diff options
Diffstat (limited to 'arch/ia64/kernel/kprobes.c')
-rw-r--r-- | arch/ia64/kernel/kprobes.c | 144 |
1 files changed, 80 insertions, 64 deletions
diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index 471086b808a..2895d6e6062 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -26,7 +26,6 @@ #include <linux/config.h> #include <linux/kprobes.h> #include <linux/ptrace.h> -#include <linux/spinlock.h> #include <linux/string.h> #include <linux/slab.h> #include <linux/preempt.h> @@ -38,13 +37,8 @@ extern void jprobe_inst_return(void); -/* kprobe_status settings */ -#define KPROBE_HIT_ACTIVE 0x00000001 -#define KPROBE_HIT_SS 0x00000002 - -static struct kprobe *current_kprobe, *kprobe_prev; -static unsigned long kprobe_status, kprobe_status_prev; -static struct pt_regs jprobe_saved_regs; +DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; +DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); enum instruction_type {A, I, M, F, B, L, X, u}; static enum instruction_type bundle_encoding[32][3] = { @@ -313,21 +307,22 @@ static int __kprobes valid_kprobe_addr(int template, int slot, return 0; } -static inline void save_previous_kprobe(void) +static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb) { - kprobe_prev = current_kprobe; - kprobe_status_prev = kprobe_status; + kcb->prev_kprobe.kp = kprobe_running(); + kcb->prev_kprobe.status = kcb->kprobe_status; } -static inline void restore_previous_kprobe(void) +static inline void restore_previous_kprobe(struct kprobe_ctlblk *kcb) { - current_kprobe = kprobe_prev; - kprobe_status = kprobe_status_prev; + __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp; + kcb->kprobe_status = kcb->prev_kprobe.status; } -static inline void set_current_kprobe(struct kprobe *p) +static inline void set_current_kprobe(struct kprobe *p, + struct kprobe_ctlblk *kcb) { - current_kprobe = p; + __get_cpu_var(current_kprobe) = p; } static void kretprobe_trampoline(void) @@ -347,11 +342,12 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) struct kretprobe_instance *ri = NULL; struct hlist_head *head; struct hlist_node *node, *tmp; - unsigned long orig_ret_address = 0; + unsigned long flags, orig_ret_address = 0; unsigned long trampoline_address = ((struct fnptr *)kretprobe_trampoline)->ip; - head = kretprobe_inst_table_head(current); + spin_lock_irqsave(&kretprobe_lock, flags); + head = kretprobe_inst_table_head(current); /* * It is possible to have multiple instances associated with a given @@ -367,9 +363,9 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) * kretprobe_trampoline */ hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { - if (ri->task != current) + if (ri->task != current) /* another task is sharing our hash bucket */ - continue; + continue; if (ri->rp && ri->rp->handler) ri->rp->handler(ri, regs); @@ -389,17 +385,19 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) BUG_ON(!orig_ret_address || (orig_ret_address == trampoline_address)); regs->cr_iip = orig_ret_address; - unlock_kprobes(); + reset_current_kprobe(); + spin_unlock_irqrestore(&kretprobe_lock, flags); preempt_enable_no_resched(); - /* - * By returning a non-zero value, we are telling - * kprobe_handler() that we have handled unlocking - * and re-enabling preemption. - */ - return 1; + /* + * By returning a non-zero value, we are telling + * kprobe_handler() that we don't want the post_handler + * to run (and have re-enabled preemption) + */ + return 1; } +/* Called with kretprobe_lock held */ void __kprobes arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs) { @@ -606,17 +604,22 @@ static int __kprobes pre_kprobes_handler(struct die_args *args) int ret = 0; struct pt_regs *regs = args->regs; kprobe_opcode_t *addr = (kprobe_opcode_t *)instruction_pointer(regs); + struct kprobe_ctlblk *kcb; + /* + * We don't want to be preempted for the entire + * duration of kprobe processing + */ preempt_disable(); + kcb = get_kprobe_ctlblk(); /* Handle recursion cases */ if (kprobe_running()) { p = get_kprobe(addr); if (p) { - if ( (kprobe_status == KPROBE_HIT_SS) && + if ((kcb->kprobe_status == KPROBE_HIT_SS) && (p->ainsn.inst_flag == INST_FLAG_BREAK_INST)) { ia64_psr(regs)->ss = 0; - unlock_kprobes(); goto no_kprobe; } /* We have reentered the pre_kprobe_handler(), since @@ -625,17 +628,17 @@ static int __kprobes pre_kprobes_handler(struct die_args *args) * just single step on the instruction of the new probe * without calling any user handlers. */ - save_previous_kprobe(); - set_current_kprobe(p); + save_previous_kprobe(kcb); + set_current_kprobe(p, kcb); p->nmissed++; prepare_ss(p, regs); - kprobe_status = KPROBE_REENTER; + kcb->kprobe_status = KPROBE_REENTER; return 1; } else if (args->err == __IA64_BREAK_JPROBE) { /* * jprobe instrumented function just completed */ - p = current_kprobe; + p = __get_cpu_var(current_kprobe); if (p->break_handler && p->break_handler(p, regs)) { goto ss_probe; } @@ -645,10 +648,8 @@ static int __kprobes pre_kprobes_handler(struct die_args *args) } } - lock_kprobes(); p = get_kprobe(addr); if (!p) { - unlock_kprobes(); if (!is_ia64_break_inst(regs)) { /* * The breakpoint instruction was removed right @@ -665,8 +666,8 @@ static int __kprobes pre_kprobes_handler(struct die_args *args) goto no_kprobe; } - kprobe_status = KPROBE_HIT_ACTIVE; - set_current_kprobe(p); + set_current_kprobe(p, kcb); + kcb->kprobe_status = KPROBE_HIT_ACTIVE; if (p->pre_handler && p->pre_handler(p, regs)) /* @@ -678,7 +679,7 @@ static int __kprobes pre_kprobes_handler(struct die_args *args) ss_probe: prepare_ss(p, regs); - kprobe_status = KPROBE_HIT_SS; + kcb->kprobe_status = KPROBE_HIT_SS; return 1; no_kprobe: @@ -688,23 +689,25 @@ no_kprobe: static int __kprobes post_kprobes_handler(struct pt_regs *regs) { - if (!kprobe_running()) + struct kprobe *cur = kprobe_running(); + struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + + if (!cur) return 0; - if ((kprobe_status != KPROBE_REENTER) && current_kprobe->post_handler) { - kprobe_status = KPROBE_HIT_SSDONE; - current_kprobe->post_handler(current_kprobe, regs, 0); + if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) { + kcb->kprobe_status = KPROBE_HIT_SSDONE; + cur->post_handler(cur, regs, 0); } - resume_execution(current_kprobe, regs); + resume_execution(cur, regs); /*Restore back the original saved kprobes variables and continue. */ - if (kprobe_status == KPROBE_REENTER) { - restore_previous_kprobe(); + if (kcb->kprobe_status == KPROBE_REENTER) { + restore_previous_kprobe(kcb); goto out; } - - unlock_kprobes(); + reset_current_kprobe(); out: preempt_enable_no_resched(); @@ -713,16 +716,15 @@ out: static int __kprobes kprobes_fault_handler(struct pt_regs *regs, int trapnr) { - if (!kprobe_running()) - return 0; + struct kprobe *cur = kprobe_running(); + struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - if (current_kprobe->fault_handler && - current_kprobe->fault_handler(current_kprobe, regs, trapnr)) + if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) return 1; - if (kprobe_status & KPROBE_HIT_SS) { - resume_execution(current_kprobe, regs); - unlock_kprobes(); + if (kcb->kprobe_status & KPROBE_HIT_SS) { + resume_execution(cur, regs); + reset_current_kprobe(); preempt_enable_no_resched(); } @@ -733,31 +735,42 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data) { struct die_args *args = (struct die_args *)data; + int ret = NOTIFY_DONE; + switch(val) { case DIE_BREAK: - if (pre_kprobes_handler(args)) - return NOTIFY_STOP; + /* err is break number from ia64_bad_break() */ + if (args->err == 0x80200 || args->err == 0x80300 || args->err == 0) + if (pre_kprobes_handler(args)) + ret = NOTIFY_STOP; break; - case DIE_SS: - if (post_kprobes_handler(args->regs)) - return NOTIFY_STOP; + case DIE_FAULT: + /* err is vector number from ia64_fault() */ + if (args->err == 36) + if (post_kprobes_handler(args->regs)) + ret = NOTIFY_STOP; break; case DIE_PAGE_FAULT: - if (kprobes_fault_handler(args->regs, args->trapnr)) - return NOTIFY_STOP; + /* kprobe_running() needs smp_processor_id() */ + preempt_disable(); + if (kprobe_running() && + kprobes_fault_handler(args->regs, args->trapnr)) + ret = NOTIFY_STOP; + preempt_enable(); default: break; } - return NOTIFY_DONE; + return ret; } int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) { struct jprobe *jp = container_of(p, struct jprobe, kp); unsigned long addr = ((struct fnptr *)(jp->entry))->ip; + struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); /* save architectural state */ - jprobe_saved_regs = *regs; + kcb->jprobe_saved_regs = *regs; /* after rfi, execute the jprobe instrumented function */ regs->cr_iip = addr & ~0xFULL; @@ -775,7 +788,10 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) { - *regs = jprobe_saved_regs; + struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + + *regs = kcb->jprobe_saved_regs; + preempt_enable_no_resched(); return 1; } |