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authorNico Boehr <nrb@linux.ibm.com>2022-05-24 15:43:20 +0200
committerHeiko Carstens <hca@linux.ibm.com>2022-05-25 11:46:02 +0200
commitc9bfb460c3e4da2462e16b0f0b200990b36b1dd2 (patch)
tree9b33bc979aa4ba843702e43862a29ea26f77df15 /arch/s390
parents390: generate register offsets into pt_regs automatically (diff)
downloadlinux-dev-c9bfb460c3e4da2462e16b0f0b200990b36b1dd2.tar.xz
linux-dev-c9bfb460c3e4da2462e16b0f0b200990b36b1dd2.zip
s390/perf: obtain sie_block from the right address
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>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/kernel/perf_event.c2
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)