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| author | James Morris <james.l.morris@oracle.com> | 2014-11-19 21:32:12 +1100 |
|---|---|---|
| committer | James Morris <james.l.morris@oracle.com> | 2014-11-19 21:32:12 +1100 |
| commit | b10778a00d40b3d9fdaaf5891e802794781ff71c (patch) | |
| tree | 6ba4cbac86eecedc3f30650e7f764ecf00c83898 /kernel/kprobes.c | |
| parent | 594081ee7145cc30a3977cb4e218f81213b63dc5 (diff) | |
| parent | bfe01a5ba2490f299e1d2d5508cbbbadd897bbe9 (diff) | |
Merge commit 'v3.17' into next
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 734e9a7d280..3995f546d0f 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)) { |