kernel/linux.git/tools/lib/subcmd, branch v6.12.80

libsubcmd: Fix null intersection case in exclude_cmds()

2026-03-04T12:20:49+00:00

[ Upstream commit b6ee9b6e206b288921c14c906eebf4b32fe0c0d8 ] When there is no exclusion occurring from the cmds list - for example - cmds contains ["read-vdso32"] and excludes contains ["archive"] - the main loop completes with ci == cj == 0. In the original code the loop processing the remaining elements in the list was conditional: if (ci != cj) { ...} So we end up in the assertion loop since ci < cmds->cnt and we incorrectly try to assert the list elements to be NULL and fail with the following error help.c:104: exclude_cmds: Assertion `cmds->names[ci] == NULL' failed. Fix this by moving the if (ci != cj) check inside of a broader loop. If ci != cj, left shift the list elements, as before, and then unconditionally advance the ci and cj indicies which also covers the ci == cj case. Fixes: 1fdf938168c4d26f ("perf tools: Fix use-after-free in help_unknown_cmd()") Reviewed-by: Guilherme Amadio Signed-off-by: Sri Jayaramappa Tested-by: Guilherme Amadio Tested-by: Ian Rogers Cc: Joshua Hunt Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20251202213632.2873731-1-sjayaram@akamai.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf subcmd: avoid crash in exclude_cmds when excludes is empty

2025-10-12T10:57:16+00:00

[ Upstream commit a5edf3550f4260504b7e0ab3d40d13ffe924b773 ] When cross-compiling the perf tool for ARM64, `perf help` may crash with the following assertion failure: help.c:122: exclude_cmds: Assertion `cmds->names[ci] == NULL' failed. This happens when the perf binary is not named exactly "perf" or when multiple "perf-*" binaries exist in the same directory. In such cases, the `excludes` command list can be empty, which leads to the final assertion in exclude_cmds() being triggered. Add a simple guard at the beginning of exclude_cmds() to return early if excludes->cnt is zero, preventing the crash. Signed-off-by: hupu Reported-by: Guilherme Amadio Reviewed-by: Namhyung Kim Link: https://lore.kernel.org/r/20250909094953.106706-1-amadio@gentoo.org Signed-off-by: Namhyung Kim Signed-off-by: Sasha Levin

perf tools: Fix use-after-free in help_unknown_cmd()

2025-08-15T10:13:51+00:00

[ Upstream commit 1fdf938168c4d26fa279d4f204768690d1f9c4ae ] Currently perf aborts when it finds an invalid command. I guess it depends on the environment as I have some custom commands in the path. $ perf bad-command perf: 'bad-command' is not a perf-command. See 'perf --help'. Aborted (core dumped) It's because the exclude_cmds() in libsubcmd has a use-after-free when it removes some entries. After copying one to another entry, it keeps the pointer in the both position. And the next copy operation will free the later one but it's the same entry in the previous one. For example, let's say cmds = { A, B, C, D, E } and excludes = { B, E }. ci cj ei cmds-name excludes -----------+-------------------- 0 0 0 | A B : cmp < 0, ci == cj 1 1 0 | B B : cmp == 0 2 1 1 | C E : cmp < 0, ci != cj At this point, it frees cmds->names[1] and cmds->names[1] is assigned to cmds->names[2]. 3 2 1 | D E : cmp < 0, ci != cj Now it frees cmds->names[2] but it's the same as cmds->names[1]. So accessing cmds->names[1] will be invalid. This makes the subcmd tests succeed. $ perf test subcmd 69: libsubcmd help tests : 69.1: Load subcmd names : Ok 69.2: Uniquify subcmd names : Ok 69.3: Exclude duplicate subcmd names : Ok Fixes: 4b96679170c6 ("libsubcmd: Avoid SEGV/use-after-free when commands aren't excluded") Reviewed-by: Ian Rogers Link: https://lore.kernel.org/r/20250701201027.1171561-3-namhyung@kernel.org Signed-off-by: Namhyung Kim Signed-off-by: Sasha Levin

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