[openeuler:openEuler-1.0-LTS 1341/1341] include/linux/uaccess.h:112:17: warning: 'spallocinfo' may be used uninitialized - Kernel

21 Dec 2024


      Hi Ding,
FYI, the error/warning still remains.
tree:   https://gitee.com/openeuler/kernel.git openEuler-1.0-LTS
head:   02951ceaa6d546dfa0f741f52f6d47e0fb0ac7b4
commit: 9469d1759c2905dcef49df7e6240ad5c32b66296 [1341/1341] ascend: share_pool: enable svm to use share pool memory
config: arm64-randconfig-002-20241220 (https://download.01.org/0day-ci/archive/20241221/202412210226.N1hHrIDJ-lkp@i...)
compiler: aarch64-linux-gcc (GCC) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241221/202412210226.N1hHrIDJ-lkp@i...)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot lkp@intel.com
| Closes: https://lore.kernel.org/oe-kbuild-all/202412210226.N1hHrIDJ-lkp@intel.com/
Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
All warnings (new ones prefixed by >>):
drivers/char/svm.c:249:21: warning: no previous prototype for 'svm_find_mem_reg_node' [-Wmissing-prototypes]
     249 | struct device_node *svm_find_mem_reg_node(struct device *dev, const char *compat)
         |                     ^~~~~~~~~~~~~~~~~~~~~
   drivers/char/svm.c:419:6: warning: no previous prototype for 'sysrq_sched_debug_show_export' [-Wmissing-prototypes]
     419 | void sysrq_sched_debug_show_export(void)
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/char/svm.c:1429:5: warning: no previous prototype for 'svm_get_pasid' [-Wmissing-prototypes]
    1429 | int svm_get_pasid(pid_t vpid, int dev_id __maybe_unused)
         |     ^~~~~~~~~~~~~
   drivers/char/svm.c:1502:5: warning: no previous prototype for '__svm_get_mpam' [-Wmissing-prototypes]
    1502 | int __svm_get_mpam(struct svm_mpam *mpam)
         |     ^~~~~~~~~~~~~~
   In file included from arch/arm64/include/asm/atomic.h:34,
                    from include/linux/atomic.h:7,
                    from include/asm-generic/bitops/atomic.h:5,
                    from arch/arm64/include/asm/bitops.h:37,
                    from include/linux/bitops.h:19,
                    from include/linux/kernel.h:11,
                    from include/asm-generic/bug.h:18,
                    from arch/arm64/include/asm/bug.h:37,
                    from arch/arm64/include/asm/memory.h:27,
                    from arch/arm64/include/asm/esr.h:21,
                    from drivers/char/svm.c:10:
   In function '__cmpxchg_case_mb_4',
       inlined from '__cmpxchg_mb' at arch/arm64/include/asm/cmpxchg.h:143:1,
       inlined from 'svm_proc_load_flag' at drivers/char/svm.c:1967:12:
   arch/arm64/include/asm/atomic_lse.h:492:9: warning: array subscript 'long unsigned int[0]' is partly outside array bounds of 'atomic_t[1]' [-Warray-bounds=]
     492 |         asm volatile(                                                   \
         |         ^~~
   arch/arm64/include/asm/atomic_lse.h:523:1: note: in expansion of macro '__CMPXCHG_CASE'
     523 | __CMPXCHG_CASE(w,  ,  mb_4, al, "memory")
         | ^~~~~~~~~~~~~~
   drivers/char/svm.c: In function 'svm_proc_load_flag':
   drivers/char/svm.c:1958:25: note: object 'l2buf_load_flag' of size 4
    1958 |         static atomic_t l2buf_load_flag = ATOMIC_INIT(0);
         |                         ^~~~~~~~~~~~~~~
   In function '__cmpxchg_case_mb_4',
       inlined from '__cmpxchg_mb' at arch/arm64/include/asm/cmpxchg.h:143:1,
       inlined from 'svm_proc_load_flag' at drivers/char/svm.c:1967:12:
   arch/arm64/include/asm/atomic_lse.h:492:9: warning: array subscript 'long unsigned int[0]' is partly outside array bounds of 'atomic_t[1]' [-Warray-bounds=]
     492 |         asm volatile(                                                   \
         |         ^~~
   arch/arm64/include/asm/atomic_lse.h:523:1: note: in expansion of macro '__CMPXCHG_CASE'
     523 | __CMPXCHG_CASE(w,  ,  mb_4, al, "memory")
         | ^~~~~~~~~~~~~~
   drivers/char/svm.c: In function 'svm_proc_load_flag':
   drivers/char/svm.c:1958:25: note: object 'l2buf_load_flag' of size 4
    1958 |         static atomic_t l2buf_load_flag = ATOMIC_INIT(0);
         |                         ^~~~~~~~~~~~~~~
   In file included from drivers/char/svm.c:29:
   In function '_copy_from_user',
       inlined from 'copy_from_user' at include/linux/uaccess.h:144:7,
       inlined from 'svm_sp_alloc_mem' at drivers/char/svm.c:2144:8:
...
...
include/linux/uaccess.h:112:17: warning: 'spallocinfo' may be used uninitialized [-Wmaybe-uninitialized]
112 |                 kasan_check_write(to, n);
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~
   In file included from include/linux/compiler.h:251,
                    from arch/arm64/include/asm/memory.h:24:
   include/linux/kasan-checks.h: In function 'svm_sp_alloc_mem':
   include/linux/kasan-checks.h:7:6: note: by argument 1 of type 'const volatile void *' to 'kasan_check_write' declared here
       7 | void kasan_check_write(const volatile void *p, unsigned int size);
         |      ^~~~~~~~~~~~~~~~~
   drivers/char/svm.c:2135:24: note: 'spallocinfo' declared here
    2135 |         struct spalloc spallocinfo;
         |                        ^~~~~~~~~~~
   In function '_copy_from_user',
       inlined from 'copy_from_user' at include/linux/uaccess.h:144:7,
       inlined from 'svm_get_phy_memory_info' at drivers/char/svm.c:1805:6:
   include/linux/uaccess.h:112:17: warning: 'para' may be used uninitialized [-Wmaybe-uninitialized]
     112 |                 kasan_check_write(to, n);
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/kasan-checks.h: In function 'svm_get_phy_memory_info':
   include/linux/kasan-checks.h:7:6: note: by argument 1 of type 'const volatile void *' to 'kasan_check_write' declared here
       7 | void kasan_check_write(const volatile void *p, unsigned int size);
         |      ^~~~~~~~~~~~~~~~~
   drivers/char/svm.c:1800:33: note: 'para' declared here
    1800 |         struct phymeminfo_ioctl para;
         |                                 ^~~~
   In function '_copy_from_user',
       inlined from 'copy_from_user' at include/linux/uaccess.h:144:7,
       inlined from 'svm_remap_proc' at drivers/char/svm.c:1863:8:
   include/linux/uaccess.h:112:17: warning: 'pmem' may be used uninitialized [-Wmaybe-uninitialized]
     112 |                 kasan_check_write(to, n);
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/kasan-checks.h: In function 'svm_remap_proc':
   include/linux/kasan-checks.h:7:6: note: by argument 1 of type 'const volatile void *' to 'kasan_check_write' declared here
       7 | void kasan_check_write(const volatile void *p, unsigned int size);
         |      ^~~~~~~~~~~~~~~~~
   drivers/char/svm.c:1849:29: note: 'pmem' declared here
    1849 |         struct svm_proc_mem pmem;
         |                             ^~~~
   In function '_copy_from_user',
       inlined from 'copy_from_user' at include/linux/uaccess.h:144:7,
       inlined from 'svm_ioctl' at drivers/char/svm.c:2217:9:
   include/linux/uaccess.h:112:17: warning: 'params' may be used uninitialized [-Wmaybe-uninitialized]
     112 |                 kasan_check_write(to, n);
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/kasan-checks.h: In function 'svm_ioctl':
   include/linux/kasan-checks.h:7:6: note: by argument 1 of type 'const volatile void *' to 'kasan_check_write' declared here
       7 | void kasan_check_write(const volatile void *p, unsigned int size);
         |      ^~~~~~~~~~~~~~~~~
   drivers/char/svm.c:2209:33: note: 'params' declared here
    2209 |         struct svm_bind_process params;
         |                                 ^~~~~~
   In function '_copy_from_user',
       inlined from 'copy_from_user' at include/linux/uaccess.h:144:7,
       inlined from 'svm_sp_free_mem' at drivers/char/svm.c:2179:8,
       inlined from 'svm_ioctl' at drivers/char/svm.c:2280:9:
...
...
include/linux/uaccess.h:112:17: warning: 'spallocinfo' may be used uninitialized [-Wmaybe-uninitialized]
112 |                 kasan_check_write(to, n);
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/kasan-checks.h: In function 'svm_ioctl':
   include/linux/kasan-checks.h:7:6: note: by argument 1 of type 'const volatile void *' to 'kasan_check_write' declared here
       7 | void kasan_check_write(const volatile void *p, unsigned int size);
         |      ^~~~~~~~~~~~~~~~~
   drivers/char/svm.c:2172:24: note: 'spallocinfo' declared here
    2172 |         struct spalloc spallocinfo;
         |                        ^~~~~~~~~~~
vim +/spallocinfo +112 include/linux/uaccess.h
d597580d373774 Al Viro        2017-03-20  104  
d597580d373774 Al Viro        2017-03-20  105  #ifdef INLINE_COPY_FROM_USER
d597580d373774 Al Viro        2017-03-20  106  static inline unsigned long
d597580d373774 Al Viro        2017-03-20  107  _copy_from_user(void *to, const void __user *from, unsigned long n)
d597580d373774 Al Viro        2017-03-20  108  {
d597580d373774 Al Viro        2017-03-20  109  	unsigned long res = n;
9c5f6908de03a4 Al Viro        2017-06-29  110  	might_fault();
4983cb67a383a7 Linus Torvalds 2019-02-14  111  	if (likely(access_ok(from, n))) {
9c5f6908de03a4 Al Viro        2017-06-29 @112  		kasan_check_write(to, n);
d597580d373774 Al Viro        2017-03-20  113  		res = raw_copy_from_user(to, from, n);
9c5f6908de03a4 Al Viro        2017-06-29  114  	}
d597580d373774 Al Viro        2017-03-20  115  	if (unlikely(res))
d597580d373774 Al Viro        2017-03-20  116  		memset(to + (n - res), 0, res);
d597580d373774 Al Viro        2017-03-20  117  	return res;
d597580d373774 Al Viro        2017-03-20  118  }
d597580d373774 Al Viro        2017-03-20  119  #else
d597580d373774 Al Viro        2017-03-20  120  extern unsigned long
d597580d373774 Al Viro        2017-03-20  121  _copy_from_user(void *, const void __user *, unsigned long);
d597580d373774 Al Viro        2017-03-20  122  #endif
d597580d373774 Al Viro        2017-03-20  123
:::::: The code at line 112 was first introduced by commit
:::::: 9c5f6908de03a4f52ba7364b11fcd6116225480c copy_{from,to}_user(): move kasan checks and might_fault() out-of-line
:::::: TO: Al Viro viro@zeniv.linux.org.uk
:::::: CC: Al Viro viro@zeniv.linux.org.uk
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