From f52487e9c0041842eeb77c6c48774414b1cede08 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 10 Sep 2009 19:53:53 -0400 Subject: tracing/kprobes: Support custom subsystem for each kprobe event Support specifying a custom subsystem(group) for each kprobe event. This allows users to create new group to control several probes at once, or add events to existing groups as additional tracepoints. New synopsis: p[:[subsys/]event-name] KADDR|KSYM[+offs] [ARGS] Signed-off-by: Masami Hiramatsu Cc: Jim Keniston Cc: Ananth N Mavinakayanahalli Cc: Andi Kleen Cc: Christoph Hellwig Cc: Frank Ch. Eigler Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Jason Baron Cc: K.Prasad Cc: Lai Jiangshan Cc: Li Zefan Cc: Peter Zijlstra Cc: Srikar Dronamraju Cc: Steven Rostedt Cc: Tom Zanussi LKML-Reference: <20090910235353.22412.15149.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker --- Documentation/trace/kprobetrace.txt | 5 +++-- kernel/trace/trace_kprobe.c | 33 +++++++++++++++++++++++++++------ 2 files changed, 30 insertions(+), 8 deletions(-) diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt index a849889e609..6521681e783 100644 --- a/Documentation/trace/kprobetrace.txt +++ b/Documentation/trace/kprobetrace.txt @@ -25,9 +25,10 @@ probe events via /sys/kernel/debug/tracing/events/kprobes//filter. Synopsis of kprobe_events ------------------------- - p[:EVENT] SYMBOL[+offs]|MEMADDR [FETCHARGS] : Set a probe - r[:EVENT] SYMBOL[+0] [FETCHARGS] : Set a return probe + p[:[GRP/]EVENT] SYMBOL[+offs]|MEMADDR [FETCHARGS] : Set a probe + r[:[GRP/]EVENT] SYMBOL[+0] [FETCHARGS] : Set a return probe + GRP : Group name. If omitted, use "kprobes" for it. EVENT : Event name. If omitted, the event name is generated based on SYMBOL+offs or MEMADDR. SYMBOL[+offs] : Symbol+offset where the probe is inserted. diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 1746afeaabf..cbc0870dcf5 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -36,6 +36,7 @@ #define MAX_TRACE_ARGS 128 #define MAX_ARGSTR_LEN 63 #define MAX_EVENT_NAME_LEN 64 +#define KPROBE_EVENT_SYSTEM "kprobes" /* currently, trace_kprobe only supports X86. */ @@ -265,7 +266,8 @@ static LIST_HEAD(probe_list); /* * Allocate new trace_probe and initialize it (including kprobes). */ -static struct trace_probe *alloc_trace_probe(const char *event, +static struct trace_probe *alloc_trace_probe(const char *group, + const char *event, void *addr, const char *symbol, unsigned long offs, @@ -298,9 +300,16 @@ static struct trace_probe *alloc_trace_probe(const char *event, if (!tp->call.name) goto error; + if (!group) + goto error; + tp->call.system = kstrdup(group, GFP_KERNEL); + if (!tp->call.system) + goto error; + INIT_LIST_HEAD(&tp->list); return tp; error: + kfree(tp->call.name); kfree(tp->symbol); kfree(tp); return ERR_PTR(-ENOMEM); @@ -322,6 +331,7 @@ static void free_trace_probe(struct trace_probe *tp) for (i = 0; i < tp->nr_args; i++) free_probe_arg(&tp->args[i]); + kfree(tp->call.system); kfree(tp->call.name); kfree(tp->symbol); kfree(tp); @@ -530,8 +540,8 @@ static int create_trace_probe(int argc, char **argv) { /* * Argument syntax: - * - Add kprobe: p[:EVENT] SYMBOL[+OFFS]|ADDRESS [FETCHARGS] - * - Add kretprobe: r[:EVENT] SYMBOL[+0] [FETCHARGS] + * - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS] + * - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS] * Fetch args: * aN : fetch Nth of function argument. (N:0-) * rv : fetch return value @@ -549,7 +559,7 @@ static int create_trace_probe(int argc, char **argv) struct trace_probe *tp; int i, ret = 0; int is_return = 0; - char *symbol = NULL, *event = NULL, *arg = NULL; + char *symbol = NULL, *event = NULL, *arg = NULL, *group = NULL; unsigned long offset = 0; void *addr = NULL; char buf[MAX_EVENT_NAME_LEN]; @@ -566,6 +576,15 @@ static int create_trace_probe(int argc, char **argv) if (argv[0][1] == ':') { event = &argv[0][2]; + if (strchr(event, '/')) { + group = event; + event = strchr(group, '/') + 1; + event[-1] = '\0'; + if (strlen(group) == 0) { + pr_info("Group name is not specifiled\n"); + return -EINVAL; + } + } if (strlen(event) == 0) { pr_info("Event name is not specifiled\n"); return -EINVAL; @@ -592,6 +611,8 @@ static int create_trace_probe(int argc, char **argv) argc -= 2; argv += 2; /* setup a probe */ + if (!group) + group = KPROBE_EVENT_SYSTEM; if (!event) { /* Make a new event name */ if (symbol) @@ -602,7 +623,8 @@ static int create_trace_probe(int argc, char **argv) is_return ? 'r' : 'p', addr); event = buf; } - tp = alloc_trace_probe(event, addr, symbol, offset, argc, is_return); + tp = alloc_trace_probe(group, event, addr, symbol, offset, argc, + is_return); if (IS_ERR(tp)) return PTR_ERR(tp); @@ -1217,7 +1239,6 @@ static int register_probe_event(struct trace_probe *tp) int ret; /* Initialize ftrace_event_call */ - call->system = "kprobes"; if (probe_is_return(tp)) { tp->event.trace = print_kretprobe_event; call->raw_init = probe_event_raw_init; -- cgit v1.2.3-70-g09d2