tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 23ee3e4e5bd27bdbc0f1785eef7209ce872794c7
commit: 47e4937a4a7ca4184fd282791dfee76c6799966a erofs: move erofs out of staging
date: 11 months ago
config: alpha-randconfig-s031-20200725 (attached as .config)
compiler: alpha-linux-gcc (GCC) 9.3.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# apt-get install sparse
# sparse version: v0.6.2-93-g4c6cbe55-dirty
git checkout 47e4937a4a7ca4184fd282791dfee76c6799966a
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=alpha
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>
sparse warnings: (new ones prefixed by >>)
fs/erofs/zdata.c: note: in included file (through arch/alpha/include/asm/cmpxchg.h, arch/alpha/include/asm/atomic.h, include/linux/atomic.h, ...):
>> arch/alpha/include/asm/xchg.h:234:32: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes fe)
>> arch/alpha/include/asm/xchg.h:236:32: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes cafe)
>> arch/alpha/include/asm/xchg.h:234:32: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes fe)
>> arch/alpha/include/asm/xchg.h:234:32: sparse: sparse: cast truncates bits from constant value (5f0edead becomes ad)
>> arch/alpha/include/asm/xchg.h:236:32: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes cafe)
>> arch/alpha/include/asm/xchg.h:236:32: sparse: sparse: cast truncates bits from constant value (5f0edead becomes dead)
vim +234 arch/alpha/include/asm/xchg.h
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 227
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 228 static __always_inline unsigned long
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 229 ____cmpxchg(, volatile void *ptr, unsigned long old, unsigned long new,
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 230 int size)
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 231 {
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 232 switch (size) {
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 233 case 1:
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 @234 return ____cmpxchg(_u8, ptr, old, new);
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 235 case 2:
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 @236 return ____cmpxchg(_u16, ptr, old, new);
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 237 case 4:
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 238 return ____cmpxchg(_u32, ptr, old, new);
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 239 case 8:
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 240 return ____cmpxchg(_u64, ptr, old, new);
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 241 }
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 242 __cmpxchg_called_with_bad_pointer();
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 243 return old;
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 244 }
a6209d6d71f2ab Ivan Kokshaysky 2009-03-31 245
:::::: The code at line 234 was first introduced by commit
:::::: a6209d6d71f2ab8c63cc1587ef65490d83022baf alpha: xchg/cmpxchg cleanup and fixes
:::::: TO: Ivan Kokshaysky <[email protected]>
:::::: CC: Linus Torvalds <[email protected]>
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]
Hi,
On Sat, Jul 25, 2020 at 03:15:39PM +0800, kernel test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: 23ee3e4e5bd27bdbc0f1785eef7209ce872794c7
> commit: 47e4937a4a7ca4184fd282791dfee76c6799966a erofs: move erofs out of staging
> date: 11 months ago
> config: alpha-randconfig-s031-20200725 (attached as .config)
> compiler: alpha-linux-gcc (GCC) 9.3.0
> reproduce:
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # apt-get install sparse
> # sparse version: v0.6.2-93-g4c6cbe55-dirty
> git checkout 47e4937a4a7ca4184fd282791dfee76c6799966a
> # save the attached .config to linux build tree
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=alpha
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <[email protected]>
>
>
> sparse warnings: (new ones prefixed by >>)
>
> fs/erofs/zdata.c: note: in included file (through arch/alpha/include/asm/cmpxchg.h, arch/alpha/include/asm/atomic.h, include/linux/atomic.h, ...):
> >> arch/alpha/include/asm/xchg.h:234:32: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes fe)
> >> arch/alpha/include/asm/xchg.h:236:32: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes cafe)
> >> arch/alpha/include/asm/xchg.h:234:32: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes fe)
> >> arch/alpha/include/asm/xchg.h:234:32: sparse: sparse: cast truncates bits from constant value (5f0edead becomes ad)
> >> arch/alpha/include/asm/xchg.h:236:32: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes cafe)
> >> arch/alpha/include/asm/xchg.h:236:32: sparse: sparse: cast truncates bits from constant value (5f0edead becomes dead)
I'm not sure what's wrong here? What should I proceed with it
(it seems relating with Alpha architecture? since I didn't notice the sparse warning in x86 and arm)
Z_EROFS_PCLUSTER_TAIL is a pointer with magic value to indicate
the end of opening decompressing chain, whose function is likewise
the function of POISON_POINTER_DELTA and CONFIG_ILLEGAL_POINTER_VALUE.
Thanks,
Gao Xiang