2021-04-29 19:18:25

by Milian Wolff

[permalink] [raw]
Subject: [PATCH] perf buildid-list: Initialize zstd_data

Fixes segmentation fault when trying to obtain buildid list (e.g. via
perf-archive) from a zstd-compressed `perf.data` file:

```
$ perf record -z ls
...
[ perf record: Captured and wrote 0,010 MB perf.data, compressed (original 0,001 MB, ratio is 2,190) ]
$ memcheck perf buildid-list
...
==57268== Invalid read of size 4
==57268== at 0x5260D88: ZSTD_decompressStream (in /usr/lib/libzstd.so.1.4.9)
==57268== by 0x4BB51B: zstd_decompress_stream (zstd.c:100)
==57268== by 0x425C6C: perf_session__process_compressed_event (session.c:73)
==57268== by 0x427450: perf_session__process_user_event (session.c:1631)
==57268== by 0x42A609: reader__process_events (session.c:2207)
==57268== by 0x42A609: __perf_session__process_events (session.c:2264)
==57268== by 0x42A609: perf_session__process_events (session.c:2297)
==57268== by 0x343A62: perf_session__list_build_ids (builtin-buildid-list.c:88)
==57268== by 0x343A62: cmd_buildid_list (builtin-buildid-list.c:120)
==57268== by 0x3C7732: run_builtin (perf.c:313)
==57268== by 0x331157: handle_internal_command (perf.c:365)
==57268== by 0x331157: run_argv (perf.c:409)
==57268== by 0x331157: main (perf.c:539)
==57268== Address 0x7470 is not stack'd, malloc'd or (recently) free'd
```

Signed-off-by: Milian Wolff <[email protected]>
---
tools/perf/builtin-buildid-list.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/tools/perf/builtin-buildid-list.c b/tools/perf/builtin-buildid-list.c
index 87f5b1a4a7fa..833405c27dae 100644
--- a/tools/perf/builtin-buildid-list.c
+++ b/tools/perf/builtin-buildid-list.c
@@ -80,6 +80,9 @@ static int perf_session__list_build_ids(bool force, bool with_hits)
if (!perf_header__has_feat(&session->header, HEADER_BUILD_ID))
with_hits = true;

+ if (zstd_init(&(session->zstd_data), 0) < 0)
+ pr_warning("Decompression initialization failed. Reported data may be incomplete.\n");
+
/*
* in pipe-mode, the only way to get the buildids is to parse
* the record stream. Buildids are stored as RECORD_HEADER_BUILD_ID
--
2.31.1


2021-05-12 15:51:44

by Milian Wolff

[permalink] [raw]
Subject: Re: [PATCH] perf buildid-list: Initialize zstd_data

On Donnerstag, 29. April 2021 20:57:59 CEST Milian Wolff wrote:
> Fixes segmentation fault when trying to obtain buildid list (e.g. via
> perf-archive) from a zstd-compressed `perf.data` file:

Ping, can someone please review and push this upstream? It's such a trivial
fix, I would like to see it fixed upstream.

Thanks

> ```
> $ perf record -z ls
> ...
> [ perf record: Captured and wrote 0,010 MB perf.data, compressed
> (original 0,001 MB, ratio is 2,190) ] $ memcheck perf buildid-list
> ...
> ==57268== Invalid read of size 4
> ==57268== at 0x5260D88: ZSTD_decompressStream (in
> /usr/lib/libzstd.so.1.4.9) ==57268== by 0x4BB51B: zstd_decompress_stream
> (zstd.c:100)
> ==57268== by 0x425C6C: perf_session__process_compressed_event
> (session.c:73) ==57268== by 0x427450: perf_session__process_user_event
> (session.c:1631) ==57268== by 0x42A609: reader__process_events
> (session.c:2207) ==57268== by 0x42A609: __perf_session__process_events
> (session.c:2264) ==57268== by 0x42A609: perf_session__process_events
> (session.c:2297) ==57268== by 0x343A62: perf_session__list_build_ids
> (builtin-buildid-list.c:88) ==57268== by 0x343A62: cmd_buildid_list
> (builtin-buildid-list.c:120) ==57268== by 0x3C7732: run_builtin
> (perf.c:313)
> ==57268== by 0x331157: handle_internal_command (perf.c:365)
> ==57268== by 0x331157: run_argv (perf.c:409)
> ==57268== by 0x331157: main (perf.c:539)
> ==57268== Address 0x7470 is not stack'd, malloc'd or (recently) free'd
> ```
>
> Signed-off-by: Milian Wolff <[email protected]>
> ---
> tools/perf/builtin-buildid-list.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/tools/perf/builtin-buildid-list.c
> b/tools/perf/builtin-buildid-list.c index 87f5b1a4a7fa..833405c27dae 100644
> --- a/tools/perf/builtin-buildid-list.c
> +++ b/tools/perf/builtin-buildid-list.c
> @@ -80,6 +80,9 @@ static int perf_session__list_build_ids(bool force, bool
> with_hits) if (!perf_header__has_feat(&session->header, HEADER_BUILD_ID))
> with_hits = true;
>
> + if (zstd_init(&(session->zstd_data), 0) < 0)
> + pr_warning("Decompression initialization failed. Reported data
may be
> incomplete.\n"); +
> /*
> * in pipe-mode, the only way to get the buildids is to parse
> * the record stream. Buildids are stored as RECORD_HEADER_BUILD_ID


--
Milian Wolff | [email protected] | Senior Software Engineer
KDAB (Deutschland) GmbH, a KDAB Group company
Tel: +49-30-521325470
KDAB - The Qt, C++ and OpenGL Experts


Attachments:
smime.p7s (5.15 kB)

2021-05-12 16:46:05

by Arnaldo Carvalho de Melo

[permalink] [raw]
Subject: Re: [PATCH] perf buildid-list: Initialize zstd_data

Em Wed, May 12, 2021 at 05:14:29PM +0200, Milian Wolff escreveu:
> On Donnerstag, 29. April 2021 20:57:59 CEST Milian Wolff wrote:
> > Fixes segmentation fault when trying to obtain buildid list (e.g. via
> > perf-archive) from a zstd-compressed `perf.data` file:
>
> Ping, can someone please review and push this upstream? It's such a trivial
> fix, I would like to see it fixed upstream.

Fell thru the cracks, processing it now.

- Arnaldo

> Thanks
>
> > ```
> > $ perf record -z ls
> > ...
> > [ perf record: Captured and wrote 0,010 MB perf.data, compressed
> > (original 0,001 MB, ratio is 2,190) ] $ memcheck perf buildid-list
> > ...
> > ==57268== Invalid read of size 4
> > ==57268== at 0x5260D88: ZSTD_decompressStream (in
> > /usr/lib/libzstd.so.1.4.9) ==57268== by 0x4BB51B: zstd_decompress_stream
> > (zstd.c:100)
> > ==57268== by 0x425C6C: perf_session__process_compressed_event
> > (session.c:73) ==57268== by 0x427450: perf_session__process_user_event
> > (session.c:1631) ==57268== by 0x42A609: reader__process_events
> > (session.c:2207) ==57268== by 0x42A609: __perf_session__process_events
> > (session.c:2264) ==57268== by 0x42A609: perf_session__process_events
> > (session.c:2297) ==57268== by 0x343A62: perf_session__list_build_ids
> > (builtin-buildid-list.c:88) ==57268== by 0x343A62: cmd_buildid_list
> > (builtin-buildid-list.c:120) ==57268== by 0x3C7732: run_builtin
> > (perf.c:313)
> > ==57268== by 0x331157: handle_internal_command (perf.c:365)
> > ==57268== by 0x331157: run_argv (perf.c:409)
> > ==57268== by 0x331157: main (perf.c:539)
> > ==57268== Address 0x7470 is not stack'd, malloc'd or (recently) free'd
> > ```
> >
> > Signed-off-by: Milian Wolff <[email protected]>
> > ---
> > tools/perf/builtin-buildid-list.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/tools/perf/builtin-buildid-list.c
> > b/tools/perf/builtin-buildid-list.c index 87f5b1a4a7fa..833405c27dae 100644
> > --- a/tools/perf/builtin-buildid-list.c
> > +++ b/tools/perf/builtin-buildid-list.c
> > @@ -80,6 +80,9 @@ static int perf_session__list_build_ids(bool force, bool
> > with_hits) if (!perf_header__has_feat(&session->header, HEADER_BUILD_ID))
> > with_hits = true;
> >
> > + if (zstd_init(&(session->zstd_data), 0) < 0)
> > + pr_warning("Decompression initialization failed. Reported data
> may be
> > incomplete.\n"); +
> > /*
> > * in pipe-mode, the only way to get the buildids is to parse
> > * the record stream. Buildids are stored as RECORD_HEADER_BUILD_ID
>
>
> --
> Milian Wolff | [email protected] | Senior Software Engineer
> KDAB (Deutschland) GmbH, a KDAB Group company
> Tel: +49-30-521325470
> KDAB - The Qt, C++ and OpenGL Experts



--

- Arnaldo