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* iio: xilinx-ams: shift-out-of-bounds in ams_enable_channel_sequence
@ 2024-03-05 17:30 Sean Anderson
  2024-03-09 19:06 ` Jonathan Cameron
  0 siblings, 1 reply; 4+ messages in thread
From: Sean Anderson @ 2024-03-05 17:30 UTC (permalink / raw)
  To: Manish Narani, Anand Ashok Dumbre, linux-iio; +Cc: Jonathan Cameron

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:

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

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: iio: xilinx-ams: shift-out-of-bounds in ams_enable_channel_sequence
  2024-03-05 17:30 iio: xilinx-ams: shift-out-of-bounds in ams_enable_channel_sequence Sean Anderson
@ 2024-03-09 19:06 ` Jonathan Cameron
  2024-03-11 16:11   ` Sean Anderson
  0 siblings, 1 reply; 4+ messages in thread
From: Jonathan Cameron @ 2024-03-09 19:06 UTC (permalink / raw)
  To: Sean Anderson
  Cc: Manish Narani, Anand Ashok Dumbre, linux-iio, Jonathan Cameron

On Tue, 5 Mar 2024 12:30:53 -0500
Sean Anderson <sean.anderson@linux.dev> 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
> 


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: iio: xilinx-ams: shift-out-of-bounds in ams_enable_channel_sequence
  2024-03-09 19:06 ` Jonathan Cameron
@ 2024-03-11 16:11   ` Sean Anderson
  2024-03-11 16:30     ` Sean Anderson
  0 siblings, 1 reply; 4+ messages in thread
From: Sean Anderson @ 2024-03-11 16:11 UTC (permalink / raw)
  To: Jonathan Cameron, O'Griofa, Conall; +Cc: linux-iio, Jonathan Cameron

+CC Conall

On 3/9/24 14:06, Jonathan Cameron wrote:
> On Tue, 5 Mar 2024 12:30:53 -0500
> Sean Anderson <sean.anderson@linux.dev> 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!

OK, so there are three groups of channels in this device, as set up by
ams_init_module:

	- CTRL channels (xlnx,zynqmp-ams)
	- PS channels (xlnx,zynqmp-ams-ps)
	- PL channels (xlnx,zynqmp-ams-pl)

According to the comment in ams_enable_channel_sequence,

	/*
	 * Enable channel sequence. First 22 bits of scan_mask represent
	 * PS channels, and next remaining bits represent PL channels.
	 */

and indeed, the following code only touches the PS and PL registers. So
I think we just need to add a check for
chan->scan_index >= AMS_CTRL_SEQ_BASE, like in ams_read_raw.

--Sean

>> 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
>> 
> 

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: iio: xilinx-ams: shift-out-of-bounds in ams_enable_channel_sequence
  2024-03-11 16:11   ` Sean Anderson
@ 2024-03-11 16:30     ` Sean Anderson
  0 siblings, 0 replies; 4+ messages in thread
From: Sean Anderson @ 2024-03-11 16:30 UTC (permalink / raw)
  To: Jonathan Cameron, O'Griofa, Conall; +Cc: linux-iio, Jonathan Cameron

On 3/11/24 12:11, Sean Anderson wrote:
> +CC Conall
> 
> On 3/9/24 14:06, Jonathan Cameron wrote:
>> On Tue, 5 Mar 2024 12:30:53 -0500
>> Sean Anderson <sean.anderson@linux.dev> 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!
> 
> OK, so there are three groups of channels in this device, as set up by
> ams_init_module:
> 
> 	- CTRL channels (xlnx,zynqmp-ams)
> 	- PS channels (xlnx,zynqmp-ams-ps)
> 	- PL channels (xlnx,zynqmp-ams-pl)
> 
> According to the comment in ams_enable_channel_sequence,
> 
> 	/*
> 	 * Enable channel sequence. First 22 bits of scan_mask represent
> 	 * PS channels, and next remaining bits represent PL channels.
> 	 */
> 
> and indeed, the following code only touches the PS and PL registers. So
> I think we just need to add a check for
> chan->scan_index >= AMS_CTRL_SEQ_BASE, like in ams_read_raw.

https://lore.kernel.org/linux-iio/20240311162800.11074-1-sean.anderson@linux.dev/

--Sean


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2024-03-11 16:30 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-03-05 17:30 iio: xilinx-ams: shift-out-of-bounds in ams_enable_channel_sequence Sean Anderson
2024-03-09 19:06 ` Jonathan Cameron
2024-03-11 16:11   ` Sean Anderson
2024-03-11 16:30     ` Sean Anderson

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