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 887DA1F874C; Wed, 26 Mar 2025 19:44:53 +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=1743018293; cv=none; b=m+giM1oWNfXj84OWkJB9p17ygr66FsTSAG0nBmOzjENgKNPAZHDFemzuqgfAVgsvR9GyHxEbLBCE9g8fXhcaBTSehxJfb2xwSAIfrC1UfmCGvTfcBssL/MTndHXTSZoP9OvEz+b5oQbrrhe5AuyEAgjwHCqqYkA/8k2j5+6Fj8Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743018293; c=relaxed/simple; bh=ZuGZdlxag0lNcb4sPp3slceQhcfQ2ep2MXXbfB+zpKc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kGYu43fkWUJSeQV8CcBx/YZoDqAcl14H+hjGwGu2TsVW6jF5weye6zoAVSy6fhA02ofk3yZh4oeixjWIKsshPagOKU7+aveWmmv3+SYbG6i7bJ0/FDwgNss4dB3SZnsUbO8sjWRHmRQwvMq+SXvU5mH9vWzZDQcwGtM2UJr6MyU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nhPRtKO0; 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="nhPRtKO0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95C59C4CEE2; Wed, 26 Mar 2025 19:44:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743018293; bh=ZuGZdlxag0lNcb4sPp3slceQhcfQ2ep2MXXbfB+zpKc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nhPRtKO0AnQM/NBgN6SXiSCbRBpj4AQWfUmkF3LraRAwVzbFk37x9f+j+tCD/d4Hw irv6oMAB6BM6RRGVl3DbqptIy4ZPDBAsHwKMTN/o0/slRGYaZi1f2c0CLWGOlIZz4g PgD659cqbqphj54H41vFwTHUUtG/9ptbORcF8LVCHOFTFQnPiQVX4YohKp1YR8A6TD 1gcI3yygcJGaCa0Uc4mO04devWFuNghggfJDFjZ6EVTKIxSFTiLYJ5xoKvLIK8MUEy UY3BZyMxZWYrjW/0EO/ZuCsvb5v0//QoZ4tjVjBl4DsgS8M5IOnonqcuX9f0sZ3Y5a 6sZjtkRHQAm+g== Date: Wed, 26 Mar 2025 12:44:51 -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 Content-Transfer-Encoding: 8bit In-Reply-To: On Wed, Mar 26, 2025 at 11:30:11AM -0700, Howard Chu wrote: > Hello Namhyung, > > LGTM. This is better. :) Great, can you please resend it with my Suggested-by? Thanks, Namhyung > > On Wed, Mar 26, 2025 at 11:21 AM Namhyung Kim wrote: > > > > 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 > >