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From:   Igor Lubashev <ilubashe@akamai.com>
To:     <linux-kernel@vger.kernel.org>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Jiri Olsa <jolsa@redhat.com>,
        Alexey Budankov <alexey.budankov@linux.intel.com>
CC:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        <linux-arm-kernel@lists.infradead.org>,
        James Morris <jmorris@namei.org>,
        Igor Lubashev <ilubashe@akamai.com>
Subject: [PATCH v2 4/4] perf: Use CAP_SYS_ADMIN instead of euid==0 with ftrace
Date:   Tue, 6 Aug 2019 23:35:57 -0400
Message-ID: <eb995d4d73fb58e6a1c1560803beec048cafb4d7.1565146171.git.ilubashe@akamai.com>
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Kernel requires CAP_SYS_ADMIN instead of euid==0 to mount debugfs for ftrace.
Make perf do the same.

Signed-off-by: Igor Lubashev <ilubashe@akamai.com>
---
 tools/perf/builtin-ftrace.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index ae1466aa3b26..d09eac8a6d57 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -13,6 +13,7 @@
 #include <signal.h>
 #include <fcntl.h>
 #include <poll.h>
+#include <linux/capability.h>
 
 #include "debug.h"
 #include <subcmd/parse-options.h>
@@ -21,6 +22,7 @@
 #include "target.h"
 #include "cpumap.h"
 #include "thread_map.h"
+#include "util/cap.h"
 #include "util/config.h"
 
 
@@ -281,7 +283,7 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 		.events = POLLIN,
 	};
 
-	if (geteuid() != 0) {
+	if (!perf_cap__capable(CAP_SYS_ADMIN)) {
 		pr_err("ftrace only works for root!\n");
 		return -1;
 	}
-- 
2.7.4