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 7BBC21F7561; Wed, 26 Mar 2025 18:21:50 +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=1743013310; cv=none; b=hZ3F03S6lDUXAIDn0ZyqDr03aWargiK51A1hiRmSIKV2pRs6Z4IZjnJNGeWDHXG9nsjrIwuxEwoXRHXOYp+AF3k5pwMdYhcdr3cO54XgwFDVY5x3EC65S3c4zftRDcqxLWZGrcXbyP8+5wdlHtvj/mAMzCWuscsV1WTDqcoXu6g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743013310; c=relaxed/simple; bh=KzXSavSeEQvSYOYQr3q8Tb6HTNl/rJqVxIkNxLAVrV0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=G+MMgrR5byfp7BoyRksbkkduvlbSTkevXGtNxT+ShzUInXOSh4P79+25yhvNtLPNBvSlKUOHSo6g9Otj9QxrSv8zwn0jblmno54pS2jkomZivqRfnE3YioWbHZP235t7ipQGm5zNcpEuKr91azzZ3WcDp6eRRICOWOXX+WtP+Mc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=vBlAVG0w; 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="vBlAVG0w" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3A5A2C4CEE2; Wed, 26 Mar 2025 18:21:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743013309; bh=KzXSavSeEQvSYOYQr3q8Tb6HTNl/rJqVxIkNxLAVrV0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vBlAVG0wBZM7HF9+mEoNEcVtcrgGer1vv+lAbs+H57fQy+LRHpt9LGCB1h5UrrB3t fVNF+hyWjEo7LBywTU7CSmfv660NbadZllILZgr6ghpdRF3lybdO25La4elmQirge6 iTy7AtT4j043KvIs9VfUGcMMJb5iHZpiKuSFOljQHHkIiMURhCoi58/SOO/feoj0FH G3wygWD5pjaqdTqwIXcUPCZx7NsAou+eIeBHUL7Qg99reIe/TR831/lRXxleRW0oZ0 NRrk3rZRicbA8ljqs/+mbKdghedRT9T6pttbWK3tFtTiFTxg4+iG6q0mnIkEIWxLAa 7wwP+/aZnvDAA== Date: Wed, 26 Mar 2025 11:21:47 -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 v1] perf trace: Fix possible insufficient allocation of argument formats Message-ID: References: <20250324235245.613063-1-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: <20250324235245.613063-1-howardchu95@gmail.com> On Mon, Mar 24, 2025 at 04:52:45PM -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/), > 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. Thanks for the fix. I've noticed this too but I feel like we can make syscall__alloc_arg_fmts() a bit simpler. How about this? Thanks, Namhyung ---8<--- diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 6ac51925ea4249c2..b9bdab52f5801c3a 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"); -- 2.49.0.395.g12beb8f557-goog