Commit c10edee2 authored by Pekka Enberg's avatar Pekka Enberg Committed by Ingo Molnar

perf tools: Fix permission checks

The perf_event_open() system call returns EACCES if the user is
not root which results in a very confusing error message:

  $ perf record -A -a -f

    Error: perfcounter syscall returned with -1 (Permission denied)

    Fatal: No CONFIG_PERF_EVENTS=y kernel support configured?

It turns out that's because perf tools are checking only for
EPERM. Fix that up to get a much better error message:

  $ perf record -A -a -f
    Fatal: Permission error - are you root?
Signed-off-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1257696066-4046-1-git-send-email-penberg@cs.helsinki.fi>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent dd77038d
...@@ -426,7 +426,7 @@ static void create_counter(int counter, int cpu, pid_t pid) ...@@ -426,7 +426,7 @@ static void create_counter(int counter, int cpu, pid_t pid)
if (fd[nr_cpu][counter] < 0) { if (fd[nr_cpu][counter] < 0) {
int err = errno; int err = errno;
if (err == EPERM) if (err == EPERM || err == EACCES)
die("Permission error - are you root?\n"); die("Permission error - are you root?\n");
else if (err == ENODEV && profile_cpu != -1) else if (err == ENODEV && profile_cpu != -1)
die("No such device - did you specify an out-of-range profile CPU?\n"); die("No such device - did you specify an out-of-range profile CPU?\n");
......
...@@ -1027,7 +1027,7 @@ static void start_counter(int i, int counter) ...@@ -1027,7 +1027,7 @@ static void start_counter(int i, int counter)
if (fd[i][counter] < 0) { if (fd[i][counter] < 0) {
int err = errno; int err = errno;
if (err == EPERM) if (err == EPERM || err == EACCES)
die("No permission - are you root?\n"); die("No permission - are you root?\n");
/* /*
* If it's cycles then fall back to hrtimer * If it's cycles then fall back to hrtimer
......
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