diff options
| -rw-r--r-- | arch/i386/kernel/kprobes.c | 25 | ||||
| -rw-r--r-- | arch/ia64/kernel/kprobes.c | 37 | ||||
| -rw-r--r-- | arch/ppc64/kernel/kprobes.c | 25 | ||||
| -rw-r--r-- | arch/sparc64/kernel/kprobes.c | 21 | ||||
| -rw-r--r-- | arch/x86_64/kernel/kprobes.c | 29 | ||||
| -rw-r--r-- | include/linux/kprobes.h | 2 | ||||
| -rw-r--r-- | kernel/kprobes.c | 2 |
7 files changed, 80 insertions, 61 deletions
diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c index ad46929..32b0c24 100644 --- a/arch/i386/kernel/kprobes.c +++ b/arch/i386/kernel/kprobes.c @@ -153,7 +153,14 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) int ret = 0; kprobe_opcode_t *addr = NULL; unsigned long *lp; - struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + struct kprobe_ctlblk *kcb; + + /* + * We don't want to be preempted for the entire + * duration of kprobe processing + */ + preempt_disable(); + kcb = get_kprobe_ctlblk(); /* Check if the application is using LDT entry for its code segment and * calculate the address by reading the base address from the LDT entry. @@ -221,11 +228,6 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) goto no_kprobe; } - /* - * This preempt_disable() matches the preempt_enable_no_resched() - * in post_kprobe_handler() - */ - preempt_disable(); set_current_kprobe(p, regs, kcb); kcb->kprobe_status = KPROBE_HIT_ACTIVE; @@ -239,6 +241,7 @@ ss_probe: return 1; no_kprobe: + preempt_enable_no_resched(); return ret; } @@ -310,8 +313,8 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) /* * By returning a non-zero value, we are telling - * kprobe_handler() that we have handled unlocking - * and re-enabling preemption + * kprobe_handler() that we don't want the post_handler + * to run (and have re-enabled preemption) */ return 1; } @@ -455,7 +458,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, struct die_args *args = (struct die_args *)data; int ret = NOTIFY_DONE; - rcu_read_lock(); switch (val) { case DIE_INT3: if (kprobe_handler(args->regs)) @@ -467,14 +469,16 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, break; case DIE_GPF: case DIE_PAGE_FAULT: + /* kprobe_running() needs smp_processor_id() */ + preempt_disable(); if (kprobe_running() && kprobe_fault_handler(args->regs, args->trapnr)) ret = NOTIFY_STOP; + preempt_enable(); break; default: break; } - rcu_read_unlock(); return ret; } @@ -537,6 +541,7 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) *regs = kcb->jprobe_saved_regs; memcpy((kprobe_opcode_t *) stack_addr, kcb->jprobes_stack, MIN_STACK_SIZE(stack_addr)); + preempt_enable_no_resched(); return 1; } return 0; diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index fddbac3..96736a1 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -389,11 +389,11 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) 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 - */ + /* + * 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; } @@ -604,7 +604,14 @@ 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 = get_kprobe_ctlblk(); + 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()) { @@ -659,11 +666,6 @@ static int __kprobes pre_kprobes_handler(struct die_args *args) goto no_kprobe; } - /* - * This preempt_disable() matches the preempt_enable_no_resched() - * in post_kprobes_handler() - */ - preempt_disable(); set_current_kprobe(p, kcb); kcb->kprobe_status = KPROBE_HIT_ACTIVE; @@ -681,6 +683,7 @@ ss_probe: return 1; no_kprobe: + preempt_enable_no_resched(); return ret; } @@ -716,9 +719,6 @@ static int __kprobes kprobes_fault_handler(struct pt_regs *regs, int trapnr) struct kprobe *cur = kprobe_running(); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - if (!cur) - return 0; - if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) return 1; @@ -737,7 +737,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, struct die_args *args = (struct die_args *)data; int ret = NOTIFY_DONE; - rcu_read_lock(); switch(val) { case DIE_BREAK: if (pre_kprobes_handler(args)) @@ -748,12 +747,15 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, ret = NOTIFY_STOP; break; case DIE_PAGE_FAULT: - if (kprobes_fault_handler(args->regs, args->trapnr)) + /* 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; } - rcu_read_unlock(); return ret; } @@ -785,6 +787,7 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); *regs = kcb->jprobe_saved_regs; + preempt_enable_no_resched(); return 1; } diff --git a/arch/ppc64/kernel/kprobes.c b/arch/ppc64/kernel/kprobes.c index e0a25b3..511af54 100644 --- a/arch/ppc64/kernel/kprobes.c +++ b/arch/ppc64/kernel/kprobes.c @@ -148,7 +148,14 @@ static inline int kprobe_handler(struct pt_regs *regs) struct kprobe *p; int ret = 0; unsigned int *addr = (unsigned int *)regs->nip; - struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + struct kprobe_ctlblk *kcb; + + /* + * We don't want to be preempted for the entire + * duration of kprobe processing + */ + preempt_disable(); + kcb = get_kprobe_ctlblk(); /* Check we're not actually recursing */ if (kprobe_running()) { @@ -207,11 +214,6 @@ static inline int kprobe_handler(struct pt_regs *regs) goto no_kprobe; } - /* - * This preempt_disable() matches the preempt_enable_no_resched() - * in post_kprobe_handler(). - */ - preempt_disable(); kcb->kprobe_status = KPROBE_HIT_ACTIVE; set_current_kprobe(p, regs, kcb); if (p->pre_handler && p->pre_handler(p, regs)) @@ -224,6 +226,7 @@ ss_probe: return 1; no_kprobe: + preempt_enable_no_resched(); return ret; } @@ -296,8 +299,8 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) /* * By returning a non-zero value, we are telling - * kprobe_handler() that we have handled unlocking - * and re-enabling preemption. + * kprobe_handler() that we don't want the post_handler + * to run (and have re-enabled preemption) */ return 1; } @@ -385,7 +388,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, struct die_args *args = (struct die_args *)data; int ret = NOTIFY_DONE; - rcu_read_lock(); switch (val) { case DIE_BPT: if (kprobe_handler(args->regs)) @@ -396,14 +398,16 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, ret = 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)) ret = NOTIFY_STOP; + preempt_enable(); break; default: break; } - rcu_read_unlock(); return ret; } @@ -440,6 +444,7 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) * saved regs... */ memcpy(regs, &kcb->jprobe_saved_regs, sizeof(struct pt_regs)); + preempt_enable_no_resched(); return 1; } diff --git a/arch/sparc64/kernel/kprobes.c b/arch/sparc64/kernel/kprobes.c index 58a815e..96bd09b 100644 --- a/arch/sparc64/kernel/kprobes.c +++ b/arch/sparc64/kernel/kprobes.c @@ -113,7 +113,14 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) struct kprobe *p; void *addr = (void *) regs->tpc; int ret = 0; - struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + 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()) { p = get_kprobe(addr); @@ -159,11 +166,6 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) goto no_kprobe; } - /* - * This preempt_disable() matches the preempt_enable_no_resched() - * in post_kprobes_handler() - */ - preempt_disable(); set_current_kprobe(p, regs, kcb); kcb->kprobe_status = KPROBE_HIT_ACTIVE; if (p->pre_handler && p->pre_handler(p, regs)) @@ -175,6 +177,7 @@ ss_probe: return 1; no_kprobe: + preempt_enable_no_resched(); return ret; } @@ -321,7 +324,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, struct die_args *args = (struct die_args *)data; int ret = NOTIFY_DONE; - rcu_read_lock(); switch (val) { case DIE_DEBUG: if (kprobe_handler(args->regs)) @@ -333,14 +335,16 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, break; case DIE_GPF: case DIE_PAGE_FAULT: + /* kprobe_running() needs smp_processor_id() */ + preempt_disable(); if (kprobe_running() && kprobe_fault_handler(args->regs, args->trapnr)) ret = NOTIFY_STOP; + preempt_enable(); break; default: break; } - rcu_read_unlock(); return ret; } @@ -426,6 +430,7 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) &(kcb->jprobe_saved_stack), sizeof(kcb->jprobe_saved_stack)); + preempt_enable_no_resched(); return 1; } return 0; diff --git a/arch/x86_64/kernel/kprobes.c b/arch/x86_64/kernel/kprobes.c index 9bef2c8..dddeb67 100644 --- a/arch/x86_64/kernel/kprobes.c +++ b/arch/x86_64/kernel/kprobes.c @@ -286,16 +286,19 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe *rp, } } -/* - * Interrupts are disabled on entry as trap3 is an interrupt gate and they - * remain disabled thorough out this function. - */ int __kprobes kprobe_handler(struct pt_regs *regs) { struct kprobe *p; int ret = 0; kprobe_opcode_t *addr = (kprobe_opcode_t *)(regs->rip - sizeof(kprobe_opcode_t)); - struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + struct kprobe_ctlblk *kcb; + + /* + * We don't want to be preempted for the entire + * duration of kprobe processing + */ + preempt_disable(); + kcb = get_kprobe_ctlblk(); /* Check we're not actually recursing */ if (kprobe_running()) { @@ -359,11 +362,6 @@ int __kprobes kprobe_handler(struct pt_regs *regs) goto no_kprobe; } - /* - * This preempt_disable() matches the preempt_enable_no_resched() - * in post_kprobe_handler() - */ - preempt_disable(); set_current_kprobe(p, regs, kcb); kcb->kprobe_status = KPROBE_HIT_ACTIVE; @@ -377,6 +375,7 @@ ss_probe: return 1; no_kprobe: + preempt_enable_no_resched(); return ret; } @@ -448,8 +447,8 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) /* * By returning a non-zero value, we are telling - * kprobe_handler() that we have handled unlocking - * and re-enabling preemption + * kprobe_handler() that we don't want the post_handler + * to run (and have re-enabled preemption) */ return 1; } @@ -594,7 +593,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, struct die_args *args = (struct die_args *)data; int ret = NOTIFY_DONE; - rcu_read_lock(); switch (val) { case DIE_INT3: if (kprobe_handler(args->regs)) @@ -606,14 +604,16 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, break; case DIE_GPF: case DIE_PAGE_FAULT: + /* kprobe_running() needs smp_processor_id() */ + preempt_disable(); if (kprobe_running() && kprobe_fault_handler(args->regs, args->trapnr)) ret = NOTIFY_STOP; + preempt_enable(); break; default: break; } - rcu_read_unlock(); return ret; } @@ -675,6 +675,7 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) *regs = kcb->jprobe_saved_regs; memcpy((kprobe_opcode_t *) stack_addr, kcb->jprobes_stack, MIN_STACK_SIZE(stack_addr)); + preempt_enable_no_resched(); return 1; } return 0; diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index cff281c..e373c4a 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -159,7 +159,7 @@ extern void show_registers(struct pt_regs *regs); extern kprobe_opcode_t *get_insn_slot(void); extern void free_insn_slot(kprobe_opcode_t *slot); -/* Get the kprobe at this addr (if any) - called under a rcu_read_lock() */ +/* Get the kprobe at this addr (if any) - called with preemption disabled */ struct kprobe *get_kprobe(void *addr); struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index cfef426..5beda37 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -167,7 +167,7 @@ static inline void reset_kprobe_instance(void) * This routine is called either: * - under the kprobe_lock spinlock - during kprobe_[un]register() * OR - * - under an rcu_read_lock() - from arch/xxx/kernel/kprobes.c + * - with preemption disabled - from arch/xxx/kernel/kprobes.c */ struct kprobe __kprobes *get_kprobe(void *addr) { |
