Re: [PATCH 06/15] perf tools: Add support to read build id from compressed elf

Arnaldo Carvalho de Melo
2020-12-15T15:56:06Z

Em Mon, Dec 14, 2020 at 11:54:48AM +0100, Jiri Olsa escreveu:
> Adding support to decompress file before reading build id.
>
> Adding filename__read_build_id and change its current
> versions to read_build_id.
>
> Shutting down stderr output of perf list in the shell test:
> 82: Check open filename arg using perf trace + vfs_getname : Ok

Tentatively cherry picking this one.

- Arnaldo

> because with decompression code in the place we the
> filename__read_build_id function is more verbose in case
> of error and the test did not account for that.
>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
> .../tests/shell/trace+probe_vfs_getname.sh | 2 +-
> tools/perf/util/symbol-elf.c | 37 ++++++++++++++++++-
> 2 files changed, 36 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/tests/shell/trace+probe_vfs_getname.sh b/tools/perf/tests/shell/trace+probe_vfs_getname.sh
> index 11cc2af13f2b..3d31c1d560d6 100755
> --- a/tools/perf/tests/shell/trace+probe_vfs_getname.sh
> +++ b/tools/perf/tests/shell/trace+probe_vfs_getname.sh
> @@ -20,7 +20,7 @@ skip_if_no_perf_trace || exit 2
> file=$(mktemp /tmp/temporary_file.XXXXX)
>
> trace_open_vfs_getname() {
> - evts=$(echo $(perf list syscalls:sys_enter_open* 2>&1 | egrep 'open(at)? ' | sed -r 's/.*sys_enter_([a-z]+) +\[.*$/\1/') | sed 's/ /,/')
> + evts=$(echo $(perf list syscalls:sys_enter_open* 2>/dev/null | egrep 'open(at)? ' | sed -r 's/.*sys_enter_([a-z]+) +\[.*$/\1/') | sed 's/ /,/')
> perf trace -e $evts touch $file 2>&1 | \
> egrep " +[0-9]+\.[0-9]+ +\( +[0-9]+\.[0-9]+ ms\): +touch\/[0-9]+ open(at)?\((dfd: +CWD, +)?filename: +${file}, +flags: CREAT\|NOCTTY\|NONBLOCK\|WRONLY, +mode: +IRUGO\|IWUGO\) += +[0-9]+$"
> }
> diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
> index 44dd86a4f25f..f3577f7d72fe 100644
> --- a/tools/perf/util/symbol-elf.c
> +++ b/tools/perf/util/symbol-elf.c
> @@ -534,7 +534,7 @@ static int elf_read_build_id(Elf *elf, void *bf, size_t size)
>
> #ifdef HAVE_LIBBFD_BUILDID_SUPPORT
>
> -int filename__read_build_id(const char *filename, struct build_id *bid)
> +static int read_build_id(const char *filename, struct build_id *bid)
> {
> size_t size = sizeof(bid->data);
> int err = -1;
> @@ -563,7 +563,7 @@ int filename__read_build_id(const char *filename, struct build_id *bid)
>
> #else // HAVE_LIBBFD_BUILDID_SUPPORT
>
> -int filename__read_build_id(const char *filename, struct build_id *bid)
> +static int read_build_id(const char *filename, struct build_id *bid)
> {
> size_t size = sizeof(bid->data);
> int fd, err = -1;
> @@ -595,6 +595,39 @@ int filename__read_build_id(const char *filename, struct build_id *bid)
>
> #endif // HAVE_LIBBFD_BUILDID_SUPPORT
>
> +int filename__read_build_id(const char *filename, struct build_id *bid)
> +{
> + struct kmod_path m = { .name = NULL, };
> + char path[PATH_MAX];
> + int err;
> +
> + if (!filename)
> + return -EFAULT;
> +
> + err = kmod_path__parse(&m, filename);
> + if (err)
> + return -1;
> +
> + if (m.comp) {
> + int error = 0, fd;
> +
> + fd = filename__decompress(filename, path, sizeof(path), m.comp, &error);
> + if (fd < 0) {
> + pr_debug("Failed to decompress (error %d) %s\n",
> + error, filename);
> + return -1;
> + }
> + close(fd);
> + filename = path;
> + }
> +
> + err = read_build_id(filename, bid);
> +
> + if (m.comp)
> + unlink(filename);
> + return err;
> +}
> +
> int sysfs__read_build_id(const char *filename, struct build_id *bid)
> {
> size_t size = sizeof(bid->data);
> --
> 2.26.2
>

--

- Arnaldo