On Mon, 1 Aug 2016 13:30:25 +0900 Tomoki Sekiyama <[email protected]> wrote:
> Currently sched_out_state() converts the prev_state u64 bitmask to a char > using the bitmask as an index, which may cause invalid memory access. > This fixes the issue by using the __ffs() returned value as an index. OK, looks good to me:) Acked-by: Masami Hiramatsu <[email protected]> Thanks! > > Signed-off-by: Tomoki Sekiyama <[email protected]> > Fixes: cdce9d738b91e ("perf sched: Add sched latency profiling") > Cc: Jiri Olsa <[email protected]> > Cc: David Ahern <[email protected]> > Cc: Namhyung Kim <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: Masami Hiramatsu <[email protected]> > --- > Changes from v3: > Added Fixes: > Split the patch into 2 pieces. > > tools/perf/builtin-sched.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c > index 0dfe8df..ce9bef6 100644 > --- a/tools/perf/builtin-sched.c > +++ b/tools/perf/builtin-sched.c > @@ -897,9 +897,10 @@ static int thread_atoms_insert(struct perf_sched *sched, > struct thread *thread) > > static char sched_out_state(u64 prev_state) > { > - const char *str = TASK_STATE_TO_CHAR_STR; > + const char str[] = TASK_STATE_TO_CHAR_STR; > + unsigned int bit = prev_state ? __ffs(prev_state) + 1 : 0; > > - return str[prev_state]; > + return bit < ARRAY_SIZE(str) - 1 ? str[bit] : '?'; > } > > static int > -- > 2.7.4 > -- Masami Hiramatsu <[email protected]>
