s390/runtime_instrumentation: fix storage key handling
[ Upstream commit 9eaba29c7985236e16468f4e6a49cc18cf01443e ]
The key member of the runtime instrumentation control block contains
only the access key, not the complete storage key. Therefore the value
must be shifted by four bits.
Note: this is only relevant for debugging purposes in case somebody
compiles a kernel with a default storage access key set to a value not
equal to zero.
Fixes: e4b8b3f33fca ("s390: add support for runtime instrumentation")
Reported-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/arch/s390/kernel/runtime_instr.c b/arch/s390/kernel/runtime_instr.c
index 125c7f6..1788a54 100644
--- a/arch/s390/kernel/runtime_instr.c
+++ b/arch/s390/kernel/runtime_instr.c
@@ -57,7 +57,7 @@
cb->k = 1;
cb->ps = 1;
cb->pc = 1;
- cb->key = PAGE_DEFAULT_KEY;
+ cb->key = PAGE_DEFAULT_KEY >> 4;
cb->v = 1;
}