kernel/tools/perf/util/build-id.h, branch linux-4.17.y

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

2017-11-02T10:10:55Z

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 header: Add struct feat_fd for write

2017-07-19T02:14:31Z

Introduce struct feat_fd. This patch uses it as a wrapper around fd in write_* functions for feature headers. Next patches will extend its functionality to other feature header functions. This patch does not change behavior. Signed-off-by: David Carrillo-Cisneros Acked-by: David Ahern Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andi Kleen Cc: He Kuang Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Paul Turner Cc: Peter Zijlstra Cc: Simon Que Cc: Stephane Eranian Cc: Wang Nan Link: http://lkml.kernel.org/r/20170718042549.145161-7-davidcc@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf buildid-cache: Cache debuginfo

2017-07-19T02:14:11Z

If a stripped binary is placed in the cache, the user is in a situation where there's a cached elf file present, but it doesn't have any symtab to use for name resolution. Grab the debuginfo for binaries that don't end in .ko. This yields a better chance of resolving symbols from older traces. Signed-off-by: Krister Johansen Cc: Alexander Shishkin Cc: Brendan Gregg Cc: Peter Zijlstra Cc: Thomas-Mich Richter Link: http://lkml.kernel.org/r/1499305693-1599-7-git-send-email-kjlx@templeofstupid.com Signed-off-by: Arnaldo Carvalho de Melo

perf buildid-cache: Support binary objects from other namespaces

2017-07-19T02:14:11Z

Teach buildid-cache how to add, remove, and update binary objects from other mount namespaces. Allow probe events tracing binaries in different namespaces to add their objects to the probe and build-id caches too. As a handy side effect, this also lets us access SDT probes in binaries from alternate mount namespaces. 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/1499305693-1599-5-git-send-email-kjlx@templeofstupid.com [ Add util/namespaces.c to tools/perf/util/python-ext-sources, to fix the python binding 'perf test' ] Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Kill dso__build_id_is_kmod()

2017-06-08T18:39:34Z

The commit e7ee40475760 ("perf symbols: Fix symbols searching for module in buildid-cache") added the function to check kernel modules reside in the build-id cache. This was because there's no way to identify a DSO which is actually a kernel module. So it searched linkname of the file and find ".ko" suffix. But this does not work for compressed kernel modules and now such DSOs hCcave correct symtab_type now. So no need to check it anymore. This patch essentially reverts the commit. Signed-off-by: Namhyung Kim Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: David Ahern Cc: Peter Zijlstra Cc: Wang Nan Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-10-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf buildid: Move prototypes from util.h to build-id.h

2017-04-25T14:45:59Z

Where they belong. Link: http://lkml.kernel.org/n/tip-94m3dziejxgo7k0488q3mqjm@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf str{filter,list}: Disentangle headers

2017-04-19T16:01:52Z

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

perf probe: Support @BUILDID or @FILE suffix for SDT events

2016-07-14T02:09:08Z

Support @BUILDID or @FILE suffix for SDT events. This allows perf to add probes on SDTs/pre-cached events on given FILE or the file which has given BUILDID (also, this complements BUILDID.) For example, both gcc and libstdc++ has same SDTs as below. If you would like to add a probe on sdt_libstdcxx:catch on gcc, you can do as below. ---- # perf list sdt | tail -n 6 sdt_libstdcxx:catch@/usr/bin/gcc(0cc207fc4b27) [SDT event] sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49) sdt_libstdcxx:rethrow@/usr/bin/gcc(0cc207fc4b27) [SDT event] sdt_libstdcxx:rethrow@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49) sdt_libstdcxx:throw@/usr/bin/gcc(0cc207fc4b27) [SDT event] sdt_libstdcxx:throw@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49) # perf probe -a %sdt_libstdcxx:catch@0cc Added new event: sdt_libstdcxx:catch (on %catch in /usr/bin/gcc) You can now use it in all perf tools, such as: perf record -e sdt_libstdcxx:catch -aR sleep 1 ---- Committer note: Doing the full sequence of steps to get the results above: With a clean build-id cache: [root@jouet ~]# rm -rf ~/.debug/ [root@jouet ~]# perf list sdt List of pre-defined events (to be used in -e): [root@jouet ~]# No events whatsoever, then, we can add all events in gcc to the build-id cache, doing a --add + --dry-run: [root@jouet ~]# perf probe --dry-run --cache -x /usr/bin/gcc --add %sdt_libstdcxx:\* Added new events: sdt_libstdcxx:throw (on %* in /usr/bin/gcc) sdt_libstdcxx:rethrow (on %* in /usr/bin/gcc) sdt_libstdcxx:catch (on %* in /usr/bin/gcc) You can now use it in all perf tools, such as: perf record -e sdt_libstdcxx:catch -aR sleep 1 [root@jouet ~]# It really didn't add any events, it just cached them: [root@jouet ~]# perf probe -l [root@jouet ~]# We can see that it was cached as: [root@jouet ~]# ls -la ~/.debug/usr/bin/gcc/9a0730e2bcc6d2a2003d21ac46807e8ee6bcb7c2/ total 976 drwxr-xr-x. 2 root root 4096 Jul 13 21:47 . drwxr-xr-x. 3 root root 4096 Jul 13 21:47 .. -rwxr-xr-x. 4 root root 985912 Jun 22 18:52 elf -rw-r--r--. 1 root root 303 Jul 13 21:47 probes [root@jouet ~]# file ~/.debug/usr/bin/gcc/9a0730e2bcc6d2a2003d21ac46807e8ee6bcb7c2/elf /root/.debug/usr/bin/gcc/9a0730e2bcc6d2a2003d21ac46807e8ee6bcb7c2/elf: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=9a0730e2bcc6d2a2003d21ac46807e8ee6bcb7c2, stripped [root@jouet ~]# cat ~/.debug/usr/bin/gcc/9a0730e2bcc6d2a2003d21ac46807e8ee6bcb7c2/probes %sdt_libstdcxx:throw=throw p:sdt_libstdcxx/throw /usr/bin/gcc:0x71ffd %sdt_libstdcxx:rethrow=rethrow p:sdt_libstdcxx/rethrow /usr/bin/gcc:0x720b8 %sdt_libstdcxx:catch=catch p:sdt_libstdcxx/catch /usr/bin/gcc:0x7307f %sdt_libgcc:unwind=unwind p:sdt_libgcc/unwind /usr/bin/gcc:0x7eec0 #sdt_libstdcxx:*=%* [root@jouet ~]# Ok, now we can use 'perf probe' to refer to those cached entries as: Humm, nope, doing as above we end up with: [root@jouet ~]# perf probe -a %sdt_libstdcxx:catch Semantic error :* is bad for event name -it must follow C symbol-naming rule. Error: Failed to add events. [root@jouet ~]# But it worked at some point, lets try not using --dry-run: Resetting everything: # rm -rf ~/.debug/ # perf probe -d *:* # perf probe -l # perf list sdt List of pre-defined events (to be used in -e): # Ok, now it cached everything, even things we haven't asked it to (sdt_libgcc:unwind): [root@jouet ~]# perf probe -x /usr/bin/gcc --add %sdt_libstdcxx:\* Added new events: sdt_libstdcxx:throw (on %* in /usr/bin/gcc) sdt_libstdcxx:rethrow (on %* in /usr/bin/gcc) sdt_libstdcxx:catch (on %* in /usr/bin/gcc) You can now use it in all perf tools, such as: perf record -e sdt_libstdcxx:catch -aR sleep 1 [root@jouet ~]# perf list sdt List of pre-defined events (to be used in -e): sdt_libgcc:unwind [SDT event] sdt_libstdcxx:catch [SDT event] sdt_libstdcxx:rethrow [SDT event] sdt_libstdcxx:throw [SDT event] [root@jouet ~]# And we have the events in place: [root@jouet ~]# perf probe -l sdt_libstdcxx:catch (on execute_cfa_program+1551@../../../libgcc/unwind-dw2.c in /usr/bin/gcc) sdt_libstdcxx:rethrow (on d_print_subexpr+280@libsupc++/cp-demangle.c in /usr/bin/gcc) sdt_libstdcxx:throw (on d_print_subexpr+93@libsupc++/cp-demangle.c in /usr/bin/gcc) [root@jouet ~]# And trying to use them at least has 'perf trace --event sdt*:*' working. Then, if we try to add the ones in libstdc++: [root@jouet ~]# perf probe -x /usr/lib64/libstdc++.so.6 -a %sdt_libstdcxx:\* Error: event "catch" already exists. Hint: Remove existing event by 'perf probe -d' or force duplicates by 'perf probe -f' or set 'force=yes' in BPF source. Error: Failed to add events. [root@jouet ~]# Doesn't work, dups, but at least this served to, unbeknownst to the user, add the SDT probes in /usr/lib64/libstdc++.so.6! [root@jouet ~]# perf list sdt List of pre-defined events (to be used in -e): sdt_libgcc:unwind [SDT event] sdt_libstdcxx:catch@/usr/bin/gcc(9a0730e2bcc6) [SDT event] sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event] sdt_libstdcxx:rethrow@/usr/bin/gcc(9a0730e2bcc6) [SDT event] sdt_libstdcxx:rethrow@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event] sdt_libstdcxx:throw@/usr/bin/gcc(9a0730e2bcc6) [SDT event] sdt_libstdcxx:throw@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event] [root@jouet ~]# Now we should be able to get to the original cset comment, if we remove all SDTs events in place, not from the cache, from the kernel, where it was set up as: [root@jouet ~]# ls -la /sys/kernel/debug/tracing/events/sdt_libstdcxx/ total 0 drwxr-xr-x. 5 root root 0 Jul 13 22:00 . drwxr-xr-x. 80 root root 0 Jul 13 21:56 .. drwxr-xr-x. 2 root root 0 Jul 13 22:00 catch -rw-r--r--. 1 root root 0 Jul 13 22:00 enable -rw-r--r--. 1 root root 0 Jul 13 22:00 filter drwxr-xr-x. 2 root root 0 Jul 13 22:00 rethrow drwxr-xr-x. 2 root root 0 Jul 13 22:00 throw [root@jouet ~]# [root@jouet ~]# head -2 /sys/kernel/debug/tracing/events/sdt_libstdcxx/throw/format name: throw ID: 2059 [root@jouet ~]# Now to remove it: [root@jouet ~]# perf probe -d sdt_libstdc*:* Removed event: sdt_libstdcxx:catch Removed event: sdt_libstdcxx:rethrow Removed event: sdt_libstdcxx:throw [root@jouet ~]# Which caused: [root@jouet ~]# ls -la /sys/kernel/debug/tracing/events/sdt_libstdcxx/ ls: cannot access '/sys/kernel/debug/tracing/events/sdt_libstdcxx/': No such file or directory [root@jouet ~]# Ok, now we can do: [root@jouet ~]# perf list sdt_libstdcxx:catch List of pre-defined events (to be used in -e): sdt_libstdcxx:catch@/usr/bin/gcc(9a0730e2bcc6) [SDT event] sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event] [root@jouet ~]# So, these are not really 'pre-defined events', i.e. we can't use them with 'perf record --event': [root@jouet ~]# perf record --event sdt_libstdcxx:catch* event syntax error: 'sdt_libstdcxx:catch*' \___ unknown tracepoint Error: File /sys/kernel/debug/tracing/events/sdt_libstdcxx/catch* not found. Hint: Perhaps this kernel misses some CONFIG_ setting to enable this feature?. [root@jouet ~]# To have it really pre-defined we must use perf probe to get its definition from the cache and set it up in the kernel, creating the tracepoint to _then_ use it with 'perf record --event': [root@jouet ~]# perf probe -a sdt_libstdcxx:catch Semantic error :There is non-digit char in line number. Oops, there is another gotcha here, we need that pesky '%' character: [root@jouet ~]# perf probe -a %sdt_libstdcxx:catch Added new events: sdt_libstdcxx:catch (on %catch in /usr/bin/gcc) sdt_libstdcxx:catch_1 (on %catch in /usr/lib64/libstdc++.so.6.0.22) You can now use it in all perf tools, such as: perf record -e sdt_libstdcxx:catch_1 -aR sleep 1 [root@jouet ~]# But then we added _two_ events, one with the name we expected, the other one with a _ added, when doing the analysis we need to pay attention to who maps to who. And here is where we get to the point of this patch, which is to be able to disambiguate those definitions for 'catch' in the build-id cache, but first we need remove those events we just added: [root@jouet ~]# perf probe -d %sdt_libstdcxx:catch Oops, that didn't remove anything, we need to _remove_ that % char in this case: [root@jouet ~]# perf probe -d sdt_libstdcxx:catch Removed event: sdt_libstdcxx:catch And we need to remove the other event added, i.e. I forgot to add a * at the end: [root@jouet ~]# perf probe -d sdt_libstdcxx:catch* Removed event: sdt_libstdcxx:catch_1 [root@jouet ~]# Ok, disambiguating it using what is in this patch: [root@jouet ~]# perf list sdt_libstdcxx:catch List of pre-defined events (to be used in -e): sdt_libstdcxx:catch@/usr/bin/gcc(9a0730e2bcc6) [SDT event] sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event] [root@jouet ~]# [root@jouet ~]# perf probe -a %sdt_libstdcxx:catch@9a07 Added new event: sdt_libstdcxx:catch (on %catch in /usr/bin/gcc) You can now use it in all perf tools, such as: perf record -e sdt_libstdcxx:catch -aR sleep 1 [root@jouet ~]# perf probe -l sdt_libstdcxx:catch (on execute_cfa_program+1551@../../../libgcc/unwind-dw2.c in /usr/bin/gcc) [root@jouet ~]# Yeah, it works! But we need to try and simplify this :-) Update: Some aspects of this simplification take place in the following patches. Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: Ananth N Mavinakayanahalli Cc: Brendan Gregg Cc: Hemant Kumar Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/146831793746.17065.13065062753978236612.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Make --list show only available cached events

2016-07-14T02:09:05Z

Make "perf probe --cache --list" show only available cached events by checking build-id validity. E.g. without this patch: ---- $ ./perf probe --cache --add oldevent=cmd_probe $ make #(to update ./perf) $ ./perf probe --cache --add newevent=cmd_probe $ ./perf probe --cache --list /home/mhiramat/ksrc/linux/tools/perf/perf (061e90539bac69 probe_perf:newevent=cmd_probe /home/mhiramat/ksrc/linux/tools/perf/perf (c2e44d614e33e1 probe_perf:oldevent=cmd_probe ---- It shows both of old and new events but user can not use old one. With this; ---- $ ./perf probe --cache -l /home/mhiramat/ksrc/linux/tools/perf/perf (061e90539bac69 probe_perf:newevent=cmd_probe ---- This shows only new events which are on the existing binary. Signed-off-by: Masami Hiramatsu Signed-off-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Brendan Gregg Cc: Hemant Kumar Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/146831789417.17065.17896487479879669610.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Show all cached probes

2016-07-01T14:34:57Z

perf probe --list shows all cached probes when --cache is given. Each caches are shown with on which binary that probed. E.g.: ----- # perf probe --cache vfs_read \$params # perf probe --cache -x /lib64/libc-2.17.so getaddrinfo \$params # perf probe --cache --list [kernel.kallsyms] (1466a0a250b5d0070c6d0f03c5fed30b237970a1): vfs_read $params /usr/lib64/libc-2.17.so (c31ffe7942bfd77b2fca8f9bd5709d387a86d3bc): getaddrinfo $params ----- Note that $params requires debuginfo. Signed-off-by: Masami Hiramatsu Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: Ananth N Mavinakayanahalli Cc: Brendan Gregg Cc: Hemant Kumar Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/146736020674.27797.13488316780383460180.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo