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authorJean Pihet <jean.pihet@linaro.org>2014-07-07 14:45:08 +0100
committerWill Deacon <will.deacon@arm.com>2014-07-09 15:05:24 +0100
commita7cc91001e36a4a4152c3ada6c8fe38adc5badbc (patch)
tree32d10331079614332cf6cc465cd36d6872d873d5 /arch/arm/kernel/perf_event.c
parent037e79aa958d325cfb3c733496af64199bba6b49 (diff)
downloadlinux-a7cc91001e36a4a4152c3ada6c8fe38adc5badbc.tar.gz
ARM: perf: Check that current->mm is alive before getting user callchain
An event may occur when an mm is already released. As per commit 20afc60f892d285fde179ead4b24e6a7938c2f1b 'x86, perf: Check that current->mm is alive before getting user callchain' Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jean Pihet <jean.pihet@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm/kernel/perf_event.c')
-rw-r--r--arch/arm/kernel/perf_event.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 4238bcba9d6..6493c4c97d4 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -590,6 +590,10 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
}
perf_callchain_store(entry, regs->ARM_pc);
+
+ if (!current->mm)
+ return;
+
tail = (struct frame_tail __user *)regs->ARM_fp - 1;
while ((entry->nr < PERF_MAX_STACK_DEPTH) &&