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authorArnd Bergmann <arnd@arndb.de>2014-09-05 16:53:56 +0200
committerArnd Bergmann <arnd@arndb.de>2014-09-05 16:53:56 +0200
commit184df9ddaab4a572e61b321abc079ca49155fc12 (patch)
tree5c99704d8508224b25552f24959b54772d8eec1e /kernel/kprobes.c
parent647f95fa99b16e7c7854a202e91e6aa22ebeecf4 (diff)
parent13298fbbdb3f6a0ef55419dc048e064c7a7b0ef8 (diff)
Merge tag 'renesas-kconfig-cleanups-for-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas into next/cleanup
Pull "Renesas ARM Based SoC Kconfig Cleanups for v3.18" from Simon Horman: * Update name of "R-Car M2-W" SoC (previously there was no "-W") * Consolidate Legacy SH_CLK_CPG and CPU_V7 Kconfig * Only select PM_RMOBILE for legacy case * Cleanup pm-rcar.o and pm-rmobile.o build using Kconfig Signed-off-by: Arnd Bergmann <arnd@arndb.de> * tag 'renesas-kconfig-cleanups-for-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas: ARM: shmobile: r8a7791 is now called "R-Car M2-W" ARM: shmobile: Consolidate Legacy SH_CLK_CPG Kconfig ARM: shmobile: Consolidate Legacy CPU_V7 Kconfig ARM: shmobile: Only select PM_RMOBILE for legacy case ARM: shmobile: Cleanup pm-rmobile.o build using Kconfig ARM: shmobile: Cleanup pm-rcar.o build using Kconfig ARM: shmobile: Introduce a Kconfig entry for R-Car Gen2 ARM: shmobile: Introduce a Kconfig entry for R-Car Gen1 ARM: shmobile: Introduce a Kconfig entry for R-Mobile Includes an update to 3.17-rc2 to avoid a dependency
Diffstat (limited to 'kernel/kprobes.c')
-rw-r--r--kernel/kprobes.c13
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)) {