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Date:   Mon, 25 Oct 2021 14:21:26 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Yafang Shao <laoar.shao@gmail.com>
Cc:     akpm@linux-foundation.org, rostedt@goodmis.org,
        mathieu.desnoyers@efficios.com, arnaldo.melo@gmail.com,
        pmladek@suse.com, peterz@infradead.org, viro@zeniv.linux.org.uk,
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        dietmar.eggemann@arm.com, mingo@redhat.com, juri.lelli@redhat.com,
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        Andrii Nakryiko <andrii.nakryiko@gmail.com>
Subject: Re: [PATCH v6 07/12] samples/bpf/offwaketime_kern: make sched_switch
 tracepoint args adopt to comm size change
Message-ID: <202110251421.0CD56F8@keescook>
References: <20211025083315.4752-1-laoar.shao@gmail.com>
 <20211025083315.4752-8-laoar.shao@gmail.com>
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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@gmail.com>
> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Al Viro <viro@zeniv.linux.org.uk>
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Petr Mladek <pmladek@suse.com>
> ---
>  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