From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andriin@fb.com>,
dwarves@vger.kernel.org, Networking <netdev@vger.kernel.org>,
bpf <bpf@vger.kernel.org>, Yonghong Song <yhs@fb.com>,
Hao Luo <haoluo@google.com>, Martin KaFai Lau <kafai@fb.com>,
Song Liu <songliubraving@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@chromium.org>,
Joe Lawrence <joe.lawrence@redhat.com>,
Mark Wielaard <mjw@redhat.com>
Subject: Re: [PATCH 1/3] elf_symtab: Add support for SHN_XINDEX index to elf_section_by_name
Date: Thu, 21 Jan 2021 15:10:25 -0800 [thread overview]
Message-ID: <CAEf4BzY5CSNjoe19V4GAbFM1N4o4jM38G6yahAhr5bAaDVcYxA@mail.gmail.com> (raw)
In-Reply-To: <20210121202203.9346-2-jolsa@kernel.org>
On Thu, Jan 21, 2021 at 12:24 PM Jiri Olsa <jolsa@kernel.org> wrote:
>
> In case the elf's header e_shstrndx contains SHN_XINDEX,
> we need to call elf_getshdrstrndx to get the proper
> string table index.
>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
> dutil.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/dutil.c b/dutil.c
> index 7b667647420f..9e0fdca3ae04 100644
> --- a/dutil.c
> +++ b/dutil.c
> @@ -179,13 +179,17 @@ Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
> {
> Elf_Scn *sec = NULL;
> size_t cnt = 1;
> + size_t str_idx;
> +
> + if (elf_getshdrstrndx(elf, &str_idx))
> + return NULL;
>
> while ((sec = elf_nextscn(elf, sec)) != NULL) {
> char *str;
>
> gelf_getshdr(sec, shp);
> - str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
> - if (!strcmp(name, str)) {
> + str = elf_strptr(elf, str_idx, shp->sh_name);
> + if (str && !strcmp(name, str)) {
if (!str) would be an error? should we bail out here?
> if (index)
> *index = cnt;
> break;
> --
> 2.27.0
>
next prev parent reply other threads:[~2021-01-21 23:11 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-21 20:22 [PATCHv2 0/3] dwarves,libbpf: Add support to use optional extended section index table Jiri Olsa
2021-01-21 20:22 ` [PATCH 1/3] elf_symtab: Add support for SHN_XINDEX index to elf_section_by_name Jiri Olsa
2021-01-21 23:10 ` Andrii Nakryiko [this message]
2021-01-21 23:34 ` Jiri Olsa
2021-01-21 20:22 ` [PATCH 2/3] bpf_encoder: Translate SHN_XINDEX in symbol's st_shndx values Jiri Olsa
2021-01-21 23:32 ` Andrii Nakryiko
2021-01-22 9:32 ` Jiri Olsa
2021-01-22 20:46 ` Jiri Olsa
2021-01-22 22:55 ` Andrii Nakryiko
2021-01-23 18:51 ` Jiri Olsa
2021-01-23 20:07 ` Andrii Nakryiko
2021-01-23 20:21 ` Mark Wielaard
2021-01-23 20:08 ` Mark Wielaard
2021-01-23 20:15 ` Jiri Olsa
2021-01-23 21:23 ` Jiri Olsa
2021-01-24 6:08 ` Andrii Nakryiko
2021-01-21 20:22 ` [PATCH bpf-next 3/3] libbpf: Use string table index from index table if needed Jiri Olsa
2021-01-21 23:46 ` Andrii Nakryiko
-- strict thread matches above, loose matches on Subject: below --
2021-01-19 22:12 [PATCH 0/3] dwarves,libbpf: Add support to use optional extended section index table Jiri Olsa
2021-01-19 22:12 ` [PATCH 1/3] elf_symtab: Add support for SHN_XINDEX index to elf_section_by_name Jiri Olsa
2021-01-20 1:23 ` Andrii Nakryiko
2021-01-20 12:20 ` Jiri Olsa
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAEf4BzY5CSNjoe19V4GAbFM1N4o4jM38G6yahAhr5bAaDVcYxA@mail.gmail.com \
--to=andrii.nakryiko@gmail.com \
--cc=acme@kernel.org \
--cc=andriin@fb.com \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=dwarves@vger.kernel.org \
--cc=haoluo@google.com \
--cc=joe.lawrence@redhat.com \
--cc=john.fastabend@gmail.com \
--cc=jolsa@kernel.org \
--cc=kafai@fb.com \
--cc=kpsingh@chromium.org \
--cc=mjw@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=songliubraving@fb.com \
--cc=yhs@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).