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 1A0324A2A for ; Sat, 9 Mar 2024 19:07:01 +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=1710011221; cv=none; b=mSi7nBKK31/swDCxbVXwvMaQTbtlPepoftG+Ci++8753YOxXohnjaC9weZ8XcGpRrVO8oxezRI7F1+YNkZpViX3tvUtOaafxIdFehW3efQw5SqFaUKfeWG/r4WzTwO5Aja5S67ENXVwoQ6D5TdVWJ9FXuD7/SxJfv//vIb418/E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710011221; c=relaxed/simple; bh=l+E5knTm106NChr1G+H7nQsZfmww+heyhg9acaF1kfk=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=nmLGoSwck1TL4fM9xY7OXuDAK+rcU96OdoylCQS1+TtG/UFAocam9M5wUYL3zXmkcJ6wuXWbzf73mGgJo3ksn3h6AoYX4S7G0L4omhaX+xXx4/PV6FjKc1Dbyi2pbmxZkUZhQuqgR9r+d6PsCvC+xHoTLxW7IdMxCcZZ3mddppo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RSgcYCY3; 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="RSgcYCY3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 849E4C433F1; Sat, 9 Mar 2024 19:06:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1710011220; bh=l+E5knTm106NChr1G+H7nQsZfmww+heyhg9acaF1kfk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=RSgcYCY34PspTvuxX9KdKgFbJ+vI3O3hmhvmLvd9ShKlgBXn4MMBhg0eA4e1d28Du UCI8aJfjfvWuQa3Up1lG10H/HnWcgkZAnPWvyQpP0gFRiBYyFaOrV6jTiMcmuFBn23 o43ABCkDQN+2SSkfb5oGHRb/Il0UeEz8uIZypIv5YQMbNoUMby+HNVv/P0ieiAoImm 2vejfXfL0nWjEQer0dH/cLVs8wAo+Af604YMM4WI9S5U7themxy4md3/MNwKiXbTnJ gPciJygbDjlU5Y/S/ev0AzlFchwnMPuNa8l4a4SOEtODXOs6NIE0rvaCJeK1igtszx 1ffXfjnBj4Fng== Date: Sat, 9 Mar 2024 19:06:49 +0000 From: Jonathan Cameron To: Sean Anderson Cc: Manish Narani , Anand Ashok Dumbre , linux-iio@vger.kernel.org, Jonathan Cameron Subject: Re: iio: xilinx-ams: shift-out-of-bounds in ams_enable_channel_sequence Message-ID: <20240309190649.04be7261@jic23-huawei> In-Reply-To: References: X-Mailer: Claws Mail 4.2.0 (GTK 3.24.41; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-iio@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 Tue, 5 Mar 2024 12:30:53 -0500 Sean Anderson wrote: > Hi, > > When enabling UBSAN on a ZynqMP Ultrascale+, I see the following error during boot: > > [ 1.447628] ================================================================================ > [ 1.447832] UBSAN: shift-out-of-bounds in ../drivers/iio/adc/xilinx-ams.c:426:16 > [ 1.448019] shift exponent 66 is too large for 64-bit type 'long long unsigned int' > [ 1.448211] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 6.6.20+ #90 > [ 1.448368] Hardware name: xlnx,zynqmp (DT) > [ 1.448475] Call trace: > [ 1.448547] dump_backtrace+0x9c/0x11c > [ 1.448655] show_stack+0x18/0x24 > [ 1.448749] dump_stack_lvl+0xac/0xd4 > [ 1.448853] dump_stack+0x18/0x24 > [ 1.448947] ubsan_epilogue+0x10/0x44 > [ 1.449051] __ubsan_handle_shift_out_of_bounds+0x98/0x134 > [ 1.449191] ams_enable_channel_sequence+0x22c/0x23c > [ 1.449324] ams_probe+0x570/0x6d4 > [ 1.449423] platform_probe+0x68/0x108 > [ 1.449530] really_probe+0x158/0x3b0 > [ 1.449632] __driver_probe_device+0x88/0x1a0 > [ 1.449747] driver_probe_device+0x3c/0x138 > [ 1.449859] __driver_attach+0xe4/0x1bc > [ 1.449964] bus_for_each_dev+0x78/0xe0 > [ 1.450068] driver_attach+0x24/0x30 > [ 1.450167] bus_add_driver+0x110/0x240 > [ 1.450271] driver_register+0x60/0x128 > [ 1.450376] __platform_driver_register+0x28/0x34 > [ 1.450500] ams_driver_init+0x1c/0x28 > [ 1.450609] do_one_initcall+0x78/0x2c8 > [ 1.450714] kernel_init_freeable+0x2f8/0x59c > [ 1.450831] kernel_init+0x30/0x150 > [ 1.450932] ret_from_fork+0x10/0x20 > [ 1.451073] ================================================================================ > > When applying the following patch: > That channel definition looks suspicious. Anyone shed light on what the channel scan index layout is supposed to be? There seem to be substantial gaps in used numbers. If I read it right the offset to jump over the AUX_CHAN is too large (22 - should be 16) but that still ends up with us going above the range of supported scan indexes. The PL Sequence mask used is GENMASK_ULL(59, 22) Whilst the bits are set, nothing actually reads them that I can see. So why are they set and how are those channels supposed to work? So agreed buggy; no idea what it supposed to do! Jonathan > diff --git a/drivers/iio/adc/xilinx-ams.c b/drivers/iio/adc/xilinx-ams.c > index f0b71a1220e0..1ced8cff461a 100644 > --- a/drivers/iio/adc/xilinx-ams.c > +++ b/drivers/iio/adc/xilinx-ams.c > @@ -414,8 +414,17 @@ static void ams_enable_channel_sequence(struct iio_dev *indio_dev) > > /* Run calibration of PS & PL as part of the sequence */ > scan_mask = BIT(0) | BIT(AMS_PS_SEQ_MAX); > - for (i = 0; i < indio_dev->num_channels; i++) > + for (i = 0; i < indio_dev->num_channels; i++) { > + if (indio_dev->channels[i].scan_index >= 64) { > + const struct iio_chan_spec *chan = &indio_dev->channels[i]; > + > + dev_warn(&indio_dev->dev, > + "channel %d (%d %d.%d @ %lx) has scan_index %d\n", > + i, chan->type, chan->channel, chan->channel2, > + chan->address, chan->scan_index); > + } > scan_mask |= BIT_ULL(indio_dev->channels[i].scan_index); > + } > > if (ams->ps_base) { > /* put sysmon in a soft reset to change the sequence */ > > I see these additional outputs: > > [ 1.447457] iio iio:device0: channel 0 (0 0.0 @ 60) has scan_index 66 > [ 1.451280] iio iio:device0: channel 1 (0 1.0 @ 6c) has scan_index 67 > [ 1.451446] iio iio:device0: channel 2 (0 2.0 @ 78) has scan_index 68 > [ 1.451612] iio iio:device0: channel 3 (0 3.0 @ 7c) has scan_index 69 > [ 1.451777] iio iio:device0: channel 4 (0 4.0 @ 80) has scan_index 70 > [ 1.451942] iio iio:device0: channel 5 (0 5.0 @ 84) has scan_index 71 > [ 1.452107] iio iio:device0: channel 6 (0 6.0 @ 9c) has scan_index 72 > > Indicating that the issue is with the ams_ctrl_channels using the > AMS_CTRL_CHAN_VOLTAGE macro. > > --Sean >