On 7/28/16 10:00 PM, Tomoki Sekiyama wrote:
sched_out_state() converts the prev_state u64 bitmask to a char in
a wrong way, which may cause invalid memory access.
TASK_STATE_TO_CHAR_STR should also be fixed to adapt current
kernel's sched.h.
Masami's point is that this should be 2 separate patches -- as suggested
by the 'also' in the description.
Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama...@hitachi.com>
Cc: Jiri Olsa <jo...@kernel.org>
Cc: David Ahern <dsah...@gmail.com>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: Masami Hiramatsu <mhira...@kernel.org>
---
tools/perf/builtin-sched.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 0dfe8df..5776263 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -70,7 +70,7 @@ struct sched_atom {
struct task_desc *wakee;
};
-#define TASK_STATE_TO_CHAR_STR "RSDTtZXxKWP"
+#define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPNn"
Patch 1 updates this macro to latest kernel version.
enum thread_state {
THREAD_SLEEPING = 0,
@@ -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
Patch 2 fixes access to str by treating prev_state as a bitmask and
adding the Fixes:
Fixes: cdce9d738b91e ("perf sched: Add sched latency profiling")
