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| author | Jiri Kosina <jkosina@suse.cz> | 2014-11-20 14:42:02 +0100 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2014-11-20 14:42:02 +0100 |
| commit | a02001086bbfb4da35d1228bebc2f1b442db455f (patch) | |
| tree | 62ab47936cef06fd08657ca5b6cd1df98c19be57 /kernel/kprobes.c | |
| parent | kernel: trace: fix printk message (diff) | |
| parent | Linux 3.18-rc5 (diff) | |
| download | linux-a02001086bbfb4da35d1228bebc2f1b442db455f.tar.xz linux-a02001086bbfb4da35d1228bebc2f1b442db455f.zip | |
Merge Linus' tree to be be to apply submitted patches to newer code than
current trivial.git base
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)) { |