+ selftests-vm-pkeys-handle-negative-sys_pkey_alloc-return-code.patch added to -mm tree

+ selftests-vm-pkeys-handle-negative-sys_pkey_alloc-return-code.patch added to -mm tree

[akpm]

The patch titled
     Subject: selftests/vm/pkeys: handle negative sys_pkey_alloc() return code
has been added to the -mm tree.  Its filename is
     selftests-vm-pkeys-handle-negative-sys_pkey_alloc-return-code.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/selftests-vm-pkeys-handle-negative-sys_pkey_alloc-return-code.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/selftests-vm-pkeys-handle-negative-sys_pkey_alloc-return-code.patch

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------------------------------------------------------
From: Dave Hansen <dave.hansen@linux.intel.com>
Subject: selftests/vm/pkeys: handle negative sys_pkey_alloc() return code

The alloc_pkey() sefltest function wraps the sys_pkey_alloc() system call.
On success, it updates its "shadow" register value because
sys_pkey_alloc() updates the real register.

But, the success check is wrong.  pkey_alloc() considers any non-zero
return code to indicate success where the pkey register will be modified. 
This fails to take negative return codes into account.

Consider only a positive return value as a successful call.

Link: https://lkml.kernel.org/r/20210611164157.87AB4246@viggo.jf.intel.com
Fixes: 5f23f6d082a9 ("x86/pkeys: Add self-tests")
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: "Desnes A. Nunes do Rosario" <desnesn@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Suchanek <msuchanek@suse.de>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 tools/testing/selftests/vm/protection_keys.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/testing/selftests/vm/protection_keys.c~selftests-vm-pkeys-handle-negative-sys_pkey_alloc-return-code
+++ a/tools/testing/selftests/vm/protection_keys.c
@@ -510,7 +510,7 @@ int alloc_pkey(void)
 			" shadow: 0x%016llx\n",
 			__func__, __LINE__, ret, __read_pkey_reg(),
 			shadow_pkey_reg);
-	if (ret) {
+	if (ret > 0) {
 		/* clear both the bits: */
 		shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, ret,
 						~PKEY_MASK);
_

Patches currently in -mm which might be from dave.hansen@linux.intel.com are

selftests-vm-pkeys-fix-alloc_random_pkey-to-make-it-really-really-random.patch
selftests-vm-pkeys-handle-negative-sys_pkey_alloc-return-code.patch
selftests-vm-pkeys-refill-shadow-register-after-implicit-kernel-write.patch
selftests-vm-pkeys-exercise-x86-xsave-init-state.patch