Re: [PATCH v3] powerpc/lockdep: fix a false positive warning

2019-09-14 Thread kbuild test robot
Hi Qian,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on linus/master]
[cannot apply to v5.3-rc8 next-20190904]
[if your patch is applied to the wrong git tree, please drop us a note to help 
improve the system]

url:
https://github.com/0day-ci/linux/commits/Qian-Cai/powerpc-lockdep-fix-a-false-positive-warning/20190910-053719
config: powerpc-ps3_defconfig (attached as .config)
compiler: powerpc64-linux-gcc (GCC) 7.4.0
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=7.4.0 make.cross ARCH=powerpc 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot 

All errors (new ones prefixed by >>):

>> kernel/locking/lockdep.o:(.toc+0x0): undefined reference to `bss_hole_start'
>> kernel/locking/lockdep.o:(.toc+0x8): undefined reference to `bss_hole_end'

---
0-DAY kernel test infrastructureOpen Source Technology Center
https://lists.01.org/pipermail/kbuild-all   Intel Corporation


.config.gz
Description: application/gzip


Re: [PATCH v3] powerpc/lockdep: fix a false positive warning

2019-09-10 Thread Michael Ellerman
Hi Qian,

Sorry I haven't replied sooner, I've been travelling.

Qian Cai  writes:
> The commit 108c14858b9e ("locking/lockdep: Add support for dynamic
> keys") introduced a boot warning on powerpc below, because since the
> commit 2d4f567103ff ("KVM: PPC: Introduce kvm_tmp framework") adds
> kvm_tmp[] into the .bss section and then free the rest of unused spaces
> back to the page allocator.

Thanks for debugging this, but I'd like to fix it differently.

kvm_tmp has caused trouble before, with kmemleak, and it can also cause
trouble with STRICT_KERNEL_RWX, so I'd like to change how it's done,
rather than doing more hacks for it.

It should just be a page in text that we use if needed, and don't free,
which should avoid all these problems.

I'll try and get that done and posted soon.

cheers