Commit 459ec28a authored Sep 13, 2009 by Ingo Molnar

perf_counter: Allow mmap if paranoid checks are turned off



Before:

  $ perf sched record -f sleep 1
  Error: failed to mmap with 1 (Operation not permitted)

After:

  $ perf sched record -f sleep 1
  [ perf record: Captured and wrote 0.095 MB perf.data (~4161 samples) ]

Note, this is only allowed if perfcounter_paranoid is set to
the most permissive (non-default) value of -1.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 1fc35b29

kernel/perf_counter.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -2315,7 +2315,8 @@ static int perf_mmap(struct file file, struct vm_area_struct vma)
		lock_limit >>= PAGE_SHIFT;
		locked = vma->vm_mm->locked_vm + extra;

		if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
		if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() &&
		!capable(CAP_IPC_LOCK)) {
		ret = -EPERM;
		goto unlock;
		}