diff options
Diffstat (limited to 'arch/i386/kernel/kprobes.c')
| -rw-r--r-- | arch/i386/kernel/kprobes.c | 22 |
1 files changed, 7 insertions, 15 deletions
diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c index 99565a66915..ad469299267 100644 --- a/arch/i386/kernel/kprobes.c +++ b/arch/i386/kernel/kprobes.c @@ -31,7 +31,6 @@ #include <linux/config.h> #include <linux/kprobes.h> #include <linux/ptrace.h> -#include <linux/spinlock.h> #include <linux/preempt.h> #include <asm/cacheflush.h> #include <asm/kdebug.h> @@ -123,6 +122,7 @@ static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs) regs->eip = (unsigned long)&p->ainsn.insn; } +/* Called with kretprobe_lock held */ void __kprobes arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs) { @@ -168,15 +168,12 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) } /* Check we're not actually recursing */ 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 (kcb->kprobe_status == KPROBE_HIT_SS && *p->ainsn.insn == BREAKPOINT_INSTRUCTION) { regs->eflags &= ~TF_MASK; regs->eflags |= kcb->kprobe_saved_eflags; - unlock_kprobes(); goto no_kprobe; } /* We have reentered the kprobe_handler(), since @@ -197,14 +194,11 @@ static int __kprobes kprobe_handler(struct pt_regs *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 (regs->eflags & VM_MASK) { /* We are in virtual-8086 mode. Return 0 */ goto no_kprobe; @@ -268,9 +262,10 @@ 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 =(unsigned long)&kretprobe_trampoline; + spin_lock_irqsave(&kretprobe_lock, flags); head = kretprobe_inst_table_head(current); /* @@ -310,7 +305,7 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) regs->eip = orig_ret_address; reset_current_kprobe(); - unlock_kprobes(); + spin_unlock_irqrestore(&kretprobe_lock, flags); preempt_enable_no_resched(); /* @@ -395,7 +390,7 @@ static void __kprobes resume_execution(struct kprobe *p, /* * Interrupts are disabled on entry as trap1 is an interrupt gate and they - * remain disabled thoroughout this function. And we hold kprobe lock. + * remain disabled thoroughout this function. */ static inline int post_kprobe_handler(struct pt_regs *regs) { @@ -419,7 +414,6 @@ static inline int post_kprobe_handler(struct pt_regs *regs) goto out; } reset_current_kprobe(); - unlock_kprobes(); out: preempt_enable_no_resched(); @@ -434,7 +428,6 @@ out: return 1; } -/* Interrupts disabled, kprobe_lock held. */ static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) { struct kprobe *cur = kprobe_running(); @@ -448,7 +441,6 @@ static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) regs->eflags |= kcb->kprobe_old_eflags; reset_current_kprobe(); - unlock_kprobes(); preempt_enable_no_resched(); } return 0; @@ -463,7 +455,7 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, struct die_args *args = (struct die_args *)data; int ret = NOTIFY_DONE; - preempt_disable(); + rcu_read_lock(); switch (val) { case DIE_INT3: if (kprobe_handler(args->regs)) @@ -482,7 +474,7 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, default: break; } - preempt_enable(); + rcu_read_unlock(); return ret; } |