Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1610042

Re: [PATCH v3 1/3] perf annotate: Fix a bug reading link name from a build-id file

From Arnaldo Carvalho de Melo <acme@kernel.org>
Newsgroups linux.kernel
Subject Re: [PATCH v3 1/3] perf annotate: Fix a bug reading link name from a build-id file
Date 2017-03-27 20:20 +0200
Message-ID <tpHpf-3Jt-15@gated-at.bofh.it> (permalink)
References <tpx6y-4iG-19@gated-at.bofh.it> <tpx6z-4iG-23@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


Em Mon, Mar 27, 2017 at 04:10:36PM +0900, Taeung Song escreveu:
> It is wrong way to read link name from a build-id file.
> Because a build-id file is not symbolic link
> but build-id directory of it is symbolic link, so fix it.

Ok, applied, in the past it was always a symlink, but the following cset
changed that, so I added:

    Fixes: 01412261d994 ("perf buildid-cache: Use path/to/bin/buildid/elf instead of path/to/bin/buildid")

Thanks,

- Arnaldo
 
> For example, if build-id file name gotten from
> dso__build_id_filename() is as below,
> 
>   /root/.debug/.build-id/4f/75c7d197c951659d1c1b8b5fd49bcdf8f3f8b1/elf
> 
> To correctly read link name of build-id,
> use the build-id dir path that is a symbolic link,
> instead of the above build-id file name like below.
> 
>   /root/.debug/.build-id/4f/75c7d197c951659d1c1b8b5fd49bcdf8f3f8b1
> 
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Jiri Olsa <jolsa@redhat.com>
> Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
> ---
>  tools/perf/util/annotate.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> index 3d0263e..6dc9148 100644
> --- a/tools/perf/util/annotate.c
> +++ b/tools/perf/util/annotate.c
> @@ -1307,6 +1307,7 @@ static int dso__disassemble_filename(struct dso *dso, char *filename, size_t fil
>  {
>  	char linkname[PATH_MAX];
>  	char *build_id_filename;
> +	char *build_id_path = NULL;
>  
>  	if (dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS &&
>  	    !dso__is_kcore(dso))
> @@ -1322,8 +1323,14 @@ static int dso__disassemble_filename(struct dso *dso, char *filename, size_t fil
>  		goto fallback;
>  	}
>  
> +	build_id_path = strdup(filename);
> +	if (!build_id_path)
> +		return -1;
> +
> +	dirname(build_id_path);
> +
>  	if (dso__is_kcore(dso) ||
> -	    readlink(filename, linkname, sizeof(linkname)) < 0 ||
> +	    readlink(build_id_path, linkname, sizeof(linkname)) < 0 ||
>  	    strstr(linkname, DSO__NAME_KALLSYMS) ||
>  	    access(filename, R_OK)) {
>  fallback:
> @@ -1335,6 +1342,7 @@ static int dso__disassemble_filename(struct dso *dso, char *filename, size_t fil
>  		__symbol__join_symfs(filename, filename_size, dso->long_name);
>  	}
>  
> +	free(build_id_path);
>  	return 0;
>  }
>  
> -- 
> 2.7.4

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH v3 1/3] perf annotate: Fix a bug reading link name from a build-id file Taeung Song <treeze.taeung@gmail.com> - 2017-03-27 09:20 +0200
  Re: [PATCH v3 1/3] perf annotate: Fix a bug reading link name from a  build-id file Arnaldo Carvalho de Melo <acme@kernel.org> - 2017-03-27 20:20 +0200
    Re: [PATCH v3 1/3] perf annotate: Fix a bug reading link name from a  build-id file Taeung Song <treeze.taeung@gmail.com> - 2017-03-28 14:00 +0200
  [tip:perf/core] perf annotate: Fix a bug following symbolic link of  a build-id file tip-bot for Taeung Song <tipbot@zytor.com> - 2017-03-28 08:10 +0200

csiph-web