11 files changed, 97 insertions, 12 deletions

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 3308b22a1660..2240974b7745 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -376,6 +376,7 @@ LIB_OBJS += $(OUTPUT)util/record.o
 LIB_OBJS += $(OUTPUT)util/srcline.o
 LIB_OBJS += $(OUTPUT)util/data.o
 LIB_OBJS += $(OUTPUT)util/tsc.o
+LIB_OBJS += $(OUTPUT)util/cloexec.o
 
 LIB_OBJS += $(OUTPUT)ui/setup.o
 LIB_OBJS += $(OUTPUT)ui/helpline.o
diff --git a/tools/perf/bench/mem-memcpy.c b/tools/perf/bench/mem-memcpy.c
index e622c3e96efc..2465141b554b 100644
--- a/tools/perf/bench/mem-memcpy.c
+++ b/tools/perf/bench/mem-memcpy.c
@@ -10,6 +10,7 @@
 #include "../util/util.h"
 #include "../util/parse-options.h"
 #include "../util/header.h"
+#include "../util/cloexec.h"
 #include "bench.h"
 #include "mem-memcpy-arch.h"
 
@@ -83,7 +84,8 @@ static struct perf_event_attr cycle_attr = {
 
 static void init_cycle(void)
 {
-        cycle_fd = sys_perf_event_open(&cycle_attr, getpid(), -1, -1, 0);
+        cycle_fd = sys_perf_event_open(&cycle_attr, getpid(), -1, -1,
+                                       perf_event_open_cloexec_flag());
 
         if (cycle_fd < 0 && errno == ENOSYS)
                 die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
diff --git a/tools/perf/bench/mem-memset.c b/tools/perf/bench/mem-memset.c
index 2a65468619f0..75fc3e65fb2a 100644
--- a/tools/perf/bench/mem-memset.c
+++ b/tools/perf/bench/mem-memset.c
@@ -10,6 +10,7 @@
 #include "../util/util.h"
 #include "../util/parse-options.h"
 #include "../util/header.h"
+#include "../util/cloexec.h"
 #include "bench.h"
 #include "mem-memset-arch.h"
 
@@ -83,7 +84,8 @@ static struct perf_event_attr cycle_attr = {
 
 static void init_cycle(void)
 {
-        cycle_fd = sys_perf_event_open(&cycle_attr, getpid(), -1, -1, 0);
+        cycle_fd = sys_perf_event_open(&cycle_attr, getpid(), -1, -1,
+                                       perf_event_open_cloexec_flag());
 
         if (cycle_fd < 0 && errno == ENOSYS)
                 die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index b7f555add0c8..f83c08c0dd87 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -10,6 +10,7 @@
 #include "util/header.h"
 #include "util/session.h"
 #include "util/tool.h"
+#include "util/cloexec.h"
 
 #include "util/parse-options.h"
 #include "util/trace-event.h"
@@ -434,7 +435,8 @@ static int self_open_counters(void)
         attr.type = PERF_TYPE_SOFTWARE;
         attr.config = PERF_COUNT_SW_TASK_CLOCK;
 
-        fd = sys_perf_event_open(&attr, 0, -1, -1, 0);
+        fd = sys_perf_event_open(&attr, 0, -1, -1,
+                                 perf_event_open_cloexec_flag());
 
         if (fd < 0)
                 pr_err("Error: sys_perf_event_open() syscall returned "
diff --git a/tools/perf/tests/bp_signal.c b/tools/perf/tests/bp_signal.c
index aba095489193..a02b035fd5aa 100644
--- a/tools/perf/tests/bp_signal.c
+++ b/tools/perf/tests/bp_signal.c
@@ -25,6 +25,7 @@
 #include "tests.h"
 #include "debug.h"
 #include "perf.h"
+#include "cloexec.h"
 
 static int fd1;
 static int fd2;
@@ -78,7 +79,8 @@ static int bp_event(void *fn, int setup_signal)
         pe.exclude_kernel = 1;
         pe.exclude_hv = 1;
 
-        fd = sys_perf_event_open(&pe, 0, -1, -1, 0);
+        fd = sys_perf_event_open(&pe, 0, -1, -1,
+                                 perf_event_open_cloexec_flag());
         if (fd < 0) {
                 pr_debug("failed opening event %llx\n", pe.config);
                 return TEST_FAIL;
diff --git a/tools/perf/tests/bp_signal_overflow.c b/tools/perf/tests/bp_signal_overflow.c
index 44ac82179708..e76537724491 100644
--- a/tools/perf/tests/bp_signal_overflow.c
+++ b/tools/perf/tests/bp_signal_overflow.c
@@ -24,6 +24,7 @@
 #include "tests.h"
 #include "debug.h"
 #include "perf.h"
+#include "cloexec.h"
 
 static int overflows;
 
@@ -91,7 +92,8 @@ int test__bp_signal_overflow(void)
         pe.exclude_kernel = 1;
         pe.exclude_hv = 1;
 
-        fd = sys_perf_event_open(&pe, 0, -1, -1, 0);
+        fd = sys_perf_event_open(&pe, 0, -1, -1,
+                                 perf_event_open_cloexec_flag());
         if (fd < 0) {
                 pr_debug("failed opening event %llx\n", pe.config);
                 return TEST_FAIL;
diff --git a/tools/perf/tests/rdpmc.c b/tools/perf/tests/rdpmc.c
index e59143fd9e71..c04d1f268576 100644
--- a/tools/perf/tests/rdpmc.c
+++ b/tools/perf/tests/rdpmc.c
@@ -6,6 +6,7 @@
 #include "perf.h"
 #include "debug.h"
 #include "tests.h"
+#include "cloexec.h"
 
 #if defined(__x86_64__) || defined(__i386__)
 
@@ -104,7 +105,8 @@ static int __test__rdpmc(void)
         sa.sa_sigaction = segfault_handler;
         sigaction(SIGSEGV, &sa, NULL);
 
-        fd = sys_perf_event_open(&attr, 0, -1, -1, 0);
+        fd = sys_perf_event_open(&attr, 0, -1, -1,
+                                 perf_event_open_cloexec_flag());
         if (fd < 0) {
                 pr_err("Error: sys_perf_event_open() syscall returned "
                        "with %d (%s)\n", fd, strerror(errno));
diff --git a/tools/perf/util/cloexec.c b/tools/perf/util/cloexec.c
new file mode 100644
index 000000000000..c5d05ec17220
--- /dev/null
+++ b/tools/perf/util/cloexec.c
@@ -0,0 +1,57 @@
+#include "util.h"
+#include "../perf.h"
+#include "cloexec.h"
+#include "asm/bug.h"
+
+static unsigned long flag = PERF_FLAG_FD_CLOEXEC;
+
+static int perf_flag_probe(void)
+{
+        /* use 'safest' configuration as used in perf_evsel__fallback() */
+        struct perf_event_attr attr = {
+                .type = PERF_COUNT_SW_CPU_CLOCK,
+                .config = PERF_COUNT_SW_CPU_CLOCK,
+        };
+        int fd;
+        int err;
+
+        /* check cloexec flag */
+        fd = sys_perf_event_open(&attr, 0, -1, -1,
+                                 PERF_FLAG_FD_CLOEXEC);
+        err = errno;
+
+        if (fd >= 0) {
+                close(fd);
+                return 1;
+        }
+
+        WARN_ONCE(err != EINVAL,
+                  "perf_event_open(..., PERF_FLAG_FD_CLOEXEC) failed with unexpected error %d (%s)\n",
+                  err, strerror(err));
+
+        /* not supported, confirm error related to PERF_FLAG_FD_CLOEXEC */
+        fd = sys_perf_event_open(&attr, 0, -1, -1, 0);
+        err = errno;
+
+        if (WARN_ONCE(fd < 0,
+                      "perf_event_open(..., 0) failed unexpectedly with error %d (%s)\n",
+                      err, strerror(err)))
+                return -1;
+
+        close(fd);
+
+        return 0;
+}
+
+unsigned long perf_event_open_cloexec_flag(void)
+{
+        static bool probed;
+
+        if (!probed) {
+                if (perf_flag_probe() <= 0)
+                        flag = 0;
+                probed = true;
+        }
+
+        return flag;
+}
diff --git a/tools/perf/util/cloexec.h b/tools/perf/util/cloexec.h
new file mode 100644
index 000000000000..94a5a7d829d5
--- /dev/null
+++ b/tools/perf/util/cloexec.h
@@ -0,0 +1,6 @@
+#ifndef __PERF_CLOEXEC_H
+#define __PERF_CLOEXEC_H
+
+unsigned long perf_event_open_cloexec_flag(void);
+
+#endif /* __PERF_CLOEXEC_H */
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 90f58cdd0fb0..21a373ebea22 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -29,6 +29,7 @@ static struct {
         bool sample_id_all;
         bool exclude_guest;
         bool mmap2;
+        bool cloexec;
 } perf_missing_features;
 
 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
@@ -994,7 +995,7 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
                               struct thread_map *threads)
 {
         int cpu, thread;
-        unsigned long flags = 0;
+        unsigned long flags = PERF_FLAG_FD_CLOEXEC;
         int pid = -1, err;
         enum { NO_CHANGE, SET_TO_MAX, INCREASED_MAX } set_rlimit = NO_CHANGE;
 
@@ -1003,11 +1004,13 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
                 return -ENOMEM;
 
         if (evsel->cgrp) {
-                flags = PERF_FLAG_PID_CGROUP;
+                flags |= PERF_FLAG_PID_CGROUP;
                 pid = evsel->cgrp->fd;
         }
 
 fallback_missing_features:
+        if (perf_missing_features.cloexec)
+                flags &= ~(unsigned long)PERF_FLAG_FD_CLOEXEC;
         if (perf_missing_features.mmap2)
                 evsel->attr.mmap2 = 0;
         if (perf_missing_features.exclude_guest)
@@ -1076,7 +1079,10 @@ try_fallback:
         if (err != -EINVAL || cpu > 0 || thread > 0)
                 goto out_close;
 
-        if (!perf_missing_features.mmap2 && evsel->attr.mmap2) {
+        if (!perf_missing_features.cloexec && (flags & PERF_FLAG_FD_CLOEXEC)) {
+                perf_missing_features.cloexec = true;
+                goto fallback_missing_features;
+        } else if (!perf_missing_features.mmap2 && evsel->attr.mmap2) {
                 perf_missing_features.mmap2 = true;
                 goto fallback_missing_features;
         } else if (!perf_missing_features.exclude_guest &&
diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c
index 165723152cfb..fe8079edbdc1 100644
--- a/tools/perf/util/record.c
+++ b/tools/perf/util/record.c
@@ -4,6 +4,7 @@
 #include "parse-events.h"
 #include <api/fs/fs.h>
 #include "util.h"
+#include "cloexec.h"
 
 typedef void (*setup_probe_fn_t)(struct perf_evsel *evsel);
 
@@ -11,6 +12,7 @@ static int perf_do_probe_api(setup_probe_fn_t fn, int cpu, const char *str)
 {
         struct perf_evlist *evlist;
         struct perf_evsel *evsel;
+        unsigned long flags = perf_event_open_cloexec_flag();
         int err = -EAGAIN, fd;
 
         evlist = perf_evlist__new();
@@ -22,14 +24,14 @@ static int perf_do_probe_api(setup_probe_fn_t fn, int cpu, const char *str)
 
         evsel = perf_evlist__first(evlist);
 
-        fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
+        fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, flags);
         if (fd < 0)
                 goto out_delete;
         close(fd);
 
         fn(evsel);
 
-        fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
+        fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, flags);
         if (fd < 0) {
                 if (errno == EINVAL)
                         err = -EINVAL;
@@ -219,7 +221,8 @@ bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str)
                 cpu = evlist->cpus->map[0];
         }
 
-        fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
+        fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1,
+                                 perf_event_open_cloexec_flag());
         if (fd >= 0) {
                 close(fd);
                 ret = true;