From a5384c426744ebe41dafc6e5fa3acecc05e43462 Mon Sep 17 00:00:00 2001
From: Ian Rogers <irogers@google.com>
Date: Fri, 25 Oct 2024 22:54:48 -0700
Subject: [PATCH] perf cap: Add __NR_capget to arch/x86 unistd

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.

Reported-by: Adrian Hunter <adrian.hunter@intel.com>
Fixes: e25ebda78e230283 ("perf cap: Tidy up and improve capability testing")
Closes: https://lore.kernel.org/lkml/cc7d6bdf-1aeb-4179-9029-4baf50b59342@intel.com/
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241026055448.312247-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 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;