From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 3044016F27F; Wed, 24 Jun 2026 23:33:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782344024; cv=none; b=QVSmt22lVKq++7dwEtP00foeVPIQUT1LaiqR3e6zcvz4NhNZBtXp5SLNlB4btnxSOgTaX4Ygf9/VkiCTd29IE709FvKgOGAfL81yp4asDT2TG+HzToAsa6i5lm6nzPkzwXCjbVSeoLQ61rk14Qm5dTRwOPZMVsjkyP4H26zg0uU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782344024; c=relaxed/simple; bh=2eORMWxcorD3GAQSTGiMyCp0CCsM1hgP033YdXPZqDU=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=cYKhIjuFKnfP5SVD9WnwF1vqYHeMZ5VzPPZ0dwnImNewaeDUD7T8sxm5/FsfGMn5jhPUZFHcJljDDMzz250Mb68yJ6Vau80i7GE/CgzoQAcAcJJ9yI+2rkZYz/lEgE8c9MlD4/3bEFag0gLB9RciYTjbcX6WDwirCCR0XpRUkHU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=c7BUcnmO; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="c7BUcnmO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9C6641F000E9; Wed, 24 Jun 2026 23:33:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782344022; bh=adqpob2PJ285ilftSDw/zm0UkI/paO9O/1Yyd2iQc4g=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=c7BUcnmOaV7QFceNFKLvWozS3pDjLp9Oj0jq56AlT9e2WIHRewYSjXAjlD4vsr8hE YOH6AE0LtILCZgU+RuiefvyWZg78sS/FQsKymWGN66NWtkmi5sNnH7zXPXjmiEY/vx IzYNSIYnzIOYJcDbj7CrV9nfb0MvAofSvl3F4XjbPmOZQ6A+UowJHPePgH5BTLxAYv +WWfuXbfpFiG6fvkmmQzlOFC76j2foyg7z2MEqjc7zWFoTl3s7jyNUkNed2sFu+Hbo WCWIMUj0+PcKD8iHxAtoEBcaDSvqXekOUsoeUFfDrkLoI4Uuzcpjgn3Zc3oLfGQWqj yiZ2d80Kauc2Q== Date: Thu, 25 Jun 2026 08:33:38 +0900 From: Masami Hiramatsu (Google) To: "Masami Hiramatsu (Google)" Cc: Steven Rostedt , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v8 01/10] tracing/probes: Make the $ prefix mandatory for comm access Message-Id: <20260625083338.60b38483b5766c841ce4af32@kernel.org> In-Reply-To: <178231209724.732967.12049805699091810641.stgit@devnote2> References: <178231208703.732967.1160700962651040729.stgit@devnote2> <178231209724.732967.12049805699091810641.stgit@devnote2> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 24 Jun 2026 23:41:37 +0900 "Masami Hiramatsu (Google)" wrote: > From: Masami Hiramatsu (Google) > > Since $comm or $COMM are not event field but special fetcharg > variables to access current->comm, It should not be accessed > without '$' prefix even with typecast. > Let me pick this to probes/core. Thanks, > Fixes: 69efd863a785 ("tracing/eprobes: Allow use of BTF names to dereference pointers") > Signed-off-by: Masami Hiramatsu (Google) > --- > Changes in v8: > - Newly added. > --- > kernel/trace/trace_probe.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c > index c10bbb0df7b9..0da7c0b53ba7 100644 > --- a/kernel/trace/trace_probe.c > +++ b/kernel/trace/trace_probe.c > @@ -342,10 +342,6 @@ static int parse_trace_event(char *arg, struct fetch_insn *code, > ret = parse_trace_event_arg(arg, code, ctx); > if (!ret) > return 0; > - if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { > - code->op = FETCH_OP_COMM; > - return 0; > - } > return -EINVAL; > } > > @@ -1065,8 +1061,14 @@ static int parse_probe_vars(char *orig_arg, const struct fetch_type *t, > int len; > > if (ctx->flags & TPARG_FL_TEVENT) { > - if (parse_trace_event(arg, code, ctx) < 0) > + if (parse_trace_event(arg, code, ctx) < 0) { > + /* 'comm' should be checked after field parsing. */ > + if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { > + code->op = FETCH_OP_COMM; > + return 0; > + } > goto inval; > + } > return 0; > } > > -- Masami Hiramatsu (Google)