[PATCH] selftests/powerpc: fix exec benchmark

The exec_target binary could segfault calling _exit(2) because r13
is not set up properly (and libc looks at that when performing a
syscall). Call SYS_exit using syscall(2) which doesn't seem to
have this problem.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 tools/testing/selftests/powerpc/benchmarks/exec_target.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/powerpc/benchmarks/exec_target.c b/tools/testing/selftests/powerpc/benchmarks/exec_target.c
index 3c9c144192be..c14b0fc1edde 100644
--- a/tools/testing/selftests/powerpc/benchmarks/exec_target.c
+++ b/tools/testing/selftests/powerpc/benchmarks/exec_target.c

@@ -6,8 +6,11 @@
  * Copyright 2018, Anton Blanchard, IBM Corp.
  */
 
-void _exit(int);
+#define _GNU_SOURCE
+#include <unistd.h>
+#include <sys/syscall.h>
+
 void _start(void)
 {
-	_exit(0);
+	syscall(SYS_exit, 0);
 }

-- 
2.17.0

Nick,

On Sat, May 12, 2018 at 5:35 AM, Nicholas Piggin [off-list ref] wrote:

Could you please apply the same patch to :

./tools/testing/selftests/size/get_size.c

It segfault on ppc32 with default cross compiler from Debian.

Thanks

On Sat, May 12, 2018 at 10:54 AM, Mathieu Malaterre [off-list ref] wrote:

Nick,

On Sat, May 12, 2018 at 5:35 AM, Nicholas Piggin [off-list ref] wrote:

quoted

The exec_target binary could segfault calling _exit(2) because r13
is not set up properly (and libc looks at that when performing a
syscall). Call SYS_exit using syscall(2) which doesn't seem to
have this problem.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 tools/testing/selftests/powerpc/benchmarks/exec_target.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/powerpc/benchmarks/exec_target.c b/tools/testing/selftests/powerpc/benchmarks/exec_target.c
index 3c9c144192be..c14b0fc1edde 100644
--- a/tools/testing/selftests/powerpc/benchmarks/exec_target.c
+++ b/tools/testing/selftests/powerpc/benchmarks/exec_target.c

@@ -6,8 +6,11 @@
  * Copyright 2018, Anton Blanchard, IBM Corp.
  */

-void _exit(int);
+#define _GNU_SOURCE
+#include <unistd.h>
+#include <sys/syscall.h>
+
 void _start(void)
 {
-       _exit(0);
+       syscall(SYS_exit, 0);
 }
--

2.17.0

Could you please apply the same patch to :

./tools/testing/selftests/size/get_size.c

It segfault on ppc32 with default cross compiler from Debian.

Nevermind, I did not tested and this seems not to be sufficient to
make the executable run properly.

On Sat, 2018-05-12 at 03:35:24 UTC, Nicholas Piggin wrote:

The exec_target binary could segfault calling _exit(2) because r13
is not set up properly (and libc looks at that when performing a
syscall). Call SYS_exit using syscall(2) which doesn't seem to
have this problem.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/c906d2c74e0bb9059fbf43e21f8a96

cheers