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From: Alexey Budankov <alexey.budankov@linux.intel.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>, Andi Kleen <ak@linux.intel.com>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: [PATCH v1] perf: extend message to mention CAP_SYS_PTRACE and perf security doc link
Date: Wed, 5 Aug 2020 10:31:20 +0300	[thread overview]
Message-ID: <6f8a7425-6e7d-19aa-1605-e59836b9e2a6@linux.intel.com> (raw)


Adjust limited access message to mention CAP_SYS_PTRACE capability
for processes of unprivileged users. Add link to perf security
document in the end of the section about capabilities.
The change has been inspired by this discussion:
https://lore.kernel.org/lkml/20200722113007.GI77866@kernel.org/

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 tools/perf/util/evsel.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 9aa51a65593d..e241ee773ccb 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2500,8 +2500,10 @@ int evsel__open_strerror(struct evsel *evsel, struct target *target,
 
 		return scnprintf(msg + printed, size - printed,
 		 "Consider adjusting /proc/sys/kernel/perf_event_paranoid setting to open\n"
-		 "access to performance monitoring and observability operations for users\n"
-		 "without CAP_PERFMON or CAP_SYS_ADMIN Linux capability.\n"
+		 "access to performance monitoring and observability operations for processes\n"
+		 "without CAP_PERFMON, CAP_SYS_PTRACE or CAP_SYS_ADMIN Linux capability.\n"
+		 "More information can be found at 'Perf events and tool security' document:\n"
+		 "https://www.kernel.org/doc/html/latest/admin-guide/perf-security.html\n"
 		 "perf_event_paranoid setting is %d:\n"
 		 "  -1: Allow use of (almost) all events by all users\n"
 		 "      Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK\n"
-- 
2.24.1

             reply	other threads:[~2020-08-05  7:31 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-05  7:31 Alexey Budankov [this message]
2020-08-06 12:14 ` [PATCH v1] perf: extend message to mention CAP_SYS_PTRACE and perf security doc link Arnaldo Carvalho de Melo

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