perf utils: use sizeof(buf) - 1 in readlink() call

Ensure that we have space for the null byte in buf.

Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170322130624.21881-5-tommi.t.rantala@nokia.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Tommi Rantala 2017-03-22 15:06:22 +02:00 committed by Arnaldo Carvalho de Melo
parent 0e6ba11511
commit b7126ef786

View File

@ -378,7 +378,7 @@ static int write_cmdline(int fd, struct perf_header *h __maybe_unused,
* actual atual path to perf binary
*/
sprintf(proc, "/proc/%d/exe", getpid());
ret = readlink(proc, buf, sizeof(buf));
ret = readlink(proc, buf, sizeof(buf) - 1);
if (ret <= 0)
return -1;