[PATCH v4] selftests/powerpc: Fix pkey syscall redefinitions

On distros using older glibc versions, the pkey tests
encounter build failures due to redefinition of the
pkey syscall numbers.

For compatibility, commit 743f3544fffb added a wrapper
for the gettid() syscall and included syscall.h if the
version of glibc used is older than 2.30. This leads
to different definitions of SYS_pkey_* as the ones in
the pkey test header set numeric constants where as the
ones from syscall.h reuse __NR_pkey_*. The compiler
complains about redefinitions since they are different.

This replaces SYS_pkey_* definitions with __NR_pkey_*
such that the definitions in both syscall.h and pkeys.h
are alike. This way, if syscall.h has to be included
for compatibility reasons, builds will still succeed.

Fixes: 743f3544fffb ("selftests/powerpc: Add wrapper for gettid")
Reported-by: Sachin Sant <redacted>
Suggested-by: David Laight <redacted>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sandipan Das <redacted>
---
Previous versions can be found at:
v3: https://lore.kernel.org/linuxppc-dev/1bb744b0c7ed3985a5b73289f4de629ac0aeaf7c.1596453627.git.sandipan@linux.ibm.com/ (local)
v2: https://lore.kernel.org/linuxppc-dev/566dde119ce71f00f9642807ba30ceb7f54c9bfa.1596441105.git.sandipan@linux.ibm.com/ (local)
v1: https://lore.kernel.org/linuxppc-dev/20200803074043.466809-1-sandipan@linux.ibm.com/ (local)

Changes in v4:
- Replace SYS_pkey_* with __NR_pkey_* based on suggestions
  from David and Michael.
- Update commit message and add fixes tag.

Changes in v3:
- Use ifndef...endif instead of undef as suggested by
  Michael.

Changes in v2:
- Fix incorrect commit message.

---
 tools/testing/selftests/powerpc/include/pkeys.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/powerpc/include/pkeys.h b/tools/testing/selftests/powerpc/include/pkeys.h
index 6ba95039a034..3312cb1b058d 100644
--- a/tools/testing/selftests/powerpc/include/pkeys.h
+++ b/tools/testing/selftests/powerpc/include/pkeys.h

@@ -31,9 +31,9 @@
 
 #define SI_PKEY_OFFSET	0x20
 
-#define SYS_pkey_mprotect	386
-#define SYS_pkey_alloc		384
-#define SYS_pkey_free		385
+#define __NR_pkey_mprotect	386
+#define __NR_pkey_alloc		384
+#define __NR_pkey_free		385
 
 #define PKEY_BITS_PER_PKEY	2
 #define NR_PKEYS		32

@@ -62,17 +62,17 @@ void pkey_set_rights(int pkey, unsigned long rights)
 
 int sys_pkey_mprotect(void *addr, size_t len, int prot, int pkey)
 {
-	return syscall(SYS_pkey_mprotect, addr, len, prot, pkey);
+	return syscall(__NR_pkey_mprotect, addr, len, prot, pkey);
 }
 
 int sys_pkey_alloc(unsigned long flags, unsigned long rights)
 {
-	return syscall(SYS_pkey_alloc, flags, rights);
+	return syscall(__NR_pkey_alloc, flags, rights);
 }
 
 int sys_pkey_free(int pkey)
 {
-	return syscall(SYS_pkey_free, pkey);
+	return syscall(__NR_pkey_free, pkey);
 }
 
 int pkeys_unsupported(void)

-- 
2.25.1