diff options
| -rw-r--r-- | arch/ia64/kernel/kprobes.c | 49 |
1 files changed, 43 insertions, 6 deletions
diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index 41e80b42d3f..5978823d5c6 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -41,8 +41,8 @@ extern void jprobe_inst_return(void); #define KPROBE_HIT_ACTIVE 0x00000001 #define KPROBE_HIT_SS 0x00000002 -static struct kprobe *current_kprobe; -static unsigned long kprobe_status; +static struct kprobe *current_kprobe, *kprobe_prev; +static unsigned long kprobe_status, kprobe_status_prev; static struct pt_regs jprobe_saved_regs; enum instruction_type {A, I, M, F, B, L, X, u}; @@ -273,6 +273,23 @@ static int valid_kprobe_addr(int template, int slot, unsigned long addr) return 0; } +static inline void save_previous_kprobe(void) +{ + kprobe_prev = current_kprobe; + kprobe_status_prev = kprobe_status; +} + +static inline void restore_previous_kprobe(void) +{ + current_kprobe = kprobe_prev; + kprobe_status = kprobe_status_prev; +} + +static inline void set_current_kprobe(struct kprobe *p) +{ + current_kprobe = p; +} + int arch_prepare_kprobe(struct kprobe *p) { unsigned long addr = (unsigned long) p->addr; @@ -436,8 +453,18 @@ static int pre_kprobes_handler(struct die_args *args) unlock_kprobes(); goto no_kprobe; } - arch_disarm_kprobe(p); - ret = 1; + /* We have reentered the pre_kprobe_handler(), since + * another probe was hit while within the handler. + * We here save the original kprobes variables and + * just single step on the instruction of the new probe + * without calling any user handlers. + */ + save_previous_kprobe(); + set_current_kprobe(p); + p->nmissed++; + prepare_ss(p, regs); + kprobe_status = KPROBE_REENTER; + return 1; } else if (args->err == __IA64_BREAK_JPROBE) { /* * jprobe instrumented function just completed @@ -460,7 +487,7 @@ static int pre_kprobes_handler(struct die_args *args) } kprobe_status = KPROBE_HIT_ACTIVE; - current_kprobe = p; + set_current_kprobe(p); if (p->pre_handler && p->pre_handler(p, regs)) /* @@ -485,12 +512,22 @@ static int post_kprobes_handler(struct pt_regs *regs) if (!kprobe_running()) return 0; - if (current_kprobe->post_handler) + if ((kprobe_status != KPROBE_REENTER) && current_kprobe->post_handler) { + kprobe_status = KPROBE_HIT_SSDONE; current_kprobe->post_handler(current_kprobe, regs, 0); + } resume_execution(current_kprobe, regs); + /*Restore back the original saved kprobes variables and continue. */ + if (kprobe_status == KPROBE_REENTER) { + restore_previous_kprobe(); + goto out; + } + unlock_kprobes(); + +out: preempt_enable_no_resched(); return 1; } |