Commit Graph

8 Commits

Author SHA1 Message Date
Arnaldo Carvalho de Melo cb76371441 perf llvm: Allow passing options to llc in addition to clang
The newly added 'llvm.opts' variable allows passing options directly to
llc, like needed to get sane DWARF in BPF ELF debug sections:

With:

  [root@seventh perf]# cat ~/.perfconfig
  [llvm]
	  dump-obj = true
	clang-opt = -g
  [root@seventh perf]#

We get:

  [root@seventh perf]# perf trace -e tools/perf/examples/bpf/hello.c cat /etc/passwd > /dev/null
  LLVM: dumping tools/perf/examples/bpf/hello.o
       0.000 __bpf_stdout__:Hello, world
       0.015 __bpf_stdout__:Hello, world
       0.187 __bpf_stdout__:Hello, world
  [root@seventh perf]# pahole tools/perf/examples/bpf/hello.o
  struct clang version 8.0.0 (http://llvm.org/git/clang.git 8587270a739ee30c926a76d5657e65e85b560f6e) (http://llvm.org/git/llvm.git 0566eefef9c3777bd780ec4cbb9efa764633b76c) {
	  clang version 8.0.0 (http://llvm.org/git/clang.git 8587270a739ee30c926a76d5657e65e85b560f6e) (http://llvm.org/git/llvm.git 0566e.org clang version 8.0.0 (http://llvm.org/git/clang.git 8587270a739ee30c926a76d5657e65e85b560f6e) (http://llvm.org/git/llvm.git 0566eefef9c3777bd780ec4cbb9efa764633b76c); /*     0     4 */
	  clang version 8.0.0 (http://llvm.org/git/clang.git 8587270a739ee30c926a76d5657e65e85b560f6e) (http://llvm.org/git/llvm.git 0566e.org clang version 8.0.0 (http://llvm.org/git/clang.git 8587270a739ee30c926a76d5657e65e85b560f6e) (http://llvm.org/git/llvm.git 0566eefef9c3777bd780ec4cbb9efa764633b76c); /*     4     4 */
	  clang version 8.0.0 (http://llvm.org/git/clang.git 8587270a739ee30c926a76d5657e65e85b560f6e) (http://llvm.org/git/llvm.git 0566e.org clang version 8.0.0 (http://llvm.org/git/clang.git 8587270a739ee30c926a76d5657e65e85b560f6e) (http://llvm.org/git/llvm.git 0566eefef9c3777bd780ec4cbb9efa764633b76c); /*     8     4 */
	  clang version 8.0.0 (http://llvm.org/git/clang.git 8587270a739ee30c926a76d5657e65e85b560f6e) (http://llvm.org/git/llvm.git 0566e.org clang version 8.0.0 (http://llvm.org/git/clang.git 8587270a739ee30c926a76d5657e65e85b560f6e) (http://llvm.org/git/llvm.git 0566eefef9c3777bd780ec4cbb9efa764633b76c); /*    12     4 */
	  clang version 8.0.0 (http://llvm.org/git/clang.git 8587270a739ee30c926a76d5657e65e85b560f6e) (http://llvm.org/git/llvm.git 0566e.org clang version 8.0.0 (http://llvm.org/git/clang.git 8587270a739ee30c926a76d5657e65e85b560f6e) (http://llvm.org/git/llvm.git 0566eefef9c3777bd780ec4cbb9efa764633b76c); /*    16     4 */
	  clang version 8.0.0 (http://llvm.org/git/clang.git 8587270a739ee30c926a76d5657e65e85b560f6e) (http://llvm.org/git/llvm.git 0566e.org clang version 8.0.0 (http://llvm.org/git/clang.git 8587270a739ee30c926a76d5657e65e85b560f6e) (http://llvm.org/git/llvm.git 0566eefef9c3777bd780ec4cbb9efa764633b76c); /*    20     4 */
	  clang version 8.0.0 (http://llvm.org/git/clang.git 8587270a739ee30c926a76d5657e65e85b560f6e) (http://llvm.org/git/llvm.git 0566e.org clang version 8.0.0 (http://llvm.org/git/clang.git 8587270a739ee30c926a76d5657e65e85b560f6e) (http://llvm.org/git/llvm.git 0566eefef9c3777bd780ec4cbb9efa764633b76c); /*    24     4 */

	  /* size: 28, cachelines: 1, members: 7 */
	  /* last cacheline: 28 bytes */
  };
  [root@seventh perf]#

Adding these options to be passed to llvm's llc:

  [root@seventh perf]# cat ~/.perfconfig
  [llvm]
	  dump-obj = true
	  clang-opt = -g
	  opts = -mattr=dwarfris
  [root@seventh perf]#

We get sane output:

  [root@seventh perf]# perf trace -e tools/perf/examples/bpf/hello.c cat /etc/passwd > /dev/null
  LLVM: dumping tools/perf/examples/bpf/hello.o
       0.000 __bpf_stdout__:Hello, world
       0.015 __bpf_stdout__:Hello, world
       0.185 __bpf_stdout__:Hello, world
  [root@seventh perf]# pahole tools/perf/examples/bpf/hello.o
  struct bpf_map {
	  unsigned int               type;                 /*     0     4 */
	  unsigned int               key_size;             /*     4     4 */
	  unsigned int               value_size;           /*     8     4 */
	  unsigned int               max_entries;          /*    12     4 */
	  unsigned int               map_flags;            /*    16     4 */
	  unsigned int               inner_map_idx;        /*    20     4 */
	  unsigned int               numa_node;            /*    24     4 */

	  /* size: 28, cachelines: 1, members: 7 */
	  /* last cacheline: 28 bytes */
  };
  [root@seventh perf]#

Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>,
Cc: Yonghong Song <yhs@fb.com>
Link: https://lkml.kernel.org/n/tip-0lrwmrip4dru1651rm8xa7tq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-08-20 08:54:58 -03:00
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
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 <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Wang Nan 2bd42de0e1 perf llvm: Extract helpers in llvm-utils.c
The following commits will use builtin clang to compile BPF scripts.

llvm__get_kbuild_opts() and llvm__get_nr_cpus() are extracted to help
building '-DKERNEL_VERSION_CODE' and '-D__NR_CPUS__' macros.

Doing object dumping in bpf loader, so further builtin clang compiling
needn't consider it.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Joe Stringer <joe@ovn.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/20161126070354.141764-7-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-12-05 15:51:42 -03:00
Wang Nan f078464925 perf llvm: Allow dump llvm output object file using llvm.dump-obj
Add a 'llvm.dump-obj' config option to enable perf dump BPF object files
compiled by LLVM.

This option is useful when using BPF objects in embedded platforms.
LLVM compiler won't be deployed in these platforms, and currently we
don't support dynamic compiling library.

Before this patch users have to explicitly issue llvm commands to
compile BPF scripts, and can't use helpers (like include path detection
and default macros) in perf. With this option, user is allowed to use
perf to compile their BPF objects then copy them into their embedded
platforms.

Committer notice:

Testing it:

  # cat ~/.perfconfig
  [llvm]
	dump-obj = true
  #
  # ls -la filter.o
  ls: cannot access filter.o: No such file or directory
  # cat filter.c
  #include <uapi/linux/bpf.h>
  #define SEC(NAME) __attribute__((section(NAME), used))

  SEC("func=hrtimer_nanosleep rqtp->tv_nsec")
  int func(void *ctx, int err, long nsec)
  {
	return nsec > 1000;
  }
  char _license[] SEC("license") = "GPL";
  int _version SEC("version") = LINUX_VERSION_CODE;
  # trace -e nanosleep --event filter.c usleep 6
  LLVM: dumping filter.o
     0.007 ( 0.007 ms): usleep/13976 nanosleep(rqtp: 0x7ffc5847f640                                        ) ...
     0.007 (         ): perf_bpf_probe:func:(ffffffff811137d0) tv_nsec=6000)
     0.070 ( 0.070 ms): usleep/13976  ... [continued]: nanosleep()) = 0
  # ls -la filter.o
  -rw-r--r--. 1 root root 776 Jun 20 17:01 filter.o
  # readelf -SW filter.o
  There are 7 section headers, starting at offset 0x148:

  Section Headers:
   [Nr] Name        Type       Address          Off    Size   ES Flg Lk Inf Al
   [ 0]             NULL       0000000000000000 000000 000000 00      0   0  0
   [ 1] .strtab     STRTAB     0000000000000000 0000e8 00005a 00      0   0  1
   [ 2] .text       PROGBITS   0000000000000000 000040 000000 00  AX  0   0  4
   [ 3] func=hrtimer_nanosleep rqtp->tv_nsec PROGBITS 0000000000000000 000040 000028 00  AX  0   0  8
   [ 4] license     PROGBITS   0000000000000000 000068 000004 00  WA  0   0  1
   [ 5] version     PROGBITS   0000000000000000 00006c 000004 00  WA  0   0  4
   [ 6] .symtab     SYMTAB     0000000000000000 000070 000078 18      1   2  8
  Key to Flags:
   W (write), A (alloc), X (execute), M (merge), S (strings)
   I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown)
   O (extra OS processing required) o (OS specific), p (processor specific)
   #

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1466064161-48553-2-git-send-email-wangnan0@huawei.com
[ s/dumpping/dumping/g ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-21 13:18:34 -03:00
Arnaldo Carvalho de Melo 3938bad44e perf tools: Remove needless 'extern' from function prototypes
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-w246stf7ponfamclsai6b9zo@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-23 15:06:35 -03:00
Wang Nan 9bc898c701 perf tests: Add LLVM test for eBPF on-the-fly compiling
Previous patches introduce llvm__compile_bpf() to compile source file to
eBPF object. This patch adds testcase to test it. It also tests libbpf
by opening generated object after applying next patch which introduces
HAVE_LIBBPF_SUPPORT option.

Since llvm__compile_bpf() prints long messages which users who don't
explicitly test llvm doesn't care, this patch set verbose to -1 to
suppress all debug, warning and error message, and hint user use 'perf
test -v' to see the full output.

For the same reason, if clang is not found in PATH and there's no [llvm]
section in .perfconfig, skip this test.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/n/1436445342-1402-17-git-send-email-wangnan0@huawei.com
[ Add tools/lib/bpf/ to tools/perf/MANIFEST, so that the tarball targets build ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:57:24 -03:00
Wang Nan 4cea3a9cb3 perf tools: Call clang to compile C source to object code
This is the core patch for supporting eBPF on-the-fly compiling, does
the following work:

 1. Search clang compiler using search_program().

 2. Run command template defined in llvm-bpf-cmd-template option in
    [llvm] config section using read_from_pipe(). Patch of clang and
    source code path is injected into shell command using environment
    variable using force_set_env().

  Commiter notice:

  When building with DEBUG=1 we get a compiler error that gets fixed with
  the same approach described in commit b236512280fb:

    perf kmem: Fix compiler warning about may be accessing uninitialized variable

    The last argument to strtok_r doesn't need to be initialized, its
    just a placeholder to make this routine reentrant, but gcc doesn't know
    about that and complains, breaking the build, fix it by setting it to
    NULL.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/n/1436445342-1402-14-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:59 -03:00
Wang Nan aa61fd05ca perf tools: Introduce llvm config options
This patch introduces [llvm] config section with 5 options. Following
patches will use then to config llvm dynamica compiling.

'llvm-utils.[ch]' is introduced in this patch for holding all
llvm/clang related stuffs.

Example:

  [llvm]
        # Path to clang. If omit, search it from $PATH.
	clang-path = "/path/to/clang"

        # Cmdline template. Following line shows its default value.
        # Environment variable is used to passing options.
        #
        # *NOTE*: -D__KERNEL__ MUST appears before $CLANG_OPTIONS,
        # so user have a chance to use -U__KERNEL__ in $CLANG_OPTIONS
        # to cancel it.
	clang-bpf-cmd-template = "$CLANG_EXEC -D__KERNEL__ $CLANG_OPTIONS \
				  $KERNEL_INC_OPTIONS -Wno-unused-value \
				  -Wno-pointer-sign -working-directory \
				  $WORKING_DIR  -c $CLANG_SOURCE -target \
				  bpf -O2 -o -"

        # Options passed to clang, will be passed to cmdline by
        # $CLANG_OPTIONS.
	clang-opt = "-Wno-unused-value -Wno-pointer-sign"

        # kbuild directory. If not set, use /lib/modules/`uname -r`/build.
        # If set to "" deliberately, skip kernel header auto-detector.
	kbuild-dir = "/path/to/kernel/build"

        # Options passed to 'make' when detecting kernel header options.
	kbuild-opts = "ARCH=x86_64"

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1437477214-149684-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:59 -03:00