe *tp = (struct trace_probe *)call->data; + + if (probe_is_return(tp)) + return enable_kretprobe(&tp->rp); + else + return enable_kprobe(&tp->kp); +} + +static void probe_event_disable(struct ftrace_event_call *call) +{ + struct trace_probe *tp = (struct trace_probe *)call->data; + + if (probe_is_return(tp)) + disable_kretprobe(&tp->rp); + else + disable_kprobe(&tp->kp); +} + +static int probe_event_raw_init(struct ftrace_event_call *event_call) +{ + INIT_LIST_HEAD(&event_call->fields); + init_preds(event_call); + return 0; +} + +#undef DEFINE_FIELD +#define DEFINE_FIELD(type, item, name, is_signed) \ + do { \ + ret = trace_define_field(event_call, #type, name, \ + offsetof(typeof(field), item), \ + sizeof(field.item), is_signed, \ + FILTER_OTHER); \ + if (ret) \ + return ret; \ + } while (0) + +static int kprobe_event_define_fields(struct ftrace_event_call *event_call) +{ + int ret, i; + struct kprobe_trace_entry field; + char buf[MAX_ARGSTR_LEN + 1]; + struct trace_probe *tp = (struct trace_probe *)event_call->data; + + ret = trace_define_common_fields(event_call); + if (!ret) + return ret; + + DEFINE_FIELD(unsigned long, ip, "ip", 0); + DEFINE_FIELD(int, nargs, "nargs", 1); + for (i = 0; i < tp->nr_args; i++) { + /* Set argN as a field */ + sprintf(buf, "arg%d", i); + DEFINE_FIELD(unsigned long, args[i], buf, 0); + /* Set argument string as an alias field */ + ret = trace_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]); + if (ret < 0) + return ret; + DEFINE_FIELD(unsigned long, args[i], buf, 0); + } + return 0; +} + +static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) +{ + int ret, i; + struct kretprobe_trace_entry field; + char buf[MAX_ARGSTR_LEN + 1]; + struct trace_probe *tp = (struct trace_probe *)event_call->data; + + ret = trace_define_common_fields(event_call); + if (!ret) + return ret; + + DEFINE_FIELD(unsigned long, func, "func", 0); + DEFINE_FIELD(unsigned long, ret_ip, "ret_ip", 0); + DEFINE_FIELD(int, nargs, "nargs", 1); + for (i = 0; i < tp->nr_args; i++) { + /* Set argN as a field */ + sprintf(buf, "arg%d", i); + DEFINE_FIELD(unsigned long, args[i], buf, 0); + /* Set argument string as an alias field */ + ret = trace_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]); + if (ret < 0) + return ret; + DEFINE_FIELD(unsigned long, args[i], buf, 0); + } + return 0; +} + +static int __probe_event_show_format(struct trace_seq *s, + struct trace_probe *tp, const char *fmt, + const char *arg) +{ + int i, ret; + char buf[MAX_ARGSTR_LEN + 1]; + + /* Show aliases */ + for (i = 0; i < tp->nr_args; i++) { + ret = trace_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]); + if (ret < 0) + return ret; + if (!trace_seq_printf(s, "\talias: %s;\toriginal: arg%d;\n", + buf, i)) + return 0; + } + /* Show format */ + if (!trace_seq_printf(s, "\nprint fmt: \"%s", fmt)) + return 0; + + for (i = 0; i < tp->nr_args; i++) + if (!trace_seq_puts(s, " 0x%lx")) + return 0; + + if (!trace_seq_printf(s, "\", %s", arg)) + return 0; + + for (i = 0; i < tp->nr_args; i++) + if (!trace_seq_printf(s, ", arg%d", i)) + return 0; + + return trace_seq_puts(s, "\n"); +} + +#undef SHOW_FIELD +#define SHOW_FIELD(type, item, name) \ + do { \ + ret = trace_seq_printf(s, "\tfield: " #type " %s;\t" \ + "offset:%u;tsize:%u;\n", name, \ + (unsigned int)offsetof(typeof(field), item),\ + (unsigned int)sizeof(type)); \ + if (!ret) \ + return 0; \ + } while (0) + +static int kprobe_event_show_format(struct ftrace_event_call *call, + struct trace_seq *s) +{ + struct kprobe_trace_entry field __attribute__((unused)); + int ret, i; + char buf[8]; + struct trace_probe *tp = (struct trace_probe *)call->data; + + SHOW_FIELD(unsigned long, ip, "ip"); + SHOW_FIELD(int, nargs, "nargs"); + + /* Show fields */ + for (i = 0; i < tp->nr_args; i++) { + sprintf(buf, "arg%d", i); + SHOW_FIELD(unsigned long, args[i], buf); + } + trace_seq_puts(s, "\n"); + + return __probe_event_show_format(s, tp, "%lx:", "ip"); +} + +static int kretprobe_event_show_format(struct ftrace_event_call *call, + struct trace_seq *s) +{ + struct kretprobe_trace_entry field __attribute__((unused)); + int ret, i; + char buf[8]; + struct trace_probe *tp = (struct trace_probe *)call->data; + + SHOW_FIELD(unsigned long, func, "func"); + SHOW_FIELD(unsigned long, ret_ip, "ret_ip"); + SHOW_FIELD(int, nargs, "nargs"); + + /* Show fields */ + for (i = 0; i < tp->nr_args; i++) { + sprintf(buf, "arg%d", i); + SHOW_FIELD(unsigned long, args[i], buf); + } + trace_seq_puts(s, "\n"); + + return __probe_event_show_format(s, tp, "%lx <- %lx:", + "func, ret_ip"); +} + +static int register_probe_event(struct trace_probe *tp) +{ + struct ftrace_event_call *call = &tp->call; + int ret; + + /* Initialize ftrace_event_call */ + call->system = "kprobes"; + if (probe_is_return(tp)) { + call->event = &kretprobe_trace_event; + call->id = TRACE_KRETPROBE; + call->raw_init = probe_event_raw_init; + call->show_format = kretprobe_event_show_format; + call->define_fields = kretprobe_event_define_fields; + } else { + call->event = &kprobe_trace_event; + call->id = TRACE_KPROBE; + call->raw_init = probe_event_raw_init; + call->show_format = kprobe_event_show_format; + call->define_fields = kprobe_event_define_fields; + } + call->enabled = 1; + call->regfunc = probe_event_enable; + call->unregfunc = probe_event_disable; + call->data = tp; + ret = trace_add_event_call(call); + if (ret) + pr_info("Failed to register kprobe event: %s\n", call->name); + return ret; +} + +static void unregister_probe_event(struct trace_probe *tp) +{ + /* + * Prevent to unregister event itself because the event is shared + * among other probes. + */ + tp->call.event = NULL; + trace_remove_event_call(&tp->call); +} + +/* Make a debugfs interface for controling probe points */ +static __init int init_kprobe_trace(void) +{ + struct dentry *d_tracer; + struct dentry *entry; + int ret; + + ret = register_ftrace_event(&kprobe_trace_event); + if (!ret) { + pr_warning("Could not register kprobe_trace_event type.\n"); + return 0; + } + ret = register_ftrace_event(&kretprobe_trace_event); + if (!ret) { + pr_warning("Could not register kretprobe_trace_event type.\n"); + return 0; + } + + d_tracer = tracing_init_dentry(); + if (!d_tracer) + return 0; + + entry = debugfs_create_file("kprobe_events", 0644, d_tracer, + NULL, &kprobe_events_ops); + + if (!entry) + pr_warning("Could not create debugfs " + "'kprobe_events' entry\n"); + return 0; +} +fs_initcall(init_kprobe_trace); + + +#ifdef CONFIG_FTRACE_STARTUP_TEST + +static int kprobe_trace_selftest_target(int a1, int a2, int a3, + int a4, int a5, int a6) +{ + return a1 + a2 + a3 + a4 + a5 + a6; +} + +static __init int kprobe_trace_self_tests_init(void) +{ + int ret; + int (*target)(int, int, int, int, int, int); + + target = kprobe_trace_selftest_target; + + pr_info("Testing kprobe tracing: "); + + ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target " + "a1 a2 a3 a4 a5 a6"); + if (WARN_ON_ONCE(ret)) + pr_warning("error enabling function entry\n"); + + ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target " + "ra rv"); + if (WARN_ON_ONCE(ret)) + pr_warning("error enabling function return\n"); + + ret = target(1, 2, 3, 4, 5, 6); + + cleanup_all_probes(); + + pr_cont("OK\n"); + return 0; +} + +late_initcall(kprobe_trace_self_tests_init); + +#endif -- cgit v1.2.3-70-g09d2 From ff50d99136c3315513ef3b2921e77f35ab04d081 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 13 Aug 2009 16:35:34 -0400 Subject: tracing: Kprobe tracer assigns new event ids for each event MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Assign new event ids for each kprobes event. This doesn't clear ring_buffer when unregistering each kprobe event. Thus, if you mind 'Unknown event' messages, clear the buffer manually after changing kprobe events. Signed-off-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Avi Kivity Cc: Andi Kleen Cc: Christoph Hellwig Cc: Frank Ch. Eigler Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Jason Baron Cc: Jim Keniston Cc: K.Prasad Cc: Lai Jiangshan Cc: Li Zefan Cc: Przemysław Pawełczyk Cc: Roland McGrath Cc: Sam Ravnborg Cc: Srikar Dronamraju Cc: Steven Rostedt Cc: Tom Zanussi Cc: Vegard Nossum LKML-Reference: <20090813203534.31965.49105.stgit@localhost.localdomain> Signed-off-by: Frederic Weisbecker --- kernel/trace/trace.h | 6 ------ kernel/trace/trace_kprobe.c | 51 +++++++++++++-------------------------------- 2 files changed, 15 insertions(+), 42 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 667f832d16b..f5362a0529e 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -38,8 +38,6 @@ enum trace_type { TRACE_KMEM_FREE, TRACE_POWER, TRACE_BLK, - TRACE_KPROBE, - TRACE_KRETPROBE, __TRACE_LAST_TYPE, }; @@ -343,10 +341,6 @@ extern void __ftrace_bad_type(void); TRACE_KMEM_ALLOC); \ IF_ASSIGN(var, ent, struct kmemtrace_free_entry, \ TRACE_KMEM_FREE); \ - IF_ASSIGN(var, ent, struct kprobe_trace_entry, \ - TRACE_KPROBE); \ - IF_ASSIGN(var, ent, struct kretprobe_trace_entry, \ - TRACE_KRETPROBE); \ __ftrace_bad_type(); \ } while (0) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 8aeb24cc295..9c067bf47d5 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -186,6 +186,7 @@ struct trace_probe { }; const char *symbol; /* symbol name */ struct ftrace_event_call call; + struct trace_event event; unsigned int nr_args; struct fetch_func args[]; }; @@ -795,7 +796,7 @@ static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs) size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args); - event = trace_current_buffer_lock_reserve(TRACE_KPROBE, size, + event = trace_current_buffer_lock_reserve(call->id, size, irq_flags, pc); if (!event) return 0; @@ -827,7 +828,7 @@ static __kprobes int kretprobe_trace_func(struct kretprobe_instance *ri, size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args); - event = trace_current_buffer_lock_reserve(TRACE_KRETPROBE, size, + event = trace_current_buffer_lock_reserve(call->id, size, irq_flags, pc); if (!event) return 0; @@ -853,7 +854,7 @@ print_kprobe_event(struct trace_iterator *iter, int flags) struct trace_seq *s = &iter->seq; int i; - trace_assign_type(field, iter->ent); + field = (struct kprobe_trace_entry *)iter->ent; if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) goto partial; @@ -880,7 +881,7 @@ print_kretprobe_event(struct trace_iterator *iter, int flags) struct trace_seq *s = &iter->seq; int i; - trace_assign_type(field, iter->ent); + field = (struct kretprobe_trace_entry *)iter->ent; if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) goto partial; @@ -906,16 +907,6 @@ partial: return TRACE_TYPE_PARTIAL_LINE; } -static struct trace_event kprobe_trace_event = { - .type = TRACE_KPROBE, - .trace = print_kprobe_event, -}; - -static struct trace_event kretprobe_trace_event = { - .type = TRACE_KRETPROBE, - .trace = print_kretprobe_event, -}; - static int probe_event_enable(struct ftrace_event_call *call) { struct trace_probe *tp = (struct trace_probe *)call->data; @@ -1104,35 +1095,35 @@ static int register_probe_event(struct trace_probe *tp) /* Initialize ftrace_event_call */ call->system = "kprobes"; if (probe_is_return(tp)) { - call->event = &kretprobe_trace_event; - call->id = TRACE_KRETPROBE; + tp->event.trace = print_kretprobe_event; call->raw_init = probe_event_raw_init; call->show_format = kretprobe_event_show_format; call->define_fields = kretprobe_event_define_fields; } else { - call->event = &kprobe_trace_event; - call->id = TRACE_KPROBE; + tp->event.trace = print_kprobe_event; call->raw_init = probe_event_raw_init; call->show_format = kprobe_event_show_format; call->define_fields = kprobe_event_define_fields; } + call->event = &tp->event; + call->id = register_ftrace_event(&tp->event); + if (!call->id) + return -ENODEV; call->enabled = 1; call->regfunc = probe_event_enable; call->unregfunc = probe_event_disable; call->data = tp; ret = trace_add_event_call(call); - if (ret) + if (ret) { pr_info("Failed to register kprobe event: %s\n", call->name); + unregister_ftrace_event(&tp->event); + } return ret; } static void unregister_probe_event(struct trace_probe *tp) { - /* - * Prevent to unregister event itself because the event is shared - * among other probes. - */ - tp->call.event = NULL; + /* tp->event is unregistered in trace_remove_event_call() */ trace_remove_event_call(&tp->call); } @@ -1141,18 +1132,6 @@ static __init int init_kprobe_trace(void) { struct dentry *d_tracer; struct dentry *entry; - int ret; - - ret = register_ftrace_event(&kprobe_trace_event); - if (!ret) { - pr_warning("Could not register kprobe_trace_event type.\n"); - return 0; - } - ret = register_ftrace_event(&kretprobe_trace_event); - if (!ret) { - pr_warning("Could not register kretprobe_trace_event type.\n"); - return 0; - } d_tracer = tracing_init_dentry(); if (!d_tracer) -- cgit v1.2.3-70-g09d2 From 1889d20922d14a97b2099fa4d47587217c0ba48b Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 24 Sep 2009 21:10:44 +0200 Subject: tracing/filters: Provide basic regex support This patch provides basic support for regular expressions in filters. It supports the following types of regexp: - *match_beginning - *match_middle* - match_end* - !don't match Example: cd /debug/tracing/events/bkl/lock_kernel echo 'file == "*reiserfs*"' > filter echo 1 > enable gedit-4941 [000] 457.735437: lock_kernel: depth: 0, fs/reiserfs/namei.c:334 reiserfs_lookup() sync_supers-227 [001] 461.379985: lock_kernel: depth: 0, fs/reiserfs/super.c:69 reiserfs_sync_fs() sync_supers-227 [000] 461.383096: lock_kernel: depth: 0, fs/reiserfs/journal.c:1069 flush_commit_list() reiserfs/1-1369 [001] 461.479885: lock_kernel: depth: 0, fs/reiserfs/journal.c:3509 flush_async_commits() Every string is now handled as a regexp in the filter framework, which helps to factorize the code for handling both simple strings and regexp comparisons. (The regexp parsing code has been wildly cherry picked from ftrace.c written by Steve.) v2: Simplify the whole and drop the filter_regex file Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt Cc: Tom Zanussi Cc: Li Zefan --- kernel/trace/trace.h | 27 ++++--- kernel/trace/trace_events_filter.c | 155 +++++++++++++++++++++++++++++++++---- 2 files changed, 157 insertions(+), 25 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 86bcff94791..8d0db6018fe 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -702,20 +702,29 @@ struct event_subsystem { }; struct filter_pred; +struct regex; typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event, int val1, int val2); +typedef int (*regex_match_func)(char *str, struct regex *r, int len); + +struct regex { + char pattern[MAX_FILTER_STR_VAL]; + int len; + int field_len; + regex_match_func match; +}; + struct filter_pred { - filter_pred_fn_t fn; - u64 val; - char str_val[MAX_FILTER_STR_VAL]; - int str_len; - char *field_name; - int offset; - int not; - int op; - int pop_n; + filter_pred_fn_t fn; + u64 val; + struct regex regex; + char *field_name; + int offset; + int not; + int op; + int pop_n; }; extern void print_event_filter(struct ftrace_event_call *call, diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 189663d82aa..d3c94c13956 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -195,9 +195,9 @@ static int filter_pred_string(struct filter_pred *pred, void *event, char *addr = (char *)(event + pred->offset); int cmp, match; - cmp = strncmp(addr, pred->str_val, pred->str_len); + cmp = pred->regex.match(addr, &pred->regex, pred->regex.field_len); - match = (!cmp) ^ pred->not; + match = cmp ^ pred->not; return match; } @@ -209,9 +209,9 @@ static int filter_pred_pchar(struct filter_pred *pred, void *event, char **addr = (char **)(event + pred->offset); int cmp, match; - cmp = strncmp(*addr, pred->str_val, pred->str_len); + cmp = pred->regex.match(*addr, &pred->regex, pred->regex.field_len); - match = (!cmp) ^ pred->not; + match = cmp ^ pred->not; return match; } @@ -235,9 +235,9 @@ static int filter_pred_strloc(struct filter_pred *pred, void *event, char *addr = (char *)(event + str_loc); int cmp, match; - cmp = strncmp(addr, pred->str_val, str_len); + cmp = pred->regex.match(addr, &pred->regex, str_len); - match = (!cmp) ^ pred->not; + match = cmp ^ pred->not; return match; } @@ -248,6 +248,126 @@ static int filter_pred_none(struct filter_pred *pred, void *event, return 0; } +/* Basic regex callbacks */ +static int regex_match_full(char *str, struct regex *r, int len) +{ + if (strncmp(str, r->pattern, len) == 0) + return 1; + return 0; +} + +static int regex_match_front(char *str, struct regex *r, int len) +{ + if (strncmp(str, r->pattern, len) == 0) + return 1; + return 0; +} + +static int regex_match_middle(char *str, struct regex *r, int len) +{ + if (strstr(str, r->pattern)) + return 1; + return 0; +} + +static int regex_match_end(char *str, struct regex *r, int len) +{ + char *ptr = strstr(str, r->pattern); + + if (ptr && (ptr[r->len] == 0)) + return 1; + return 0; +} + +enum regex_type { + MATCH_FULL, + MATCH_FRONT_ONLY, + MATCH_MIDDLE_ONLY, + MATCH_END_ONLY, +}; + +/* + * Pass in a buffer containing a regex and this function will + * set search to point to the search part of the buffer and + * return the type of search it is (see enum above). + * This does modify buff. + * + * Returns enum type. + * search returns the pointer to use for comparison. + * not returns 1 if buff started with a '!' + * 0 otherwise. + */ +static enum regex_type +filter_parse_regex(char *buff, int len, char **search, int *not) +{ + int type = MATCH_FULL; + int i; + + if (buff[0] == '!') { + *not = 1; + buff++; + len--; + } else + *not = 0; + + *search = buff; + + for (i = 0; i < len; i++) { + if (buff[i] == '*') { + if (!i) { + *search = buff + 1; + type = MATCH_END_ONLY; + } else { + if (type == MATCH_END_ONLY) + type = MATCH_MIDDLE_ONLY; + else + type = MATCH_FRONT_ONLY; + buff[i] = 0; + break; + } + } + } + + return type; +} + +static int filter_build_regex(struct filter_pred *pred) +{ + struct regex *r = &pred->regex; + char *search, *dup; + enum regex_type type; + int not; + + type = filter_parse_regex(r->pattern, r->len, &search, ¬); + dup = kstrdup(search, GFP_KERNEL); + if (!dup) + return -ENOMEM; + + strcpy(r->pattern, dup); + kfree(dup); + + r->len = strlen(r->pattern); + + switch (type) { + case MATCH_FULL: + r->match = regex_match_full; + break; + case MATCH_FRONT_ONLY: + r->match = regex_match_front; + break; + case MATCH_MIDDLE_ONLY: + r->match = regex_match_middle; + break; + case MATCH_END_ONLY: + r->match = regex_match_end; + break; + } + + pred->not ^= not; + + return 0; +} + /* return 1 if event matches, 0 otherwise (discard) */ int filter_match_preds(struct ftrace_event_call *call, void *rec) { @@ -394,7 +514,7 @@ static void filter_clear_pred(struct filter_pred *pred) { kfree(pred->field_name); pred->field_name = NULL; - pred->str_len = 0; + pred->regex.len = 0; } static int filter_set_pred(struct filter_pred *dest, @@ -658,21 +778,24 @@ static int filter_add_pred(struct filter_parse_state *ps, } if (is_string_field(field)) { - pred->str_len = field->size; + ret = filter_build_regex(pred); + if (ret) + return ret; - if (field->filter_type == FILTER_STATIC_STRING) + if (field->filter_type == FILTER_STATIC_STRING) { fn = filter_pred_string; - else if (field->filter_type == FILTER_DYN_STRING) - fn = filter_pred_strloc; + pred->regex.field_len = field->size; + } else if (field->filter_type == FILTER_DYN_STRING) + fn = filter_pred_strloc; else { fn = filter_pred_pchar; - pred->str_len = strlen(pred->str_val); + pred->regex.field_len = strlen(pred->regex.pattern); } } else { if (field->is_signed) - ret = strict_strtoll(pred->str_val, 0, &val); + ret = strict_strtoll(pred->regex.pattern, 0, &val); else - ret = strict_strtoull(pred->str_val, 0, &val); + ret = strict_strtoull(pred->regex.pattern, 0, &val); if (ret) { parse_error(ps, FILT_ERR_ILLEGAL_INTVAL, 0); return -EINVAL; @@ -1042,8 +1165,8 @@ static struct filter_pred *create_pred(int op, char *operand1, char *operand2) return NULL; } - strcpy(pred->str_val, operand2); - pred->str_len = strlen(operand2); + strcpy(pred->regex.pattern, operand2); + pred->regex.len = strlen(pred->regex.pattern); pred->op = op; -- cgit v1.2.3-70-g09d2 From 3f6fe06dbf67b46d36fedec502300e04dffeb67a Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 24 Sep 2009 21:31:51 +0200 Subject: tracing/filters: Unify the regex parsing helpers The filter code has stolen the regex parsing function from ftrace to get the regex support. We have duplicated this code, so factorize it in the filter area and make it generally available, as the filter code is the most suited to host this feature. Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt Cc: Tom Zanussi Cc: Li Zefan --- kernel/trace/ftrace.c | 64 +++----------------------------------- kernel/trace/trace.h | 9 ++++++ kernel/trace/trace_events_filter.c | 20 ++++++------ 3 files changed, 23 insertions(+), 70 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index cc615f84751..ddf23a225b5 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1655,60 +1655,6 @@ ftrace_regex_lseek(struct file *file, loff_t offset, int origin) return ret; } -enum { - MATCH_FULL, - MATCH_FRONT_ONLY, - MATCH_MIDDLE_ONLY, - MATCH_END_ONLY, -}; - -/* - * (static function - no need for kernel doc) - * - * Pass in a buffer containing a glob and this function will - * set search to point to the search part of the buffer and - * return the type of search it is (see enum above). - * This does modify buff. - * - * Returns enum type. - * search returns the pointer to use for comparison. - * not returns 1 if buff started with a '!' - * 0 otherwise. - */ -static int -ftrace_setup_glob(char *buff, int len, char **search, int *not) -{ - int type = MATCH_FULL; - int i; - - if (buff[0] == '!') { - *not = 1; - buff++; - len--; - } else - *not = 0; - - *search = buff; - - for (i = 0; i < len; i++) { - if (buff[i] == '*') { - if (!i) { - *search = buff + 1; - type = MATCH_END_ONLY; - } else { - if (type == MATCH_END_ONLY) - type = MATCH_MIDDLE_ONLY; - else - type = MATCH_FRONT_ONLY; - buff[i] = 0; - break; - } - } - } - - return type; -} - static int ftrace_match(char *str, char *regex, int len, int type) { int matched = 0; @@ -1757,7 +1703,7 @@ static void ftrace_match_records(char *buff, int len, int enable) int not; flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; - type = ftrace_setup_glob(buff, len, &search, ¬); + type = filter_parse_regex(buff, len, &search, ¬); search_len = strlen(search); @@ -1825,7 +1771,7 @@ static void ftrace_match_module_records(char *buff, char *mod, int enable) } if (strlen(buff)) { - type = ftrace_setup_glob(buff, strlen(buff), &search, ¬); + type = filter_parse_regex(buff, strlen(buff), &search, ¬); search_len = strlen(search); } @@ -1990,7 +1936,7 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, int count = 0; char *search; - type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); + type = filter_parse_regex(glob, strlen(glob), &search, ¬); len = strlen(search); /* we do not support '!' for function probes */ @@ -2067,7 +2013,7 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, else if (glob) { int not; - type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); + type = filter_parse_regex(glob, strlen(glob), &search, ¬); len = strlen(search); /* we do not support '!' for function probes */ @@ -2520,7 +2466,7 @@ ftrace_set_func(unsigned long *array, int *idx, char *buffer) return -ENODEV; /* decode regex */ - type = ftrace_setup_glob(buffer, strlen(buffer), &search, ¬); + type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); if (not) return -EINVAL; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 8d0db6018fe..db6b83edd49 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -709,6 +709,13 @@ typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event, typedef int (*regex_match_func)(char *str, struct regex *r, int len); +enum regex_type { + MATCH_FULL, + MATCH_FRONT_ONLY, + MATCH_MIDDLE_ONLY, + MATCH_END_ONLY, +}; + struct regex { char pattern[MAX_FILTER_STR_VAL]; int len; @@ -727,6 +734,8 @@ struct filter_pred { int pop_n; }; +extern enum regex_type +filter_parse_regex(char *buff, int len, char **search, int *not); extern void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s); extern int apply_event_filter(struct ftrace_event_call *call, diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index d3c94c13956..8c194de675b 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -279,15 +279,14 @@ static int regex_match_end(char *str, struct regex *r, int len) return 0; } -enum regex_type { - MATCH_FULL, - MATCH_FRONT_ONLY, - MATCH_MIDDLE_ONLY, - MATCH_END_ONLY, -}; - -/* - * Pass in a buffer containing a regex and this function will +/** + * filter_parse_regex - parse a basic regex + * @buff: the raw regex + * @len: length of the regex + * @search: will point to the beginning of the string to compare + * @not: tell whether the match will have to be inverted + * + * This passes in a buffer containing a regex and this function will * set search to point to the search part of the buffer and * return the type of search it is (see enum above). * This does modify buff. @@ -297,8 +296,7 @@ enum regex_type { * not returns 1 if buff started with a '!' * 0 otherwise. */ -static enum regex_type -filter_parse_regex(char *buff, int len, char **search, int *not) +enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not) { int type = MATCH_FULL; int i; -- cgit v1.2.3-70-g09d2 From bf7c5b43a12614847b83f507fb169ad30640e406 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 12 Oct 2009 22:31:32 +0200 Subject: tracing: Remove unused ftrace_trace_addr helper Remove the ftrace_trace_addr() function as only its off-case is implemented and there are no users of it currently. But we keep ftrace_graph_addr() off-case, in case someone come to use the function graph tracer to profit from top-level callers filtering. Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt Cc: Li Zefan --- kernel/trace/trace.h | 4 ---- 1 file changed, 4 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 365fb19d9e1..f22a7ac3238 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -483,10 +483,6 @@ static inline int ftrace_graph_addr(unsigned long addr) return 0; } #else -static inline int ftrace_trace_addr(unsigned long addr) -{ - return 1; -} static inline int ftrace_graph_addr(unsigned long addr) { return 1; -- cgit v1.2.3-70-g09d2 From 756d17ee7ee4fbc8238bdf97100af63e6ac441ef Mon Sep 17 00:00:00 2001 From: "jolsa@redhat.com" Date: Tue, 13 Oct 2009 16:33:52 -0400 Subject: tracing: Support multiple pids in set_pid_ftrace file Adding the possibility to set more than 1 pid in the set_pid_ftrace file, thus allowing to trace more than 1 independent processes. Usage: sh-4.0# echo 284 > ./set_ftrace_pid sh-4.0# cat ./set_ftrace_pid 284 sh-4.0# echo 1 >> ./set_ftrace_pid sh-4.0# echo 0 >> ./set_ftrace_pid sh-4.0# cat ./set_ftrace_pid swapper tasks 1 284 sh-4.0# echo 4 > ./set_ftrace_pid sh-4.0# cat ./set_ftrace_pid 4 sh-4.0# echo > ./set_ftrace_pid sh-4.0# cat ./set_ftrace_pid no pid sh-4.0# Signed-off-by: Jiri Olsa Cc: Frederic Weisbecker LKML-Reference: <20091013203425.565454612@goodmis.org> Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 234 +++++++++++++++++++++++++++++++++++--------------- kernel/trace/trace.h | 4 +- 2 files changed, 167 insertions(+), 71 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 45c965919cf..0c799d1af70 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -60,6 +60,13 @@ static int last_ftrace_enabled; /* Quick disabling of function tracer. */ int function_trace_stop; +/* List for set_ftrace_pid's pids. */ +LIST_HEAD(ftrace_pids); +struct ftrace_pid { + struct list_head list; + struct pid *pid; +}; + /* * ftrace_disabled is set when an anomaly is discovered. * ftrace_disabled is much stronger than ftrace_enabled. @@ -159,7 +166,7 @@ static int __register_ftrace_function(struct ftrace_ops *ops) else func = ftrace_list_func; - if (ftrace_pid_trace) { + if (!list_empty(&ftrace_pids)) { set_ftrace_pid_function(func); func = ftrace_pid_func; } @@ -207,7 +214,7 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) if (ftrace_list->next == &ftrace_list_end) { ftrace_func_t func = ftrace_list->func; - if (ftrace_pid_trace) { + if (!list_empty(&ftrace_pids)) { set_ftrace_pid_function(func); func = ftrace_pid_func; } @@ -235,7 +242,7 @@ static void ftrace_update_pid_func(void) func = __ftrace_trace_function; #endif - if (ftrace_pid_trace) { + if (!list_empty(&ftrace_pids)) { set_ftrace_pid_function(func); func = ftrace_pid_func; } else { @@ -825,8 +832,6 @@ static __init void ftrace_profile_debugfs(struct dentry *d_tracer) } #endif /* CONFIG_FUNCTION_PROFILER */ -/* set when tracing only a pid */ -struct pid *ftrace_pid_trace; static struct pid * const ftrace_swapper_pid = &init_struct_pid; #ifdef CONFIG_DYNAMIC_FTRACE @@ -2758,23 +2763,6 @@ static inline void ftrace_startup_enable(int command) { } # define ftrace_shutdown_sysctl() do { } while (0) #endif /* CONFIG_DYNAMIC_FTRACE */ -static ssize_t -ftrace_pid_read(struct file *file, char __user *ubuf, - size_t cnt, loff_t *ppos) -{ - char buf[64]; - int r; - - if (ftrace_pid_trace == ftrace_swapper_pid) - r = sprintf(buf, "swapper tasks\n"); - else if (ftrace_pid_trace) - r = sprintf(buf, "%u\n", pid_vnr(ftrace_pid_trace)); - else - r = sprintf(buf, "no pid\n"); - - return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); -} - static void clear_ftrace_swapper(void) { struct task_struct *p; @@ -2825,14 +2813,12 @@ static void set_ftrace_pid(struct pid *pid) rcu_read_unlock(); } -static void clear_ftrace_pid_task(struct pid **pid) +static void clear_ftrace_pid_task(struct pid *pid) { - if (*pid == ftrace_swapper_pid) + if (pid == ftrace_swapper_pid) clear_ftrace_swapper(); else - clear_ftrace_pid(*pid); - - *pid = NULL; + clear_ftrace_pid(pid); } static void set_ftrace_pid_task(struct pid *pid) @@ -2843,11 +2829,140 @@ static void set_ftrace_pid_task(struct pid *pid) set_ftrace_pid(pid); } +static int ftrace_pid_add(int p) +{ + struct pid *pid; + struct ftrace_pid *fpid; + int ret = -EINVAL; + + mutex_lock(&ftrace_lock); + + if (!p) + pid = ftrace_swapper_pid; + else + pid = find_get_pid(p); + + if (!pid) + goto out; + + ret = 0; + + list_for_each_entry(fpid, &ftrace_pids, list) + if (fpid->pid == pid) + goto out_put; + + ret = -ENOMEM; + + fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); + if (!fpid) + goto out_put; + + list_add(&fpid->list, &ftrace_pids); + fpid->pid = pid; + + set_ftrace_pid_task(pid); + + ftrace_update_pid_func(); + ftrace_startup_enable(0); + + mutex_unlock(&ftrace_lock); + return 0; + +out_put: + if (pid != ftrace_swapper_pid) + put_pid(pid); + +out: + mutex_unlock(&ftrace_lock); + return ret; +} + +static void ftrace_pid_reset(void) +{ + struct ftrace_pid *fpid, *safe; + + mutex_lock(&ftrace_lock); + list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { + struct pid *pid = fpid->pid; + + clear_ftrace_pid_task(pid); + + list_del(&fpid->list); + kfree(fpid); + } + + ftrace_update_pid_func(); + ftrace_startup_enable(0); + + mutex_unlock(&ftrace_lock); +} + +static void *fpid_start(struct seq_file *m, loff_t *pos) +{ + mutex_lock(&ftrace_lock); + + if (list_empty(&ftrace_pids) && (!*pos)) + return (void *) 1; + + return seq_list_start(&ftrace_pids, *pos); +} + +static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) +{ + if (v == (void *)1) + return NULL; + + return seq_list_next(v, &ftrace_pids, pos); +} + +static void fpid_stop(struct seq_file *m, void *p) +{ + mutex_unlock(&ftrace_lock); +} + +static int fpid_show(struct seq_file *m, void *v) +{ + const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); + + if (v == (void *)1) { + seq_printf(m, "no pid\n"); + return 0; + } + + if (fpid->pid == ftrace_swapper_pid) + seq_printf(m, "swapper tasks\n"); + else + seq_printf(m, "%u\n", pid_vnr(fpid->pid)); + + return 0; +} + +static const struct seq_operations ftrace_pid_sops = { + .start = fpid_start, + .next = fpid_next, + .stop = fpid_stop, + .show = fpid_show, +}; + +static int +ftrace_pid_open(struct inode *inode, struct file *file) +{ + int ret = 0; + + if ((file->f_mode & FMODE_WRITE) && + (file->f_flags & O_TRUNC)) + ftrace_pid_reset(); + + if (file->f_mode & FMODE_READ) + ret = seq_open(file, &ftrace_pid_sops); + + return ret; +} + static ssize_t ftrace_pid_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { - struct pid *pid; char buf[64]; long val; int ret; @@ -2860,57 +2975,38 @@ ftrace_pid_write(struct file *filp, const char __user *ubuf, buf[cnt] = 0; + /* + * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" + * to clean the filter quietly. + */ + strstrip(buf); + if (strlen(buf) == 0) + return 1; + ret = strict_strtol(buf, 10, &val); if (ret < 0) return ret; - mutex_lock(&ftrace_lock); - if (val < 0) { - /* disable pid tracing */ - if (!ftrace_pid_trace) - goto out; - - clear_ftrace_pid_task(&ftrace_pid_trace); - - } else { - /* swapper task is special */ - if (!val) { - pid = ftrace_swapper_pid; - if (pid == ftrace_pid_trace) - goto out; - } else { - pid = find_get_pid(val); - - if (pid == ftrace_pid_trace) { - put_pid(pid); - goto out; - } - } - - if (ftrace_pid_trace) - clear_ftrace_pid_task(&ftrace_pid_trace); - - if (!pid) - goto out; - - ftrace_pid_trace = pid; - - set_ftrace_pid_task(ftrace_pid_trace); - } + ret = ftrace_pid_add(val); - /* update the function call */ - ftrace_update_pid_func(); - ftrace_startup_enable(0); + return ret ? ret : cnt; +} - out: - mutex_unlock(&ftrace_lock); +static int +ftrace_pid_release(struct inode *inode, struct file *file) +{ + if (file->f_mode & FMODE_READ) + seq_release(inode, file); - return cnt; + return 0; } static const struct file_operations ftrace_pid_fops = { - .read = ftrace_pid_read, - .write = ftrace_pid_write, + .open = ftrace_pid_open, + .write = ftrace_pid_write, + .read = seq_read, + .llseek = seq_lseek, + .release = ftrace_pid_release, }; static __init int ftrace_init_debugfs(void) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index f22a7ac3238..acef8b4636f 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -496,12 +496,12 @@ print_graph_function(struct trace_iterator *iter) } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ -extern struct pid *ftrace_pid_trace; +extern struct list_head ftrace_pids; #ifdef CONFIG_FUNCTION_TRACER static inline int ftrace_trace_task(struct task_struct *task) { - if (!ftrace_pid_trace) + if (list_empty(&ftrace_pids)) return 1; return test_tsk_trace_trace(task); -- cgit v1.2.3-70-g09d2 From fce29d15b59245597f7f320db4a9f2be0f5fb512 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 15 Oct 2009 11:20:34 +0800 Subject: tracing/filters: Refactor subsystem filter code Change: for_each_pred for_each_subsystem To: for_each_subsystem for_each_pred This change also prepares for later patches. Signed-off-by: Li Zefan Acked-by: Peter Zijlstra Acked-by: Frederic Weisbecker Cc: Steven Rostedt Cc: Tom Zanussi LKML-Reference: <4AD69502.8060903@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace.h | 1 - kernel/trace/trace_events_filter.c | 124 ++++++++++++++----------------------- 2 files changed, 45 insertions(+), 80 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index acef8b4636f..628614532d1 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -683,7 +683,6 @@ struct event_filter { int n_preds; struct filter_pred **preds; char *filter_string; - bool no_reset; }; struct event_subsystem { diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 92672016da2..9c4f9a0dae2 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -615,14 +615,7 @@ static int init_subsystem_preds(struct event_subsystem *system) return 0; } -enum { - FILTER_DISABLE_ALL, - FILTER_INIT_NO_RESET, - FILTER_SKIP_NO_RESET, -}; - -static void filter_free_subsystem_preds(struct event_subsystem *system, - int flag) +static void filter_free_subsystem_preds(struct event_subsystem *system) { struct ftrace_event_call *call; @@ -633,14 +626,6 @@ static void filter_free_subsystem_preds(struct event_subsystem *system, if (strcmp(call->system, system->name) != 0) continue; - if (flag == FILTER_INIT_NO_RESET) { - call->filter->no_reset = false; - continue; - } - - if (flag == FILTER_SKIP_NO_RESET && call->filter->no_reset) - continue; - filter_disable_preds(call); remove_filter_string(call->filter); } @@ -817,44 +802,6 @@ add_pred_fn: return 0; } -static int filter_add_subsystem_pred(struct filter_parse_state *ps, - struct event_subsystem *system, - struct filter_pred *pred, - char *filter_string, - bool dry_run) -{ - struct ftrace_event_call *call; - int err = 0; - bool fail = true; - - list_for_each_entry(call, &ftrace_events, list) { - - if (!call->define_fields) - continue; - - if (strcmp(call->system, system->name)) - continue; - - if (call->filter->no_reset) - continue; - - err = filter_add_pred(ps, call, pred, dry_run); - if (err) - call->filter->no_reset = true; - else - fail = false; - - if (!dry_run) - replace_filter_string(call->filter, filter_string); - } - - if (fail) { - parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0); - return err; - } - return 0; -} - static void parse_init(struct filter_parse_state *ps, struct filter_op *ops, char *infix_string) @@ -1209,8 +1156,7 @@ static int check_preds(struct filter_parse_state *ps) return 0; } -static int replace_preds(struct event_subsystem *system, - struct ftrace_event_call *call, +static int replace_preds(struct ftrace_event_call *call, struct filter_parse_state *ps, char *filter_string, bool dry_run) @@ -1257,11 +1203,7 @@ static int replace_preds(struct event_subsystem *system, add_pred: if (!pred) return -ENOMEM; - if (call) - err = filter_add_pred(ps, call, pred, false); - else - err = filter_add_subsystem_pred(ps, system, pred, - filter_string, dry_run); + err = filter_add_pred(ps, call, pred, dry_run); filter_free_pred(pred); if (err) return err; @@ -1272,6 +1214,44 @@ add_pred: return 0; } +static int replace_system_preds(struct event_subsystem *system, + struct filter_parse_state *ps, + char *filter_string) +{ + struct ftrace_event_call *call; + int err; + bool fail = true; + + list_for_each_entry(call, &ftrace_events, list) { + + if (!call->define_fields) + continue; + + if (strcmp(call->system, system->name) != 0) + continue; + + /* try to see if the filter can be applied */ + err = replace_preds(call, ps, filter_string, true); + if (err) + continue; + + /* really apply the filter */ + filter_disable_preds(call); + err = replace_preds(call, ps, filter_string, false); + if (err) + filter_disable_preds(call); + else + replace_filter_string(call->filter, filter_string); + fail = false; + } + + if (fail) { + parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0); + return err; + } + return 0; +} + int apply_event_filter(struct ftrace_event_call *call, char *filter_string) { int err; @@ -1306,7 +1286,7 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string) goto out; } - err = replace_preds(NULL, call, ps, filter_string, false); + err = replace_preds(call, ps, filter_string, false); if (err) append_filter_err(ps, call->filter); @@ -1334,7 +1314,7 @@ int apply_subsystem_event_filter(struct event_subsystem *system, goto out_unlock; if (!strcmp(strstrip(filter_string), "0")) { - filter_free_subsystem_preds(system, FILTER_DISABLE_ALL); + filter_free_subsystem_preds(system); remove_filter_string(system->filter); mutex_unlock(&event_mutex); return 0; @@ -1354,23 +1334,9 @@ int apply_subsystem_event_filter(struct event_subsystem *system, goto out; } - filter_free_subsystem_preds(system, FILTER_INIT_NO_RESET); - - /* try to see the filter can be applied to which events */ - err = replace_preds(system, NULL, ps, filter_string, true); - if (err) { - append_filter_err(ps, system->filter); - goto out; - } - - filter_free_subsystem_preds(system, FILTER_SKIP_NO_RESET); - - /* really apply the filter to the events */ - err = replace_preds(system, NULL, ps, filter_string, false); - if (err) { + err = replace_system_preds(system, ps, filter_string); + if (err) append_filter_err(ps, system->filter); - filter_free_subsystem_preds(system, 2); - } out: filter_opstack_clear(ps); -- cgit v1.2.3-70-g09d2 From b0f1a59a98d7ac2102e7e4f22904c26d564a5628 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 15 Oct 2009 11:21:12 +0800 Subject: tracing/filters: Use a different op for glob match "==" will always do a full match, and "~" will do a glob match. In the future, we may add "=~" for regex match. Signed-off-by: Li Zefan Acked-by: Peter Zijlstra Acked-by: Frederic Weisbecker Cc: Steven Rostedt Cc: Tom Zanussi LKML-Reference: <4AD69528.3050309@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace.h | 2 +- kernel/trace/trace_events_filter.c | 59 ++++++++++++++++++-------------------- 2 files changed, 29 insertions(+), 32 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 628614532d1..ffe53ddbe67 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -702,7 +702,7 @@ typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event, typedef int (*regex_match_func)(char *str, struct regex *r, int len); enum regex_type { - MATCH_FULL, + MATCH_FULL = 0, MATCH_FRONT_ONLY, MATCH_MIDDLE_ONLY, MATCH_END_ONLY, diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 9c4f9a0dae2..273845fce39 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -29,6 +29,7 @@ enum filter_op_ids { OP_OR, OP_AND, + OP_GLOB, OP_NE, OP_EQ, OP_LT, @@ -46,16 +47,17 @@ struct filter_op { }; static struct filter_op filter_ops[] = { - { OP_OR, "||", 1 }, - { OP_AND, "&&", 2 }, - { OP_NE, "!=", 4 }, - { OP_EQ, "==", 4 }, - { OP_LT, "<", 5 }, - { OP_LE, "<=", 5 }, - { OP_GT, ">", 5 }, - { OP_GE, ">=", 5 }, - { OP_NONE, "OP_NONE", 0 }, - { OP_OPEN_PAREN, "(", 0 }, + { OP_OR, "||", 1 }, + { OP_AND, "&&", 2 }, + { OP_GLOB, "~", 4 }, + { OP_NE, "!=", 4 }, + { OP_EQ, "==", 4 }, + { OP_LT, "<", 5 }, + { OP_LE, "<=", 5 }, + { OP_GT, ">", 5 }, + { OP_GE, ">=", 5 }, + { OP_NONE, "OP_NONE", 0 }, + { OP_OPEN_PAREN, "(", 0 }, }; enum { @@ -329,22 +331,18 @@ enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not) return type; } -static int filter_build_regex(struct filter_pred *pred) +static void filter_build_regex(struct filter_pred *pred) { struct regex *r = &pred->regex; - char *search, *dup; - enum regex_type type; - int not; - - type = filter_parse_regex(r->pattern, r->len, &search, ¬); - dup = kstrdup(search, GFP_KERNEL); - if (!dup) - return -ENOMEM; - - strcpy(r->pattern, dup); - kfree(dup); - - r->len = strlen(r->pattern); + char *search; + enum regex_type type = MATCH_FULL; + int not = 0; + + if (pred->op == OP_GLOB) { + type = filter_parse_regex(r->pattern, r->len, &search, ¬); + r->len = strlen(search); + memmove(r->pattern, search, r->len+1); + } switch (type) { case MATCH_FULL: @@ -362,8 +360,6 @@ static int filter_build_regex(struct filter_pred *pred) } pred->not ^= not; - - return 0; } /* return 1 if event matches, 0 otherwise (discard) */ @@ -676,7 +672,10 @@ static bool is_string_field(struct ftrace_event_field *field) static int is_legal_op(struct ftrace_event_field *field, int op) { - if (is_string_field(field) && (op != OP_EQ && op != OP_NE)) + if (is_string_field(field) && + (op != OP_EQ && op != OP_NE && op != OP_GLOB)) + return 0; + if (!is_string_field(field) && op == OP_GLOB) return 0; return 1; @@ -761,15 +760,13 @@ static int filter_add_pred(struct filter_parse_state *ps, } if (is_string_field(field)) { - ret = filter_build_regex(pred); - if (ret) - return ret; + filter_build_regex(pred); if (field->filter_type == FILTER_STATIC_STRING) { fn = filter_pred_string; pred->regex.field_len = field->size; } else if (field->filter_type == FILTER_DYN_STRING) - fn = filter_pred_strloc; + fn = filter_pred_strloc; else { fn = filter_pred_pchar; pred->regex.field_len = strlen(pred->regex.pattern); -- cgit v1.2.3-70-g09d2 From 6fb2915df7f0747d9044da9dbff5b46dc2e20830 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 15 Oct 2009 11:21:42 +0800 Subject: tracing/profile: Add filter support - Add an ioctl to allocate a filter for a perf event. - Free the filter when the associated perf event is to be freed. - Do the filtering in perf_swevent_match(). Signed-off-by: Li Zefan Acked-by: Peter Zijlstra Acked-by: Frederic Weisbecker Cc: Steven Rostedt Cc: Tom Zanussi LKML-Reference: <4AD69546.8050401@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- include/linux/ftrace_event.h | 11 ++- include/linux/perf_counter.h | 1 + include/linux/perf_event.h | 6 ++ kernel/perf_event.c | 80 ++++++++++++++++++++-- kernel/trace/trace.h | 3 +- kernel/trace/trace_events_filter.c | 133 +++++++++++++++++++++++++++++-------- 6 files changed, 199 insertions(+), 35 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index 4ec5e67e18c..d11770472bc 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -144,7 +144,7 @@ extern char *trace_profile_buf_nmi; #define MAX_FILTER_STR_VAL 256 /* Should handle KSYM_SYMBOL_LEN */ extern void destroy_preds(struct ftrace_event_call *call); -extern int filter_match_preds(struct ftrace_event_call *call, void *rec); +extern int filter_match_preds(struct event_filter *filter, void *rec); extern int filter_current_check_discard(struct ring_buffer *buffer, struct ftrace_event_call *call, void *rec, @@ -186,4 +186,13 @@ do { \ __trace_printk(ip, fmt, ##args); \ } while (0) +#ifdef CONFIG_EVENT_PROFILE +struct perf_event; +extern int ftrace_profile_enable(int event_id); +extern void ftrace_profile_disable(int event_id); +extern int ftrace_profile_set_filter(struct perf_event *event, int event_id, + char *filter_str); +extern void ftrace_profile_free_filter(struct perf_event *event); +#endif + #endif /* _LINUX_FTRACE_EVENT_H */ diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 7b7fbf433cf..91a2b4309e7 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -225,6 +225,7 @@ struct perf_counter_attr { #define PERF_COUNTER_IOC_RESET _IO ('$', 3) #define PERF_COUNTER_IOC_PERIOD _IOW('$', 4, u64) #define PERF_COUNTER_IOC_SET_OUTPUT _IO ('$', 5) +#define PERF_COUNTER_IOC_SET_FILTER _IOW('$', 6, char *) enum perf_counter_ioc_flags { PERF_IOC_FLAG_GROUP = 1U << 0, diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 2e6d95f9741..df9d964c15f 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -221,6 +221,7 @@ struct perf_event_attr { #define PERF_EVENT_IOC_RESET _IO ('$', 3) #define PERF_EVENT_IOC_PERIOD _IOW('$', 4, u64) #define PERF_EVENT_IOC_SET_OUTPUT _IO ('$', 5) +#define PERF_EVENT_IOC_SET_FILTER _IOW('$', 6, char *) enum perf_event_ioc_flags { PERF_IOC_FLAG_GROUP = 1U << 0, @@ -633,7 +634,12 @@ struct perf_event { struct pid_namespace *ns; u64 id; + +#ifdef CONFIG_EVENT_PROFILE + struct event_filter *filter; #endif + +#endif /* CONFIG_PERF_EVENTS */ }; /** diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 9d0b5c66588..12b5ec39bf9 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -28,6 +28,7 @@ #include #include #include +#include #include @@ -1658,6 +1659,8 @@ static struct perf_event_context *find_get_context(pid_t pid, int cpu) return ERR_PTR(err); } +static void perf_event_free_filter(struct perf_event *event); + static void free_event_rcu(struct rcu_head *head) { struct perf_event *event; @@ -1665,6 +1668,7 @@ static void free_event_rcu(struct rcu_head *head) event = container_of(head, struct perf_event, rcu_head); if (event->ns) put_pid_ns(event->ns); + perf_event_free_filter(event); kfree(event); } @@ -1974,7 +1978,8 @@ unlock: return ret; } -int perf_event_set_output(struct perf_event *event, int output_fd); +static int perf_event_set_output(struct perf_event *event, int output_fd); +static int perf_event_set_filter(struct perf_event *event, void __user *arg); static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -2002,6 +2007,9 @@ static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) case PERF_EVENT_IOC_SET_OUTPUT: return perf_event_set_output(event, arg); + case PERF_EVENT_IOC_SET_FILTER: + return perf_event_set_filter(event, (void __user *)arg); + default: return -ENOTTY; } @@ -3806,9 +3814,14 @@ static int perf_swevent_is_counting(struct perf_event *event) return 1; } +static int perf_tp_event_match(struct perf_event *event, + struct perf_sample_data *data); + static int perf_swevent_match(struct perf_event *event, enum perf_type_id type, - u32 event_id, struct pt_regs *regs) + u32 event_id, + struct perf_sample_data *data, + struct pt_regs *regs) { if (!perf_swevent_is_counting(event)) return 0; @@ -3826,6 +3839,10 @@ static int perf_swevent_match(struct perf_event *event, return 0; } + if (event->attr.type == PERF_TYPE_TRACEPOINT && + !perf_tp_event_match(event, data)) + return 0; + return 1; } @@ -3842,7 +3859,7 @@ static void perf_swevent_ctx_event(struct perf_event_context *ctx, rcu_read_lock(); list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { - if (perf_swevent_match(event, type, event_id, regs)) + if (perf_swevent_match(event, type, event_id, data, regs)) perf_swevent_add(event, nr, nmi, data, regs); } rcu_read_unlock(); @@ -4086,6 +4103,7 @@ static const struct pmu perf_ops_task_clock = { }; #ifdef CONFIG_EVENT_PROFILE + void perf_tp_event(int event_id, u64 addr, u64 count, void *record, int entry_size) { @@ -4109,8 +4127,15 @@ void perf_tp_event(int event_id, u64 addr, u64 count, void *record, } EXPORT_SYMBOL_GPL(perf_tp_event); -extern int ftrace_profile_enable(int); -extern void ftrace_profile_disable(int); +static int perf_tp_event_match(struct perf_event *event, + struct perf_sample_data *data) +{ + void *record = data->raw->data; + + if (likely(!event->filter) || filter_match_preds(event->filter, record)) + return 1; + return 0; +} static void tp_perf_event_destroy(struct perf_event *event) { @@ -4135,12 +4160,53 @@ static const struct pmu *tp_perf_event_init(struct perf_event *event) return &perf_ops_generic; } + +static int perf_event_set_filter(struct perf_event *event, void __user *arg) +{ + char *filter_str; + int ret; + + if (event->attr.type != PERF_TYPE_TRACEPOINT) + return -EINVAL; + + filter_str = strndup_user(arg, PAGE_SIZE); + if (IS_ERR(filter_str)) + return PTR_ERR(filter_str); + + ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); + + kfree(filter_str); + return ret; +} + +static void perf_event_free_filter(struct perf_event *event) +{ + ftrace_profile_free_filter(event); +} + #else + +static int perf_tp_event_match(struct perf_event *event, + struct perf_sample_data *data) +{ + return 1; +} + static const struct pmu *tp_perf_event_init(struct perf_event *event) { return NULL; } -#endif + +static int perf_event_set_filter(struct perf_event *event, void __user *arg) +{ + return -ENOENT; +} + +static void perf_event_free_filter(struct perf_event *event) +{ +} + +#endif /* CONFIG_EVENT_PROFILE */ atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX]; @@ -4394,7 +4460,7 @@ err_size: goto out; } -int perf_event_set_output(struct perf_event *event, int output_fd) +static int perf_event_set_output(struct perf_event *event, int output_fd) { struct perf_event *output_event = NULL; struct file *output_file = NULL; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index ffe53ddbe67..4959ada9e0b 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -743,7 +743,8 @@ filter_check_discard(struct ftrace_event_call *call, void *rec, struct ring_buffer *buffer, struct ring_buffer_event *event) { - if (unlikely(call->filter_active) && !filter_match_preds(call, rec)) { + if (unlikely(call->filter_active) && + !filter_match_preds(call->filter, rec)) { ring_buffer_discard_commit(buffer, event); return 1; } diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 273845fce39..e27bb6acc2d 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -21,6 +21,7 @@ #include #include #include +#include #include "trace.h" #include "trace_output.h" @@ -363,9 +364,8 @@ static void filter_build_regex(struct filter_pred *pred) } /* return 1 if event matches, 0 otherwise (discard) */ -int filter_match_preds(struct ftrace_event_call *call, void *rec) +int filter_match_preds(struct event_filter *filter, void *rec) { - struct event_filter *filter = call->filter; int match, top = 0, val1 = 0, val2 = 0; int stack[MAX_FILTER_PRED]; struct filter_pred *pred; @@ -538,9 +538,8 @@ static void filter_disable_preds(struct ftrace_event_call *call) filter->preds[i]->fn = filter_pred_none; } -void destroy_preds(struct ftrace_event_call *call) +static void __free_preds(struct event_filter *filter) { - struct event_filter *filter = call->filter; int i; if (!filter) @@ -553,21 +552,24 @@ void destroy_preds(struct ftrace_event_call *call) kfree(filter->preds); kfree(filter->filter_string); kfree(filter); +} + +void destroy_preds(struct ftrace_event_call *call) +{ + __free_preds(call->filter); call->filter = NULL; + call->filter_active = 0; } -static int init_preds(struct ftrace_event_call *call) +static struct event_filter *__alloc_preds(void) { struct event_filter *filter; struct filter_pred *pred; int i; - if (call->filter) - return 0; - - filter = call->filter = kzalloc(sizeof(*filter), GFP_KERNEL); - if (!call->filter) - return -ENOMEM; + filter = kzalloc(sizeof(*filter), GFP_KERNEL); + if (!filter) + return ERR_PTR(-ENOMEM); filter->n_preds = 0; @@ -583,12 +585,24 @@ static int init_preds(struct ftrace_event_call *call) filter->preds[i] = pred; } - return 0; + return filter; oom: - destroy_preds(call); + __free_preds(filter); + return ERR_PTR(-ENOMEM); +} + +static int init_preds(struct ftrace_event_call *call) +{ + if (call->filter) + return 0; + + call->filter_active = 0; + call->filter = __alloc_preds(); + if (IS_ERR(call->filter)) + return PTR_ERR(call->filter); - return -ENOMEM; + return 0; } static int init_subsystem_preds(struct event_subsystem *system) @@ -629,10 +643,10 @@ static void filter_free_subsystem_preds(struct event_subsystem *system) static int filter_add_pred_fn(struct filter_parse_state *ps, struct ftrace_event_call *call, + struct event_filter *filter, struct filter_pred *pred, filter_pred_fn_t fn) { - struct event_filter *filter = call->filter; int idx, err; if (filter->n_preds == MAX_FILTER_PRED) { @@ -647,7 +661,6 @@ static int filter_add_pred_fn(struct filter_parse_state *ps, return err; filter->n_preds++; - call->filter_active = 1; return 0; } @@ -726,6 +739,7 @@ static filter_pred_fn_t select_comparison_fn(int op, int field_size, static int filter_add_pred(struct filter_parse_state *ps, struct ftrace_event_call *call, + struct event_filter *filter, struct filter_pred *pred, bool dry_run) { @@ -795,7 +809,7 @@ static int filter_add_pred(struct filter_parse_state *ps, add_pred_fn: if (!dry_run) - return filter_add_pred_fn(ps, call, pred, fn); + return filter_add_pred_fn(ps, call, filter, pred, fn); return 0; } @@ -1154,6 +1168,7 @@ static int check_preds(struct filter_parse_state *ps) } static int replace_preds(struct ftrace_event_call *call, + struct event_filter *filter, struct filter_parse_state *ps, char *filter_string, bool dry_run) @@ -1200,7 +1215,7 @@ static int replace_preds(struct ftrace_event_call *call, add_pred: if (!pred) return -ENOMEM; - err = filter_add_pred(ps, call, pred, dry_run); + err = filter_add_pred(ps, call, filter, pred, dry_run); filter_free_pred(pred); if (err) return err; @@ -1216,6 +1231,7 @@ static int replace_system_preds(struct event_subsystem *system, char *filter_string) { struct ftrace_event_call *call; + struct event_filter *filter; int err; bool fail = true; @@ -1228,17 +1244,19 @@ static int replace_system_preds(struct event_subsystem *system, continue; /* try to see if the filter can be applied */ - err = replace_preds(call, ps, filter_string, true); + err = replace_preds(call, filter, ps, filter_string, true); if (err) continue; /* really apply the filter */ filter_disable_preds(call); - err = replace_preds(call, ps, filter_string, false); + err = replace_preds(call, filter, ps, filter_string, false); if (err) filter_disable_preds(call); - else - replace_filter_string(call->filter, filter_string); + else { + call->filter_active = 1; + replace_filter_string(filter, filter_string); + } fail = false; } @@ -1252,7 +1270,6 @@ static int replace_system_preds(struct event_subsystem *system, int apply_event_filter(struct ftrace_event_call *call, char *filter_string) { int err; - struct filter_parse_state *ps; mutex_lock(&event_mutex); @@ -1283,10 +1300,11 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string) goto out; } - err = replace_preds(call, ps, filter_string, false); + err = replace_preds(call, call->filter, ps, filter_string, false); if (err) append_filter_err(ps, call->filter); - + else + call->filter_active = 1; out: filter_opstack_clear(ps); postfix_clear(ps); @@ -1301,7 +1319,6 @@ int apply_subsystem_event_filter(struct event_subsystem *system, char *filter_string) { int err; - struct filter_parse_state *ps; mutex_lock(&event_mutex); @@ -1345,3 +1362,67 @@ out_unlock: return err; } +#ifdef CONFIG_EVENT_PROFILE + +void ftrace_profile_free_filter(struct perf_event *event) +{ + struct event_filter *filter = event->filter; + + event->filter = NULL; + __free_preds(filter); +} + +int ftrace_profile_set_filter(struct perf_event *event, int event_id, + char *filter_str) +{ + int err; + struct event_filter *filter; + struct filter_parse_state *ps; + struct ftrace_event_call *call = NULL; + + mutex_lock(&event_mutex); + + list_for_each_entry(call, &ftrace_events, list) { + if (call->id == event_id) + break; + } + if (!call) + return -EINVAL; + + if (event->filter) + return -EEXIST; + + filter = __alloc_preds(); + if (IS_ERR(filter)) + return PTR_ERR(filter); + + err = -ENOMEM; + ps = kzalloc(sizeof(*ps), GFP_KERNEL); + if (!ps) + goto free_preds; + + parse_init(ps, filter_ops, filter_str); + err = filter_parse(ps); + if (err) + goto free_ps; + + err = replace_preds(call, filter, ps, filter_str, false); + if (!err) + event->filter = filter; + +free_ps: + filter_opstack_clear(ps); + postfix_clear(ps); + kfree(ps); + +free_preds: + if (err) + __free_preds(filter); + + mutex_unlock(&event_mutex); + + return err; +} + +#endif /* CONFIG_EVENT_PROFILE */ + -- cgit v1.2.3-70-g09d2 From 24f1e32c60c45c89a997c73395b69c8af6f0a84e Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 9 Sep 2009 19:22:48 +0200 Subject: hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events This patch rebase the implementation of the breakpoints API on top of perf events instances. Each breakpoints are now perf events that handle the register scheduling, thread/cpu attachment, etc.. The new layering is now made as follows: ptrace kgdb ftrace perf syscall \ | / / \ | / / / Core breakpoint API / / | / | / Breakpoints perf events | | Breakpoints PMU ---- Debug Register constraints handling (Part of core breakpoint API) | | Hardware debug registers Reasons of this rewrite: - Use the centralized/optimized pmu registers scheduling, implying an easier arch integration - More powerful register handling: perf attributes (pinned/flexible events, exclusive/non-exclusive, tunable period, etc...) Impact: - New perf ABI: the hardware breakpoints counters - Ptrace breakpoints setting remains tricky and still needs some per thread breakpoints references. Todo (in the order): - Support breakpoints perf counter events for perf tools (ie: implement perf_bpcounter_event()) - Support from perf tools Changes in v2: - Follow the perf "event " rename - The ptrace regression have been fixed (ptrace breakpoint perf events weren't released when a task ended) - Drop the struct hw_breakpoint and store generic fields in perf_event_attr. - Separate core and arch specific headers, drop asm-generic/hw_breakpoint.h and create linux/hw_breakpoint.h - Use new generic len/type for breakpoint - Handle off case: when breakpoints api is not supported by an arch Changes in v3: - Fix broken CONFIG_KVM, we need to propagate the breakpoint api changes to kvm when we exit the guest and restore the bp registers to the host. Changes in v4: - Drop the hw_breakpoint_restore() stub as it is only used by KVM - EXPORT_SYMBOL_GPL hw_breakpoint_restore() as KVM can be built as a module - Restore the breakpoints unconditionally on kvm guest exit: TIF_DEBUG_THREAD doesn't anymore cover every cases of running breakpoints and vcpu->arch.switch_db_regs might not always be set when the guest used debug registers. (Waiting for a reliable optimization) Changes in v5: - Split-up the asm-generic/hw-breakpoint.h moving to linux/hw_breakpoint.h into a separate patch - Optimize the breakpoints restoring while switching from kvm guest to host. We only want to restore the state if we have active breakpoints to the host, otherwise we don't care about messed-up address registers. - Add asm/hw_breakpoint.h to Kbuild - Fix bad breakpoint type in trace_selftest.c Changes in v6: - Fix wrong header inclusion in trace.h (triggered a build error with CONFIG_FTRACE_SELFTEST Signed-off-by: Frederic Weisbecker Cc: Prasad Cc: Alan Stern Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Steven Rostedt Cc: Ingo Molnar Cc: Jan Kiszka Cc: Jiri Slaby Cc: Li Zefan Cc: Avi Kivity Cc: Paul Mackerras Cc: Mike Galbraith Cc: Masami Hiramatsu Cc: Paul Mundt --- arch/Kconfig | 3 + arch/x86/include/asm/Kbuild | 1 + arch/x86/include/asm/debugreg.h | 11 +- arch/x86/include/asm/hw_breakpoint.h | 58 +++-- arch/x86/include/asm/processor.h | 12 +- arch/x86/kernel/hw_breakpoint.c | 391 +++++++++++++++++++++----------- arch/x86/kernel/process.c | 7 +- arch/x86/kernel/process_32.c | 26 +-- arch/x86/kernel/process_64.c | 26 +-- arch/x86/kernel/ptrace.c | 182 ++++++++++----- arch/x86/kernel/smpboot.c | 3 - arch/x86/kvm/x86.c | 18 +- arch/x86/power/cpu.c | 6 - include/linux/hw_breakpoint.h | 243 ++++++++++---------- include/linux/perf_event.h | 26 ++- kernel/exit.c | 5 + kernel/hw_breakpoint.c | 424 ++++++++++++++--------------------- kernel/perf_event.c | 53 ++++- kernel/trace/trace.h | 5 +- kernel/trace/trace_entries.h | 6 +- kernel/trace/trace_ksym.c | 126 +++++------ kernel/trace/trace_selftest.c | 3 +- 22 files changed, 885 insertions(+), 750 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/arch/Kconfig b/arch/Kconfig index acb66439794..eef3bbb9707 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -128,6 +128,9 @@ config HAVE_DEFAULT_NO_SPIN_MUTEXES config HAVE_HW_BREAKPOINT bool + depends on HAVE_PERF_EVENTS + select ANON_INODES + select PERF_EVENTS source "kernel/gcov/Kconfig" diff --git a/arch/x86/include/asm/Kbuild b/arch/x86/include/asm/Kbuild index 4a8e80cdcfa..9f828f87ca3 100644 --- a/arch/x86/include/asm/Kbuild +++ b/arch/x86/include/asm/Kbuild @@ -10,6 +10,7 @@ header-y += ptrace-abi.h header-y += sigcontext32.h header-y += ucontext.h header-y += processor-flags.h +header-y += hw_breakpoint.h unifdef-y += e820.h unifdef-y += ist.h diff --git a/arch/x86/include/asm/debugreg.h b/arch/x86/include/asm/debugreg.h index 23439fbb1d0..9a3333c91f9 100644 --- a/arch/x86/include/asm/debugreg.h +++ b/arch/x86/include/asm/debugreg.h @@ -75,13 +75,8 @@ */ #ifdef __KERNEL__ -/* For process management */ -extern void flush_thread_hw_breakpoint(struct task_struct *tsk); -extern int copy_thread_hw_breakpoint(struct task_struct *tsk, - struct task_struct *child, unsigned long clone_flags); +DECLARE_PER_CPU(unsigned long, dr7); -/* For CPU management */ -extern void load_debug_registers(void); static inline void hw_breakpoint_disable(void) { /* Zero the control register for HW Breakpoint */ @@ -94,6 +89,10 @@ static inline void hw_breakpoint_disable(void) set_debugreg(0UL, 3); } +#ifdef CONFIG_KVM +extern void hw_breakpoint_restore(void); +#endif + #endif /* __KERNEL__ */ #endif /* _ASM_X86_DEBUGREG_H */ diff --git a/arch/x86/include/asm/hw_breakpoint.h b/arch/x86/include/asm/hw_breakpoint.h index 3cfca8e2b5f..0675a7c4c20 100644 --- a/arch/x86/include/asm/hw_breakpoint.h +++ b/arch/x86/include/asm/hw_breakpoint.h @@ -4,6 +4,11 @@ #ifdef __KERNEL__ #define __ARCH_HW_BREAKPOINT_H +/* + * The name should probably be something dealt in + * a higher level. While dealing with the user + * (display/resolving) + */ struct arch_hw_breakpoint { char *name; /* Contains name of the symbol to set bkpt */ unsigned long address; @@ -12,44 +17,57 @@ struct arch_hw_breakpoint { }; #include -#include +#include +#include /* Available HW breakpoint length encodings */ -#define HW_BREAKPOINT_LEN_1 0x40 -#define HW_BREAKPOINT_LEN_2 0x44 -#define HW_BREAKPOINT_LEN_4 0x4c -#define HW_BREAKPOINT_LEN_EXECUTE 0x40 +#define X86_BREAKPOINT_LEN_1 0x40 +#define X86_BREAKPOINT_LEN_2 0x44 +#define X86_BREAKPOINT_LEN_4 0x4c +#define X86_BREAKPOINT_LEN_EXECUTE 0x40 #ifdef CONFIG_X86_64 -#define HW_BREAKPOINT_LEN_8 0x48 +#define X86_BREAKPOINT_LEN_8 0x48 #endif /* Available HW breakpoint type encodings */ /* trigger on instruction execute */ -#define HW_BREAKPOINT_EXECUTE 0x80 +#define X86_BREAKPOINT_EXECUTE 0x80 /* trigger on memory write */ -#define HW_BREAKPOINT_WRITE 0x81 +#define X86_BREAKPOINT_WRITE 0x81 /* trigger on memory read or write */ -#define HW_BREAKPOINT_RW 0x83 +#define X86_BREAKPOINT_RW 0x83 /* Total number of available HW breakpoint registers */ #define HBP_NUM 4 -extern struct hw_breakpoint *hbp_kernel[HBP_NUM]; -DECLARE_PER_CPU(struct hw_breakpoint*, this_hbp_kernel[HBP_NUM]); -extern unsigned int hbp_user_refcount[HBP_NUM]; +struct perf_event; +struct pmu; -extern void arch_install_thread_hw_breakpoint(struct task_struct *tsk); -extern void arch_uninstall_thread_hw_breakpoint(void); extern int arch_check_va_in_userspace(unsigned long va, u8 hbp_len); -extern int arch_validate_hwbkpt_settings(struct hw_breakpoint *bp, - struct task_struct *tsk); -extern void arch_update_user_hw_breakpoint(int pos, struct task_struct *tsk); -extern void arch_flush_thread_hw_breakpoint(struct task_struct *tsk); -extern void arch_update_kernel_hw_breakpoint(void *); +extern int arch_validate_hwbkpt_settings(struct perf_event *bp, + struct task_struct *tsk); extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused, - unsigned long val, void *data); + unsigned long val, void *data); + + +int arch_install_hw_breakpoint(struct perf_event *bp); +void arch_uninstall_hw_breakpoint(struct perf_event *bp); +void hw_breakpoint_pmu_read(struct perf_event *bp); +void hw_breakpoint_pmu_unthrottle(struct perf_event *bp); + +extern void +arch_fill_perf_breakpoint(struct perf_event *bp); + +unsigned long encode_dr7(int drnum, unsigned int len, unsigned int type); +int decode_dr7(unsigned long dr7, int bpnum, unsigned *len, unsigned *type); + +extern int arch_bp_generic_fields(int x86_len, int x86_type, + int *gen_len, int *gen_type); + +extern struct pmu perf_ops_bp; + #endif /* __KERNEL__ */ #endif /* _I386_HW_BREAKPOINT_H */ diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 61aafb71c7e..820f3000f73 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -423,6 +423,8 @@ extern unsigned int xstate_size; extern void free_thread_xstate(struct task_struct *); extern struct kmem_cache *task_xstate_cachep; +struct perf_event; + struct thread_struct { /* Cached TLS descriptors: */ struct desc_struct tls_array[GDT_ENTRY_TLS_ENTRIES]; @@ -444,12 +446,10 @@ struct thread_struct { unsigned long fs; #endif unsigned long gs; - /* Hardware debugging registers: */ - unsigned long debugreg[HBP_NUM]; - unsigned long debugreg6; - unsigned long debugreg7; - /* Hardware breakpoint info */ - struct hw_breakpoint *hbp[HBP_NUM]; + /* Save middle states of ptrace breakpoints */ + struct perf_event *ptrace_bps[HBP_NUM]; + /* Debug status used for traps, single steps, etc... */ + unsigned long debugreg6; /* Fault info: */ unsigned long cr2; unsigned long trap_no; diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c index 9316a9de4de..e622620790b 100644 --- a/arch/x86/kernel/hw_breakpoint.c +++ b/arch/x86/kernel/hw_breakpoint.c @@ -15,6 +15,7 @@ * * Copyright (C) 2007 Alan Stern * Copyright (C) 2009 IBM Corporation + * Copyright (C) 2009 Frederic Weisbecker */ /* @@ -22,6 +23,8 @@ * using the CPU's debug registers. */ +#include +#include #include #include #include @@ -38,26 +41,24 @@ #include #include -/* Unmasked kernel DR7 value */ -static unsigned long kdr7; +/* Per cpu debug control register value */ +DEFINE_PER_CPU(unsigned long, dr7); + +/* Per cpu debug address registers values */ +static DEFINE_PER_CPU(unsigned long, cpu_debugreg[HBP_NUM]); /* - * Masks for the bits corresponding to registers DR0 - DR3 in DR7 register. - * Used to clear and verify the status of bits corresponding to DR0 - DR3 + * Stores the breakpoints currently in use on each breakpoint address + * register for each cpus */ -static const unsigned long dr7_masks[HBP_NUM] = { - 0x000f0003, /* LEN0, R/W0, G0, L0 */ - 0x00f0000c, /* LEN1, R/W1, G1, L1 */ - 0x0f000030, /* LEN2, R/W2, G2, L2 */ - 0xf00000c0 /* LEN3, R/W3, G3, L3 */ -}; +static DEFINE_PER_CPU(struct perf_event *, bp_per_reg[HBP_NUM]); /* * Encode the length, type, Exact, and Enable bits for a particular breakpoint * as stored in debug register 7. */ -static unsigned long encode_dr7(int drnum, unsigned int len, unsigned int type) +unsigned long encode_dr7(int drnum, unsigned int len, unsigned int type) { unsigned long bp_info; @@ -68,64 +69,89 @@ static unsigned long encode_dr7(int drnum, unsigned int len, unsigned int type) return bp_info; } -void arch_update_kernel_hw_breakpoint(void *unused) +/* + * Decode the length and type bits for a particular breakpoint as + * stored in debug register 7. Return the "enabled" status. + */ +int decode_dr7(unsigned long dr7, int bpnum, unsigned *len, unsigned *type) { - struct hw_breakpoint *bp; - int i, cpu = get_cpu(); - unsigned long temp_kdr7 = 0; - - /* Don't allow debug exceptions while we update the registers */ - set_debugreg(0UL, 7); + int bp_info = dr7 >> (DR_CONTROL_SHIFT + bpnum * DR_CONTROL_SIZE); - for (i = hbp_kernel_pos; i < HBP_NUM; i++) { - per_cpu(this_hbp_kernel[i], cpu) = bp = hbp_kernel[i]; - if (bp) { - temp_kdr7 |= encode_dr7(i, bp->info.len, bp->info.type); - set_debugreg(bp->info.address, i); - } - } + *len = (bp_info & 0xc) | 0x40; + *type = (bp_info & 0x3) | 0x80; - /* No need to set DR6. Update the debug registers with kernel-space - * breakpoint values from kdr7 and user-space requests from the - * current process - */ - kdr7 = temp_kdr7; - set_debugreg(kdr7 | current->thread.debugreg7, 7); - put_cpu(); + return (dr7 >> (bpnum * DR_ENABLE_SIZE)) & 0x3; } /* - * Install the thread breakpoints in their debug registers. + * Install a perf counter breakpoint. + * + * We seek a free debug address register and use it for this + * breakpoint. Eventually we enable it in the debug control register. + * + * Atomic: we hold the counter->ctx->lock and we only handle variables + * and registers local to this cpu. */ -void arch_install_thread_hw_breakpoint(struct task_struct *tsk) +int arch_install_hw_breakpoint(struct perf_event *bp) { - struct thread_struct *thread = &(tsk->thread); - - switch (hbp_kernel_pos) { - case 4: - set_debugreg(thread->debugreg[3], 3); - case 3: - set_debugreg(thread->debugreg[2], 2); - case 2: - set_debugreg(thread->debugreg[1], 1); - case 1: - set_debugreg(thread->debugreg[0], 0); - default: - break; + struct arch_hw_breakpoint *info = counter_arch_bp(bp); + unsigned long *dr7; + int i; + + for (i = 0; i < HBP_NUM; i++) { + struct perf_event **slot = &__get_cpu_var(bp_per_reg[i]); + + if (!*slot) { + *slot = bp; + break; + } } - /* No need to set DR6 */ - set_debugreg((kdr7 | thread->debugreg7), 7); + if (WARN_ONCE(i == HBP_NUM, "Can't find any breakpoint slot")) + return -EBUSY; + + set_debugreg(info->address, i); + __get_cpu_var(cpu_debugreg[i]) = info->address; + + dr7 = &__get_cpu_var(dr7); + *dr7 |= encode_dr7(i, info->len, info->type); + + set_debugreg(*dr7, 7); + + return 0; } /* - * Install the debug register values for just the kernel, no thread. + * Uninstall the breakpoint contained in the given counter. + * + * First we search the debug address register it uses and then we disable + * it. + * + * Atomic: we hold the counter->ctx->lock and we only handle variables + * and registers local to this cpu. */ -void arch_uninstall_thread_hw_breakpoint(void) +void arch_uninstall_hw_breakpoint(struct perf_event *bp) { - /* Clear the user-space portion of debugreg7 by setting only kdr7 */ - set_debugreg(kdr7, 7); + struct arch_hw_breakpoint *info = counter_arch_bp(bp); + unsigned long *dr7; + int i; + + for (i = 0; i < HBP_NUM; i++) { + struct perf_event **slot = &__get_cpu_var(bp_per_reg[i]); + + if (*slot == bp) { + *slot = NULL; + break; + } + } + + if (WARN_ONCE(i == HBP_NUM, "Can't find any breakpoint slot")) + return; + dr7 = &__get_cpu_var(dr7); + *dr7 &= ~encode_dr7(i, info->len, info->type); + + set_debugreg(*dr7, 7); } static int get_hbp_len(u8 hbp_len) @@ -133,17 +159,17 @@ static int get_hbp_len(u8 hbp_len) unsigned int len_in_bytes = 0; switch (hbp_len) { - case HW_BREAKPOINT_LEN_1: + case X86_BREAKPOINT_LEN_1: len_in_bytes = 1; break; - case HW_BREAKPOINT_LEN_2: + case X86_BREAKPOINT_LEN_2: len_in_bytes = 2; break; - case HW_BREAKPOINT_LEN_4: + case X86_BREAKPOINT_LEN_4: len_in_bytes = 4; break; #ifdef CONFIG_X86_64 - case HW_BREAKPOINT_LEN_8: + case X86_BREAKPOINT_LEN_8: len_in_bytes = 8; break; #endif @@ -178,67 +204,146 @@ static int arch_check_va_in_kernelspace(unsigned long va, u8 hbp_len) /* * Store a breakpoint's encoded address, length, and type. */ -static int arch_store_info(struct hw_breakpoint *bp, struct task_struct *tsk) +static int arch_store_info(struct perf_event *bp) { - /* - * User-space requests will always have the address field populated - * Symbol names from user-space are rejected - */ - if (tsk && bp->info.name) - return -EINVAL; + struct arch_hw_breakpoint *info = counter_arch_bp(bp); /* * For kernel-addresses, either the address or symbol name can be * specified. */ - if (bp->info.name) - bp->info.address = (unsigned long) - kallsyms_lookup_name(bp->info.name); - if (bp->info.address) + if (info->name) + info->address = (unsigned long) + kallsyms_lookup_name(info->name); + if (info->address) return 0; + return -EINVAL; } -/* - * Validate the arch-specific HW Breakpoint register settings - */ -int arch_validate_hwbkpt_settings(struct hw_breakpoint *bp, - struct task_struct *tsk) +int arch_bp_generic_fields(int x86_len, int x86_type, + int *gen_len, int *gen_type) { - unsigned int align; - int ret = -EINVAL; + /* Len */ + switch (x86_len) { + case X86_BREAKPOINT_LEN_1: + *gen_len = HW_BREAKPOINT_LEN_1; + break; + case X86_BREAKPOINT_LEN_2: + *gen_len = HW_BREAKPOINT_LEN_2; + break; + case X86_BREAKPOINT_LEN_4: + *gen_len = HW_BREAKPOINT_LEN_4; + break; +#ifdef CONFIG_X86_64 + case X86_BREAKPOINT_LEN_8: + *gen_len = HW_BREAKPOINT_LEN_8; + break; +#endif + default: + return -EINVAL; + } - switch (bp->info.type) { - /* - * Ptrace-refactoring code - * For now, we'll allow instruction breakpoint only for user-space - * addresses - */ - case HW_BREAKPOINT_EXECUTE: - if ((!arch_check_va_in_userspace(bp->info.address, - bp->info.len)) && - bp->info.len != HW_BREAKPOINT_LEN_EXECUTE) - return ret; + /* Type */ + switch (x86_type) { + case X86_BREAKPOINT_EXECUTE: + *gen_type = HW_BREAKPOINT_X; break; - case HW_BREAKPOINT_WRITE: + case X86_BREAKPOINT_WRITE: + *gen_type = HW_BREAKPOINT_W; break; - case HW_BREAKPOINT_RW: + case X86_BREAKPOINT_RW: + *gen_type = HW_BREAKPOINT_W | HW_BREAKPOINT_R; break; default: - return ret; + return -EINVAL; } - switch (bp->info.len) { + return 0; +} + + +static int arch_build_bp_info(struct perf_event *bp) +{ + struct arch_hw_breakpoint *info = counter_arch_bp(bp); + + info->address = bp->attr.bp_addr; + + /* Len */ + switch (bp->attr.bp_len) { case HW_BREAKPOINT_LEN_1: - align = 0; + info->len = X86_BREAKPOINT_LEN_1; break; case HW_BREAKPOINT_LEN_2: - align = 1; + info->len = X86_BREAKPOINT_LEN_2; break; case HW_BREAKPOINT_LEN_4: - align = 3; + info->len = X86_BREAKPOINT_LEN_4; break; #ifdef CONFIG_X86_64 case HW_BREAKPOINT_LEN_8: + info->len = X86_BREAKPOINT_LEN_8; + break; +#endif + default: + return -EINVAL; + } + + /* Type */ + switch (bp->attr.bp_type) { + case HW_BREAKPOINT_W: + info->type = X86_BREAKPOINT_WRITE; + break; + case HW_BREAKPOINT_W | HW_BREAKPOINT_R: + info->type = X86_BREAKPOINT_RW; + break; + case HW_BREAKPOINT_X: + info->type = X86_BREAKPOINT_EXECUTE; + break; + default: + return -EINVAL; + } + + return 0; +} +/* + * Validate the arch-specific HW Breakpoint register settings + */ +int arch_validate_hwbkpt_settings(struct perf_event *bp, + struct task_struct *tsk) +{ + struct arch_hw_breakpoint *info = counter_arch_bp(bp); + unsigned int align; + int ret; + + + ret = arch_build_bp_info(bp); + if (ret) + return ret; + + ret = -EINVAL; + + if (info->type == X86_BREAKPOINT_EXECUTE) + /* + * Ptrace-refactoring code + * For now, we'll allow instruction breakpoint only for user-space + * addresses + */ + if ((!arch_check_va_in_userspace(info->address, info->len)) && + info->len != X86_BREAKPOINT_EXECUTE) + return ret; + + switch (info->len) { + case X86_BREAKPOINT_LEN_1: + align = 0; + break; + case X86_BREAKPOINT_LEN_2: + align = 1; + break; + case X86_BREAKPOINT_LEN_4: + align = 3; + break; +#ifdef CONFIG_X86_64 + case X86_BREAKPOINT_LEN_8: align = 7; break; #endif @@ -246,8 +351,8 @@ int arch_validate_hwbkpt_settings(struct hw_breakpoint *bp, return ret; } - if (bp->triggered) - ret = arch_store_info(bp, tsk); + if (bp->callback) + ret = arch_store_info(bp); if (ret < 0) return ret; @@ -255,44 +360,47 @@ int arch_validate_hwbkpt_settings(struct hw_breakpoint *bp, * Check that the low-order bits of the address are appropriate * for the alignment implied by len. */ - if (bp->info.address & align) + if (info->address & align) return -EINVAL; /* Check that the virtual address is in the proper range */ if (tsk) { - if (!arch_check_va_in_userspace(bp->info.address, bp->info.len)) + if (!arch_check_va_in_userspace(info->address, info->len)) return -EFAULT; } else { - if (!arch_check_va_in_kernelspace(bp->info.address, - bp->info.len)) + if (!arch_check_va_in_kernelspace(info->address, info->len)) return -EFAULT; } + return 0; } -void arch_update_user_hw_breakpoint(int pos, struct task_struct *tsk) +/* + * Release the user breakpoints used by ptrace + */ +void flush_ptrace_hw_breakpoint(struct task_struct *tsk) { - struct thread_struct *thread = &(tsk->thread); - struct hw_breakpoint *bp = thread->hbp[pos]; - - thread->debugreg7 &= ~dr7_masks[pos]; - if (bp) { - thread->debugreg[pos] = bp->info.address; - thread->debugreg7 |= encode_dr7(pos, bp->info.len, - bp->info.type); - } else - thread->debugreg[pos] = 0; + int i; + struct thread_struct *t = &tsk->thread; + + for (i = 0; i < HBP_NUM; i++) { + unregister_hw_breakpoint(t->ptrace_bps[i]); + t->ptrace_bps[i] = NULL; + } } -void arch_flush_thread_hw_breakpoint(struct task_struct *tsk) +#ifdef CONFIG_KVM +void hw_breakpoint_restore(void) { - int i; - struct thread_struct *thread = &(tsk->thread); - - thread->debugreg7 = 0; - for (i = 0; i < HBP_NUM; i++) - thread->debugreg[i] = 0; + set_debugreg(__get_cpu_var(cpu_debugreg[0]), 0); + set_debugreg(__get_cpu_var(cpu_debugreg[1]), 1); + set_debugreg(__get_cpu_var(cpu_debugreg[2]), 2); + set_debugreg(__get_cpu_var(cpu_debugreg[3]), 3); + set_debugreg(current->thread.debugreg6, 6); + set_debugreg(__get_cpu_var(dr7), 7); } +EXPORT_SYMBOL_GPL(hw_breakpoint_restore); +#endif /* * Handle debug exception notifications. @@ -313,7 +421,7 @@ void arch_flush_thread_hw_breakpoint(struct task_struct *tsk) static int __kprobes hw_breakpoint_handler(struct die_args *args) { int i, cpu, rc = NOTIFY_STOP; - struct hw_breakpoint *bp; + struct perf_event *bp; unsigned long dr7, dr6; unsigned long *dr6_p; @@ -325,10 +433,6 @@ static int __kprobes hw_breakpoint_handler(struct die_args *args) if ((dr6 & DR_TRAP_BITS) == 0) return NOTIFY_DONE; - /* Lazy debug register switching */ - if (!test_tsk_thread_flag(current, TIF_DEBUG)) - arch_uninstall_thread_hw_breakpoint(); - get_debugreg(dr7, 7); /* Disable breakpoints during exception handling */ set_debugreg(0UL, 7); @@ -344,17 +448,18 @@ static int __kprobes hw_breakpoint_handler(struct die_args *args) for (i = 0; i < HBP_NUM; ++i) { if (likely(!(dr6 & (DR_TRAP0 << i)))) continue; + /* - * Find the corresponding hw_breakpoint structure and - * invoke its triggered callback. + * The counter may be concurrently released but that can only + * occur from a call_rcu() path. We can then safely fetch + * the breakpoint, use its callback, touch its counter + * while we are in an rcu_read_lock() path. */ - if (i >= hbp_kernel_pos) - bp = per_cpu(this_hbp_kernel[i], cpu); - else { - bp = current->thread.hbp[i]; - if (bp) - rc = NOTIFY_DONE; - } + rcu_read_lock(); + + bp = per_cpu(bp_per_reg[i], cpu); + if (bp) + rc = NOTIFY_DONE; /* * Reset the 'i'th TRAP bit in dr6 to denote completion of * exception handling @@ -362,19 +467,23 @@ static int __kprobes hw_breakpoint_handler(struct die_args *args) (*dr6_p) &= ~(DR_TRAP0 << i); /* * bp can be NULL due to lazy debug register switching - * or due to the delay between updates of hbp_kernel_pos - * and this_hbp_kernel. + * or due to concurrent perf counter removing. */ - if (!bp) - continue; + if (!bp) { + rcu_read_unlock(); + break; + } + + (bp->callback)(bp, args->regs); - (bp->triggered)(bp, args->regs); + rcu_read_unlock(); } if (dr6 & (~DR_TRAP_BITS)) rc = NOTIFY_DONE; set_debugreg(dr7, 7); put_cpu(); + return rc; } @@ -389,3 +498,13 @@ int __kprobes hw_breakpoint_exceptions_notify( return hw_breakpoint_handler(data); } + +void hw_breakpoint_pmu_read(struct perf_event *bp) +{ + /* TODO */ +} + +void hw_breakpoint_pmu_unthrottle(struct perf_event *bp) +{ + /* TODO */ +} diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index cf8ee001630..744508e7cfd 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -18,7 +19,6 @@ #include #include #include -#include unsigned long idle_halt; EXPORT_SYMBOL(idle_halt); @@ -47,8 +47,6 @@ void free_thread_xstate(struct task_struct *tsk) kmem_cache_free(task_xstate_cachep, tsk->thread.xstate); tsk->thread.xstate = NULL; } - if (unlikely(test_tsk_thread_flag(tsk, TIF_DEBUG))) - flush_thread_hw_breakpoint(tsk); WARN(tsk->thread.ds_ctx, "leaking DS context\n"); } @@ -107,8 +105,7 @@ void flush_thread(void) } #endif - if (unlikely(test_tsk_thread_flag(tsk, TIF_DEBUG))) - flush_thread_hw_breakpoint(tsk); + flush_ptrace_hw_breakpoint(tsk); memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array)); /* * Forget coprocessor state.. diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 209e7480176..d5bd3132ee7 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -59,7 +59,6 @@ #include #include #include -#include asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); @@ -264,9 +263,8 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, p->thread.io_bitmap_ptr = NULL; tsk = current; err = -ENOMEM; - if (unlikely(test_tsk_thread_flag(tsk, TIF_DEBUG))) - if (copy_thread_hw_breakpoint(tsk, p, clone_flags)) - goto out; + + memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps)); if (unlikely(test_tsk_thread_flag(tsk, TIF_IO_BITMAP))) { p->thread.io_bitmap_ptr = kmemdup(tsk->thread.io_bitmap_ptr, @@ -287,13 +285,10 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, err = do_set_thread_area(p, -1, (struct user_desc __user *)childregs->si, 0); -out: if (err && p->thread.io_bitmap_ptr) { kfree(p->thread.io_bitmap_ptr); p->thread.io_bitmap_max = 0; } - if (err) - flush_thread_hw_breakpoint(p); clear_tsk_thread_flag(p, TIF_DS_AREA_MSR); p->thread.ds_ctx = NULL; @@ -437,23 +432,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) lazy_load_gs(next->gs); percpu_write(current_task, next_p); - /* - * There's a problem with moving the arch_install_thread_hw_breakpoint() - * call before current is updated. Suppose a kernel breakpoint is - * triggered in between the two, the hw-breakpoint handler will see that - * the 'current' task does not have TIF_DEBUG flag set and will think it - * is leftover from an old task (lazy switching) and will erase it. Then - * until the next context switch, no user-breakpoints will be installed. - * - * The real problem is that it's impossible to update both current and - * physical debug registers at the same instant, so there will always be - * a window in which they disagree and a breakpoint might get triggered. - * Since we use lazy switching, we are forced to assume that a - * disagreement means that current is correct and the exception is due - * to lazy debug register switching. - */ - if (unlikely(test_tsk_thread_flag(next_p, TIF_DEBUG))) - arch_install_thread_hw_breakpoint(next_p); return prev_p; } diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 72edac026a7..5bafdec3444 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -53,7 +53,6 @@ #include #include #include -#include asmlinkage extern void ret_from_fork(void); @@ -244,8 +243,6 @@ void release_thread(struct task_struct *dead_task) BUG(); } } - if (unlikely(dead_task->thread.debugreg7)) - flush_thread_hw_breakpoint(dead_task); } static inline void set_32bit_tls(struct task_struct *t, int tls, u32 addr) @@ -309,9 +306,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, savesegment(ds, p->thread.ds); err = -ENOMEM; - if (unlikely(test_tsk_thread_flag(me, TIF_DEBUG))) - if (copy_thread_hw_breakpoint(me, p, clone_flags)) - goto out; + memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps)); if (unlikely(test_tsk_thread_flag(me, TIF_IO_BITMAP))) { p->thread.io_bitmap_ptr = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL); @@ -351,8 +346,6 @@ out: kfree(p->thread.io_bitmap_ptr); p->thread.io_bitmap_max = 0; } - if (err) - flush_thread_hw_breakpoint(p); return err; } @@ -508,23 +501,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) */ if (preload_fpu) __math_state_restore(); - /* - * There's a problem with moving the arch_install_thread_hw_breakpoint() - * call before current is updated. Suppose a kernel breakpoint is - * triggered in between the two, the hw-breakpoint handler will see that - * the 'current' task does not have TIF_DEBUG flag set and will think it - * is leftover from an old task (lazy switching) and will erase it. Then - * until the next context switch, no user-breakpoints will be installed. - * - * The real problem is that it's impossible to update both current and - * physical debug registers at the same instant, so there will always be - * a window in which they disagree and a breakpoint might get triggered. - * Since we use lazy switching, we are forced to assume that a - * disagreement means that current is correct and the exception is due - * to lazy debug register switching. - */ - if (unlikely(test_tsk_thread_flag(next_p, TIF_DEBUG))) - arch_install_thread_hw_breakpoint(next_p); return prev_p; } diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 267cb85b479..e79610d9597 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -22,6 +22,8 @@ #include #include #include +#include +#include #include #include @@ -441,54 +443,59 @@ static int genregs_set(struct task_struct *target, return ret; } -/* - * Decode the length and type bits for a particular breakpoint as - * stored in debug register 7. Return the "enabled" status. - */ -static int decode_dr7(unsigned long dr7, int bpnum, unsigned *len, - unsigned *type) -{ - int bp_info = dr7 >> (DR_CONTROL_SHIFT + bpnum * DR_CONTROL_SIZE); - - *len = (bp_info & 0xc) | 0x40; - *type = (bp_info & 0x3) | 0x80; - return (dr7 >> (bpnum * DR_ENABLE_SIZE)) & 0x3; -} - -static void ptrace_triggered(struct hw_breakpoint *bp, struct pt_regs *regs) +static void ptrace_triggered(struct perf_event *bp, void *data) { - struct thread_struct *thread = &(current->thread); int i; + struct thread_struct *thread = &(current->thread); /* * Store in the virtual DR6 register the fact that the breakpoint * was hit so the thread's debugger will see it. */ - for (i = 0; i < hbp_kernel_pos; i++) - /* - * We will check bp->info.address against the address stored in - * thread's hbp structure and not debugreg[i]. This is to ensure - * that the corresponding bit for 'i' in DR7 register is enabled - */ - if (bp->info.address == thread->hbp[i]->info.address) + for (i = 0; i < HBP_NUM; i++) { + if (thread->ptrace_bps[i] == bp) break; + } thread->debugreg6 |= (DR_TRAP0 << i); } +/* + * Walk through every ptrace breakpoints for this thread and + * build the dr7 value on top of their attributes. + * + */ +static unsigned long ptrace_get_dr7(struct perf_event *bp[]) +{ + int i; + int dr7 = 0; + struct arch_hw_breakpoint *info; + + for (i = 0; i < HBP_NUM; i++) { + if (bp[i] && !bp[i]->attr.disabled) { + info = counter_arch_bp(bp[i]); + dr7 |= encode_dr7(i, info->len, info->type); + } + } + + return dr7; +} + /* * Handle ptrace writes to debug register 7. */ static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data) { struct thread_struct *thread = &(tsk->thread); - unsigned long old_dr7 = thread->debugreg7; + unsigned long old_dr7; int i, orig_ret = 0, rc = 0; int enabled, second_pass = 0; unsigned len, type; - struct hw_breakpoint *bp; + int gen_len, gen_type; + struct perf_event *bp; data &= ~DR_CONTROL_RESERVED; + old_dr7 = ptrace_get_dr7(thread->ptrace_bps); restore: /* * Loop through all the hardware breakpoints, making the @@ -496,11 +503,12 @@ restore: */ for (i = 0; i < HBP_NUM; i++) { enabled = decode_dr7(data, i, &len, &type); - bp = thread->hbp[i]; + bp = thread->ptrace_bps[i]; if (!enabled) { if (bp) { - /* Don't unregister the breakpoints right-away, + /* + * Don't unregister the breakpoints right-away, * unless all register_user_hw_breakpoint() * requests have succeeded. This prevents * any window of opportunity for debug @@ -508,27 +516,45 @@ restore: */ if (!second_pass) continue; - unregister_user_hw_breakpoint(tsk, bp); - kfree(bp); + thread->ptrace_bps[i] = NULL; + unregister_hw_breakpoint(bp); } continue; } + + /* + * We shoud have at least an inactive breakpoint at this + * slot. It means the user is writing dr7 without having + * written the address register first + */ if (!bp) { - rc = -ENOMEM; - bp = kzalloc(sizeof(struct hw_breakpoint), GFP_KERNEL); - if (bp) { - bp->info.address = thread->debugreg[i]; - bp->triggered = ptrace_triggered; - bp->info.len = len; - bp->info.type = type; - rc = register_user_hw_breakpoint(tsk, bp); - if (rc) - kfree(bp); - } - } else - rc = modify_user_hw_breakpoint(tsk, bp); + rc = -EINVAL; + break; + } + + rc = arch_bp_generic_fields(len, type, &gen_len, &gen_type); if (rc) break; + + /* + * This is a temporary thing as bp is unregistered/registered + * to simulate modification + */ + bp = modify_user_hw_breakpoint(bp, bp->attr.bp_addr, gen_len, + gen_type, bp->callback, + tsk, true); + thread->ptrace_bps[i] = NULL; + + if (!bp) { /* incorrect bp, or we have a bug in bp API */ + rc = -EINVAL; + break; + } + if (IS_ERR(bp)) { + rc = PTR_ERR(bp); + bp = NULL; + break; + } + thread->ptrace_bps[i] = bp; } /* * Make a second pass to free the remaining unused breakpoints @@ -553,15 +579,63 @@ static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n) struct thread_struct *thread = &(tsk->thread); unsigned long val = 0; - if (n < HBP_NUM) - val = thread->debugreg[n]; - else if (n == 6) + if (n < HBP_NUM) { + struct perf_event *bp; + bp = thread->ptrace_bps[n]; + if (!bp) + return 0; + val = bp->hw.info.address; + } else if (n == 6) { val = thread->debugreg6; - else if (n == 7) - val = thread->debugreg7; + } else if (n == 7) { + val = ptrace_get_dr7(thread->ptrace_bps); + } return val; } +static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr, + unsigned long addr) +{ + struct perf_event *bp; + struct thread_struct *t = &tsk->thread; + + if (!t->ptrace_bps[nr]) { + /* + * Put stub len and type to register (reserve) an inactive but + * correct bp + */ + bp = register_user_hw_breakpoint(addr, HW_BREAKPOINT_LEN_1, + HW_BREAKPOINT_W, + ptrace_triggered, tsk, + false); + } else { + bp = t->ptrace_bps[nr]; + t->ptrace_bps[nr] = NULL; + bp = modify_user_hw_breakpoint(bp, addr, bp->attr.bp_len, + bp->attr.bp_type, + bp->callback, + tsk, + bp->attr.disabled); + } + + if (!bp) + return -EIO; + /* + * CHECKME: the previous code returned -EIO if the addr wasn't a + * valid task virtual addr. The new one will return -EINVAL in this + * case. + * -EINVAL may be what we want for in-kernel breakpoints users, but + * -EIO looks better for ptrace, since we refuse a register writing + * for the user. And anyway this is the previous behaviour. + */ + if (IS_ERR(bp)) + return PTR_ERR(bp); + + t->ptrace_bps[nr] = bp; + + return 0; +} + /* * Handle PTRACE_POKEUSR calls for the debug register area. */ @@ -575,19 +649,13 @@ int ptrace_set_debugreg(struct task_struct *tsk, int n, unsigned long val) return -EIO; if (n == 6) { - tsk->thread.debugreg6 = val; + thread->debugreg6 = val; goto ret_path; } if (n < HBP_NUM) { - if (thread->hbp[n]) { - if (arch_check_va_in_userspace(val, - thread->hbp[n]->info.len) == 0) { - rc = -EIO; - goto ret_path; - } - thread->hbp[n]->info.address = val; - } - thread->debugreg[n] = val; + rc = ptrace_set_breakpoint_addr(tsk, n, val); + if (rc) + return rc; } /* All that's left is DR7 */ if (n == 7) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 213a7a3e456..565ebc65920 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -64,7 +64,6 @@ #include #include #include -#include #include #include @@ -328,7 +327,6 @@ notrace static void __cpuinit start_secondary(void *unused) x86_cpuinit.setup_percpu_clockev(); wmb(); - load_debug_registers(); cpu_idle(); } @@ -1269,7 +1267,6 @@ void cpu_disable_common(void) remove_cpu_from_maps(cpu); unlock_vector_lock(); fixup_irqs(); - hw_breakpoint_disable(); } int native_cpu_disable(void) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index fc2974adf9b..22dee7aa781 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -42,6 +42,7 @@ #define CREATE_TRACE_POINTS #include "trace.h" +#include #include #include #include @@ -3643,14 +3644,15 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) trace_kvm_entry(vcpu->vcpu_id); kvm_x86_ops->run(vcpu, kvm_run); - if (unlikely(vcpu->arch.switch_db_regs || test_thread_flag(TIF_DEBUG))) { - set_debugreg(current->thread.debugreg[0], 0); - set_debugreg(current->thread.debugreg[1], 1); - set_debugreg(current->thread.debugreg[2], 2); - set_debugreg(current->thread.debugreg[3], 3); - set_debugreg(current->thread.debugreg6, 6); - set_debugreg(current->thread.debugreg7, 7); - } + /* + * If the guest has used debug registers, at least dr7 + * will be disabled while returning to the host. + * If we don't have active breakpoints in the host, we don't + * care about the messed up debug address registers. But if + * we have some of them active, restore the old state. + */ + if (__get_cpu_var(dr7) & DR_GLOBAL_ENABLE_MASK) + hw_breakpoint_restore(); set_bit(KVM_REQ_KICK, &vcpu->requests); local_irq_enable(); diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c index e09a44fc466..0a979f3e5b8 100644 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -105,7 +105,6 @@ static void __save_processor_state(struct saved_context *ctxt) ctxt->cr4 = read_cr4(); ctxt->cr8 = read_cr8(); #endif - hw_breakpoint_disable(); } /* Needed by apm.c */ @@ -144,11 +143,6 @@ static void fix_processor_context(void) #endif load_TR_desc(); /* This does ltr */ load_LDT(¤t->active_mm->context); /* This does lldt */ - - /* - * Now maybe reload the debug registers - */ - load_debug_registers(); } /** diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h index 61ccc8f17ea..7eba9b92e5f 100644 --- a/include/linux/hw_breakpoint.h +++ b/include/linux/hw_breakpoint.h @@ -1,136 +1,131 @@ #ifndef _LINUX_HW_BREAKPOINT_H #define _LINUX_HW_BREAKPOINT_H +#include -#ifdef __KERNEL__ -#include -#include -#include - -/** - * struct hw_breakpoint - unified kernel/user-space hardware breakpoint - * @triggered: callback invoked after target address access - * @info: arch-specific breakpoint info (address, length, and type) - * - * %hw_breakpoint structures are the kernel's way of representing - * hardware breakpoints. These are data breakpoints - * (also known as "watchpoints", triggered on data access), and the breakpoint's - * target address can be located in either kernel space or user space. - * - * The breakpoint's address, length, and type are highly - * architecture-specific. The values are encoded in the @info field; you - * specify them when registering the breakpoint. To examine the encoded - * values use hw_breakpoint_get_{kaddress,uaddress,len,type}(), declared - * below. - * - * The address is specified as a regular kernel pointer (for kernel-space - * breakponts) or as an %__user pointer (for user-space breakpoints). - * With register_user_hw_breakpoint(), the address must refer to a - * location in user space. The breakpoint will be active only while the - * requested task is running. Conversely with - * register_kernel_hw_breakpoint(), the address must refer to a location - * in kernel space, and the breakpoint will be active on all CPUs - * regardless of the current task. - * - * The length is the breakpoint's extent in bytes, which is subject to - * certain limitations. include/asm/hw_breakpoint.h contains macros - * defining the available lengths for a specific architecture. Note that - * the address's alignment must match the length. The breakpoint will - * catch accesses to any byte in the range from address to address + - * (length - 1). - * - * The breakpoint's type indicates the sort of access that will cause it - * to trigger. Possible values may include: - * - * %HW_BREAKPOINT_RW (triggered on read or write access), - * %HW_BREAKPOINT_WRITE (triggered on write access), and - * %HW_BREAKPOINT_READ (triggered on read access). - * - * Appropriate macros are defined in include/asm/hw_breakpoint.h; not all - * possibilities are available on all architectures. Execute breakpoints - * must have length equal to the special value %HW_BREAKPOINT_LEN_EXECUTE. - * - * When a breakpoint gets hit, the @triggered callback is - * invoked in_interrupt with a pointer to the %hw_breakpoint structure and the - * processor registers. - * Data breakpoints occur after the memory access has taken place. - * Breakpoints are disabled during execution @triggered, to avoid - * recursive traps and allow unhindered access to breakpointed memory. - * - * This sample code sets a breakpoint on pid_max and registers a callback - * function for writes to that variable. Note that it is not portable - * as written, because not all architectures support HW_BREAKPOINT_LEN_4. - * - * ---------------------------------------------------------------------- - * - * #include - * - * struct hw_breakpoint my_bp; - * - * static void my_triggered(struct hw_breakpoint *bp, struct pt_regs *regs) - * { - * printk(KERN_DEBUG "Inside triggered routine of breakpoint exception\n"); - * dump_stack(); - * ............... - * } - * - * static struct hw_breakpoint my_bp; - * - * static int init_module(void) - * { - * ...................... - * my_bp.info.type = HW_BREAKPOINT_WRITE; - * my_bp.info.len = HW_BREAKPOINT_LEN_4; - * - * my_bp.installed = (void *)my_bp_installed; - * - * rc = register_kernel_hw_breakpoint(&my_bp); - * ...................... - * } - * - * static void cleanup_module(void) - * { - * ...................... - * unregister_kernel_hw_breakpoint(&my_bp); - * ...................... - * } - * - * ---------------------------------------------------------------------- - */ -struct hw_breakpoint { - void (*triggered)(struct hw_breakpoint *, struct pt_regs *); - struct arch_hw_breakpoint info; +enum { + HW_BREAKPOINT_LEN_1 = 1, + HW_BREAKPOINT_LEN_2 = 2, + HW_BREAKPOINT_LEN_4 = 4, + HW_BREAKPOINT_LEN_8 = 8, }; -/* - * len and type values are defined in include/asm/hw_breakpoint.h. - * Available values vary according to the architecture. On i386 the - * possibilities are: - * - * HW_BREAKPOINT_LEN_1 - * HW_BREAKPOINT_LEN_2 - * HW_BREAKPOINT_LEN_4 - * HW_BREAKPOINT_RW - * HW_BREAKPOINT_READ - * - * On other architectures HW_BREAKPOINT_LEN_8 may be available, and the - * 1-, 2-, and 4-byte lengths may be unavailable. There also may be - * HW_BREAKPOINT_WRITE. You can use #ifdef to check at compile time. - */ +enum { + HW_BREAKPOINT_R = 1, + HW_BREAKPOINT_W = 2, + HW_BREAKPOINT_X = 4, +}; + +static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp) +{ + return &bp->hw.info; +} + +static inline unsigned long hw_breakpoint_addr(struct perf_event *bp) +{ + return bp->attr.bp_addr; +} + +static inline int hw_breakpoint_type(struct perf_event *bp) +{ + return bp->attr.bp_type; +} + +static inline int hw_breakpoint_len(struct perf_event *bp) +{ + return bp->attr.bp_len; +} + +#ifdef CONFIG_HAVE_HW_BREAKPOINT +extern struct perf_event * +register_user_hw_breakpoint(unsigned long addr, + int len, + int type, + perf_callback_t triggered, + struct task_struct *tsk, + bool active); + +/* FIXME: only change from the attr, and don't unregister */ +extern struct perf_event * +modify_user_hw_breakpoint(struct perf_event *bp, + unsigned long addr, + int len, + int type, + perf_callback_t triggered, + struct task_struct *tsk, + bool active); -extern int register_user_hw_breakpoint(struct task_struct *tsk, - struct hw_breakpoint *bp); -extern int modify_user_hw_breakpoint(struct task_struct *tsk, - struct hw_breakpoint *bp); -extern void unregister_user_hw_breakpoint(struct task_struct *tsk, - struct hw_breakpoint *bp); /* * Kernel breakpoints are not associated with any particular thread. */ -extern int register_kernel_hw_breakpoint(struct hw_breakpoint *bp); -extern void unregister_kernel_hw_breakpoint(struct hw_breakpoint *bp); +extern struct perf_event * +register_wide_hw_breakpoint_cpu(unsigned long addr, + int len, + int type, + perf_callback_t triggered, + int cpu, + bool active); + +extern struct perf_event ** +register_wide_hw_breakpoint(unsigned long addr, + int len, + int type, + perf_callback_t triggered, + bool active); + +extern int register_perf_hw_breakpoint(struct perf_event *bp); +extern int __register_perf_hw_breakpoint(struct perf_event *bp); +extern void unregister_hw_breakpoint(struct perf_event *bp); +extern void unregister_wide_hw_breakpoint(struct perf_event **cpu_events); + +extern int reserve_bp_slot(struct perf_event *bp); +extern void release_bp_slot(struct perf_event *bp); + +extern void flush_ptrace_hw_breakpoint(struct task_struct *tsk); + +#else /* !CONFIG_HAVE_HW_BREAKPOINT */ + +static inline struct perf_event * +register_user_hw_breakpoint(unsigned long addr, + int len, + int type, + perf_callback_t triggered, + struct task_struct *tsk, + bool active) { return NULL; } +static inline struct perf_event * +modify_user_hw_breakpoint(struct perf_event *bp, + unsigned long addr, + int len, + int type, + perf_callback_t triggered, + struct task_struct *tsk, + bool active) { return NULL; } +static inline struct perf_event * +register_wide_hw_breakpoint_cpu(unsigned long addr, + int len, + int type, + perf_callback_t triggered, + int cpu, + bool active) { return NULL; } +static inline struct perf_event ** +register_wide_hw_breakpoint(unsigned long addr, + int len, + int type, + perf_callback_t triggered, + bool active) { return NULL; } +static inline int +register_perf_hw_breakpoint(struct perf_event *bp) { return -ENOSYS; } +static inline int +__register_perf_hw_breakpoint(struct perf_event *bp) { return -ENOSYS; } +static inline void unregister_hw_breakpoint(struct perf_event *bp) { } +static inline void +unregister_wide_hw_breakpoint(struct perf_event **cpu_events) { } +static inline int +reserve_bp_slot(struct perf_event *bp) {return -ENOSYS; } +static inline void release_bp_slot(struct perf_event *bp) { } + +static inline void flush_ptrace_hw_breakpoint(struct task_struct *tsk) { } -extern unsigned int hbp_kernel_pos; +#endif /* CONFIG_HAVE_HW_BREAKPOINT */ -#endif /* __KERNEL__ */ -#endif /* _LINUX_HW_BREAKPOINT_H */ +#endif /* _LINUX_HW_BREAKPOINT_H */ diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 8d54e6d25ee..cead64ea6c1 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -18,6 +18,10 @@ #include #include +#ifdef CONFIG_HAVE_HW_BREAKPOINT +#include +#endif + /* * User-space ABI bits: */ @@ -31,6 +35,7 @@ enum perf_type_id { PERF_TYPE_TRACEPOINT = 2, PERF_TYPE_HW_CACHE = 3, PERF_TYPE_RAW = 4, + PERF_TYPE_BREAKPOINT = 5, PERF_TYPE_MAX, /* non-ABI */ }; @@ -207,6 +212,15 @@ struct perf_event_attr { __u32 wakeup_events; /* wakeup every n events */ __u32 wakeup_watermark; /* bytes before wakeup */ }; + + union { + struct { /* Hardware breakpoint info */ + __u64 bp_addr; + __u32 bp_type; + __u32 bp_len; + }; + }; + __u32 __reserved_2; __u64 __reserved_3; @@ -476,6 +490,11 @@ struct hw_perf_event { atomic64_t count; struct hrtimer hrtimer; }; +#ifdef CONFIG_HAVE_HW_BREAKPOINT + union { /* breakpoint */ + struct arch_hw_breakpoint info; + }; +#endif }; atomic64_t prev_count; u64 sample_period; @@ -588,7 +607,7 @@ struct perf_event { u64 tstamp_running; u64 tstamp_stopped; - struct perf_event_attr attr; + struct perf_event_attr attr; struct hw_perf_event hw; struct perf_event_context *ctx; @@ -643,6 +662,8 @@ struct perf_event { perf_callback_t callback; + perf_callback_t event_callback; + #endif /* CONFIG_PERF_EVENTS */ }; @@ -831,6 +852,7 @@ extern int sysctl_perf_event_sample_rate; extern void perf_event_init(void); extern void perf_tp_event(int event_id, u64 addr, u64 count, void *record, int entry_size); +extern void perf_bp_event(struct perf_event *event, void *data); #ifndef perf_misc_flags #define perf_misc_flags(regs) (user_mode(regs) ? PERF_RECORD_MISC_USER : \ @@ -865,6 +887,8 @@ static inline int perf_event_task_enable(void) { return -EINVAL; } static inline void perf_sw_event(u32 event_id, u64 nr, int nmi, struct pt_regs *regs, u64 addr) { } +static inline void +perf_bp_event(struct perf_event *event, void *data) { } static inline void perf_event_mmap(struct vm_area_struct *vma) { } static inline void perf_event_comm(struct task_struct *tsk) { } diff --git a/kernel/exit.c b/kernel/exit.c index e61891f8012..266f8920628 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -49,6 +49,7 @@ #include #include #include +#include #include #include @@ -979,6 +980,10 @@ NORET_TYPE void do_exit(long code) proc_exit_connector(tsk); + /* + * FIXME: do that only when needed, using sched_exit tracepoint + */ + flush_ptrace_hw_breakpoint(tsk); /* * Flush inherited counters to the parent - before the parent * gets woken up by child-exit notifications. diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c index c1f64e65a9f..08f6d016320 100644 --- a/kernel/hw_breakpoint.c +++ b/kernel/hw_breakpoint.c @@ -15,6 +15,7 @@ * * Copyright (C) 2007 Alan Stern * Copyright (C) IBM Corporation, 2009 + * Copyright (C) 2009, Frederic Weisbecker */ /* @@ -35,334 +36,242 @@ #include #include -#include +#include + #include #ifdef CONFIG_X86 #include #endif -/* - * Spinlock that protects all (un)register operations over kernel/user-space - * breakpoint requests - */ -static DEFINE_SPINLOCK(hw_breakpoint_lock); - -/* Array of kernel-space breakpoint structures */ -struct hw_breakpoint *hbp_kernel[HBP_NUM]; - -/* - * Per-processor copy of hbp_kernel[]. Used only when hbp_kernel is being - * modified but we need the older copy to handle any hbp exceptions. It will - * sync with hbp_kernel[] value after updation is done through IPIs. - */ -DEFINE_PER_CPU(struct hw_breakpoint*, this_hbp_kernel[HBP_NUM]); - -/* - * Kernel breakpoints grow downwards, starting from HBP_NUM - * 'hbp_kernel_pos' denotes lowest numbered breakpoint register occupied for - * kernel-space request. We will initialise it here and not in an __init - * routine because load_debug_registers(), which uses this variable can be - * called very early during CPU initialisation. - */ -unsigned int hbp_kernel_pos = HBP_NUM; -/* - * An array containing refcount of threads using a given bkpt register - * Accesses are synchronised by acquiring hw_breakpoint_lock - */ -unsigned int hbp_user_refcount[HBP_NUM]; +static atomic_t bp_slot; -/* - * Load the debug registers during startup of a CPU. - */ -void load_debug_registers(void) +int reserve_bp_slot(struct perf_event *bp) { - unsigned long flags; - struct task_struct *tsk = current; - - spin_lock_bh(&hw_breakpoint_lock); - - /* Prevent IPIs for new kernel breakpoint updates */ - local_irq_save(flags); - arch_update_kernel_hw_breakpoint(NULL); - local_irq_restore(flags); - - if (test_tsk_thread_flag(tsk, TIF_DEBUG)) - arch_install_thread_hw_breakpoint(tsk); - - spin_unlock_bh(&hw_breakpoint_lock); -} + if (atomic_inc_return(&bp_slot) == HBP_NUM) { + atomic_dec(&bp_slot); -/* - * Erase all the hardware breakpoint info associated with a thread. - * - * If tsk != current then tsk must not be usable (for example, a - * child being cleaned up from a failed fork). - */ -void flush_thread_hw_breakpoint(struct task_struct *tsk) -{ - int i; - struct thread_struct *thread = &(tsk->thread); - - spin_lock_bh(&hw_breakpoint_lock); - - /* The thread no longer has any breakpoints associated with it */ - clear_tsk_thread_flag(tsk, TIF_DEBUG); - for (i = 0; i < HBP_NUM; i++) { - if (thread->hbp[i]) { - hbp_user_refcount[i]--; - kfree(thread->hbp[i]); - thread->hbp[i] = NULL; - } + return -ENOSPC; } - arch_flush_thread_hw_breakpoint(tsk); - - /* Actually uninstall the breakpoints if necessary */ - if (tsk == current) - arch_uninstall_thread_hw_breakpoint(); - spin_unlock_bh(&hw_breakpoint_lock); + return 0; } -/* - * Copy the hardware breakpoint info from a thread to its cloned child. - */ -int copy_thread_hw_breakpoint(struct task_struct *tsk, - struct task_struct *child, unsigned long clone_flags) +void release_bp_slot(struct perf_event *bp) { - /* - * We will assume that breakpoint settings are not inherited - * and the child starts out with no debug registers set. - * But what about CLONE_PTRACE? - */ - clear_tsk_thread_flag(child, TIF_DEBUG); - - /* We will call flush routine since the debugregs are not inherited */ - arch_flush_thread_hw_breakpoint(child); - - return 0; + atomic_dec(&bp_slot); } -static int __register_user_hw_breakpoint(int pos, struct task_struct *tsk, - struct hw_breakpoint *bp) +int __register_perf_hw_breakpoint(struct perf_event *bp) { - struct thread_struct *thread = &(tsk->thread); - int rc; + int ret; - /* Do not overcommit. Fail if kernel has used the hbp registers */ - if (pos >= hbp_kernel_pos) - return -ENOSPC; + ret = reserve_bp_slot(bp); + if (ret) + return ret; - rc = arch_validate_hwbkpt_settings(bp, tsk); - if (rc) - return rc; + if (!bp->attr.disabled) + ret = arch_validate_hwbkpt_settings(bp, bp->ctx->task); - thread->hbp[pos] = bp; - hbp_user_refcount[pos]++; + return ret; +} - arch_update_user_hw_breakpoint(pos, tsk); - /* - * Does it need to be installed right now? - * Otherwise it will get installed the next time tsk runs - */ - if (tsk == current) - arch_install_thread_hw_breakpoint(tsk); +int register_perf_hw_breakpoint(struct perf_event *bp) +{ + bp->callback = perf_bp_event; - return rc; + return __register_perf_hw_breakpoint(bp); } /* - * Modify the address of a hbp register already in use by the task - * Do not invoke this in-lieu of a __unregister_user_hw_breakpoint() + * Register a breakpoint bound to a task and a given cpu. + * If cpu is -1, the breakpoint is active for the task in every cpu + * If the task is -1, the breakpoint is active for every tasks in the given + * cpu. */ -static int __modify_user_hw_breakpoint(int pos, struct task_struct *tsk, - struct hw_breakpoint *bp) +static struct perf_event * +register_user_hw_breakpoint_cpu(unsigned long addr, + int len, + int type, + perf_callback_t triggered, + pid_t pid, + int cpu, + bool active) { - struct thread_struct *thread = &(tsk->thread); - - if ((pos >= hbp_kernel_pos) || (arch_validate_hwbkpt_settings(bp, tsk))) - return -EINVAL; - - if (thread->hbp[pos] == NULL) - return -EINVAL; - - thread->hbp[pos] = bp; + struct perf_event_attr *attr; + struct perf_event *bp; + + attr = kzalloc(sizeof(*attr), GFP_KERNEL); + if (!attr) + return ERR_PTR(-ENOMEM); + + attr->type = PERF_TYPE_BREAKPOINT; + attr->size = sizeof(*attr); + attr->bp_addr = addr; + attr->bp_len = len; + attr->bp_type = type; /* - * 'pos' must be that of a hbp register already used by 'tsk' - * Otherwise arch_modify_user_hw_breakpoint() will fail + * Such breakpoints are used by debuggers to trigger signals when + * we hit the excepted memory op. We can't miss such events, they + * must be pinned. */ - arch_update_user_hw_breakpoint(pos, tsk); + attr->pinned = 1; - if (tsk == current) - arch_install_thread_hw_breakpoint(tsk); + if (!active) + attr->disabled = 1; - return 0; -} - -static void __unregister_user_hw_breakpoint(int pos, struct task_struct *tsk) -{ - hbp_user_refcount[pos]--; - tsk->thread.hbp[pos] = NULL; + bp = perf_event_create_kernel_counter(attr, cpu, pid, triggered); + kfree(attr); - arch_update_user_hw_breakpoint(pos, tsk); - - if (tsk == current) - arch_install_thread_hw_breakpoint(tsk); + return bp; } /** * register_user_hw_breakpoint - register a hardware breakpoint for user space + * @addr: is the memory address that triggers the breakpoint + * @len: the length of the access to the memory (1 byte, 2 bytes etc...) + * @type: the type of the access to the memory (read/write/exec) + * @triggered: callback to trigger when we hit the breakpoint * @tsk: pointer to 'task_struct' of the process to which the address belongs - * @bp: the breakpoint structure to register - * - * @bp.info->name or @bp.info->address, @bp.info->len, @bp.info->type and - * @bp->triggered must be set properly before invocation + * @active: should we activate it while registering it * */ -int register_user_hw_breakpoint(struct task_struct *tsk, - struct hw_breakpoint *bp) +struct perf_event * +register_user_hw_breakpoint(unsigned long addr, + int len, + int type, + perf_callback_t triggered, + struct task_struct *tsk, + bool active) { - struct thread_struct *thread = &(tsk->thread); - int i, rc = -ENOSPC; - - spin_lock_bh(&hw_breakpoint_lock); - - for (i = 0; i < hbp_kernel_pos; i++) { - if (!thread->hbp[i]) { - rc = __register_user_hw_breakpoint(i, tsk, bp); - break; - } - } - if (!rc) - set_tsk_thread_flag(tsk, TIF_DEBUG); - - spin_unlock_bh(&hw_breakpoint_lock); - return rc; + return register_user_hw_breakpoint_cpu(addr, len, type, triggered, + tsk->pid, -1, active); } EXPORT_SYMBOL_GPL(register_user_hw_breakpoint); /** * modify_user_hw_breakpoint - modify a user-space hardware breakpoint + * @bp: the breakpoint structure to modify + * @addr: is the memory address that triggers the breakpoint + * @len: the length of the access to the memory (1 byte, 2 bytes etc...) + * @type: the type of the access to the memory (read/write/exec) + * @triggered: callback to trigger when we hit the breakpoint * @tsk: pointer to 'task_struct' of the process to which the address belongs - * @bp: the breakpoint structure to unregister - * + * @active: should we activate it while registering it */ -int modify_user_hw_breakpoint(struct task_struct *tsk, struct hw_breakpoint *bp) +struct perf_event * +modify_user_hw_breakpoint(struct perf_event *bp, + unsigned long addr, + int len, + int type, + perf_callback_t triggered, + struct task_struct *tsk, + bool active) { - struct thread_struct *thread = &(tsk->thread); - int i, ret = -ENOENT; + /* + * FIXME: do it without unregistering + * - We don't want to lose our slot + * - If the new bp is incorrect, don't lose the older one + */ + unregister_hw_breakpoint(bp); - spin_lock_bh(&hw_breakpoint_lock); - for (i = 0; i < hbp_kernel_pos; i++) { - if (bp == thread->hbp[i]) { - ret = __modify_user_hw_breakpoint(i, tsk, bp); - break; - } - } - spin_unlock_bh(&hw_breakpoint_lock); - return ret; + return register_user_hw_breakpoint(addr, len, type, triggered, + tsk, active); } EXPORT_SYMBOL_GPL(modify_user_hw_breakpoint); /** - * unregister_user_hw_breakpoint - unregister a user-space hardware breakpoint - * @tsk: pointer to 'task_struct' of the process to which the address belongs + * unregister_hw_breakpoint - unregister a user-space hardware breakpoint * @bp: the breakpoint structure to unregister - * */ -void unregister_user_hw_breakpoint(struct task_struct *tsk, - struct hw_breakpoint *bp) +void unregister_hw_breakpoint(struct perf_event *bp) { - struct thread_struct *thread = &(tsk->thread); - int i, pos = -1, hbp_counter = 0; - - spin_lock_bh(&hw_breakpoint_lock); - for (i = 0; i < hbp_kernel_pos; i++) { - if (thread->hbp[i]) - hbp_counter++; - if (bp == thread->hbp[i]) - pos = i; - } - if (pos >= 0) { - __unregister_user_hw_breakpoint(pos, tsk); - hbp_counter--; - } - if (!hbp_counter) - clear_tsk_thread_flag(tsk, TIF_DEBUG); - - spin_unlock_bh(&hw_breakpoint_lock); + if (!bp) + return; + perf_event_release_kernel(bp); +} +EXPORT_SYMBOL_GPL(unregister_hw_breakpoint); + +static struct perf_event * +register_kernel_hw_breakpoint_cpu(unsigned long addr, + int len, + int type, + perf_callback_t triggered, + int cpu, + bool active) +{ + return register_user_hw_breakpoint_cpu(addr, len, type, triggered, + -1, cpu, active); } -EXPORT_SYMBOL_GPL(unregister_user_hw_breakpoint); /** - * register_kernel_hw_breakpoint - register a hardware breakpoint for kernel space - * @bp: the breakpoint structure to register - * - * @bp.info->name or @bp.info->address, @bp.info->len, @bp.info->type and - * @bp->triggered must be set properly before invocation + * register_wide_hw_breakpoint - register a wide breakpoint in the kernel + * @addr: is the memory address that triggers the breakpoint + * @len: the length of the access to the memory (1 byte, 2 bytes etc...) + * @type: the type of the access to the memory (read/write/exec) + * @triggered: callback to trigger when we hit the breakpoint + * @active: should we activate it while registering it * + * @return a set of per_cpu pointers to perf events */ -int register_kernel_hw_breakpoint(struct hw_breakpoint *bp) +struct perf_event ** +register_wide_hw_breakpoint(unsigned long addr, + int len, + int type, + perf_callback_t triggered, + bool active) { - int rc; + struct perf_event **cpu_events, **pevent, *bp; + long err; + int cpu; + + cpu_events = alloc_percpu(typeof(*cpu_events)); + if (!cpu_events) + return ERR_PTR(-ENOMEM); - rc = arch_validate_hwbkpt_settings(bp, NULL); - if (rc) - return rc; + for_each_possible_cpu(cpu) { + pevent = per_cpu_ptr(cpu_events, cpu); + bp = register_kernel_hw_breakpoint_cpu(addr, len, type, + triggered, cpu, active); - spin_lock_bh(&hw_breakpoint_lock); + *pevent = bp; - rc = -ENOSPC; - /* Check if we are over-committing */ - if ((hbp_kernel_pos > 0) && (!hbp_user_refcount[hbp_kernel_pos-1])) { - hbp_kernel_pos--; - hbp_kernel[hbp_kernel_pos] = bp; - on_each_cpu(arch_update_kernel_hw_breakpoint, NULL, 1); - rc = 0; + if (IS_ERR(bp) || !bp) { + err = PTR_ERR(bp); + goto fail; + } } - spin_unlock_bh(&hw_breakpoint_lock); - return rc; + return cpu_events; + +fail: + for_each_possible_cpu(cpu) { + pevent = per_cpu_ptr(cpu_events, cpu); + if (IS_ERR(*pevent) || !*pevent) + break; + unregister_hw_breakpoint(*pevent); + } + free_percpu(cpu_events); + /* return the error if any */ + return ERR_PTR(err); } -EXPORT_SYMBOL_GPL(register_kernel_hw_breakpoint); /** - * unregister_kernel_hw_breakpoint - unregister a HW breakpoint for kernel space - * @bp: the breakpoint structure to unregister - * - * Uninstalls and unregisters @bp. + * unregister_wide_hw_breakpoint - unregister a wide breakpoint in the kernel + * @cpu_events: the per cpu set of events to unregister */ -void unregister_kernel_hw_breakpoint(struct hw_breakpoint *bp) +void unregister_wide_hw_breakpoint(struct perf_event **cpu_events) { - int i, j; - - spin_lock_bh(&hw_breakpoint_lock); - - /* Find the 'bp' in our list of breakpoints for kernel */ - for (i = hbp_kernel_pos; i < HBP_NUM; i++) - if (bp == hbp_kernel[i]) - break; + int cpu; + struct perf_event **pevent; - /* Check if we did not find a match for 'bp'. If so return early */ - if (i == HBP_NUM) { - spin_unlock_bh(&hw_breakpoint_lock); - return; + for_each_possible_cpu(cpu) { + pevent = per_cpu_ptr(cpu_events, cpu); + unregister_hw_breakpoint(*pevent); } - - /* - * We'll shift the breakpoints one-level above to compact if - * unregistration creates a hole - */ - for (j = i; j > hbp_kernel_pos; j--) - hbp_kernel[j] = hbp_kernel[j-1]; - - hbp_kernel[hbp_kernel_pos] = NULL; - on_each_cpu(arch_update_kernel_hw_breakpoint, NULL, 1); - hbp_kernel_pos++; - - spin_unlock_bh(&hw_breakpoint_lock); + free_percpu(cpu_events); } -EXPORT_SYMBOL_GPL(unregister_kernel_hw_breakpoint); + static struct notifier_block hw_breakpoint_exceptions_nb = { .notifier_call = hw_breakpoint_exceptions_notify, @@ -374,5 +283,12 @@ static int __init init_hw_breakpoint(void) { return register_die_notifier(&hw_breakpoint_exceptions_nb); } - core_initcall(init_hw_breakpoint); + + +struct pmu perf_ops_bp = { + .enable = arch_install_hw_breakpoint, + .disable = arch_uninstall_hw_breakpoint, + .read = hw_breakpoint_pmu_read, + .unthrottle = hw_breakpoint_pmu_unthrottle +}; diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 5087125e2a0..98dc56b2ebe 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -29,6 +29,7 @@ #include #include #include +#include #include @@ -4229,6 +4230,51 @@ static void perf_event_free_filter(struct perf_event *event) #endif /* CONFIG_EVENT_PROFILE */ +#ifdef CONFIG_HAVE_HW_BREAKPOINT +static void bp_perf_event_destroy(struct perf_event *event) +{ + release_bp_slot(event); +} + +static const struct pmu *bp_perf_event_init(struct perf_event *bp) +{ + int err; + /* + * The breakpoint is already filled if we haven't created the counter + * through perf syscall + * FIXME: manage to get trigerred to NULL if it comes from syscalls + */ + if (!bp->callback) + err = register_perf_hw_breakpoint(bp); + else + err = __register_perf_hw_breakpoint(bp); + if (err) + return ERR_PTR(err); + + bp->destroy = bp_perf_event_destroy; + + return &perf_ops_bp; +} + +void perf_bp_event(struct perf_event *bp, void *regs) +{ + /* TODO */ +} +#else +static void bp_perf_event_destroy(struct perf_event *event) +{ +} + +static const struct pmu *bp_perf_event_init(struct perf_event *bp) +{ + return NULL; +} + +void perf_bp_event(struct perf_event *bp, void *regs) +{ +} +#endif + atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX]; static void sw_perf_event_destroy(struct perf_event *event) @@ -4375,6 +4421,11 @@ perf_event_alloc(struct perf_event_attr *attr, pmu = tp_perf_event_init(event); break; + case PERF_TYPE_BREAKPOINT: + pmu = bp_perf_event_init(event); + break; + + default: break; } @@ -4686,7 +4737,7 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, ctx = find_get_context(pid, cpu); if (IS_ERR(ctx)) - return NULL ; + return NULL; event = perf_event_alloc(attr, cpu, ctx, NULL, NULL, callback, GFP_KERNEL); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 91c3d0e9a5a..d72f06ff263 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -11,14 +11,11 @@ #include #include #include +#include #include #include -#ifdef CONFIG_KSYM_TRACER -#include -#endif - enum trace_type { __TRACE_FIRST_TYPE = 0, diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index e19747d4f86..c16a08f399d 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -372,11 +372,11 @@ FTRACE_ENTRY(ksym_trace, ksym_trace_entry, F_STRUCT( __field( unsigned long, ip ) __field( unsigned char, type ) - __array( char , ksym_name, KSYM_NAME_LEN ) __array( char , cmd, TASK_COMM_LEN ) + __field( unsigned long, addr ) ), - F_printk("ip: %pF type: %d ksym_name: %s cmd: %s", + F_printk("ip: %pF type: %d ksym_name: %pS cmd: %s", (void *)__entry->ip, (unsigned int)__entry->type, - __entry->ksym_name, __entry->cmd) + (void *)__entry->addr, __entry->cmd) ); diff --git a/kernel/trace/trace_ksym.c b/kernel/trace/trace_ksym.c index 6d5609c6737..fea83eeeef0 100644 --- a/kernel/trace/trace_ksym.c +++ b/kernel/trace/trace_ksym.c @@ -29,7 +29,11 @@ #include "trace_stat.h" #include "trace.h" -/* For now, let us restrict the no. of symbols traced simultaneously to number +#include +#include + +/* + * For now, let us restrict the no. of symbols traced simultaneously to number * of available hardware breakpoint registers. */ #define KSYM_TRACER_MAX HBP_NUM @@ -37,8 +41,10 @@ #define KSYM_TRACER_OP_LEN 3 /* rw- */ struct trace_ksym { - struct hw_breakpoint *ksym_hbp; + struct perf_event **ksym_hbp; unsigned long ksym_addr; + int type; + int len; #ifdef CONFIG_PROFILE_KSYM_TRACER unsigned long counter; #endif @@ -75,10 +81,11 @@ void ksym_collect_stats(unsigned long hbp_hit_addr) } #endif /* CONFIG_PROFILE_KSYM_TRACER */ -void ksym_hbp_handler(struct hw_breakpoint *hbp, struct pt_regs *regs) +void ksym_hbp_handler(struct perf_event *hbp, void *data) { struct ring_buffer_event *event; struct ksym_trace_entry *entry; + struct pt_regs *regs = data; struct ring_buffer *buffer; int pc; @@ -96,12 +103,12 @@ void ksym_hbp_handler(struct hw_breakpoint *hbp, struct pt_regs *regs) entry = ring_buffer_event_data(event); entry->ip = instruction_pointer(regs); - entry->type = hbp->info.type; - strlcpy(entry->ksym_name, hbp->info.name, KSYM_SYMBOL_LEN); + entry->type = hw_breakpoint_type(hbp); + entry->addr = hw_breakpoint_addr(hbp); strlcpy(entry->cmd, current->comm, TASK_COMM_LEN); #ifdef CONFIG_PROFILE_KSYM_TRACER - ksym_collect_stats(hbp->info.address); + ksym_collect_stats(hw_breakpoint_addr(hbp)); #endif /* CONFIG_PROFILE_KSYM_TRACER */ trace_buffer_unlock_commit(buffer, event, 0, pc); @@ -120,31 +127,21 @@ static int ksym_trace_get_access_type(char *str) int access = 0; if (str[0] == 'r') - access += 4; - else if (str[0] != '-') - return -EINVAL; + access |= HW_BREAKPOINT_R; if (str[1] == 'w') - access += 2; - else if (str[1] != '-') - return -EINVAL; + access |= HW_BREAKPOINT_W; - if (str[2] != '-') - return -EINVAL; + if (str[2] == 'x') + access |= HW_BREAKPOINT_X; switch (access) { - case 6: - access = HW_BREAKPOINT_RW; - break; - case 4: - access = -EINVAL; - break; - case 2: - access = HW_BREAKPOINT_WRITE; - break; + case HW_BREAKPOINT_W: + case HW_BREAKPOINT_W | HW_BREAKPOINT_R: + return access; + default: + return -EINVAL; } - - return access; } /* @@ -194,36 +191,33 @@ int process_new_ksym_entry(char *ksymname, int op, unsigned long addr) if (!entry) return -ENOMEM; - entry->ksym_hbp = kzalloc(sizeof(struct hw_breakpoint), GFP_KERNEL); - if (!entry->ksym_hbp) - goto err; - - entry->ksym_hbp->info.name = kstrdup(ksymname, GFP_KERNEL); - if (!entry->ksym_hbp->info.name) - goto err; - - entry->ksym_hbp->info.type = op; - entry->ksym_addr = entry->ksym_hbp->info.address = addr; -#ifdef CONFIG_X86 - entry->ksym_hbp->info.len = HW_BREAKPOINT_LEN_4; -#endif - entry->ksym_hbp->triggered = (void *)ksym_hbp_handler; + entry->type = op; + entry->ksym_addr = addr; + entry->len = HW_BREAKPOINT_LEN_4; + + ret = -EAGAIN; + entry->ksym_hbp = register_wide_hw_breakpoint(entry->ksym_addr, + entry->len, entry->type, + ksym_hbp_handler, true); + if (IS_ERR(entry->ksym_hbp)) { + entry->ksym_hbp = NULL; + ret = PTR_ERR(entry->ksym_hbp); + } - ret = register_kernel_hw_breakpoint(entry->ksym_hbp); - if (ret < 0) { + if (!entry->ksym_hbp) { printk(KERN_INFO "ksym_tracer request failed. Try again" " later!!\n"); - ret = -EAGAIN; goto err; } + hlist_add_head_rcu(&(entry->ksym_hlist), &ksym_filter_head); ksym_filter_entry_count++; + return 0; + err: - if (entry->ksym_hbp) - kfree(entry->ksym_hbp->info.name); - kfree(entry->ksym_hbp); kfree(entry); + return ret; } @@ -244,10 +238,10 @@ static ssize_t ksym_trace_filter_read(struct file *filp, char __user *ubuf, mutex_lock(&ksym_tracer_mutex); hlist_for_each_entry(entry, node, &ksym_filter_head, ksym_hlist) { - ret = trace_seq_printf(s, "%s:", entry->ksym_hbp->info.name); - if (entry->ksym_hbp->info.type == HW_BREAKPOINT_WRITE) + ret = trace_seq_printf(s, "%pS:", (void *)entry->ksym_addr); + if (entry->type == HW_BREAKPOINT_W) ret = trace_seq_puts(s, "-w-\n"); - else if (entry->ksym_hbp->info.type == HW_BREAKPOINT_RW) + else if (entry->type == (HW_BREAKPOINT_W | HW_BREAKPOINT_R)) ret = trace_seq_puts(s, "rw-\n"); WARN_ON_ONCE(!ret); } @@ -269,12 +263,10 @@ static void __ksym_trace_reset(void) mutex_lock(&ksym_tracer_mutex); hlist_for_each_entry_safe(entry, node, node1, &ksym_filter_head, ksym_hlist) { - unregister_kernel_hw_breakpoint(entry->ksym_hbp); + unregister_wide_hw_breakpoint(entry->ksym_hbp); ksym_filter_entry_count--; hlist_del_rcu(&(entry->ksym_hlist)); synchronize_rcu(); - kfree(entry->ksym_hbp->info.name); - kfree(entry->ksym_hbp); kfree(entry); } mutex_unlock(&ksym_tracer_mutex); @@ -327,7 +319,7 @@ static ssize_t ksym_trace_filter_write(struct file *file, hlist_for_each_entry(entry, node, &ksym_filter_head, ksym_hlist) { if (entry->ksym_addr == ksym_addr) { /* Check for malformed request: (6) */ - if (entry->ksym_hbp->info.type != op) + if (entry->type != op) changed = 1; else goto out; @@ -335,18 +327,21 @@ static ssize_t ksym_trace_filter_write(struct file *file, } } if (changed) { - unregister_kernel_hw_breakpoint(entry->ksym_hbp); - entry->ksym_hbp->info.type = op; + unregister_wide_hw_breakpoint(entry->ksym_hbp); + entry->type = op; if (op > 0) { - ret = register_kernel_hw_breakpoint(entry->ksym_hbp); - if (ret == 0) + entry->ksym_hbp = + register_wide_hw_breakpoint(entry->ksym_addr, + entry->len, entry->type, + ksym_hbp_handler, true); + if (IS_ERR(entry->ksym_hbp)) + entry->ksym_hbp = NULL; + if (!entry->ksym_hbp) goto out; } ksym_filter_entry_count--; hlist_del_rcu(&(entry->ksym_hlist)); synchronize_rcu(); - kfree(entry->ksym_hbp->info.name); - kfree(entry->ksym_hbp); kfree(entry); ret = 0; goto out; @@ -413,16 +408,16 @@ static enum print_line_t ksym_trace_output(struct trace_iterator *iter) trace_assign_type(field, entry); - ret = trace_seq_printf(s, "%11s-%-5d [%03d] %-30s ", field->cmd, - entry->pid, iter->cpu, field->ksym_name); + ret = trace_seq_printf(s, "%11s-%-5d [%03d] %pS", field->cmd, + entry->pid, iter->cpu, (char *)field->addr); if (!ret) return TRACE_TYPE_PARTIAL_LINE; switch (field->type) { - case HW_BREAKPOINT_WRITE: + case HW_BREAKPOINT_W: ret = trace_seq_printf(s, " W "); break; - case HW_BREAKPOINT_RW: + case HW_BREAKPOINT_R | HW_BREAKPOINT_W: ret = trace_seq_printf(s, " RW "); break; default: @@ -490,14 +485,13 @@ static int ksym_tracer_stat_show(struct seq_file *m, void *v) entry = hlist_entry(stat, struct trace_ksym, ksym_hlist); - if (entry->ksym_hbp) - access_type = entry->ksym_hbp->info.type; + access_type = entry->type; switch (access_type) { - case HW_BREAKPOINT_WRITE: + case HW_BREAKPOINT_W: seq_puts(m, " W "); break; - case HW_BREAKPOINT_RW: + case HW_BREAKPOINT_R | HW_BREAKPOINT_W: seq_puts(m, " RW "); break; default: diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 7179c12e4f0..27c5072c2e6 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -828,7 +828,8 @@ trace_selftest_startup_ksym(struct tracer *trace, struct trace_array *tr) ksym_selftest_dummy = 0; /* Register the read-write tracing request */ - ret = process_new_ksym_entry(KSYM_SELFTEST_ENTRY, HW_BREAKPOINT_RW, + ret = process_new_ksym_entry(KSYM_SELFTEST_ENTRY, + HW_BREAKPOINT_R | HW_BREAKPOINT_W, (unsigned long)(&ksym_selftest_dummy)); if (ret < 0) { -- cgit v1.2.3-70-g09d2 From 30ff21e31fe5c8b7b1b7d30cc41e32bc4ee9f175 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 10 Sep 2009 09:35:20 +0800 Subject: ksym_tracer: Remove KSYM_SELFTEST_ENTRY The macro used to be used in both trace_selftest.c and trace_ksym.c, but no longer, so remove it from header file. Signed-off-by: Li Zefan Cc: Prasad Signed-off-by: Frederic Weisbecker --- kernel/trace/trace.h | 1 - kernel/trace/trace_selftest.c | 3 ++- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index d72f06ff263..ee00475742e 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -367,7 +367,6 @@ int register_tracer(struct tracer *type); void unregister_tracer(struct tracer *type); int is_tracing_stopped(void); -#define KSYM_SELFTEST_ENTRY "ksym_selftest_dummy" extern int process_new_ksym_entry(char *ksymname, int op, unsigned long addr); extern unsigned long nsecs_to_usecs(unsigned long nsecs); diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 27c5072c2e6..dc98309e839 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -828,7 +828,8 @@ trace_selftest_startup_ksym(struct tracer *trace, struct trace_array *tr) ksym_selftest_dummy = 0; /* Register the read-write tracing request */ - ret = process_new_ksym_entry(KSYM_SELFTEST_ENTRY, + + ret = process_new_ksym_entry("ksym_selftest_dummy", HW_BREAKPOINT_R | HW_BREAKPOINT_W, (unsigned long)(&ksym_selftest_dummy)); -- cgit v1.2.3-70-g09d2 From 99df5a6a215f026e62287083de2b44b22edd3623 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Wed, 25 Nov 2009 01:14:59 -0600 Subject: trace/syscalls: Change ret param in struct syscall_trace_exit to long Commit ee949a86b3aef15845ea677aa60231008de62672 ("tracing/syscalls: Use long for syscall ret format and field definitions") changed the syscall exit return type to long, but forgot to change it in the struct. Signed-off-by: Tom Zanussi Cc: Steven Rostedt Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker LKML-Reference: <1259133299-23594-3-git-send-email-tzanussi@gmail.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 4da6ede7440..1d7f4830a80 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -100,7 +100,7 @@ struct syscall_trace_enter { struct syscall_trace_exit { struct trace_entry ent; int nr; - unsigned long ret; + long ret; }; struct kprobe_trace_entry { -- cgit v1.2.3-70-g09d2