From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A955B18EBF for ; Thu, 18 Jul 2024 03:12:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721272330; cv=none; b=QTjqjBCphNLPJbVJFcSJ31eEcUI112VgnYiLHFaK77FuKb84kUs8pSheMogyadKX3oF9BLmm+4Z6KxSX1oNwLbxFIkpQT5P3kvHduSpXxkAe6si5cKwPEYgX2dzTow+GjGeU0yr4Ye+1MaUdvwjJqoMu/B2wmHMkD4tcXvSOjg0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721272330; c=relaxed/simple; bh=w5/85RdFl+8Vx0ZQWvP37cBxciSRDyJRRx6d6zPWtVY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Gfy9F5VHOOaoG87XspEcpNNBA6Wpyt3dphfuRfwUDIUCdHnoiFyR3KcYp98WY6GzPOuA35RRaBARK0yUVJR6EbujDnBCgwcWQ3MVlhRoti5I78hj5whbuN09HX80Saedq8h5HblFt1uvsWmiWKUwWQMdej84ijDVlWmWRG+uYrY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pw9UDoQa; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="pw9UDoQa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F2BC2C2BD10; Thu, 18 Jul 2024 03:12:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1721272330; bh=w5/85RdFl+8Vx0ZQWvP37cBxciSRDyJRRx6d6zPWtVY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pw9UDoQaCsFwxkJf/XAg+UeOc7qkWRqIs8a1ALcstA65iOAyZMoc+lEgarig9Irh5 AQJt/hrg1kcRUumfwjhfA3kN4UnsgKouTCsIsqgyCA5k9D6LduIZCNq85zuykucl3j NFbgsxuqVNMcmder7Zfw9ak1sBwN3Xc2/cDXd3luLscv6xuQB/zYnTAjev7l0tmN6Y atLkVC8ceFhRsfOSlodF6NnnExjcgAGjRMUv1sn0G73T/SGX7XBbSMIXBU5MxVvDFC z83IWnYT7I3I3PDuVNmGZFVOlvxuWVS9YOHarP74WyZV/JOkIsF3yHYh/EfVEkLPiV pCLcrjxOqjsFA== Date: Wed, 17 Jul 2024 20:12:07 -0700 From: Namhyung Kim To: Aditya Gupta Cc: linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , Jiri Olsa , Ian Rogers Subject: Re: [RFC PATCH] tools/lib/subcmd: Don't free the usage string Message-ID: References: <20240717103351.268344-1-adityag@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20240717103351.268344-1-adityag@linux.ibm.com> On Wed, Jul 17, 2024 at 04:03:51PM +0530, Aditya Gupta wrote: > 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: > > commit 230a7a71f9221 ("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/ > > Cc: Arnaldo Carvalho de Melo > Cc: Jiri Olsa > Cc: Ian Rogers > Cc: Namhyung Kim > Fixes: 230a7a71f922 ("libsubcmd: Fix parse-options memory leak") > Suggested-by: Namhyung Kim > Signed-off-by: Aditya Gupta Acked-by: Namhyung Kim Thanks, Namhyung > --- > 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 6fd95be5032b..6b88b8b40784 100644 > --- a/tools/perf/builtin-kmem.c > +++ b/tools/perf/builtin-kmem.c > @@ -2058,6 +2058,8 @@ 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 71165036e4ca..988bef73bd09 100644 > --- a/tools/perf/builtin-kvm.c > +++ b/tools/perf/builtin-kvm.c > @@ -2187,5 +2187,8 @@ 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 56e3f3a5e03a..fd53838b5a78 100644 > --- a/tools/perf/builtin-kwork.c > +++ b/tools/perf/builtin-kwork.c > @@ -2520,5 +2520,8 @@ 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 0253184b3b58..b25d50716e63 100644 > --- a/tools/perf/builtin-lock.c > +++ b/tools/perf/builtin-lock.c > @@ -2713,6 +2713,9 @@ 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 863fcd735dae..b7c1cf6d0e5a 100644 > --- a/tools/perf/builtin-mem.c > +++ b/tools/perf/builtin-mem.c > @@ -517,5 +517,8 @@ 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 8750b5f2d49b..d6acc53ae89e 100644 > --- a/tools/perf/builtin-sched.c > +++ b/tools/perf/builtin-sched.c > @@ -3805,5 +3805,8 @@ 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; > } > -- > 2.45.2 >