perf tools: Fixup exit path when not able to open events
We have to deal with the TUI mode in perf top, so that we don't end up
with a garbled screen when, say, a non root user on a machine with a
paranoid setting (the default) tries to use 'perf top'.
Introduce a ui__warning_paranoid() routine shared by top and record that
tells the user the valid values for /proc/sys/kernel/perf_event_paranoid.
Cc: David Ahern <daahern@cisco.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 6febcc1..623695e 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -275,11 +275,10 @@
!no_inherit) < 0) {
int err = errno;
- if (err == EPERM || err == EACCES)
- die("Permission error - are you root?\n"
- "\t Consider tweaking"
- " /proc/sys/kernel/perf_event_paranoid.\n");
- else if (err == ENODEV && cpu_list) {
+ if (err == EPERM || err == EACCES) {
+ ui__warning_paranoid();
+ exit(EXIT_FAILURE);
+ } else if (err == ENODEV && cpu_list) {
die("No such device - did you specify"
" an out-of-range profile CPU?\n");
} else if (err == EINVAL && sample_id_all_avail) {
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 676b4fb..935fc4f 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -850,10 +850,10 @@
top.evlist->threads, group, inherit) < 0) {
int err = errno;
- if (err == EPERM || err == EACCES)
- die("Permission error - are you root?\n"
- "\t Consider tweaking"
- " /proc/sys/kernel/perf_event_paranoid.\n");
+ if (err == EPERM || err == EACCES) {
+ ui__warning_paranoid();
+ goto out_err;
+ }
/*
* If it's cycles then fall back to hrtimer
* based cpu-clock-tick sw counter, which
@@ -861,25 +861,35 @@
*/
if (attr->type == PERF_TYPE_HARDWARE &&
attr->config == PERF_COUNT_HW_CPU_CYCLES) {
-
if (verbose)
- warning(" ... trying to fall back to cpu-clock-ticks\n");
+ ui__warning("Cycles event not supported,\n"
+ "trying to fall back to cpu-clock-ticks\n");
attr->type = PERF_TYPE_SOFTWARE;
attr->config = PERF_COUNT_SW_CPU_CLOCK;
goto try_again;
}
- printf("\n");
- error("sys_perf_event_open() syscall returned with %d "
- "(%s). /bin/dmesg may provide additional information.\n",
- err, strerror(err));
- die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
- exit(-1);
+
+ ui__warning("The sys_perf_event_open() syscall "
+ "returned with %d (%s). /bin/dmesg "
+ "may provide additional information.\n"
+ "No CONFIG_PERF_EVENTS=y kernel support "
+ "configured?\n", err, strerror(err));
+ goto out_err;
}
}
- if (perf_evlist__mmap(evlist, mmap_pages, false) < 0)
- die("failed to mmap with %d (%s)\n", errno, strerror(errno));
+ if (perf_evlist__mmap(evlist, mmap_pages, false) < 0) {
+ ui__warning("Failed to mmap with %d (%s)\n",
+ errno, strerror(errno));
+ goto out_err;
+ }
+
+ return;
+
+out_err:
+ exit_browser(0);
+ exit(0);
}
static int __cmd_top(void)
diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index d4536a9..155749d 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -57,6 +57,16 @@
}
#endif
+void ui__warning_paranoid(void)
+{
+ ui__warning("Permission error - are you root?\n"
+ "Consider tweaking /proc/sys/kernel/perf_event_paranoid:\n"
+ " -1 - Not paranoid at all\n"
+ " 0 - Disallow raw tracepoint access for unpriv\n"
+ " 1 - Disallow cpu events for unpriv\n"
+ " 2 - Disallow kernel profiling for unpriv\n");
+}
+
void trace_event(union perf_event *event)
{
unsigned char *raw_event = (void *)event;
diff --git a/tools/perf/util/debug.h b/tools/perf/util/debug.h
index 93516cf4..fd53db4 100644
--- a/tools/perf/util/debug.h
+++ b/tools/perf/util/debug.h
@@ -36,5 +36,6 @@
#endif
void ui__warning(const char *format, ...) __attribute__((format(printf, 1, 2)));
+void ui__warning_paranoid(void);
#endif /* __PERF_DEBUG_H */
