linux.git/tools/perf/util/llvm-utils.c, branch v6.0

perf bpf: Convert legacy map definition to BTF-defined

2022-08-01T17:43:13+00:00

The libbpf is switching off support for legacy map definitions [1],
which will break the perf llvm tests.

Moving the base source map definition to BTF-defined, so we need
to use -g compile option for to add debug/BTF info.

[1] https://lore.kernel.org/bpf/20220627211527.2245459-1-andrii@kernel.org/

Signed-off-by: Jiri Olsa 
Acked-by: Andrii Nakryiko 
Cc: Alexander Shishkin 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20220704152721.352046-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix LLVM download hint link

2021-08-31T18:18:16+00:00

http://llvm.org/apt returns 404, it has moved to https://apt.llvm.org/

Signed-off-by: James Clark 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: clang-built-linux@googlegroups.com
Link: http://lore.kernel.org/lkml/20210831145501.2135754-3-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix LLVM test failure when running in verbose mode

2021-08-31T18:17:45+00:00

A CI system might want to run all tests in verbose mode so that there is
enough information to diagnose issues. This LLVM test is the only test
that uses "-v" to signify to not skip the test if the preconditions
aren't met (LLVM isn't installed). This means that running the test in
verbose mode without LLVM installed causes a test failure.

For consistency with the other tests, remove this verbose/skip check. An
alternate solution would be to make _all_ tests not skip when run in
verbose mode, but I don't think that would be intuitive.

Also change the search_program() call to search_program_and_warn().
Previously the hint about installing LLVM was only printed by the actual
test because this check was skipped in verbose mode. To maintain the old
behaviour, the precondition check must also print the full warning.

Previous output:

  $ ./perf test llvm
  40: LLVM search and compile                                     :
  40.1: Basic BPF llvm compile                                    : Skip

  $ ./perf test -v llvm
  40: LLVM search and compile                                     :
  40.1: Basic BPF llvm compile                                    :
  --- start ---
  test child forked, pid 2085835
  ERROR:	unable to find clang.
  Hint:	Try to install latest clang/llvm to support BPF. Check your $PATH
  ...
  test child finished with -1
  ---- end ----
  LLVM search and compile subtest 1: FAILED!

New output (non verbose mode is identical, verbose changes from fail to
skip):

  $ ./perf test llvm
  40: LLVM search and compile                                     :
  40.1: Basic BPF llvm compile                                    : Skip

  $ ./perf test -v llvm
  40: LLVM search and compile                                     :
  40.1: Basic BPF llvm compile                                    :
  --- start ---
  test child forked, pid 2087680
  ERROR:	unable to find clang.
  Hint:	Try to install latest clang/llvm to support BPF. Check your $PATH
  ...
  No clang, skip this test
  test child finished with -2
  ---- end ----
  LLVM search and compile subtest 1: Skip

Signed-off-by: James Clark 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: clang-built-linux@googlegroups.com
Link: http://lore.kernel.org/lkml/20210831145501.2135754-2-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Refactor LLVM test warning for missing binary

2021-08-31T18:17:07+00:00

The same warning is duplicated in two places so refactor it into a
single function "search_program_and_warn". This will be used a third
time in a later commit.

Signed-off-by: James Clark 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: clang-built-linux@googlegroups.com
Link: http://lore.kernel.org/lkml/20210831145501.2135754-1-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf llvm: Return -ENOMEM when asprintf() fails

2021-07-01T19:14:37+00:00

Zhihao sent a patch but it made llvm__compile_bpf() return what
asprintf() returns on error, which is just -1, but since this function
returns -errno, fix it by returning -ENOMEM for this case instead.

Fixes: cb76371441d098 ("perf llvm: Allow passing options to llc ...")
Fixes: 5eab5a7ee032ac ("perf llvm: Display eBPF compiling command ...")
Reported-by: Hulk Robot 
Reported-by: Zhihao Cheng 
Cc: Alexei Starovoitov 
Cc: Andrii Nakryiko 
Cc: Daniel Borkmann 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Peter Zijlstra 
Cc: Yu Kuai 
Cc: clang-built-linux@googlegroups.com
Link: http://lore.kernel.org/lkml/20210609115945.2193194-1-chengzhihao1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix various typos in comments

2021-03-23T20:13:43+00:00

Fix ~124 single-word typos and a few spelling errors in the perf tooling code,
accumulated over the years.

Signed-off-by: Ingo Molnar 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20210321113734.GA248990@gmail.com
Link: http://lore.kernel.org/lkml/20210323160915.GA61903@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo

perf llvm: Add debug hint message about missing kernel-devel package

2020-03-04T13:34:10+00:00

To help in debugging, add this extra message:

  detect_kbuild_dir: Couldn't find "/lib/modules/5.4.20-200.fc31.x86_64/build/include/generated/autoconf.h", missing kernel-devel package?.

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Signed-off-by: Arnaldo Carvalho de Melo

perf llvm: Fix script used to obtain kernel make directives to work with new kbuild

2020-02-14T13:06:00+00:00

Before this patch:

  # ./perf test 39 41
  39: LLVM search and compile                               :
  39.1: Basic BPF llvm compile                              : Ok
  39.2: kbuild searching                                    : FAILED!
  39.3: Compile source for BPF prologue generation          : Skip
  39.4: Compile source for BPF relocation                   : Skip
  41: BPF filter                                            :
  41.1: Basic BPF filtering                                 : Ok
  41.2: BPF pinning                                         : Ok
  41.3: BPF prologue generation                             : FAILED!
  41.4: BPF relocation checker                              : Skip
  #

Using 'perf test -v' for these tests shows that it is not finding
uapi/linux/fs.h, which ends up being because we don't setup the right header
path. Fix it.

After this patch:

  # perf test 39 41
  39: LLVM search and compile                               :
  39.1: Basic BPF llvm compile                              : Ok
  39.2: kbuild searching                                    : Ok
  39.3: Compile source for BPF prologue generation          : Ok
  39.4: Compile source for BPF relocation                   : Ok
  41: BPF filter                                            :
  41.1: Basic BPF filtering                                 : Ok
  41.2: BPF pinning                                         : Ok
  41.3: BPF prologue generation                             : Ok
  41.4: BPF relocation checker                              : Ok
  #

Longer description:

In llvm-utils.c we use some techniques to obtain the kbuild make
directives and that recently stopped working as now 'ar' gets called and
expects to find the dummy.o used to echo these variables:

  $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS)

Add the $(CC) line to satisfy that, making sure this works with all
kernels, i.e. preserving the temp directory and files in it used for
this technique we can see that it works everywhere:

  # make -s -C /lib/modules/5.4.18-100.fc30.x86_64/build M=/tmp/tmp.qgaFHgxjZ4/ clean
  # ls -la /tmp/tmp.qgaFHgxjZ4/
  total 4
  drwx------.  2 root root   80 Feb 14 09:42 .
  drwxrwxrwt. 47 root root 1200 Feb 14 09:42 ..
  -rw-r--r--.  1 root root    0 Feb 13 17:14 dummy.c
  -rw-r--r--.  1 root root  121 Feb 13 17:14 Makefile
  #
  # cat /tmp/tmp.qgaFHgxjZ4/Makefile
  obj-y := dummy.o
  $(obj)/%.o: $(src)/%.c
          @echo -n "$(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS)"
          $(CC) -c -o $@ $<
  #

Then build with an old kernel Makefile:

  # make -s -C /lib/modules/5.4.18-100.fc30.x86_64/build M=/tmp/tmp.qgaFHgxjZ4/ dummy.o
  -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/9/include -I./arch/x86/include -I./arch/x86/include/generated  -I./include -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h
  #
  # ls -la /tmp/tmp.qgaFHgxjZ4/
  total 8
  drwx------.  2 root root  100 Feb 14 09:43 .
  drwxrwxrwt. 47 root root 1200 Feb 14 09:43 ..
  -rw-r--r--.  1 root root    0 Feb 13 17:14 dummy.c
  -rw-r--r--.  1 root root  936 Feb 14 09:43 dummy.o
  -rw-r--r--.  1 root root  121 Feb 13 17:14 Makefile
  #

And a new one:

  # make -s -C /lib/modules/5.4.18-100.fc30.x86_64/build M=/tmp/tmp.qgaFHgxjZ4/ clean
  # ls -la /tmp/tmp.qgaFHgxjZ4/
  total 4
  drwx------.  2 root root   80 Feb 14 09:43 .
  drwxrwxrwt. 47 root root 1200 Feb 14 09:43 ..
  -rw-r--r--.  1 root root    0 Feb 13 17:14 dummy.c
  -rw-r--r--.  1 root root  121 Feb 13 17:14 Makefile
  # make -s -C /lib/modules/5.6.0-rc1+/build M=/tmp/tmp.qgaFHgxjZ4/ dummy.o
   -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/9/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h
  #
  # ls -la /tmp/tmp.qgaFHgxjZ4/
  total 16
  drwx------.  2 root root  160 Feb 14 09:44 .
  drwxrwxrwt. 47 root root 1200 Feb 14 09:44 ..
  -rw-r--r--.  1 root root  158 Feb 14 09:44 built-in.a
  -rw-r--r--.  1 root root  149 Feb 14 09:44 .built-in.a.cmd
  -rw-r--r--.  1 root root    0 Feb 13 17:14 dummy.c
  -rw-r--r--.  1 root root  936 Feb 14 09:44 dummy.o
  -rw-r--r--.  1 root root  121 Feb 13 17:14 Makefile
  -rw-r--r--.  1 root root    0 Feb 14 09:44 modules.order
  #

Reported-by: Thomas Richter 
Tested-by: Thomas Richter 
Cc: Adrian Hunter 
Cc: Daniel Borkmann 
Cc: He Kuang 
Cc: Jiri Olsa 
Cc: Masahiro Yamada 
Cc: Namhyung Kim 
Cc: Sumanth Korikkar 
Cc: Vasily Gorbik 
Cc: Wang Nan 
Cc: Zefan Li 
Link: https://www.spinics.net/lists/linux-perf-users/msg10600.html
Signed-off-by: Arnaldo Carvalho de Melo

perf llvm: Make .o saving a debug message, not an info one

2019-11-06T18:43:05+00:00

Its a bit annoying to have that message, better make it a debug one.

I.e. now this message will only appear when using '-v':

  [root@quaco tracebuffer]# trace -e bristot.c
  LLVM: dumping bristot.o
  ^C[root@quaco tracebuffer]#

Cc: Adrian Hunter 
Cc: Daniel Bristot de Oliveira 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Luis Cláudio Gonçalves 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-o7jd4i7s66kosec5torubqps@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf llvm: Don't access out-of-scope array

2019-09-30T20:29:35+00:00

The 'test_dir' variable is assigned to the 'release' array which is
out-of-scope 3 lines later.

Extend the scope of the 'release' array so that an out-of-scope array
isn't accessed.

Bug detected by clang's address sanitizer.

Fixes: 07bc5c699a3d ("perf tools: Make fetch_kernel_version() publicly available")
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: Ian Rogers 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Wang Nan 
Link: http://lore.kernel.org/lkml/20190926220018.25402-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo