Messages in this thread | | | Date | Sat, 21 Oct 2023 19:03:15 +0300 | Subject | Re: [PATCH v2 0/2] Sanity-check available_scan_masks array | From | Matti Vaittinen <> |
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On 10/21/23 18:55, Jonathan Cameron wrote: > On Mon, 16 Oct 2023 14:04:11 +0300 > Matti Vaittinen <mazziesaccount@gmail.com> wrote: > >> Sanity-check available_scan_masks array >> >> The available_scan_masks is an array of bitmasks representing the >> channels which can be simultaneously(*) scanned by a driver from the >> device. Following special characteristics apply: >> >> - When IIO is scanning through the array it will use the first mask >> which can be used to scan all enabled channels. This means drivers >> should order the array in the order of the preference. This does also >> mean that a mask which is a subset of a mask located earler in array >> will never be used because the earlier one will be picked by the core. >> - Masks wider than size of long are supported only to some extent. The >> code scanning through the array will interpret the first mask with >> first long zeroed as end-of-array terminator. Changing this behaviour >> would make mask-arrays for multi-long masks to be terminated by more >> than one zero long. Failure to do so would result kernel to read >> beyond the array generating a potentially hazardous bug. >> >> Add a sanity-check to IIO-device registration emitting a warning if >> available_scan_mask array is misordered or if mask width is larger than >> a long while available_scan_mask-array is populated. Currently there >> should be no in-tree drivers with available_scan_mask populated and mask >> wider than a long. >> >> Revision history: >> v1 => v2: >> - Add patch 2/2 documenting why iio_scan_mask_match() checks only >> a long worth of bits while searching for the end of the >> available_scan_mask-array. >> - Styling of patch 1/2 as per comments from Jonathan >> v1 and related discussion here: >> https://lore.kernel.org/lkml/ZRvjuZaQWdZw1U1I@dc78bmyyyyyyyyyyyyydt-3.rev.dnainternet.fi/ >> >> Matti Vaittinen (2): >> iio: sanity check available_scan_masks array >> iio: buffer: document known issue >> >> drivers/iio/industrialio-buffer.c | 16 ++++++++ >> drivers/iio/industrialio-core.c | 63 +++++++++++++++++++++++++++++++ >> 2 files changed, 79 insertions(+) >> > > Hi Matti, > > Just a quick note to say this looks fine to me, but I don't want to queue it up > just yet given proximity to merge window etc.
Makes perfect sense to me.
> I'll aim to pick it up early > in next cycle. Give me a poke if I still haven't by rc3 or so.
Ouch... My memory gets worse year by year - well, I'll try to remember :)
Yours, -- Matti
-- Matti Vaittinen Linux kernel developer at ROHM Semiconductors Oulu Finland
~~ When things go utterly wrong vim users can always type :help! ~~
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