[PATCH 1/2 v5] perf sched: fix wrong conversion of task state

[PATCH 1/2 v5] perf sched: fix wrong conversion of task state

[Tomoki Sekiyama]

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.

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
Fixes: cdce9d738b91e ("perf sched: Add sched latency profiling")
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: David Ahern <dsahern@gmail.com>
---
 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

[PATCH 2/2 v5] perf sched: adapt TASK_STATE_TO_CHAR_STR to the latest kernel

[Tomoki Sekiyama]

Update TASK_STATE_TO_CHAR_STR macro to one from sched.h in the latest
kernel.

Related kernel commits:
 - commit ad86622b478e ("wait: swap EXIT_ZOMBIE and EXIT_DEAD to hide
   EXIT_TRACE from user-space"):
   'Z' and 'X' are swapped

 - commit 80ed87c8a9ca ("sched/wait: Introduce TASK_NOLOAD and TASK_IDLE"):
   Introduces new state 'N'

 - commit 7dc603c9028e ("sched/fair: Fix PELT integrity for new tasks"):
   Introduces new state 'n'

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
---
Changes from v4:
  Removed 'Fixes:' tag and added related commits in the commit message

 tools/perf/builtin-sched.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index ce9bef6..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"
 
 enum thread_state {
 	THREAD_SLEEPING = 0,
-- 
2.7.4

Re: [PATCH 2/2 v5] perf sched: adapt TASK_STATE_TO_CHAR_STR to the latest kernel

[Masami Hiramatsu]

On Tue,  2 Aug 2016 14:35:29 +0900
Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com> wrote:

> Update TASK_STATE_TO_CHAR_STR macro to one from sched.h in the latest
> kernel.
> 
> Related kernel commits:
>  - commit ad86622b478e ("wait: swap EXIT_ZOMBIE and EXIT_DEAD to hide
>    EXIT_TRACE from user-space"):
>    'Z' and 'X' are swapped
> 
>  - commit 80ed87c8a9ca ("sched/wait: Introduce TASK_NOLOAD and TASK_IDLE"):
>    Introduces new state 'N'
> 
>  - commit 7dc603c9028e ("sched/fair: Fix PELT integrity for new tasks"):
>    Introduces new state 'n'
> 

Ah, here is the newer one :)

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>

Thanks!

> Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: David Ahern <dsahern@gmail.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> ---
> Changes from v4:
>   Removed 'Fixes:' tag and added related commits in the commit message
> 
>  tools/perf/builtin-sched.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
> index ce9bef6..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"
>  
>  enum thread_state {
>  	THREAD_SLEEPING = 0,
> -- 
> 2.7.4
> 


-- 
Masami Hiramatsu <mhiramat@kernel.org>

Re: [PATCH 1/2 v5] perf sched: fix wrong conversion of task state

[Masami Hiramatsu]

On Tue,  2 Aug 2016 14:35:28 +0900
Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com> 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.
> 
> Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
> Fixes: cdce9d738b91e ("perf sched: Add sched latency profiling")
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: David Ahern <dsahern@gmail.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> Acked-by: David Ahern <dsahern@gmail.com>

OK, I also give my ack on this version.

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>

Thanks!

> ---
>  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 <mhiramat@kernel.org>

Re: [PATCH 2/2 v5] perf sched: adapt TASK_STATE_TO_CHAR_STR to the latest kernel

[David Ahern]

On 8/1/16 11:35 PM, Tomoki Sekiyama wrote:
> Update TASK_STATE_TO_CHAR_STR macro to one from sched.h in the latest
> kernel.
>
> Related kernel commits:
>  - commit ad86622b478e ("wait: swap EXIT_ZOMBIE and EXIT_DEAD to hide
>    EXIT_TRACE from user-space"):
>    'Z' and 'X' are swapped
>
>  - commit 80ed87c8a9ca ("sched/wait: Introduce TASK_NOLOAD and TASK_IDLE"):
>    Introduces new state 'N'
>
>  - commit 7dc603c9028e ("sched/fair: Fix PELT integrity for new tasks"):
>    Introduces new state 'n'
>
> Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: David Ahern <dsahern@gmail.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> ---
> Changes from v4:
>   Removed 'Fixes:' tag and added related commits in the commit message

Acked-by: David Ahern <dsahern@gmail.com>