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 02156320F; Sun, 30 Mar 2025 05:31:03 +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=1743312664; cv=none; b=cfHfLhUPSOHvrHdAMaJstzmyBiEE73Z9qzl+73k2A8NUEVNA44ZQNzm8+BnfIzjH/FAzrFRyV3lWk0/G0Y2UOSSOtCE1asw9X9i1U0PrhO/GJNiGXr2YxWGH7rAVk1FPMwgUlwSIItp47O/GQC7et/8k9jl7/6RD17NhRHBCue8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743312664; c=relaxed/simple; bh=NFU/YikADQxcJQeCAfrzyx+W1ZgmCapXzp4xW1oVzkE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jZEiUclA9+juxBAHOgypCjPpndxV6mrgUsSakb4ofDqgH9Wn0a6TVf5HH9oOOszoTxHV3Tb1kGlAGWkbrANSkbmAYCJgeJJJEM3cdWdEcrLIgzc+YceubSmkAxpuqik7tpukZQWIHQaL8gfDx2NoEVOsQj9IP9Rw0EFTFkP1yjw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MMljdRl6; 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="MMljdRl6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE5EBC4CEDD; Sun, 30 Mar 2025 05:31:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743312663; bh=NFU/YikADQxcJQeCAfrzyx+W1ZgmCapXzp4xW1oVzkE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MMljdRl6RVvimS+EeN6782HtBFiJjgINqI62G+m+pB30edB9+/37x+Qm4IhmpHevi 5uWHIndM1LCpGOjbqTk4hEoOrzM8LqqHKiBv9eRL/2/DpH1OMP9rmdiLqmbc3joQYW Zynlii8eRjmXmnatXyzaWNn+BhkWN/Tc3SPW1sHKxhsfMP/6rF7dRBcgQqfDLXNM65 +wwsIqnSdfoiSBDvYlwMV29V0wKwnPX5a5b4B+dZxZ074PiUfQFwkG4PggXp7HShn1 4Cnmn2C84BTgeocjOKS0Izg0a5yBSYD4nx0abnHiUF74eP6tlaGa27OnT4Yqqo1haw jog/dWHYhA4vQ== Date: Sat, 29 Mar 2025 22:31:01 -0700 From: Namhyung Kim To: Howard Chu Cc: acme@kernel.org, mingo@redhat.com, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, peterz@infradead.org, kan.liang@linux.intel.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4] perf trace: Fix possible insufficient allocation of argument formats Message-ID: References: <20250327150712.1966188-1-howardchu95@gmail.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: <20250327150712.1966188-1-howardchu95@gmail.com> Hello, On Thu, Mar 27, 2025 at 08:07:12AM -0700, Howard Chu wrote: > In my previous fix of runtime error(Link: > https://lore.kernel.org/linux-perf-users/20250122025519.361873-1-howardchu95@gmail.com/), We usually handle this by adding a footnote style link like, [1]. > I made a mistake of decrementing one unconditionally, regardless of > whether an extra 'syscall_nr' or 'nr' field was present in > libtraceevent's tp_format. This may cause perf trace to allocate one > fewer arg_fmt entry than needed for the accurate representation of syscall > arguments. > > This patch corrects the mistake by checking the presence of'syscall_nr' or > 'nr', and adjusting the length of arg_fmt[] accordingly. > > Signed-off-by: Howard Chu > Suggested-by: Namhyung Kim > Fixes: c7b87ce0dd10 ("perf trace: Fix runtime error of index out of bounds") And add the link here. [1] (actual URL here) Also you need to keep three dashes "---" before the change log so that it can be treated as comments (and not added to the commit message). Please take a look at my previous posting. https://lore.kernel.org/r/20250326044001.3503432-1-namhyung@kernel.org Thanks, Namhyung > > Changes in v4: > - Make the patch apply > > Changes in v3: > - Add 'Fixes:' tag > > Changes in v2: > - Simplify the code (written by Namhyung) > > tools/perf/builtin-trace.c | 16 +++++----------- > 1 file changed, 5 insertions(+), 11 deletions(-) > > diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c > index a102748bd0c9..439e152186da 100644 > --- a/tools/perf/builtin-trace.c > +++ b/tools/perf/builtin-trace.c > @@ -2022,9 +2022,6 @@ static int syscall__alloc_arg_fmts(struct syscall *sc, int nr_args) > { > int idx; > > - if (nr_args == RAW_SYSCALL_ARGS_NUM && sc->fmt && sc->fmt->nr_args != 0) > - nr_args = sc->fmt->nr_args; > - > sc->arg_fmt = calloc(nr_args, sizeof(*sc->arg_fmt)); > if (sc->arg_fmt == NULL) > return -1; > @@ -2034,7 +2031,6 @@ static int syscall__alloc_arg_fmts(struct syscall *sc, int nr_args) > sc->arg_fmt[idx] = sc->fmt->arg[idx]; > } > > - sc->nr_args = nr_args; > return 0; > } > > @@ -2176,14 +2172,9 @@ static int syscall__read_info(struct syscall *sc, struct trace *trace) > return err; > } > > - /* > - * The tracepoint format contains __syscall_nr field, so it's one more > - * than the actual number of syscall arguments. > - */ > - if (syscall__alloc_arg_fmts(sc, sc->tp_format->format.nr_fields - 1)) > - return -ENOMEM; > - > sc->args = sc->tp_format->format.fields; > + sc->nr_args = sc->tp_format->format.nr_fields; > + > /* > * We need to check and discard the first variable '__syscall_nr' > * or 'nr' that mean the syscall number. It is needless here. > @@ -2194,6 +2185,9 @@ static int syscall__read_info(struct syscall *sc, struct trace *trace) > --sc->nr_args; > } > > + if (syscall__alloc_arg_fmts(sc, sc->nr_args)) > + return -ENOMEM; > + > sc->is_exit = !strcmp(name, "exit_group") || !strcmp(name, "exit"); > sc->is_open = !strcmp(name, "open") || !strcmp(name, "openat"); > > -- > 2.45.2 >