LinuxLists.cc - arch/sparc/include/asm/cmpxchg_64.h:161:55: sparse: sparse: cast truncates bits from constant value (ffffffffe0f510cc becomes cc)

2020-08-12 01:54:00

Subject: arch/sparc/include/asm/cmpxchg_64.h:161:55: sparse: sparse: cast truncates bits from constant value (ffffffffe0f510cc becomes cc)

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: fb893de323e2d39f7a1f6df425703a2edbdf56ea
commit: 47e4937a4a7ca4184fd282791dfee76c6799966a erofs: move erofs out of staging
date: 12 months ago
config: sparc64-randconfig-s032-20200812 (attached as .config)
compiler: sparc64-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: v0.6.2-168-g9554805c-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=sparc64

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/utils.c: note: in included file (through arch/sparc/include/asm/cmpxchg.h, arch/sparc/include/asm/atomic_64.h, arch/sparc/include/asm/atomic.h, ...):
>> arch/sparc/include/asm/cmpxchg_64.h:161:55: sparse: sparse: cast truncates bits from constant value (ffffffffe0f510cc becomes cc)
--
fs/erofs/zdata.c: note: in included file (through arch/sparc/include/asm/cmpxchg.h, arch/sparc/include/asm/atomic_64.h, arch/sparc/include/asm/atomic.h, ...):
>> arch/sparc/include/asm/cmpxchg_64.h:161:55: sparse: sparse: cast truncates bits from constant value (ffffffffe0f510cc becomes cc)
arch/sparc/include/asm/cmpxchg_64.h:161:50: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes fe)
arch/sparc/include/asm/cmpxchg_64.h:161:50: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes fe)
arch/sparc/include/asm/cmpxchg_64.h:161:55: sparse: sparse: cast truncates bits from constant value (5f0edead becomes ad)

vim +161 arch/sparc/include/asm/cmpxchg_64.h

d550bbd40c0e10 David Howells 2012-03-28 155
d550bbd40c0e10 David Howells 2012-03-28 156 static inline unsigned long
d550bbd40c0e10 David Howells 2012-03-28 157 __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
d550bbd40c0e10 David Howells 2012-03-28 158 {
d550bbd40c0e10 David Howells 2012-03-28 159 switch (size) {
a12ee2349312d7 Babu Moger 2017-05-24 160 case 1:
a12ee2349312d7 Babu Moger 2017-05-24 @161 return __cmpxchg_u8(ptr, old, new);
d550bbd40c0e10 David Howells 2012-03-28 162 case 4:
d550bbd40c0e10 David Howells 2012-03-28 163 return __cmpxchg_u32(ptr, old, new);
d550bbd40c0e10 David Howells 2012-03-28 164 case 8:
d550bbd40c0e10 David Howells 2012-03-28 165 return __cmpxchg_u64(ptr, old, new);
d550bbd40c0e10 David Howells 2012-03-28 166 }
d550bbd40c0e10 David Howells 2012-03-28 167 __cmpxchg_called_with_bad_pointer();
d550bbd40c0e10 David Howells 2012-03-28 168 return old;
d550bbd40c0e10 David Howells 2012-03-28 169 }
d550bbd40c0e10 David Howells 2012-03-28 170

:::::: The code at line 161 was first introduced by commit
:::::: a12ee2349312d7112b9b7c6ac2e70c5ec2ca334e arch/sparc: Introduce cmpxchg_u8 SPARC

:::::: TO: Babu Moger <[email protected]>
:::::: CC: David S. Miller <[email protected]>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]

Attachments:

(No filename) (3.40 kB)
.config.gz (26.74 kB)
Download all attachments

2020-08-12 03:11:45

by Gao Xiang

[permalink] [raw]

Subject: Re: arch/sparc/include/asm/cmpxchg_64.h:161:55: sparse: sparse: cast truncates bits from constant value (ffffffffe0f510cc becomes cc)

Hi,

On Wed, Aug 12, 2020 at 09:49:38AM +0800, kernel test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: fb893de323e2d39f7a1f6df425703a2edbdf56ea
> commit: 47e4937a4a7ca4184fd282791dfee76c6799966a erofs: move erofs out of staging
> date: 12 months ago
> config: sparc64-randconfig-s032-20200812 (attached as .config)
> compiler: sparc64-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: v0.6.2-168-g9554805c-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=sparc64
>
> 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/utils.c: note: in included file (through arch/sparc/include/asm/cmpxchg.h, arch/sparc/include/asm/atomic_64.h, arch/sparc/include/asm/atomic.h, ...):
> >> arch/sparc/include/asm/cmpxchg_64.h:161:55: sparse: sparse: cast truncates bits from constant value (ffffffffe0f510cc becomes cc)
> --
> fs/erofs/zdata.c: note: in included file (through arch/sparc/include/asm/cmpxchg.h, arch/sparc/include/asm/atomic_64.h, arch/sparc/include/asm/atomic.h, ...):
> >> arch/sparc/include/asm/cmpxchg_64.h:161:55: sparse: sparse: cast truncates bits from constant value (ffffffffe0f510cc becomes cc)
> arch/sparc/include/asm/cmpxchg_64.h:161:50: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes fe)
> arch/sparc/include/asm/cmpxchg_64.h:161:50: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes fe)
> arch/sparc/include/asm/cmpxchg_64.h:161:55: sparse: sparse: cast truncates bits from constant value (5f0edead becomes ad)
>
> vim +161 arch/sparc/include/asm/cmpxchg_64.h
>
> d550bbd40c0e10 David Howells 2012-03-28 155
> d550bbd40c0e10 David Howells 2012-03-28 156 static inline unsigned long
> d550bbd40c0e10 David Howells 2012-03-28 157 __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
> d550bbd40c0e10 David Howells 2012-03-28 158 {
> d550bbd40c0e10 David Howells 2012-03-28 159 switch (size) {
> a12ee2349312d7 Babu Moger 2017-05-24 160 case 1:
> a12ee2349312d7 Babu Moger 2017-05-24 @161 return __cmpxchg_u8(ptr, old, new);
> d550bbd40c0e10 David Howells 2012-03-28 162 case 4:
> d550bbd40c0e10 David Howells 2012-03-28 163 return __cmpxchg_u32(ptr, old, new);
> d550bbd40c0e10 David Howells 2012-03-28 164 case 8:
> d550bbd40c0e10 David Howells 2012-03-28 165 return __cmpxchg_u64(ptr, old, new);
> d550bbd40c0e10 David Howells 2012-03-28 166 }
> d550bbd40c0e10 David Howells 2012-03-28 167 __cmpxchg_called_with_bad_pointer();
> d550bbd40c0e10 David Howells 2012-03-28 168 return old;
> d550bbd40c0e10 David Howells 2012-03-28 169 }
> d550bbd40c0e10 David Howells 2012-03-28 170

Again, I have no idea how to deal with that in my current
gatekeeping code.

I got these reports, but I cannot help to resolve that.
Even I don't know if that's another sparse issue (since I
only got such reports on sparc and alpha arch, but no x86
or arm64.)

https://lore.kernel.org/r/202007251532.y5A10ZoO%[email protected]
https://lore.kernel.org/r/202007272132.1AgbBO3U%[email protected]
https://lore.kernel.org/r/202008100408.Wc6WGrac%[email protected]
https://lore.kernel.org/r/202008120933.YrVhHyoA%[email protected]

If no one can help that, could you please silence such reports.
It really makes me confusing.

Thanks,
Gao Xiang

>
> :::::: The code at line 161 was first introduced by commit
> :::::: a12ee2349312d7112b9b7c6ac2e70c5ec2ca334e arch/sparc: Introduce cmpxchg_u8 SPARC
>
> :::::: TO: Babu Moger <[email protected]>
> :::::: CC: David S. Miller <[email protected]>
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/[email protected]

2020-08-12 03:24:54

by Chen, Rong A

[permalink] [raw]

Subject: Re: [kbuild-all] Re: arch/sparc/include/asm/cmpxchg_64.h:161:55: sparse: sparse: cast truncates bits from constant value (ffffffffe0f510cc becomes cc)

On 8/12/20 11:09 AM, Gao Xiang wrote:
> Hi,
>
> On Wed, Aug 12, 2020 at 09:49:38AM +0800, kernel test robot wrote:
>> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
>> head: fb893de323e2d39f7a1f6df425703a2edbdf56ea
>> commit: 47e4937a4a7ca4184fd282791dfee76c6799966a erofs: move erofs out of staging
>> date: 12 months ago
>> config: sparc64-randconfig-s032-20200812 (attached as .config)
>> compiler: sparc64-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: v0.6.2-168-g9554805c-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=sparc64
>>
>> 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/utils.c: note: in included file (through arch/sparc/include/asm/cmpxchg.h, arch/sparc/include/asm/atomic_64.h, arch/sparc/include/asm/atomic.h, ...):
>>>> arch/sparc/include/asm/cmpxchg_64.h:161:55: sparse: sparse: cast truncates bits from constant value (ffffffffe0f510cc becomes cc)
>> --
>> fs/erofs/zdata.c: note: in included file (through arch/sparc/include/asm/cmpxchg.h, arch/sparc/include/asm/atomic_64.h, arch/sparc/include/asm/atomic.h, ...):
>>>> arch/sparc/include/asm/cmpxchg_64.h:161:55: sparse: sparse: cast truncates bits from constant value (ffffffffe0f510cc becomes cc)
>> arch/sparc/include/asm/cmpxchg_64.h:161:50: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes fe)
>> arch/sparc/include/asm/cmpxchg_64.h:161:50: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes fe)
>> arch/sparc/include/asm/cmpxchg_64.h:161:55: sparse: sparse: cast truncates bits from constant value (5f0edead becomes ad)
>>
>> vim +161 arch/sparc/include/asm/cmpxchg_64.h
>>
>> d550bbd40c0e10 David Howells 2012-03-28 155
>> d550bbd40c0e10 David Howells 2012-03-28 156 static inline unsigned long
>> d550bbd40c0e10 David Howells 2012-03-28 157 __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
>> d550bbd40c0e10 David Howells 2012-03-28 158 {
>> d550bbd40c0e10 David Howells 2012-03-28 159 switch (size) {
>> a12ee2349312d7 Babu Moger 2017-05-24 160 case 1:
>> a12ee2349312d7 Babu Moger 2017-05-24 @161 return __cmpxchg_u8(ptr, old, new);
>> d550bbd40c0e10 David Howells 2012-03-28 162 case 4:
>> d550bbd40c0e10 David Howells 2012-03-28 163 return __cmpxchg_u32(ptr, old, new);
>> d550bbd40c0e10 David Howells 2012-03-28 164 case 8:
>> d550bbd40c0e10 David Howells 2012-03-28 165 return __cmpxchg_u64(ptr, old, new);
>> d550bbd40c0e10 David Howells 2012-03-28 166 }
>> d550bbd40c0e10 David Howells 2012-03-28 167 __cmpxchg_called_with_bad_pointer();
>> d550bbd40c0e10 David Howells 2012-03-28 168 return old;
>> d550bbd40c0e10 David Howells 2012-03-28 169 }
>> d550bbd40c0e10 David Howells 2012-03-28 170
> Again, I have no idea how to deal with that in my current
> gatekeeping code.
>
> I got these reports, but I cannot help to resolve that.
> Even I don't know if that's another sparse issue (since I
> only got such reports on sparc and alpha arch, but no x86
> or arm64.)
>
> https://lore.kernel.org/r/202007251532.y5A10ZoO%[email protected]
> https://lore.kernel.org/r/202007272132.1AgbBO3U%[email protected]
> https://lore.kernel.org/r/202008100408.Wc6WGrac%[email protected]
> https://lore.kernel.org/r/202008120933.YrVhHyoA%[email protected]
>
> If no one can help that, could you please silence such reports.
> It really makes me confusing.

Hi Gao Xiang,

Sorry for the inconvenience, we'll silence the reports on this commit.

Best Regards,
Rong Chen

>
> Thanks,
> Gao Xiang
>
>> :::::: The code at line 161 was first introduced by commit
>> :::::: a12ee2349312d7112b9b7c6ac2e70c5ec2ca334e arch/sparc: Introduce cmpxchg_u8 SPARC
>>
>> :::::: TO: Babu Moger <[email protected]>
>> :::::: CC: David S. Miller <[email protected]>
>>
>> ---
>> 0-DAY CI Kernel Test Service, Intel Corporation
>> https://lists.01.org/hyperkitty/list/[email protected]
> _______________________________________________
> kbuild-all mailing list -- [email protected]
> To unsubscribe send an email to [email protected]