linux-stable.git/tools/perf/util/map.c, branch v4.14.331

Revert "perf map: Fix dso->nsinfo refcounting"

2021-08-04T10:22:17+00:00

commit 9bac1bd6e6d36459087a728a968e79e37ebcea1a upstream.

This makes 'perf top' abort in some cases, and the right fix will
involve surgery that is too much to do at this stage, so revert for now
and fix it in the next merge window.

This reverts commit 2d6b74baa7147251c30a46c4996e8cc224aa2dc5.

Cc: Riccardo Mancini 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Krister Johansen 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf map: Fix dso->nsinfo refcounting

2021-07-28T09:12:17+00:00

[ Upstream commit 2d6b74baa7147251c30a46c4996e8cc224aa2dc5 ]

ASan reports a memory leak of nsinfo during the execution of

  # perf test "31: Lookup mmap thread"

The leak is caused by a refcounted variable being replaced without
dropping the refcount.

This patch makes sure that the refcnt of nsinfo is decreased whenever a
refcounted variable is replaced with a new value.

Signed-off-by: Riccardo Mancini 
Fixes: bf2e710b3cb8445c ("perf maps: Lookup maps in both intitial mountns and inner mountns.")
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Krister Johansen 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/55223bc8821b34ccb01f92ef1401c02b6a32e61f.1626343282.git.rickyman7@gmail.com
[ Split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf map: Tighten snprintf() string precision to pass gcc check on some 32-bit arches

2021-04-16T09:57:53+00:00

commit 77d02bd00cea9f1a87afe58113fa75b983d6c23a upstream.

Noticed on a debian:experimental mips and mipsel cross build build
environment:

  perfbuilder@ec265a086e9b:~$ mips-linux-gnu-gcc --version | head -1
  mips-linux-gnu-gcc (Debian 10.2.1-3) 10.2.1 20201224
  perfbuilder@ec265a086e9b:~$

    CC       /tmp/build/perf/util/map.o
  util/map.c: In function 'map__new':
  util/map.c:109:5: error: '%s' directive output may be truncated writing between 1 and 2147483645 bytes into a region of size 4096 [-Werror=format-truncation=]
    109 |    "%s/platforms/%s/arch-%s/usr/lib/%s",
        |     ^~
  In file included from /usr/mips-linux-gnu/include/stdio.h:867,
                   from util/symbol.h:11,
                   from util/map.c:2:
  /usr/mips-linux-gnu/include/bits/stdio2.h:67:10: note: '__builtin___snprintf_chk' output 32 or more bytes (assuming 4294967321) into a destination of size 4096
     67 |   return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
        |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     68 |        __bos (__s), __fmt, __va_arg_pack ());
        |        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors

Since we have the lenghts for what lands in that place, use it to give
the compiler more info and make it happy.

Signed-off-by: Arnaldo Carvalho de Melo 
Cc: Anders Roxell 
Signed-off-by: Greg Kroah-Hartman

perf map: Fix off by one in strncpy() size argument

2020-04-02T14:34:38+00:00

commit db2c549407d4a76563c579e4768f7d6d32afefba upstream.

This patch fixes an off-by-one error in strncpy size argument in
tools/perf/util/map.c. The issue is that in:

        strncmp(filename, "/system/lib/", 11)

the passed string literal: "/system/lib/" has 12 bytes (without the NULL
byte) and the passed size argument is 11. As a result, the logic won't
match the ending "/" byte and will pass filepaths that are stored in
other directories e.g. "/system/libmalicious/bin" or just
"/system/libmalicious".

This functionality seems to be present only on Android. I assume the
/system/ directory is only writable by the root user, so I don't think
this bug has much (or any) security impact.

Fixes: eca818369996 ("perf tools: Add automatic remapping of Android libraries")
Signed-off-by: disconnect3d 
Cc: Alexander Shishkin 
Cc: Changbin Du 
Cc: Jiri Olsa 
Cc: John Keeping 
Cc: Mark Rutland 
Cc: Michael Lentine 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Stephane Eranian 
Link: http://lore.kernel.org/lkml/20200309104855.3775-1-dominik.b.czarnota@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf map: Fix overlapped map handling

2019-11-06T11:43:03+00:00

[ Upstream commit ee212d6ea20887c0ef352be8563ca13dbf965906 ]

Whenever an mmap/mmap2 event occurs, the map tree must be updated to add a new
entry. If a new map overlaps a previous map, the overlapped section of the
previous map is effectively unmapped, but the non-overlapping sections are
still valid.

maps__fixup_overlappings() is responsible for creating any new map entries from
the previously overlapped map. It optionally creates a before and an after map.

When creating the after map the existing code failed to adjust the map.pgoff.
This meant the new after map would incorrectly calculate the file offset
for the ip. This results in incorrect symbol name resolution for any ip in the
after region.

Make maps__fixup_overlappings() correctly populate map.pgoff.

Add an assert that new mapping matches old mapping at the beginning of
the after map.

Committer-testing:

Validated correct parsing of libcoreclr.so symbols from .NET Core 3.0 preview9
(which didn't strip symbols).

Preparation:

  ~/dotnet3.0-preview9/dotnet new webapi -o perfSymbol
  cd perfSymbol
  ~/dotnet3.0-preview9/dotnet publish
  perf record ~/dotnet3.0-preview9/dotnet \
      bin/Debug/netcoreapp3.0/publish/perfSymbol.dll
  ^C

Before:

  perf script --show-mmap-events 2>&1 | grep -e MMAP -e unknown |\
     grep libcoreclr.so | head -n 4
        dotnet  1907 373352.698780: PERF_RECORD_MMAP2 1907/1907: \
            [0x7fe615726000(0x768000) @ 0 08:02 5510620 765057155]: \
            r-xp .../3.0.0-preview9-19423-09/libcoreclr.so
        dotnet  1907 373352.701091: PERF_RECORD_MMAP2 1907/1907: \
            [0x7fe615974000(0x1000) @ 0x24e000 08:02 5510620 765057155]: \
            rwxp .../3.0.0-preview9-19423-09/libcoreclr.so
        dotnet  1907 373352.701241: PERF_RECORD_MMAP2 1907/1907: \
            [0x7fe615c42000(0x1000) @ 0x51c000 08:02 5510620 765057155]: \
            rwxp .../3.0.0-preview9-19423-09/libcoreclr.so
        dotnet  1907 373352.705249:     250000 cpu-clock: \
             7fe6159a1f99 [unknown] \
             (.../3.0.0-preview9-19423-09/libcoreclr.so)

After:

  perf script --show-mmap-events 2>&1 | grep -e MMAP -e unknown |\
     grep libcoreclr.so | head -n 4
        dotnet  1907 373352.698780: PERF_RECORD_MMAP2 1907/1907: \
            [0x7fe615726000(0x768000) @ 0 08:02 5510620 765057155]: \
            r-xp .../3.0.0-preview9-19423-09/libcoreclr.so
        dotnet  1907 373352.701091: PERF_RECORD_MMAP2 1907/1907: \
            [0x7fe615974000(0x1000) @ 0x24e000 08:02 5510620 765057155]: \
            rwxp .../3.0.0-preview9-19423-09/libcoreclr.so
        dotnet  1907 373352.701241: PERF_RECORD_MMAP2 1907/1907: \
            [0x7fe615c42000(0x1000) @ 0x51c000 08:02 5510620 765057155]: \
            rwxp .../3.0.0-preview9-19423-09/libcoreclr.so

All the [unknown] symbols were resolved.

Signed-off-by: Steve MacLean 
Tested-by: Brian Robbins 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Davidlohr Bueso 
Cc: Eric Saint-Etienne 
Cc: John Keeping 
Cc: John Salem 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Stephane Eranian 
Cc: Tom McDonald 
Link: http://lore.kernel.org/lkml/BN8PR21MB136270949F22A6A02335C238F7800@BN8PR21MB1362.namprd21.prod.outlook.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart 
Reviewed-by: Philippe Ombredanne 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

perf maps: Lookup maps in both intitial mountns and inner mountns.

2017-07-19T02:14:09+00:00

If a process is in a mountns and has symbols in /tmp/perf-.map,
look first in the namespace using the tgid for the pidns that the
process might be in.  If the map isn't found there, try looking in the
mountns where perf is running, and use the tgid that's appropriate for
perf's pid namespace.  If all else fails, use the original pid.

This allows us to locate a symbol map file in the mount namespace, if it
was generated there.  However, we also try the tool's /tmp in case it's
there instead.

Signed-off-by: Krister Johansen 
Tested-by: Brendan Gregg 
Cc: Alexander Shishkin 
Cc: Peter Zijlstra 
Cc: Thomas-Mich Richter 
Link: http://lkml.kernel.org/r/1499305693-1599-3-git-send-email-kjlx@templeofstupid.com
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Find symbols in different mount namespace

2017-07-19T02:14:09+00:00

Teach perf how to resolve symbols from binaries that are in a different
mount namespace from the tool.  This allows perf to generate meaningful
stack traces even if the binary resides in a different mount namespace
from the tool.

Signed-off-by: Krister Johansen 
Tested-by: Brendan Gregg 
Cc: Alexander Shishkin 
Cc: Peter Zijlstra 
Cc: Thomas-Mich Richter 
Link: http://lkml.kernel.org/r/1499305693-1599-2-git-send-email-kjlx@templeofstupid.com
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Allow user probes on versioned symbols

2017-05-02T21:23:11+00:00

Symbol versioning, as in glibc, results in symbols being defined as:

  @[@]

(Note that "@@" identifies a default symbol, if the symbol name is
repeated.)

perf is currently unable to deal with this, and is unable to create user
probes at such symbols:

  --
  $ nm /lib/powerpc64le-linux-gnu/libpthread.so.0 | grep pthread_create
  0000000000008d30 t __pthread_create_2_1
  0000000000008d30 T pthread_create@@GLIBC_2.17
  $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 pthread_create
  probe-definition(0): pthread_create
  symbol:pthread_create file:(null) line:0 offset:0 return:0 lazy:(null)
  0 arguments
  Open Debuginfo file: /usr/lib/debug/lib/powerpc64le-linux-gnu/libpthread-2.19.so
  Try to find probe point from debuginfo.
  Probe point 'pthread_create' not found.
     Error: Failed to add events. Reason: No such file or directory (Code: -2)
  --

One is not able to specify the fully versioned symbol, either, due to
syntactic conflicts with other uses of "@" by perf:

  --
  $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 pthread_create@@GLIBC_2.17
  probe-definition(0): pthread_create@@GLIBC_2.17
  Semantic error :SRC@SRC is not allowed.
  0 arguments
     Error: Command Parse Error. Reason: Invalid argument (Code: -22)
  --

This patch ignores versioning for default symbols, thus allowing probes to be
created for these symbols:

  --
  $ /usr/bin/sudo ./perf probe -x /lib/powerpc64le-linux-gnu/libpthread.so.0 pthread_create
  Added new event:
     probe_libpthread:pthread_create (on pthread_create in /lib/powerpc64le-linux-gnu/libpthread-2.19.so)

  You can now use it in all perf tools, such as:

           perf record -e probe_libpthread:pthread_create -aR sleep 1

  $ /usr/bin/sudo ./perf record -e probe_libpthread:pthread_create -aR ./test 2
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.052 MB perf.data (2 samples) ]
  $ /usr/bin/sudo ./perf script
               test  2915 [000] 19124.260729: probe_libpthread:pthread_create: (3fff99248d38)
               test  2916 [000] 19124.260962: probe_libpthread:pthread_create: (3fff99248d38)
  $ /usr/bin/sudo ./perf probe --del=probe_libpthread:pthread_create
  Removed event: probe_libpthread:pthread_create
  --

Committer note:

Change the variable storing the result of strlen() to 'int', to fix the build
on debian:experimental-x-mipsel, fedora:24-x-ARC-uClibc, ubuntu:16.04-x-arm,
etc:

  util/symbol.c: In function 'symbol__match_symbol_name':
  util/symbol.c:422:11: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     if (len < versioning - name)
             ^

Signed-off-by: Paul A. Clarke 
Tested-by: Arnaldo Carvalho de Melo 
Acked-by: Masami Hiramatsu 
Cc: David Ahern 
Link: http://lkml.kernel.org/r/c2b18d9c-17f8-9285-4868-f58b6359ccac@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf str{filter,list}: Disentangle headers

2017-04-19T16:01:52+00:00

There are places where we just need a forward declaration, and others
were we need to include strlist.h and/or strfilter.h, reducing the
impact of changes in headers on the build time, do it.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-zab42gbiki88y9k0csorxekb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo