diff options
| author | Ingo Molnar <[email protected]> | 2014-11-12 15:09:01 +0100 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2014-11-12 15:09:01 +0100 |
| commit | 890ca861f868a10617029ffc87eae7d48ea6876c (patch) | |
| tree | 713383f4e3bbd94ddb9816a25e6b3911511908f1 /kernel/kprobes.c | |
| parent | 03452d27c6cd9cebb59a6bb0fb6bd8557916c263 (diff) | |
| parent | 206c5f60a3d902bc4b56dab2de3e88de5eb06108 (diff) | |
Merge tag 'v3.18-rc4' into x86/cleanups, to refresh the tree before pulling new changes.
Signed-off-by: Ingo Molnar <[email protected]>
Diffstat (limited to 'kernel/kprobes.c')
| -rw-r--r-- | kernel/kprobes.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 734e9a7d280b..3995f546d0f3 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1778,7 +1778,18 @@ static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) unsigned long hash, flags = 0; struct kretprobe_instance *ri; - /*TODO: consider to only swap the RA after the last pre_handler fired */ + /* + * To avoid deadlocks, prohibit return probing in NMI contexts, + * just skip the probe and increase the (inexact) 'nmissed' + * statistical counter, so that the user is informed that + * something happened: + */ + if (unlikely(in_nmi())) { + rp->nmissed++; + return 0; + } + + /* TODO: consider to only swap the RA after the last pre_handler fired */ hash = hash_ptr(current, KPROBE_HASH_BITS); raw_spin_lock_irqsave(&rp->lock, flags); if (!hlist_empty(&rp->free_instances)) { |