diff options
Diffstat (limited to 'arch/sparc64/kernel/kprobes.c')
| -rw-r--r-- | arch/sparc64/kernel/kprobes.c | 62 |
1 files changed, 49 insertions, 13 deletions
diff --git a/arch/sparc64/kernel/kprobes.c b/arch/sparc64/kernel/kprobes.c index d67195ba3fa..bdac631cf01 100644 --- a/arch/sparc64/kernel/kprobes.c +++ b/arch/sparc64/kernel/kprobes.c @@ -65,19 +65,40 @@ void arch_remove_kprobe(struct kprobe *p) { } -/* kprobe_status settings */ -#define KPROBE_HIT_ACTIVE 0x00000001 -#define KPROBE_HIT_SS 0x00000002 - static struct kprobe *current_kprobe; static unsigned long current_kprobe_orig_tnpc; static unsigned long current_kprobe_orig_tstate_pil; static unsigned int kprobe_status; +static struct kprobe *kprobe_prev; +static unsigned long kprobe_orig_tnpc_prev; +static unsigned long kprobe_orig_tstate_pil_prev; +static unsigned int kprobe_status_prev; -static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs) +static inline void save_previous_kprobe(void) +{ + kprobe_status_prev = kprobe_status; + kprobe_orig_tnpc_prev = current_kprobe_orig_tnpc; + kprobe_orig_tstate_pil_prev = current_kprobe_orig_tstate_pil; + kprobe_prev = current_kprobe; +} + +static inline void restore_previous_kprobe(void) +{ + kprobe_status = kprobe_status_prev; + current_kprobe_orig_tnpc = kprobe_orig_tnpc_prev; + current_kprobe_orig_tstate_pil = kprobe_orig_tstate_pil_prev; + current_kprobe = kprobe_prev; +} + +static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs) { current_kprobe_orig_tnpc = regs->tnpc; current_kprobe_orig_tstate_pil = (regs->tstate & TSTATE_PIL); + current_kprobe = p; +} + +static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs) +{ regs->tstate |= TSTATE_PIL; /*single step inline, if it a breakpoint instruction*/ @@ -110,12 +131,18 @@ static int kprobe_handler(struct pt_regs *regs) unlock_kprobes(); goto no_kprobe; } - arch_disarm_kprobe(p); - regs->tpc = (unsigned long) p->addr; - regs->tnpc = current_kprobe_orig_tnpc; - regs->tstate = ((regs->tstate & ~TSTATE_PIL) | - current_kprobe_orig_tstate_pil); - ret = 1; + /* We have reentered the 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, regs); + p->nmissed++; + kprobe_status = KPROBE_REENTER; + prepare_singlestep(p, regs); + return 1; } else { p = current_kprobe; if (p->break_handler && p->break_handler(p, regs)) @@ -143,8 +170,8 @@ static int kprobe_handler(struct pt_regs *regs) goto no_kprobe; } + set_current_kprobe(p, regs); kprobe_status = KPROBE_HIT_ACTIVE; - current_kprobe = p; if (p->pre_handler && p->pre_handler(p, regs)) return 1; @@ -250,12 +277,20 @@ static inline int post_kprobe_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; @@ -397,3 +432,4 @@ int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) } return 0; } + |