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authorAnanth N Mavinakayanahalli <ananth@in.ibm.com>2009-03-18 17:06:21 +0530
committerIngo Molnar <mingo@elte.hu>2009-03-18 12:51:16 +0100
commitf02b8624fedca39886b0eef770dca70c2f0749b3 (patch)
tree68583a9e84eacb3203e338c28f9236494ebb40ec /kernel/kprobes.c
parent03418c7efaa429dc7647ac93e3862e3fe1816873 (diff)
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@in.ibm.com> Tested-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> [2.6.29.x, 2.6.28.x, 2.6.27.x] LKML-Reference: <20090318113621.GB4129@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/kprobes.c')
-rw-r--r--kernel/kprobes.c4
1 files changed, 1 insertions, 3 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 479d4d5672f..5016bfb682b 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);