From 1a5efc9e13f357abc396dbf445b25d08914c8060 Mon Sep 17 00:00:00 2001 From: Aditya Gupta Date: Wed, 4 Sep 2024 11:48:30 +0530 Subject: [PATCH] libsubcmd: Don't free the usage string 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/lib/subcmd/parse-options.c | 8 +++----- tools/perf/builtin-kmem.c | 2 ++ tools/perf/builtin-kvm.c | 3 +++ tools/perf/builtin-kwork.c | 3 +++ tools/perf/builtin-lock.c | 3 +++ tools/perf/builtin-mem.c | 3 +++ tools/perf/builtin-sched.c | 3 +++ 7 files changed, 20 insertions(+), 5 deletions(-) diff --git a/tools/lib/subcmd/parse-options.c b/tools/lib/subcmd/parse-options.c index 4b60ec03b0bb..eb896d30545b 100644 --- a/tools/lib/subcmd/parse-options.c +++ b/tools/lib/subcmd/parse-options.c @@ -633,10 +633,11 @@ int parse_options_subcommand(int argc, const char **argv, const struct option *o const char *const subcommands[], const char *usagestr[], int flags) { struct parse_opt_ctx_t ctx; - char *buf = NULL; /* build usage string if it's not provided */ if (subcommands && !usagestr[0]) { + char *buf = NULL; + astrcatf(&buf, "%s %s [] {", subcmd_config.exec_name, argv[0]); for (int i = 0; subcommands[i]; i++) { @@ -678,10 +679,7 @@ int parse_options_subcommand(int argc, const char **argv, const struct option *o astrcatf(&error_buf, "unknown switch `%c'", *ctx.opt); usage_with_options(usagestr, options); } - if (buf) { - usagestr[0] = NULL; - free(buf); - } + return parse_options_end(&ctx); } diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c index b3cbac40b8c7..a756147e2eec 100644 --- a/tools/perf/builtin-kmem.c +++ b/tools/perf/builtin-kmem.c @@ -2057,6 +2057,8 @@ int cmd_kmem(int argc, const char **argv) out_delete: perf_session__delete(session); + /* free usage string allocated by parse_options_subcommand */ + free((void *)kmem_usage[0]); return ret; } diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c index 692267b1b7e8..55ea17c5ff02 100644 --- a/tools/perf/builtin-kvm.c +++ b/tools/perf/builtin-kvm.c @@ -2184,5 +2184,8 @@ int cmd_kvm(int argc, const char **argv) else usage_with_options(kvm_usage, kvm_options); + /* free usage string allocated by parse_options_subcommand */ + free((void *)kvm_usage[0]); + return 0; } diff --git a/tools/perf/builtin-kwork.c b/tools/perf/builtin-kwork.c index 6a4281b8fd10..c1daf82c9b92 100644 --- a/tools/perf/builtin-kwork.c +++ b/tools/perf/builtin-kwork.c @@ -2519,5 +2519,8 @@ int cmd_kwork(int argc, const char **argv) } else usage_with_options(kwork_usage, kwork_options); + /* free usage string allocated by parse_options_subcommand */ + free((void *)kwork_usage[0]); + return 0; } diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c index 2c216427e929..062e2b56a2ab 100644 --- a/tools/perf/builtin-lock.c +++ b/tools/perf/builtin-lock.c @@ -2712,6 +2712,9 @@ int cmd_lock(int argc, const char **argv) usage_with_options(lock_usage, lock_options); } + /* free usage string allocated by parse_options_subcommand */ + free((void *)lock_usage[0]); + zfree(&lockhash_table); return rc; } diff --git a/tools/perf/builtin-mem.c b/tools/perf/builtin-mem.c index 18e5f9a0ddc2..bb38bb5a1c26 100644 --- a/tools/perf/builtin-mem.c +++ b/tools/perf/builtin-mem.c @@ -546,5 +546,8 @@ int cmd_mem(int argc, const char **argv) else usage_with_options(mem_usage, mem_options); + /* free usage string allocated by parse_options_subcommand */ + free((void *)mem_usage[0]); + return 0; } diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index 0a7b2b2acd56..5981cc51abc8 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -3954,5 +3954,8 @@ int cmd_sched(int argc, const char **argv) usage_with_options(sched_usage, sched_options); } + /* free usage string allocated by parse_options_subcommand */ + free((void *)sched_usage[0]); + return 0; }