Messages in this thread | | | From | Linus Walleij <> | Date | Tue, 14 Mar 2023 22:12:08 +0100 | Subject | Re: [PATCH] iio: adc: qcom-pm8xxx-xoadc: Remove useless condition in pm8xxx_xoadc_parse_channel() |
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On Tue, Mar 14, 2023 at 8:37 PM Kasumov Ruslan <xhxgldhlpfy@gmail.com> wrote:
> 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++; 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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