[PATCH] selftests/proc: proc-pid-vm: fix unused variable warning on non-x86

[PATCH] selftests/proc: proc-pid-vm: fix unused variable warning on non-x86

[Sasha Levin]

g_vsyscall is only used by the x86_64 test, so other architectures get:

  proc-pid-vm.c:224:21: warning: unused variable 'g_vsyscall' [-Wunused-variable]

Mark it __maybe_unused, like str_vsyscall next to it.

Fixes: 17415606f9d8b ("tools/testing/selftests/proc/proc-pid-vm.c: test with vsyscall in mind")
Assisted-by: LLM
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/proc/proc-pid-vm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/proc/proc-pid-vm.c b/tools/testing/selftests/proc/proc-pid-vm.c
index 4e6a3e53f9757..c5a66f481ab4d 100644
--- a/tools/testing/selftests/proc/proc-pid-vm.c
+++ b/tools/testing/selftests/proc/proc-pid-vm.c
@@ -221,7 +221,7 @@ static int make_exe(const uint8_t *payload, size_t len)
  * 1: vsyscall VMA is --xp		vsyscall=xonly
  * 2: vsyscall VMA is r-xp		vsyscall=emulate
  */
-static volatile int g_vsyscall;
+static volatile int g_vsyscall __maybe_unused;
 static const char *str_vsyscall __maybe_unused;
 
 static const char str_vsyscall_0[] __maybe_unused = "";
-- 
2.53.0

Re: [PATCH] selftests/proc: proc-pid-vm: fix unused variable warning on non-x86

[Andrew Morton]

On Sun, 11 Oct 2026 18:33:39 -0400 Sasha Levin <sashal@kernel.org> wrote:

> g_vsyscall is only used by the x86_64 test, so other architectures get:
> 
>   proc-pid-vm.c:224:21: warning: unused variable 'g_vsyscall' [-Wunused-variable]
> 
> Mark it __maybe_unused, like str_vsyscall next to it.
> 
> ...
>
> --- a/tools/testing/selftests/proc/proc-pid-vm.c
> +++ b/tools/testing/selftests/proc/proc-pid-vm.c
> @@ -221,7 +221,7 @@ static int make_exe(const uint8_t *payload, size_t len)
>   * 1: vsyscall VMA is --xp		vsyscall=xonly
>   * 2: vsyscall VMA is r-xp		vsyscall=emulate
>   */
> -static volatile int g_vsyscall;
> +static volatile int g_vsyscall __maybe_unused;
>  static const char *str_vsyscall __maybe_unused;
>  
>  static const char str_vsyscall_0[] __maybe_unused = "";

Can't all the x86-specific stuff be moved after the #ifdef __x86_64__
which is a few lines later?

[PATCH v2] selftests/proc: proc-pid-vm: fix unused variable warning on non-x86

[Sasha Levin]

g_vsyscall is only used by the x86_64 test, so clang builds for other
architectures get:

  proc-pid-vm.c:224:21: warning: unused variable 'g_vsyscall' [-Wunused-variable]

The vsyscall strings next to it had the same problem and were marked
__maybe_unused for it. Move all of the vsyscall variables into the
__x86_64__ block that uses them instead, and drop those annotations
along with the local __maybe_unused fallback that was added for them.

Fixes: 17415606f9d8b ("tools/testing/selftests/proc/proc-pid-vm.c: test with vsyscall in mind")
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Assisted-by: LLM
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
Changes in v2:
- Move the vsyscall variables into the __x86_64__ block instead of marking
  g_vsyscall __maybe_unused, and drop the existing annotations (Andrew Morton)
- Link to v1: https://lore.kernel.org/r/20261011223358.2327625-11-sashal@kernel.org

 tools/testing/selftests/proc/proc-pid-vm.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/proc/proc-pid-vm.c b/tools/testing/selftests/proc/proc-pid-vm.c
index 4e6a3e53f9757..98e882e568154 100644
--- a/tools/testing/selftests/proc/proc-pid-vm.c
+++ b/tools/testing/selftests/proc/proc-pid-vm.c
@@ -47,10 +47,6 @@
 #include <sys/resource.h>
 #include <linux/fs.h>
 
-#ifndef __maybe_unused
-#define __maybe_unused __attribute__((__unused__))
-#endif
-
 #include "kselftest.h"
 
 static inline long sys_execveat(int dirfd, const char *pathname, char **argv, char **envp, int flags)
@@ -214,7 +210,6 @@ static int make_exe(const uint8_t *payload, size_t len)
 
 	return fd1;
 }
-#endif
 
 /*
  * 0: vsyscall VMA doesn't exist	vsyscall=none
@@ -222,15 +217,14 @@ static int make_exe(const uint8_t *payload, size_t len)
  * 2: vsyscall VMA is r-xp		vsyscall=emulate
  */
 static volatile int g_vsyscall;
-static const char *str_vsyscall __maybe_unused;
+static const char *str_vsyscall;
 
-static const char str_vsyscall_0[] __maybe_unused = "";
-static const char str_vsyscall_1[] __maybe_unused =
+static const char str_vsyscall_0[] = "";
+static const char str_vsyscall_1[] =
 "ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0                  [vsyscall]\n";
-static const char str_vsyscall_2[] __maybe_unused =
+static const char str_vsyscall_2[] =
 "ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]\n";
 
-#ifdef __x86_64__
 static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___)
 {
 	_exit(g_vsyscall);
-- 
2.53.0