diff options
Diffstat (limited to 'arch/sparc64/kernel/kprobes.c')
| -rw-r--r-- | arch/sparc64/kernel/kprobes.c | 165 |
1 files changed, 82 insertions, 83 deletions
diff --git a/arch/sparc64/kernel/kprobes.c b/arch/sparc64/kernel/kprobes.c index 0d66d07c8c6e..96bd09b098f4 100644 --- a/arch/sparc64/kernel/kprobes.c +++ b/arch/sparc64/kernel/kprobes.c @@ -38,6 +38,9 @@ * - Mark that we are no longer actively in a kprobe. */ +DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; +DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); + int __kprobes arch_prepare_kprobe(struct kprobe *p) { return 0; @@ -66,46 +69,39 @@ void __kprobes arch_remove_kprobe(struct kprobe *p) { } -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 save_previous_kprobe(void) +static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb) { - 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; + kcb->prev_kprobe.kp = kprobe_running(); + kcb->prev_kprobe.status = kcb->kprobe_status; + kcb->prev_kprobe.orig_tnpc = kcb->kprobe_orig_tnpc; + kcb->prev_kprobe.orig_tstate_pil = kcb->kprobe_orig_tstate_pil; } -static inline void restore_previous_kprobe(void) +static inline void restore_previous_kprobe(struct kprobe_ctlblk *kcb) { - 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; + __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp; + kcb->kprobe_status = kcb->prev_kprobe.status; + kcb->kprobe_orig_tnpc = kcb->prev_kprobe.orig_tnpc; + kcb->kprobe_orig_tstate_pil = kcb->prev_kprobe.orig_tstate_pil; } -static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs) +static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs, + struct kprobe_ctlblk *kcb) { - current_kprobe_orig_tnpc = regs->tnpc; - current_kprobe_orig_tstate_pil = (regs->tstate & TSTATE_PIL); - current_kprobe = p; + __get_cpu_var(current_kprobe) = p; + kcb->kprobe_orig_tnpc = regs->tnpc; + kcb->kprobe_orig_tstate_pil = (regs->tstate & TSTATE_PIL); } -static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs) +static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs, + struct kprobe_ctlblk *kcb) { regs->tstate |= TSTATE_PIL; /*single step inline, if it a breakpoint instruction*/ if (p->opcode == BREAKPOINT_INSTRUCTION) { regs->tpc = (unsigned long) p->addr; - regs->tnpc = current_kprobe_orig_tnpc; + regs->tnpc = kcb->kprobe_orig_tnpc; } else { regs->tpc = (unsigned long) &p->ainsn.insn[0]; regs->tnpc = (unsigned long) &p->ainsn.insn[1]; @@ -117,19 +113,21 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) struct kprobe *p; void *addr = (void *) regs->tpc; int ret = 0; + struct kprobe_ctlblk *kcb; + /* + * We don't want to be preempted for the entire + * duration of kprobe processing + */ preempt_disable(); + kcb = get_kprobe_ctlblk(); if (kprobe_running()) { - /* We *are* holding lock here, so this is safe. - * Disarm the probe we just hit, and ignore it. - */ p = get_kprobe(addr); if (p) { - if (kprobe_status == KPROBE_HIT_SS) { + if (kcb->kprobe_status == KPROBE_HIT_SS) { regs->tstate = ((regs->tstate & ~TSTATE_PIL) | - current_kprobe_orig_tstate_pil); - unlock_kprobes(); + kcb->kprobe_orig_tstate_pil); goto no_kprobe; } /* We have reentered the kprobe_handler(), since @@ -138,25 +136,22 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) * just single step on the instruction of the new probe * without calling any user handlers. */ - save_previous_kprobe(); - set_current_kprobe(p, regs); + save_previous_kprobe(kcb); + set_current_kprobe(p, regs, kcb); p->nmissed++; - kprobe_status = KPROBE_REENTER; - prepare_singlestep(p, regs); + kcb->kprobe_status = KPROBE_REENTER; + prepare_singlestep(p, regs, kcb); return 1; } else { - p = current_kprobe; + p = __get_cpu_var(current_kprobe); if (p->break_handler && p->break_handler(p, regs)) goto ss_probe; } - /* If it's not ours, can't be delete race, (we hold lock). */ goto no_kprobe; } - lock_kprobes(); p = get_kprobe(addr); if (!p) { - unlock_kprobes(); if (*(u32 *)addr != BREAKPOINT_INSTRUCTION) { /* * The breakpoint instruction was removed right @@ -171,14 +166,14 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) goto no_kprobe; } - set_current_kprobe(p, regs); - kprobe_status = KPROBE_HIT_ACTIVE; + set_current_kprobe(p, regs, kcb); + kcb->kprobe_status = KPROBE_HIT_ACTIVE; if (p->pre_handler && p->pre_handler(p, regs)) return 1; ss_probe: - prepare_singlestep(p, regs); - kprobe_status = KPROBE_HIT_SS; + prepare_singlestep(p, regs, kcb); + kcb->kprobe_status = KPROBE_HIT_SS; return 1; no_kprobe: @@ -260,11 +255,12 @@ static void __kprobes retpc_fixup(struct pt_regs *regs, u32 insn, * This function prepares to return from the post-single-step * breakpoint trap. */ -static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) +static void __kprobes resume_execution(struct kprobe *p, + struct pt_regs *regs, struct kprobe_ctlblk *kcb) { u32 insn = p->ainsn.insn[0]; - regs->tpc = current_kprobe_orig_tnpc; + regs->tpc = kcb->kprobe_orig_tnpc; regs->tnpc = relbranch_fixup(insn, (unsigned long) p->addr, (unsigned long) &p->ainsn.insn[0], @@ -272,44 +268,48 @@ static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) retpc_fixup(regs, insn, (unsigned long) p->addr); regs->tstate = ((regs->tstate & ~TSTATE_PIL) | - current_kprobe_orig_tstate_pil); + kcb->kprobe_orig_tstate_pil); } static inline int post_kprobe_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, kcb); /*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(); return 1; } -/* Interrupts disabled, kprobe_lock held. */ static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) { - if (current_kprobe->fault_handler - && current_kprobe->fault_handler(current_kprobe, regs, trapnr)) + struct kprobe *cur = kprobe_running(); + struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + + if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) return 1; - if (kprobe_status & KPROBE_HIT_SS) { - resume_execution(current_kprobe, regs); + if (kcb->kprobe_status & KPROBE_HIT_SS) { + resume_execution(cur, regs, kcb); - unlock_kprobes(); + reset_current_kprobe(); preempt_enable_no_resched(); } return 0; @@ -322,29 +322,30 @@ 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_DEBUG: if (kprobe_handler(args->regs)) - return NOTIFY_STOP; + ret = NOTIFY_STOP; break; case DIE_DEBUG_2: if (post_kprobe_handler(args->regs)) - return NOTIFY_STOP; + ret = NOTIFY_STOP; break; case DIE_GPF: - if (kprobe_running() && - kprobe_fault_handler(args->regs, args->trapnr)) - return NOTIFY_STOP; - break; case DIE_PAGE_FAULT: + /* kprobe_running() needs smp_processor_id() */ + preempt_disable(); if (kprobe_running() && kprobe_fault_handler(args->regs, args->trapnr)) - return NOTIFY_STOP; + ret = NOTIFY_STOP; + preempt_enable(); break; default: break; } - return NOTIFY_DONE; + return ret; } asmlinkage void __kprobes kprobe_trap(unsigned long trap_level, @@ -368,24 +369,21 @@ asmlinkage void __kprobes kprobe_trap(unsigned long trap_level, } /* Jprobes support. */ -static struct pt_regs jprobe_saved_regs; -static struct pt_regs *jprobe_saved_regs_location; -static struct sparc_stackf jprobe_saved_stack; - int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) { struct jprobe *jp = container_of(p, struct jprobe, kp); + struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - jprobe_saved_regs_location = regs; - memcpy(&jprobe_saved_regs, regs, sizeof(*regs)); + kcb->jprobe_saved_regs_location = regs; + memcpy(&(kcb->jprobe_saved_regs), regs, sizeof(*regs)); /* Save a whole stack frame, this gets arguments * pushed onto the stack after using up all the * arg registers. */ - memcpy(&jprobe_saved_stack, + memcpy(&(kcb->jprobe_saved_stack), (char *) (regs->u_regs[UREG_FP] + STACK_BIAS), - sizeof(jprobe_saved_stack)); + sizeof(kcb->jprobe_saved_stack)); regs->tpc = (unsigned long) jp->entry; regs->tnpc = ((unsigned long) jp->entry) + 0x4UL; @@ -396,7 +394,6 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) void __kprobes jprobe_return(void) { - preempt_enable_no_resched(); __asm__ __volatile__( ".globl jprobe_return_trap_instruction\n" "jprobe_return_trap_instruction:\n\t" @@ -410,14 +407,15 @@ extern void __show_regs(struct pt_regs * regs); int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) { u32 *addr = (u32 *) regs->tpc; + struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); if (addr == (u32 *) jprobe_return_trap_instruction) { - if (jprobe_saved_regs_location != regs) { + if (kcb->jprobe_saved_regs_location != regs) { printk("JPROBE: Current regs (%p) does not match " "saved regs (%p).\n", - regs, jprobe_saved_regs_location); + regs, kcb->jprobe_saved_regs_location); printk("JPROBE: Saved registers\n"); - __show_regs(jprobe_saved_regs_location); + __show_regs(kcb->jprobe_saved_regs_location); printk("JPROBE: Current registers\n"); __show_regs(regs); BUG(); @@ -426,12 +424,13 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) * first so that UREG_FP is the original one for * the stack frame restore. */ - memcpy(regs, &jprobe_saved_regs, sizeof(*regs)); + memcpy(regs, &(kcb->jprobe_saved_regs), sizeof(*regs)); memcpy((char *) (regs->u_regs[UREG_FP] + STACK_BIAS), - &jprobe_saved_stack, - sizeof(jprobe_saved_stack)); + &(kcb->jprobe_saved_stack), + sizeof(kcb->jprobe_saved_stack)); + preempt_enable_no_resched(); return 1; } return 0; |