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>
This commit is contained in:
Jean Pihet 2014-07-07 14:45:08 +01:00 committed by Will Deacon
parent 037e79aa95
commit a7cc91001e

View File

@ -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) &&