linux-stable.git/tools/lib/subcmd, branch v6.12.35

libsubcmd: Silence compiler warning

2025-03-28T21:03:33+00:00

commit 7a4ffec9fd54ea27395e24dff726dbf58e2fe06b upstream.

Initialize the pointer 'o' in options__order to NULL to prevent a
compiler warning/error which is observed when compiling with the '-Og'
option, but is not emitted by the compiler with the current default
compilation options.

For example, when compiling libsubcmd with

 $ make "EXTRA_CFLAGS=-Og" -C tools/lib/subcmd/ clean all

Clang version 17.0.6 and GCC 13.3.1 fail to compile parse-options.c due
to following error:

  parse-options.c: In function ‘options__order’:
  parse-options.c:832:9: error: ‘o’ may be used uninitialized [-Werror=maybe-uninitialized]
    832 |         memcpy(&ordered[nr_opts], o, sizeof(*o));
        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  parse-options.c:810:30: note: ‘o’ was declared here
    810 |         const struct option *o, *p = opts;
        |                              ^
  cc1: all warnings being treated as errors

Signed-off-by: Eder Zulian 
Signed-off-by: Andrii Nakryiko 
Acked-by: Arnaldo Carvalho de Melo 
Acked-by: Jiri Olsa 
Link: https://lore.kernel.org/bpf/20241022172329.3871958-4-ezulian@redhat.com
Signed-off-by: Bin Lan 
Signed-off-by: He Zhe 
Signed-off-by: Greg Kroah-Hartman

tools: Drop nonsensical -O6

2024-09-11T16:08:36+00:00

-O6 is very much not-a-thing. Really, this should've been dropped
entirely in 49b3cd306e60b9d8 ("tools: Set the maximum optimization level
according to the compiler being used") instead of just passing it for
not-Clang.

Just collapse it down to -O3, instead of "-O6 unless Clang, in which case
-O3".

GCC interprets > -O3 as -O3. It doesn't even interpret > -O3 as -Ofast,
which is a good thing, given -Ofast has specific (non-)requirements for
code built using it. So, this does nothing except look a bit daft.

Remove the silliness and also save a few lines in the Makefiles accordingly.

Reviewed-by: Ian Rogers 
Reviewed-by: Jesper Juhl 
Signed-off-by: Sam James 
Acked-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Bill Wendling 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Justin Stitt 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Peter Zijlstra 
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/4f01524fa4ea91c7146a41e26ceaf9dae4c127e4.1725821201.git.sam@gentoo.org
Signed-off-by: Arnaldo Carvalho de Melo

libsubcmd: Don't free the usage string

2024-09-04T12:54:24+00:00

Currently, commands which depend on 'parse_options_subcommand()' don't
show the usage string, and instead show '(null)'

    $ ./perf sched
	Usage: (null)

    -D, --dump-raw-trace  dump raw trace in ASCII
    -f, --force           don't complain, do it
    -i, --input     input file name
    -v, --verbose         be more verbose (show symbol address, etc)

'parse_options_subcommand()' is generally expected to initialise the usage
string, with information in the passed 'subcommands[]' array

This behaviour was changed in:

  230a7a71f92212e7 ("libsubcmd: Fix parse-options memory leak")

Where the generated usage string is deallocated, and usage[0] string is
reassigned as NULL.

As discussed in [1], free the allocated usage string in the main
function itself, and don't reset usage string to NULL in
parse_options_subcommand

With this change, the behaviour is restored.

    $ ./perf sched
        Usage: perf sched [] {record|latency|map|replay|script|timehist}

           -D, --dump-raw-trace  dump raw trace in ASCII
           -f, --force           don't complain, do it
           -i, --input     input file name
           -v, --verbose         be more verbose (show symbol address, etc)

[1]: https://lore.kernel.org/linux-perf-users/htq5vhx6piet4nuq2mmhk7fs2bhfykv52dbppwxmo3s7du2odf@styd27tioc6e/

Fixes: 230a7a71f92212e7 ("libsubcmd: Fix parse-options memory leak")
Suggested-by: Namhyung Kim 
Signed-off-by: Aditya Gupta 
Acked-by: Namhyung Kim 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Athira Rajeev 
Cc: Disha Goel 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Kajol Jain 
Cc: Madhavan Srinivasan 
Cc: Namhyung Kim 
Link: https://lore.kernel.org/r/20240904061836.55873-2-adityag@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

tools build: Correct libsubcmd fixdep dependencies

2024-08-05T15:08:29+00:00

All built targets need fixdep to be built first, before handling object
dependencies [1]. We're missing one such dependency before the libsubcmd
target.

This resolves .cmd file generation issues such that the following
sequence produces many fewer results:

  $ git clean -xfd tools/
  $ make tools/objtool
  $ grep "cannot find fixdep" $(find tools/objtool -name '*.cmd')

In particular, only a buggy tools/objtool/libsubcmd/.fixdep.o.cmd
remains, due to circular dependencies of fixdep on itself.

Such incomplete .cmd files don't usually cause a direct problem, since
they're designed to fail "open", but they can cause some subtle problems
that would otherwise be handled by proper fixdep'd dependency files. [2]

[1] This problem is better described in commit abb26210a395 ("perf
tools: Force fixdep compilation at the start of the build"). I don't
apply its solution here, because additional recursive make can be a bit
of overkill.

[2] Example failure case:

  cp -arl linux-src linux-src2
  cd linux-src2
  make O=/path/to/out
  cd ../linux-src
  rm -rf ../linux-src2
  make O=/path/to/out

Previously, we'd see errors like:

  make[6]: *** No rule to make target
  '/path/to/linux-src2/tools/include/linux/compiler.h', needed by
  '/path/to/out/tools/bpf/resolve_btfids/libsubcmd/exec-cmd.o'.  Stop.

Now, the properly-fixdep'd .cmd files will ignore a missing
/path/to/linux-src2/...

Signed-off-by: Brian Norris 
Acked-by: Jiri Olsa 
Cc: Ian Rogers 
Cc: Josh Poimboeuf 
Cc: Masahiro Yamada 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Thomas Richter 
Link: https://lore.kernel.org/all/ZGVi9HbI43R5trN8@bhelgaas/
Link: https://lore.kernel.org/all/Zk-C5Eg84yt6_nml@google.com/
Link: https://lore.kernel.org/r/20240715203325.3832977-2-briannorris@chromium.org
Signed-off-by: Arnaldo Carvalho de Melo

tools lib subcmd: Show parent options in help

2024-05-13T00:09:52+00:00

I've just realized that help message in a subcommand didn't show one
in the parent command.  Since the option parser understands the parent,
display code should do the same.  For example, `perf ftrace latency -h`
should show options in the `perf ftrace` command too.

Before:

  $ perf ftrace latency -h

   Usage: perf ftrace [] []
      or: perf ftrace [] -- [] []
      or: perf ftrace {trace|latency} [] []
      or: perf ftrace {trace|latency} [] -- [] []

      -b, --use-bpf         Use BPF to measure function latency
      -n, --use-nsec        Use nano-second histogram
      -T, --trace-funcs 
                            Show latency of given function

After:

  $ perf ftrace latency -h

   Usage: perf ftrace [] []
      or: perf ftrace [] -- [] []
      or: perf ftrace {trace|latency} [] []
      or: perf ftrace {trace|latency} [] -- [] []

      -a, --all-cpus        System-wide collection from all CPUs
      -b, --use-bpf         Use BPF to measure function latency
      -C, --cpu        List of cpus to monitor
      -n, --use-nsec        Use nano-second histogram
      -p, --pid        Trace on existing process id
      -T, --trace-funcs 
                            Show latency of given function
      -v, --verbose         Be more verbose
          --tid        Trace on existing thread id (exclusive to --pid)

Reviewed-by: Ian Rogers 
Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20240429233707.1511175-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

libsubcmd: Fix parse-options memory leak

2024-05-10T14:16:48+00:00

If a usage string is built in parse_options_subcommand, also free it.

Fixes: 901421a5bdf605d2 ("perf tools: Remove subcmd dependencies on strbuf")
Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Josh Poimboeuf 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20240509052015.1914670-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

tools subcmd: Add check_if_command_finished()

2024-04-08T20:43:20+00:00

Add non-blocking function to check if a 'struct child_process' has
completed. If the process has completed the exit code is stored in the
'struct child_process' so that finish_command() returns it.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20240405070931.1231245-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

tools subcmd: Add a no exec function call option

2024-02-22T17:12:25+00:00

Tools like perf fork tests in case they crash, but they don't want to
exec a full binary. Add an option to call a function rather than do an
exec. The child process exits with the result of the function call and
is passed the struct of the run_command, things like container_of can
then allow the child process function to determine additional
arguments.

Signed-off-by: Ian Rogers 
Cc: James Clark 
Cc: Justin Stitt 
Cc: Bill Wendling 
Cc: Nick Desaulniers 
Cc: Yang Jihong 
Cc: Nathan Chancellor 
Cc: Kan Liang 
Cc: Athira Jajeev 
Cc: llvm@lists.linux.dev
Signed-off-by: Namhyung Kim 
Link: https://lore.kernel.org/r/20240221034155.1500118-5-irogers@google.com

libsubcmd: Fix memory leak in uniq()

2024-01-04T21:29:17+00:00

uniq() will write one command name over another causing the overwritten
string to be leaked. Fix by doing a pass that removes duplicates and a
second that removes the holes.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Chenyuan Mi 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20231208000515.1693746-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

libsubcmd: Avoid SEGV/use-after-free when commands aren't excluded

2023-07-11T19:44:12+00:00

The array shortening may perform unnecessary array copies.

Before commit 657a3efee43a ("lib subcmd: Avoid memory leak in
exclude_cmds") this was benign, but afterwards this could lead to a
SEGV.

Fixes: 657a3efee43a29d1 ("lib subcmd: Avoid memory leak in exclude_cmds")
Signed-off-by: Ian Rogers 
Acked-by: Namhyung Kim 
Cc: Chenyuan Mi 
Cc: Ian Rogers 
Link: https://lore.kernel.org/r/20230707230926.841086-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo