Re: [PATCH v6 07/12] samples/bpf/offwaketime_kern: make sched_switch tracepoint args adopt to comm size change

From: Kees Cook
Date: Mon Oct 25 2021 - 17:21:34 EST


On Mon, Oct 25, 2021 at 08:33:10AM +0000, Yafang Shao wrote:
> The sched:sched_switch tracepoint is derived from kernel, we should make
> its args compitable with the kernel.
>
> Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
> Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
> Cc: Arnaldo Carvalho de Melo <arnaldo.melo@xxxxxxxxx>
> Cc: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Petr Mladek <pmladek@xxxxxxxx>
> ---
> samples/bpf/offwaketime_kern.c | 4 ++--

Seems this should be merged with the prior bpf samples patch?

-Kees

> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/samples/bpf/offwaketime_kern.c b/samples/bpf/offwaketime_kern.c
> index 4866afd054da..eb4d94742e6b 100644
> --- a/samples/bpf/offwaketime_kern.c
> +++ b/samples/bpf/offwaketime_kern.c
> @@ -113,11 +113,11 @@ static inline int update_counts(void *ctx, u32 pid, u64 delta)
> /* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */
> struct sched_switch_args {
> unsigned long long pad;
> - char prev_comm[16];
> + char prev_comm[TASK_COMM_LEN];
> int prev_pid;
> int prev_prio;
> long long prev_state;
> - char next_comm[16];
> + char next_comm[TASK_COMM_LEN];
> int next_pid;
> int next_prio;
> };
> --
> 2.17.1
>

--
Kees Cook