Re: [PATCH 3/3] kasan: stackdepot: move filter_irq_stacks() to stackdepot.c

[Alexander Potapenko <glider@google.com>]

On Thu, Feb 27, 2020 at 4:16 AM Greentime Hu <green.hu@gmail.com> wrote:
>
> Alexander Potapenko <glider@google.com> 於 2020年2月26日 週三 下午5:53寫道：
> >
> > Hi Andes maintainers,
> >
> > On Tue, Feb 25, 2020 at 9:26 PM kbuild test robot <lkp@intel.com> wrote:
> > >
> > > Hi,
> > >
> > > I love your patch! Yet something to improve:
> > >
> > > [auto build test ERROR on linus/master]
> > > [also build test ERROR on v5.6-rc3 next-20200225]
> > > [if your patch is applied to the wrong git tree, please drop us a note to help
> > > improve the system. BTW, we also suggest to use '--base' option to specify the
> > > base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
> > >
> > > url:    https://github.com/0day-ci/linux/commits/glider-google-com/stackdepot-check-depot_index-before-accessing-the-stack-slab/20200222-065605
> > > base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 0c0ddd6ae47c9238c18f475bcca675ca74c9dc31
> > > config: nds32-randconfig-a001-20200225 (attached as .config)
> > > compiler: nds32le-linux-gcc (GCC) 9.2.0
> > > reproduce:
> > >         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> > >         chmod +x ~/bin/make.cross
> > >         # save the attached .config to linux build tree
> > >         GCC_VERSION=9.2.0 make.cross ARCH=nds32
> > >
> > > If you fix the issue, kindly add following tag
> > > Reported-by: kbuild test robot <lkp@intel.com>
> > >
> > > All errors (new ones prefixed by >>):
> > >
> > >    nds32le-linux-ld: lib/stackdepot.o: in function `filter_irq_stacks':
> > > >> stackdepot.c:(.text+0xc6): undefined reference to `__softirqentry_text_start'
> > > >> nds32le-linux-ld: stackdepot.c:(.text+0xca): undefined reference to `__softirqentry_text_start'
> > > >> nds32le-linux-ld: stackdepot.c:(.text+0xce): undefined reference to `__softirqentry_text_end'
> > >    nds32le-linux-ld: stackdepot.c:(.text+0xd2): undefined reference to `__softirqentry_text_end'
> >
> > Can you please help me with this?
> > I couldn't find out where this section needs to be declared, and I
> > don't really know whether nds32 is supposed to have softirqs or not.
> > Maybe filter_irq_stacks() should be no-op on nds32?
>
> Hi Alexander,
>
> I've disccussed this with Nick.
> There might be 2 solutions, but we are not sure which one is better or
> maybe there are another better solutions.
> Since nds32 doesn't support KASAN, we might not need to use this section.
>
> Solution 1.
>   We may just add the dependency in STACKDEPOT depend on KASAN
>
> Solution 2.
>   Just add SOFTIRQENTRY_TEXT this section to nds32's linker script
>
> What do you think? :)
Hi,

I think the latter solution actually makes sense.


-- 
Alexander Potapenko
Software Engineer

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