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| author | Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> | 2006-07-30 03:03:21 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-07-31 13:28:38 -0700 |
| commit | c39df470e04822965d945473d831786ab79dd4cd (patch) | |
| tree | 5a16bc4b29c71d9ae3cd234995c66daedc85e6bf /arch/i386 | |
| parent | 2a8a3d5b65e86ec1dfef7d268c64a909eab94af7 (diff) | |
| download | linux-c39df470e04822965d945473d831786ab79dd4cd.tar.gz linux-c39df470e04822965d945473d831786ab79dd4cd.tar.bz2 linux-c39df470e04822965d945473d831786ab79dd4cd.zip | |
[PATCH] kprobe-booster: disable in preemptible kernel
The kprobe-booster's safety check against preemption does not work well
now, because the preemption count has been modified by read_rcu_lock() in
atomic_notifier_call_chain() before we check it. So, I'd like to prevent
boosting kprobe temporarily if the kernel is preemptable.
Now we are searching for the good solution.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/i386')
| -rw-r--r-- | arch/i386/kernel/kprobes.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c index de2e16e561c0..afe6505ca0b3 100644 --- a/arch/i386/kernel/kprobes.c +++ b/arch/i386/kernel/kprobes.c @@ -256,11 +256,6 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) int ret = 0; kprobe_opcode_t *addr; struct kprobe_ctlblk *kcb; -#ifdef CONFIG_PREEMPT - unsigned pre_preempt_count = preempt_count(); -#else - unsigned pre_preempt_count = 1; -#endif addr = (kprobe_opcode_t *)(regs->eip - sizeof(kprobe_opcode_t)); @@ -338,13 +333,15 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) return 1; ss_probe: - if (pre_preempt_count && p->ainsn.boostable == 1 && !p->post_handler){ +#ifndef CONFIG_PREEMPT + if (p->ainsn.boostable == 1 && !p->post_handler){ /* Boost up -- we can execute copied instructions directly */ reset_current_kprobe(); regs->eip = (unsigned long)p->ainsn.insn; preempt_enable_no_resched(); return 1; } +#endif prepare_singlestep(p, regs); kcb->kprobe_status = KPROBE_HIT_SS; return 1; |