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| author | Nico Boehr <nrb@linux.ibm.com> | 2022-05-24 16:43:20 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-09 11:21:24 +0300 |
| commit | 74114d26e9dbe647ebb264ef5e1dcda2fbd6efd5 (patch) | |
| tree | 1a4235046d04cb4c5fdd147d872f6ee0c136aad5 /arch/s390 | |
| parent | 7994d890123a6cad033f2842ff0177a9bda1cb23 (diff) | |
| download | linux-74114d26e9dbe647ebb264ef5e1dcda2fbd6efd5.tar.xz | |
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>
Diffstat (limited to 'arch/s390')
| -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 1e75cc983546..b922dc0c8130 100644 --- a/arch/s390/kernel/perf_event.c +++ b/arch/s390/kernel/perf_event.c @@ -51,7 +51,7 @@ 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) |