Messages in this thread | | | Date | Mon, 20 Nov 2023 15:14:37 +0800 | From | Yujie Liu <> | Subject | Re: arch/arm/kernel/hibernate.c:29:40: warning: array subscript -1 is outside array bounds of 'const void[2147483647]' |
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On Mon, Nov 06, 2023 at 02:19:33PM +0100, Linus Walleij wrote: > Hi Robot, > > On Wed, Oct 18, 2023 at 2:17 PM kernel test robot <lkp@intel.com> wrote: > > > arch/arm/kernel/hibernate.c: In function 'pfn_is_nosave': > > >> arch/arm/kernel/hibernate.c:29:40: warning: array subscript -1 is outside array bounds of 'const void[2147483647]' [-Warray-bounds=] > > 29 | unsigned long nosave_end_pfn = virt_to_pfn(&__nosave_end - 1); > > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > So the concern is that &__nosave_end could be 0 and the -1 would make > it wrap around? > > It still has nothing to do with arrays, I don't get it.
Hi Linus Walleij, sorry that we couldn't explain this warning very clearly. Let's consult Kees for more input.
Hi Kees, our robot has sent out several reports of "-Warray-bounds" warnings. Thanks a lot for helping to analyze them. [1][2]
[1] https://lore.kernel.org/all/202309200904.CEED70DA33@keescook/ [2] https://lore.kernel.org/all/202311071521.099CAEA58@keescook/
As for some other reports, developers have some doubt about them that we are not sure how to explain, such as the one in this report and [3][4][5][6]. If it's not too much trouble, could you please help take a look to see if these are valid warnings or false positives? Thanks a lot.
[3] https://lore.kernel.org/oe-kbuild-all/CACRpkdZ-1OcZ-cz0V218-VxAc07DMPvKWee3MHngs6Hrwv4zPA@mail.gmail.com/ [4] https://lore.kernel.org/oe-kbuild-all/20231019092258.c2cbwmmgffa33bro@vireshk-i7/ [5] https://lore.kernel.org/oe-kbuild-all/CANn89iKdMVNrV_0QienhpCJ98D7hj2sqOOYFhhSHBVHzvtkgWQ@mail.gmail.com/ [6] https://lore.kernel.org/oe-kbuild-all/CAOQ4uxjTv+5cB4z8TZQ02c5F3rags1HARoEQG9834A0+_+_twA@mail.gmail.com/
Best Regards, Yujie
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