@@ -284,10 +284,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
.events = POLLIN,
};
- if (!perf_cap__capable(CAP_SYS_ADMIN)) {
+ if (!(perf_cap__capable(CAP_PERFMON) ||
+ perf_cap__capable(CAP_SYS_ADMIN))) {
pr_err("ftrace only works for %s!\n",
#ifdef HAVE_LIBCAP_SUPPORT
- "users with the SYS_ADMIN capability"
+ "users with the CAP_PERFMON or CAP_SYS_ADMIN capability"
#else
"root"
#endif
@@ -258,7 +258,8 @@ gets schedule to. Per task counters can be created by any user, for
their own tasks.
A 'pid == -1' and 'cpu == x' counter is a per CPU counter that counts
-all events on CPU-x. Per CPU counters need CAP_SYS_ADMIN privilege.
+all events on CPU-x. Per CPU counters need CAP_PERFMON or CAP_SYS_ADMIN
+privilege.
The 'flags' parameter is currently unused and must be zero.
@@ -29,4 +29,8 @@ static inline bool perf_cap__capable(int cap __maybe_unused)
#define CAP_SYSLOG 34
#endif
+#ifndef CAP_PERFMON
+#define CAP_PERFMON 38
+#endif
+
#endif /* __PERF_CAP_H */
@@ -2491,14 +2491,14 @@ int perf_evsel__open_strerror(struct evsel *evsel, struct target *target,
"You may not have permission to collect %sstats.\n\n"
"Consider tweaking /proc/sys/kernel/perf_event_paranoid,\n"
"which controls use of the performance events system by\n"
- "unprivileged users (without CAP_SYS_ADMIN).\n\n"
+ "unprivileged users (without CAP_PERFMON or CAP_SYS_ADMIN).\n\n"
"The current value is %d:\n\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"
- ">= 0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN\n"
- " Disallow raw tracepoint access by users without CAP_SYS_ADMIN\n"
- ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n"
- ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN\n\n"
+ ">= 0: Disallow ftrace function tracepoint by users without CAP_PERFMON or CAP_SYS_ADMIN\n"
+ " Disallow raw tracepoint access by users without CAP_SYS_PERFMON or CAP_SYS_ADMIN\n"
+ ">= 1: Disallow CPU event access by users without CAP_PERFMON or CAP_SYS_ADMIN\n"
+ ">= 2: Disallow kernel profiling by users without CAP_PERFMON or CAP_SYS_ADMIN\n\n"
"To make this setting permanent, edit /etc/sysctl.conf too, e.g.:\n\n"
" kernel.perf_event_paranoid = -1\n" ,
target->system_wide ? "system-wide " : "",
@@ -272,6 +272,7 @@ int perf_event_paranoid(void)
bool perf_event_paranoid_check(int max_level)
{
return perf_cap__capable(CAP_SYS_ADMIN) ||
+ perf_cap__capable(CAP_PERFMON) ||
perf_event_paranoid() <= max_level;
}
Extend error messages to mention CAP_PERFMON capability as an option to substitute CAP_SYS_ADMIN capability for secure system performance monitoring and observability operations. Make perf_event_paranoid_check() and __cmd_ftrace() to be aware of CAP_PERFMON capability. Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> --- tools/perf/builtin-ftrace.c | 5 +++-- tools/perf/design.txt | 3 ++- tools/perf/util/cap.h | 4 ++++ tools/perf/util/evsel.c | 10 +++++----- tools/perf/util/util.c | 1 + 5 files changed, 15 insertions(+), 8 deletions(-)