From: Yonghong Song <yhs@fb.com>
To: Wenbo Zhang <ethercflow@gmail.com>
Cc: "bpf@vger.kernel.org" <bpf@vger.kernel.org>,
"ast@kernel.org" <ast@kernel.org>,
"daniel@iogearbox.net" <daniel@iogearbox.net>,
"andrii.nakryiko@gmail.com" <andrii.nakryiko@gmail.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [PATCH bpf-next v12 1/2] bpf: add new helper get_file_path for mapping a file descriptor to a pathname
Date: Tue, 17 Dec 2019 06:33:12 +0000 [thread overview]
Message-ID: <fecf759e-2941-3920-82d5-45a556f4dd1d@fb.com> (raw)
In-Reply-To: <CABtjQmZcbhcab0a7ksuggg3ZoDwM5s3ucjeA_baPTpAJQvKQLA@mail.gmail.com>
On 12/16/19 10:26 PM, Wenbo Zhang wrote:
>>> + * - a regular full path (include mountable fs eg: /proc, /sys)
>>> + * - a regular full path with "(deleted)" at the end.
>
>> Let us say with " (deleted)" is appended to be consistent with comments
>> in d_path() and is more clear to user what the format will looks like.
>
> Thank you, I'll fix this.
>
>>> + ret = strlen(p);
>>> + memmove(dst, p, ret);
>>> + dst[ret++] = '\0';
>
>> nit: you could do memmove(dst, p, ret + 1)?
>
> I did with `dst[ret++]='\0';` to return value length including
> trailing '\0'. as you mentioned below:
>
>>> + fput(f);
>>> + return ret;
>
>> The description says the return value length including trailing '\0'.
>> The above 'ret' does not include trailing '\0'.
>
> It seems `[ret++]` not very clear to read and '\0' can be done by
> `memmove`. I think I'll refactor to
>
> ```
> ret = strlen(p) + 1;
> memmove(dst, p, ret);
> fput(f);
> return ret;
> ```
>
> Is this better?
Ah, I missed ret++ in dst[ret++]. Indeed the above code is better.
next prev parent reply other threads:[~2019-12-17 6:33 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-19 13:27 [PATCH bpf-next v10 0/2] bpf: adding get_file_path helper Wenbo Zhang
2019-11-19 13:27 ` [PATCH bpf-next v10 1/2] bpf: add new helper get_file_path for mapping a file descriptor to a pathname Wenbo Zhang
2019-11-23 3:18 ` Alexei Starovoitov
2019-11-23 4:43 ` Al Viro
2019-11-23 4:51 ` Al Viro
2019-11-23 5:19 ` Alexei Starovoitov
2019-11-23 5:35 ` Al Viro
2019-11-23 6:04 ` Alexei Starovoitov
2019-12-13 19:51 ` Brendan Gregg
2019-12-05 4:20 ` [PATCH bpf-next v11 0/2] bpf: adding get_file_path helper Wenbo Zhang
2019-12-05 4:20 ` [PATCH bpf-next v11 1/2] bpf: add new helper get_file_path for mapping a file descriptor to a pathname Wenbo Zhang
2019-12-05 7:19 ` Alexei Starovoitov
2019-12-05 9:47 ` Wenbo Zhang
2019-12-15 4:01 ` [PATCH bpf-next v12 0/2] bpf: adding get_file_path helper Wenbo Zhang
2019-12-15 4:01 ` [PATCH bpf-next v12 1/2] bpf: add new helper get_file_path for mapping a file descriptor to a pathname Wenbo Zhang
2019-12-15 16:05 ` Yonghong Song
2019-12-17 6:26 ` Wenbo Zhang
2019-12-17 6:33 ` Yonghong Song [this message]
2019-12-15 16:10 ` Yonghong Song
2019-12-17 6:27 ` Wenbo Zhang
2019-12-16 22:09 ` Brendan Gregg
2019-12-17 4:05 ` Wenbo Zhang
2019-12-17 9:47 ` [PATCH bpf-next v13 0/2] bpf: adding get_fd_path helper Wenbo Zhang
2019-12-17 9:47 ` [PATCH bpf-next v13 1/2] bpf: add new helper get_fd_path for mapping a file descriptor to a pathname Wenbo Zhang
2019-12-17 16:29 ` Yonghong Song
2019-12-17 19:39 ` Daniel Borkmann
2019-12-18 0:11 ` Wenbo Zhang
2019-12-18 0:06 ` Wenbo Zhang
2019-12-18 0:56 ` [PATCH bpf-next v14 0/2] bpf: adding get_fd_path helper Wenbo Zhang
2019-12-18 0:56 ` [PATCH bpf-next v14 1/2] bpf: add new helper get_fd_path for mapping a file descriptor to a pathname Wenbo Zhang
2019-12-18 3:27 ` Yonghong Song
2019-12-19 16:14 ` Daniel Borkmann
2019-12-20 3:35 ` Wenbo Zhang
2020-01-16 8:59 ` Jiri Olsa
2020-02-10 4:43 ` Brendan Gregg
2020-02-11 0:01 ` Daniel Borkmann
2020-02-12 15:21 ` Jiri Olsa
2020-06-01 14:17 ` Wenbo Zhang
2020-06-01 16:38 ` Alexei Starovoitov
2020-06-02 3:04 ` Wenbo Zhang
2020-06-02 8:14 ` Jiri Olsa
2019-12-18 0:56 ` [PATCH bpf-next v14 2/2] selftests/bpf: test for bpf_get_fd_path() from tracepoint Wenbo Zhang
2019-12-18 3:27 ` Yonghong Song
2019-12-17 9:47 ` [PATCH bpf-next v13 " Wenbo Zhang
2019-12-17 16:32 ` Yonghong Song
2019-12-15 4:01 ` [PATCH bpf-next v12 2/2] selftests/bpf: test for bpf_get_file_path() " Wenbo Zhang
2019-12-15 16:24 ` Yonghong Song
2019-12-17 4:01 ` Wenbo Zhang
2019-12-17 4:13 ` Yonghong Song
2019-12-17 9:44 ` Wenbo Zhang
2019-12-05 4:20 ` [PATCH bpf-next v11 " Wenbo Zhang
2019-11-19 13:27 ` [PATCH bpf-next v10 " Wenbo Zhang
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