Messages in this thread | | | Date | Tue, 14 Mar 2023 22:28:51 +0100 | From | Andi Shyti <> | Subject | Re: [PATCH] iio: adc: qcom-pm8xxx-xoadc: Remove useless condition in pm8xxx_xoadc_parse_channel() |
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Hi,
> > The left side of the loop condition never becomes false. > > hwchan cannot be NULL, because it points to elements of the > > hw_channels array that takes one of 4 predefined values: > > pm8018_xoadc_channels, pm8038_xoadc_channels, > > pm8058_xoadc_channels, pm8921_xoadc_channels. > > > > Found by Linux Verification Center (linuxtesting.org) with SVACE. > > I am not impressed with that tool. See below: > > > Fixes: 63c3ecd946d4 ("iio: adc: add a driver for Qualcomm PM8xxx HK/XOADC") > > Signed-off-by: Kasumov Ruslan <s02210418@gse.cs.msu.ru> > > (...) > > hwchan = &hw_channels[0]; > > - while (hwchan && hwchan->datasheet_name) { > > + while (hwchan->datasheet_name) { > > if (hwchan->pre_scale_mux == pre_scale_mux && > > hwchan->amux_channel == amux_channel) > > break; > > NAK have you tested this on a real system? > > Here is the complete loop: > > hwchan = &hw_channels[0]; > while (hwchan && hwchan->datasheet_name) { > if (hwchan->pre_scale_mux == pre_scale_mux && > hwchan->amux_channel == amux_channel) > break; > hwchan++;
ops, yes, sorry, I overlooked at this... This becomes NULL at some point as there is a sentinel in the _variant structures.
Thanks, Andi
> chid++; > } > > Notice how hwchan is used as iterator in hwchan++. > > What you are doing will cause a zero-pointer dereference. > > Whoever is developing "SVACE" needs to fix the tool to understand > this kind of usage. > > Yours, > Linus Walleij
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