Commit-ID: f02b8624fedca39886b0eef770dca70c2f0749b3 Gitweb: http://git.kernel.org/tip/f02b8624fedca39886b0eef770dca70c2f0749b3 Author: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx> AuthorDate: Wed, 18 Mar 2009 17:06:21 +0530 Commit: Ingo Molnar <mingo@xxxxxxx> CommitDate: Wed, 18 Mar 2009 12:51:16 +0100 kprobes: Fix locking imbalance in kretprobes Fix locking imbalance in kretprobes: ===================================== [ BUG: bad unlock balance detected! ] ------------------------------------- kthreadd/2 is trying to release lock (&rp->lock) at: [<c06b3080>] pre_handler_kretprobe+0xea/0xf4 but there are no more locks to release! other info that might help us debug this: 1 lock held by kthreadd/2: #0: (rcu_read_lock){..--}, at: [<c06b2b24>] __atomic_notifier_call_chain+0x0/0x5a stack backtrace: Pid: 2, comm: kthreadd Not tainted 2.6.29-rc8 #1 Call Trace: [<c06ae498>] ? printk+0xf/0x17 [<c06b3080>] ? pre_handler_kretprobe+0xea/0xf4 [<c044ce6c>] print_unlock_inbalance_bug+0xc3/0xce [<c0444d4b>] ? clocksource_read+0x7/0xa [<c04450a4>] ? getnstimeofday+0x5f/0xf6 [<c044a9ca>] ? register_lock_class+0x17/0x293 [<c044b72c>] ? mark_lock+0x1e/0x30b [<c0448956>] ? tick_dev_program_event+0x4a/0xbc [<c0498100>] ? __slab_alloc+0xa5/0x415 [<c06b2fbe>] ? pre_handler_kretprobe+0x28/0xf4 [<c06b3080>] ? pre_handler_kretprobe+0xea/0xf4 [<c044cf1b>] lock_release_non_nested+0xa4/0x1a5 [<c06b3080>] ? pre_handler_kretprobe+0xea/0xf4 [<c044d15d>] lock_release+0x141/0x166 [<c06b07dd>] _spin_unlock_irqrestore+0x19/0x50 [<c06b3080>] pre_handler_kretprobe+0xea/0xf4 [<c06b20b5>] kprobe_exceptions_notify+0x1c9/0x43e [<c06b2b02>] notifier_call_chain+0x26/0x48 [<c06b2b5b>] __atomic_notifier_call_chain+0x37/0x5a [<c06b2b24>] ? __atomic_notifier_call_chain+0x0/0x5a [<c06b2b8a>] atomic_notifier_call_chain+0xc/0xe [<c0442d0d>] notify_die+0x2d/0x2f [<c06b0f9c>] do_int3+0x1f/0x71 [<c06b0e84>] int3+0x2c/0x34 [<c042d476>] ? do_fork+0x1/0x288 [<c040221b>] ? kernel_thread+0x71/0x79 [<c043ed1b>] ? kthread+0x0/0x60 [<c043ed1b>] ? kthread+0x0/0x60 [<c04040b8>] ? kernel_thread_helper+0x0/0x10 [<c043ec7f>] kthreadd+0xac/0x148 [<c043ebd3>] ? kthreadd+0x0/0x148 [<c04040bf>] kernel_thread_helper+0x7/0x10 Signed-off-by: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx> Tested-by: Bharata B Rao <bharata@xxxxxxxxxxxxxxxxxx> Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Cc: Jim Keniston <jkenisto@xxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxx> [2.6.29.x, 2.6.28.x, 2.6.27.x] LKML-Reference: <20090318113621.GB4129@xxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- kernel/kprobes.c | 4 +--- 1 files changed, 1 insertions(+), 3 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 479d4d5..5016bfb 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -919,10 +919,8 @@ static int __kprobes pre_handler_kretprobe(struct kprobe *p, ri->rp = rp; ri->task = current; - if (rp->entry_handler && rp->entry_handler(ri, regs)) { - spin_unlock_irqrestore(&rp->lock, flags); + if (rp->entry_handler && rp->entry_handler(ri, regs)) return 0; - } arch_prepare_kretprobe(ri, regs); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html