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Subject: Re: [V2] trace: Fix passing zero to PTR_ERR()
To:     Wang Qing <wangqing@vivo.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ingo Molnar <mingo@redhat.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>,
        Andrii Nakryiko <andrii@kernel.org>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@chromium.org>, <netdev@vger.kernel.org>,
        <bpf@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <1604730896-3335-1-git-send-email-wangqing@vivo.com>
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On 11/6/20 10:34 PM, Wang Qing wrote:
> There is a bug when passing zero to PTR_ERR() and return.
> Fix smatch err.
> 
> Signed-off-by: Wang Qing <wangqing@vivo.com>

For clarity, the subject probably should be
   bpf: Fix passing zero to PTR_ERR()
to indicate this is a bpf related fix. The tag should
be something like
   [PATCH bpf v2] or [PATCH v2 bpf]
depending on your preference, to indicate this is for bpf tree.

If another version is sent, the above "v2" should change to "v3".

> ---
>   kernel/trace/bpf_trace.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 4517c8b..5113fd4
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -1198,7 +1198,7 @@ static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
>   	*btf = bpf_get_btf_vmlinux();
>   
>   	if (IS_ERR_OR_NULL(*btf))
> -		return PTR_ERR(*btf);
> +		return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
>   
>   	if (ptr->type_id > 0)
>   		*btf_id = ptr->type_id;
>