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selftests/powerpc: fix exec benchmark

PATCH Applied Nicholas Piggin 3 participants 4 messages May 12, 2018 – May 16, 2018

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Nicholas Piggin

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#0 lore raw

PATCH 1/1 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 <[email protected]>
---
 tools/testing/selftests/powerpc/benchmarks/exec_target.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
tools/testing/selftests/powerpc/benchmarks/exec_target.c +5 -2
index 3c9c144192be..c14b0fc1edde 100644
@@ -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);
 }
Signature · 1 line
2.17.0
#1 lore raw

Nick,

Quoted 29 lines · Nicholas Piggin

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 <[email protected]>
---
 tools/testing/selftests/powerpc/benchmarks/exec_target.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
tools/testing/selftests/powerpc/benchmarks/exec_target.c +5 -3
index 3c9c144192be..c14b0fc1edde 100644
@@ -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);
 }
--
Quoted 2 lines

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.

Thanks

#2 lore raw
Quoted 37 lines · Mathieu Malaterre

Nick,

Quoted 29 lines · Nicholas Piggin

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 <[email protected]>
---
 tools/testing/selftests/powerpc/benchmarks/exec_target.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
tools/testing/selftests/powerpc/benchmarks/exec_target.c +5 -3
index 3c9c144192be..c14b0fc1edde 100644
@@ -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);
 }
--
Quoted 2 lines

2.17.0

Could you please apply the same patch to :

Quoted 3 lines

./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.