diff options
| author | Nico Boehr <nrb@linux.ibm.com> | 2022-05-24 15:43:20 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-09 10:23:21 +0200 |
| commit | 42b2f5ddc2204db845cf1f78ae296194557df714 (patch) | |
| tree | 3ddcb0f5f0acaa044d8e49ad0975940c6bdb756a | |
| parent | 20e6ec76aed47c65ee2dd7636f4911396c9396c7 (diff) | |
s390/perf: obtain sie_block from the right address
commit c9bfb460c3e4da2462e16b0f0b200990b36b1dd2 upstream.
Since commit 1179f170b6f0 ("s390: fix fpu restore in entry.S"), the
sie_block pointer is located at empty1[1], but in sie_block() it was
taken from empty1[0].
This leads to a random pointer being dereferenced, possibly causing
system crash.
This problem can be observed when running a simple guest with an endless
loop and recording the cpu-clock event:
sudo perf kvm --guestvmlinux=<guestkernel> --guest top -e cpu-clock
With this fix, the correct guest address is shown.
Fixes: 1179f170b6f0 ("s390: fix fpu restore in entry.S")
Cc: stable@vger.kernel.org
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/s390/kernel/perf_event.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/s390/kernel/perf_event.c b/arch/s390/kernel/perf_event.c index ea7729bebaa0..a7f8db73984b 100644 --- a/arch/s390/kernel/perf_event.c +++ b/arch/s390/kernel/perf_event.c @@ -30,7 +30,7 @@ static struct kvm_s390_sie_block *sie_block(struct pt_regs *regs) if (!stack) return NULL; - return (struct kvm_s390_sie_block *) stack->empty1[0]; + return (struct kvm_s390_sie_block *)stack->empty1[1]; } static bool is_in_guest(struct pt_regs *regs) |