[PATCH v1] perf cap: Add __NR_capget to arch/x86 unistd

From: Ian Rogers
Date: Sat Oct 26 2024 - 01:55:01 EST


As there are duplicated kernel headers in tools/include libc can pick
up the wrong definitions. This was causing the wrong system call for
capget in perf.

Closes: https://lore.kernel.org/lkml/cc7d6bdf-1aeb-4179-9029-4baf50b59342@xxxxxxxxx/
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/arch/x86/include/uapi/asm/unistd_32.h | 3 +++
tools/arch/x86/include/uapi/asm/unistd_64.h | 3 +++
tools/perf/util/cap.c | 10 +++-------
3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/tools/arch/x86/include/uapi/asm/unistd_32.h b/tools/arch/x86/include/uapi/asm/unistd_32.h
index 9de35df1afc3..63182a023e9d 100644
--- a/tools/arch/x86/include/uapi/asm/unistd_32.h
+++ b/tools/arch/x86/include/uapi/asm/unistd_32.h
@@ -11,6 +11,9 @@
#ifndef __NR_getpgid
#define __NR_getpgid 132
#endif
+#ifndef __NR_capget
+#define __NR_capget 184
+#endif
#ifndef __NR_gettid
#define __NR_gettid 224
#endif
diff --git a/tools/arch/x86/include/uapi/asm/unistd_64.h b/tools/arch/x86/include/uapi/asm/unistd_64.h
index d0f2043d7132..77311e8d1b5d 100644
--- a/tools/arch/x86/include/uapi/asm/unistd_64.h
+++ b/tools/arch/x86/include/uapi/asm/unistd_64.h
@@ -11,6 +11,9 @@
#ifndef __NR_getpgid
#define __NR_getpgid 121
#endif
+#ifndef __NR_capget
+#define __NR_capget 125
+#endif
#ifndef __NR_gettid
#define __NR_gettid 186
#endif
diff --git a/tools/perf/util/cap.c b/tools/perf/util/cap.c
index 7574a67651bc..69d9a2bcd40b 100644
--- a/tools/perf/util/cap.c
+++ b/tools/perf/util/cap.c
@@ -7,13 +7,9 @@
#include "debug.h"
#include <errno.h>
#include <string.h>
-#include <unistd.h>
#include <linux/capability.h>
#include <sys/syscall.h>
-
-#ifndef SYS_capget
-#define SYS_capget 90
-#endif
+#include <unistd.h>

#define MAX_LINUX_CAPABILITY_U32S _LINUX_CAPABILITY_U32S_3

@@ -21,9 +17,9 @@ bool perf_cap__capable(int cap, bool *used_root)
{
struct __user_cap_header_struct header = {
.version = _LINUX_CAPABILITY_VERSION_3,
- .pid = getpid(),
+ .pid = 0,
};
- struct __user_cap_data_struct data[MAX_LINUX_CAPABILITY_U32S];
+ struct __user_cap_data_struct data[MAX_LINUX_CAPABILITY_U32S] = {};
__u32 cap_val;

*used_root = false;
--
2.47.0.163.g1226f6d8fa-goog