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[2/2] selftests: vm: pkeys: Fix powerpc access right updates

Message ID 5f65cf37be993760de8112a88da194e3ccbb2bf8.1588959697.git.sandipan@linux.ibm.com
State New
Headers show
Series selftests: vm: pkeys: Some powerpc fixes | expand

Commit Message

Sandipan Das May 8, 2020, 5:49 p.m. UTC
The Power ISA mandates that all writes to the Authority
Mask Register (AMR) must always be preceded as well as
succeeded by a context-synchronizing instruction. This
applies to both the privileged and unprivileged variants
of the Move To AMR instruction.

Fixes: 130f573c2a79 ("selftests/vm/pkeys: introduce powerpc support")
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Suggested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
 tools/testing/selftests/vm/pkey-powerpc.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/tools/testing/selftests/vm/pkey-powerpc.h b/tools/testing/selftests/vm/pkey-powerpc.h
index eb5077de8f1e..1ebb586b2fbc 100644
--- a/tools/testing/selftests/vm/pkey-powerpc.h
+++ b/tools/testing/selftests/vm/pkey-powerpc.h
@@ -55,7 +55,8 @@  static inline void __write_pkey_reg(u64 pkey_reg)
 	dprintf4("%s() changing %016llx to %016llx\n",
 			 __func__, __read_pkey_reg(), pkey_reg);
 
-	asm volatile("mtspr 0xd, %0" : : "r" ((unsigned long)(amr)) : "memory");
+	asm volatile("isync; mtspr 0xd, %0; isync"
+		     : : "r" ((unsigned long)(amr)) : "memory");
 
 	dprintf4("%s() pkey register after changing %016llx to %016llx\n",
 			__func__, __read_pkey_reg(), pkey_reg);