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 E2B95395D87; Sat, 7 Mar 2026 15:12:38 +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=1772896359; cv=none; b=mtfLsUrDhtnIQ/B65SoNXV5Z33ziv+nHd+zeBNTTpsAZioAeR8pPKHaegWQ+PCeKT0XJpp4UMkjRcbaNOHKmE6ILWh5rw8GizvvAxjMifSbcbkwK3EKAzqcEnaCgya+NdRiPqi9xwNZZGkjl1UOTCajsRL3EPFEn5wur1Ra38LY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772896359; c=relaxed/simple; bh=WAy+8low3pplFgAVrxMFFzftkqpYzsxhPoP9RFA1wOg=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=BOVoslQjAsz3bZMXo9t7v1yHUEYCfHMM7VSbQv/nWr4D3UqgGXZ9kMR8yoqK8cXRUPURvBLfPcSeS7zYBlCj1cHYpZCmYAfxKR/bH2jQ1dLDDWY+1DPP+8cKD1chaKuBAqb9Pwj34Ps3clS0jHe9YcGShFI7eAwUJPYUPxHu4KE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TmWEfbYk; 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="TmWEfbYk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA136C2BCAF; Sat, 7 Mar 2026 15:12:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772896358; bh=WAy+8low3pplFgAVrxMFFzftkqpYzsxhPoP9RFA1wOg=; h=Date:From:To:Cc:Subject:References:From; b=TmWEfbYk5kXp+T06ZIjvWlf+KPf/bm8/wNHLbeNJeKLoxZ3yDxkRtQfApY0Yf2Q/9 lMYbk/BzMt0zRRJ+Y6JIHvbSgfqodEj4W1D+5yLOcwNuj2fZViQqtYVguo76IB4g1L M0bvt0m/MzKGnNODs/9kwjLrjTmfWhYZqnc44vmiK8euj6NRsVT2Q5lARN8257DtWY luYs0YdIHLbJaHcfgXTIVUnE7KVAstFu7gC3pYsSIR9Bmq5pxMJ1zLCBYA1/xbP28n Cw1O+W84dtyy9cnsn0Kl5TMQ5cQ+6ELuUo+wkIVStXJqmBwnqbM4TC5sWjh1zGXoo9 F/ge1MQQHu+2w== Received: from rostedt by gandalf with local (Exim 4.99.1) (envelope-from ) id 1vytKc-000000010Ns-08Vs; Sat, 07 Mar 2026 10:12:42 -0500 Message-ID: <20260307151241.888254981@kernel.org> User-Agent: quilt/0.69 Date: Sat, 07 Mar 2026 10:12:26 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , stable@vger.kernel.org, Andrei-Alexandru Tachici Subject: [for-linus][PATCH 2/3] tracing: Fix enabling multiple events on the kernel command line and bootconfig References: <20260307151224.447677123@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: Andrei-Alexandru Tachici Multiple events can be enabled on the kernel command line via a comma separator. But if the are specified one at a time, then only the last event is enabled. This is because the event names are saved in a temporary buffer, and each call by the init cmdline code will reset that buffer. This also affects names in the boot config file, as it may call the callback multiple times with an example of: kernel.trace_event = ":mod:rproc_qcom_common", ":mod:qrtr", ":mod:qcom_aoss" Change the cmdline callback function to append a comma and the next value if the temporary buffer already has content. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Link: https://patch.msgid.link/20260302-trace-events-allow-multiple-modules-v1-1-ce4436e37fb8@oss.qualcomm.com Signed-off-by: Andrei-Alexandru Tachici Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_events.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index b7343fdfd7b0..249d1cba72c0 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -4493,7 +4493,11 @@ static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata; static __init int setup_trace_event(char *str) { - strscpy(bootup_event_buf, str, COMMAND_LINE_SIZE); + if (bootup_event_buf[0] != '\0') + strlcat(bootup_event_buf, ",", COMMAND_LINE_SIZE); + + strlcat(bootup_event_buf, str, COMMAND_LINE_SIZE); + trace_set_ring_buffer_expanded(NULL); disable_tracing_selftest("running event tracing"); -- 2.51.0