7 files changed, 71 insertions, 0 deletions

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 7abf05131889..7cda749059a9 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -148,6 +148,8 @@ perf-$(CONFIG_ZLIB) += zlib.o
 perf-$(CONFIG_LZMA) += lzma.o
 perf-$(CONFIG_ZSTD) += zstd.o
 
+perf-$(CONFIG_LIBCAP) += cap.o
+
 perf-y += demangle-java.o
 perf-y += demangle-rust.o
 
diff --git a/tools/perf/util/cap.c b/tools/perf/util/cap.c
new file mode 100644
index 000000000000..c3ba841bbf37
--- /dev/null
+++ b/tools/perf/util/cap.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Capability utilities
+ */
+
+#ifdef HAVE_LIBCAP_SUPPORT
+
+#include "cap.h"
+#include <stdbool.h>
+#include <sys/capability.h>
+
+bool perf_cap__capable(cap_value_t cap)
+{
+        cap_flag_value_t val;
+        cap_t caps = cap_get_proc();
+
+        if (!caps)
+                return false;
+
+        if (cap_get_flag(caps, cap, CAP_EFFECTIVE, &val) != 0)
+                val = CAP_CLEAR;
+
+        if (cap_free(caps) != 0)
+                return false;
+
+        return val == CAP_SET;
+}
+
+#endif  /* HAVE_LIBCAP_SUPPORT */
diff --git a/tools/perf/util/cap.h b/tools/perf/util/cap.h
new file mode 100644
index 000000000000..10af94e473da
--- /dev/null
+++ b/tools/perf/util/cap.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PERF_CAP_H
+#define __PERF_CAP_H
+
+#include <stdbool.h>
+#include <linux/capability.h>
+#include <linux/compiler.h>
+
+#ifdef HAVE_LIBCAP_SUPPORT
+
+#include <sys/capability.h>
+
+bool perf_cap__capable(cap_value_t cap);
+
+#else
+
+#include <unistd.h>
+#include <sys/types.h>
+
+static inline bool perf_cap__capable(int cap __maybe_unused)
+{
+        return geteuid() == 0;
+}
+
+#endif /* HAVE_LIBCAP_SUPPORT */
+
+#endif /* __PERF_CAP_H */
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 70841d115349..0e164e8ae28d 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -851,6 +851,7 @@ void  cpu_map_data__synthesize(struct cpu_map_data *data, struct perf_cpu_map *m
 void event_attr_init(struct perf_event_attr *attr);
 
 int perf_event_paranoid(void);
+bool perf_event_paranoid_check(int max_level);
 
 extern int sysctl_perf_event_max_stack;
 extern int sysctl_perf_event_max_contexts_per_stack;
diff --git a/tools/perf/util/python-ext-sources b/tools/perf/util/python-ext-sources
index 235bd9803390..c6dd478956f1 100644
--- a/tools/perf/util/python-ext-sources
+++ b/tools/perf/util/python-ext-sources
@@ -7,6 +7,7 @@
 
 util/python.c
 ../lib/ctype.c
+util/cap.c
 util/evlist.c
 util/evsel.c
 util/cpumap.c
diff --git a/tools/perf/util/setup.py b/tools/perf/util/setup.py
index d48f9cd58964..aa344a163eaf 100644
--- a/tools/perf/util/setup.py
+++ b/tools/perf/util/setup.py
@@ -59,6 +59,8 @@ ext_sources = list(map(lambda x: '%s/%s' % (src_perf, x) , ext_sources))
 extra_libraries = []
 if '-DHAVE_LIBNUMA_SUPPORT' in cflags:
     extra_libraries = [ 'numa' ]
+if '-DHAVE_LIBCAP_SUPPORT' in cflags:
+    extra_libraries += [ 'cap' ]
 
 perf = Extension('perf',
                   sources = ext_sources,
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 9c3c97697387..6fd130a5d8f2 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -16,10 +16,12 @@
 #include <string.h>
 #include <errno.h>
 #include <limits.h>
+#include <linux/capability.h>
 #include <linux/kernel.h>
 #include <linux/log2.h>
 #include <linux/time64.h>
 #include <unistd.h>
+#include "cap.h"
 #include "strlist.h"
 #include "string2.h"
 
@@ -403,6 +405,13 @@ int perf_event_paranoid(void)
 
         return value;
 }
+
+bool perf_event_paranoid_check(int max_level)
+{
+        return perf_cap__capable(CAP_SYS_ADMIN) ||
+                        perf_event_paranoid() <= max_level;
+}
+
 static int
 fetch_ubuntu_kernel_version(unsigned int *puint)
 {