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

Arnaldo Carvalho de Melo
2020-12-28T16:35:17Z

Em Tue, Dec 15, 2020 at 12:55:03PM -0300, Arnaldo Carvalho de Melo escreveu:
> 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.

This one made into v5.11. Processing the tooling bits in the other
patches now, into perf/core.

- 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

--

- Arnaldo