[openeuler:openEuler-1.0-LTS 5957/23714] include/linux/uaccess.h:112:17: warning: 'params' may be used uninitialized - Kernel

16 Sep 2024


      tree:   https://gitee.com/openeuler/kernel.git openEuler-1.0-LTS
head:   37aeb7e817053fbf532b214aa02858b3c23af0b1
commit: 2dd8345826607c5d2d6528de872118da554015b6 [5957/23714] vfio: Add support for Shared Virtual Addressing
config: arm64-randconfig-001-20240913 (https://download.01.org/0day-ci/archive/20240916/202409161055.v0wzDm7V-lkp@i...)
compiler: aarch64-linux-gcc (GCC) 14.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240916/202409161055.v0wzDm7V-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/202409161055.v0wzDm7V-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 >>):
In file included from drivers/vfio/vfio_iommu_type1.c:31:
   include/linux/module.h:134:13: warning: 'init_module' specifies less restrictive attribute than its target 'vfio_iommu_type1_init': 'cold' [-Wmissing-attributes]
     134 |         int init_module(void) __attribute__((alias(#initfn)));
         |             ^~~~~~~~~~~
   drivers/vfio/vfio_iommu_type1.c:2222:1: note: in expansion of macro 'module_init'
    2222 | module_init(vfio_iommu_type1_init);
         | ^~~~~~~~~~~
   drivers/vfio/vfio_iommu_type1.c:2212:19: note: 'init_module' target declared here
    2212 | static int __init vfio_iommu_type1_init(void)
         |                   ^~~~~~~~~~~~~~~~~~~~~
   include/linux/module.h:140:14: warning: 'cleanup_module' specifies less restrictive attribute than its target 'vfio_iommu_type1_cleanup': 'cold' [-Wmissing-attributes]
     140 |         void cleanup_module(void) __attribute__((alias(#exitfn)));
         |              ^~~~~~~~~~~~~~
   drivers/vfio/vfio_iommu_type1.c:2223:1: note: in expansion of macro 'module_exit'
    2223 | module_exit(vfio_iommu_type1_cleanup);
         | ^~~~~~~~~~~
   drivers/vfio/vfio_iommu_type1.c:2217:20: note: 'cleanup_module' target declared here
    2217 | static void __exit vfio_iommu_type1_cleanup(void)
         |                    ^~~~~~~~~~~~~~~~~~~~~~~~
   In file included from include/linux/compat.h:19,
                    from drivers/vfio/vfio_iommu_type1.c:27:
   In function '_copy_from_user',
       inlined from 'copy_from_user' at include/linux/uaccess.h:144:7,
       inlined from 'vfio_iommu_type1_bind_process' at drivers/vfio/vfio_iommu_type1.c:1933:6:
...
...
include/linux/uaccess.h:112:17: warning: 'params' may be used uninitialized [-Wmaybe-uninitialized]
112 |                 kasan_check_write(to, n);
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~
   In file included from include/linux/compiler.h:251,
                    from include/asm-generic/div64.h:25,
                    from ./arch/arm64/include/generated/asm/div64.h:1,
                    from include/linux/math64.h:6,
                    from include/linux/time64.h:5,
                    from include/linux/compat_time.h:6,
                    from include/linux/compat.h:10:
   include/linux/kasan-checks.h: In function 'vfio_iommu_type1_bind_process':
   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/vfio/vfio_iommu_type1.c:1920:46: note: 'params' declared here
    1920 |         struct vfio_iommu_type1_bind_process params;
         |                                              ^~~~~~
   In function '_copy_from_user',
       inlined from 'copy_from_user' at include/linux/uaccess.h:144:7,
       inlined from 'vfio_iommu_type1_unbind_process' at drivers/vfio/vfio_iommu_type1.c:2021:6:
...
...
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 'vfio_iommu_type1_unbind_process':
   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/vfio/vfio_iommu_type1.c:2014:46: note: 'params' declared here
    2014 |         struct vfio_iommu_type1_bind_process params;
         |                                              ^~~~~~
   In function '_copy_from_user',
       inlined from 'copy_from_user' at include/linux/uaccess.h:144:7,
       inlined from 'vfio_iommu_type1_ioctl' at drivers/vfio/vfio_iommu_type1.c:2084:7:
   include/linux/uaccess.h:112:17: warning: 'info' may be used uninitialized [-Wmaybe-uninitialized]
     112 |                 kasan_check_write(to, n);
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/kasan-checks.h: In function 'vfio_iommu_type1_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/vfio/vfio_iommu_type1.c:2080:46: note: 'info' declared here
    2080 |                 struct vfio_iommu_type1_info info;
         |                                              ^~~~
   In function '_copy_from_user',
       inlined from 'copy_from_user' at include/linux/uaccess.h:144:7,
       inlined from 'vfio_iommu_type1_ioctl' at drivers/vfio/vfio_iommu_type1.c:2104:7:
   include/linux/uaccess.h:112:17: warning: 'map' may be used uninitialized [-Wmaybe-uninitialized]
     112 |                 kasan_check_write(to, n);
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/kasan-checks.h: In function 'vfio_iommu_type1_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/vfio/vfio_iommu_type1.c:2098:49: note: 'map' declared here
    2098 |                 struct vfio_iommu_type1_dma_map map;
         |                                                 ^~~
   In function '_copy_from_user',
       inlined from 'copy_from_user' at include/linux/uaccess.h:144:7,
       inlined from 'vfio_iommu_type1_ioctl' at drivers/vfio/vfio_iommu_type1.c:2118:7:
   include/linux/uaccess.h:112:17: warning: 'unmap' may be used uninitialized [-Wmaybe-uninitialized]
     112 |                 kasan_check_write(to, n);
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/kasan-checks.h: In function 'vfio_iommu_type1_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/vfio/vfio_iommu_type1.c:2113:51: note: 'unmap' declared here
    2113 |                 struct vfio_iommu_type1_dma_unmap unmap;
         |                                                   ^~~~~
   In function '_copy_from_user',
       inlined from 'copy_from_user' at include/linux/uaccess.h:144:7,
       inlined from 'vfio_iommu_type1_ioctl' at drivers/vfio/vfio_iommu_type1.c:2136:7:
...
...
include/linux/uaccess.h:112:17: warning: 'bind' may be used uninitialized [-Wmaybe-uninitialized]
112 |                 kasan_check_write(to, n);
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/kasan-checks.h: In function 'vfio_iommu_type1_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/vfio/vfio_iommu_type1.c:2132:46: note: 'bind' declared here
    2132 |                 struct vfio_iommu_type1_bind bind;
         |                                              ^~~~
   In function '_copy_from_user',
       inlined from 'copy_from_user' at include/linux/uaccess.h:144:7,
       inlined from 'vfio_iommu_type1_ioctl' at drivers/vfio/vfio_iommu_type1.c:2155:7:
...
...
include/linux/uaccess.h:112:17: warning: 'bind' may be used uninitialized [-Wmaybe-uninitialized]
112 |                 kasan_check_write(to, n);
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/kasan-checks.h: In function 'vfio_iommu_type1_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/vfio/vfio_iommu_type1.c:2151:46: note: 'bind' declared here
    2151 |                 struct vfio_iommu_type1_bind bind;
         |                                              ^~~~
vim +/params +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  
d597580d373774 Al Viro        2017-03-20  124  #ifdef INLINE_COPY_TO_USER
d597580d373774 Al Viro        2017-03-20  125  static inline unsigned long
d597580d373774 Al Viro        2017-03-20  126  _copy_to_user(void __user *to, const void *from, unsigned long n)
d597580d373774 Al Viro        2017-03-20  127  {
9c5f6908de03a4 Al Viro        2017-06-29  128  	might_fault();
4983cb67a383a7 Linus Torvalds 2019-02-14  129  	if (access_ok(to, n)) {
9c5f6908de03a4 Al Viro        2017-06-29  130  		kasan_check_read(from, n);
d597580d373774 Al Viro        2017-03-20  131  		n = raw_copy_to_user(to, from, n);
9c5f6908de03a4 Al Viro        2017-06-29  132  	}
d597580d373774 Al Viro        2017-03-20  133  	return n;
d597580d373774 Al Viro        2017-03-20  134  }
d597580d373774 Al Viro        2017-03-20  135  #else
d597580d373774 Al Viro        2017-03-20  136  extern unsigned long
d597580d373774 Al Viro        2017-03-20  137  _copy_to_user(void __user *, const void *, unsigned long);
d597580d373774 Al Viro        2017-03-20  138  #endif
d597580d373774 Al Viro        2017-03-20  139  
d597580d373774 Al Viro        2017-03-20  140  static __always_inline unsigned long __must_check
d597580d373774 Al Viro        2017-03-20  141  copy_from_user(void *to, const void __user *from, unsigned long n)
d597580d373774 Al Viro        2017-03-20  142  {
b0377fedb65280 Al Viro        2017-06-29  143  	if (likely(check_copy_size(to, n, false)))
d597580d373774 Al Viro        2017-03-20 @144  		n = _copy_from_user(to, from, n);
d597580d373774 Al Viro        2017-03-20  145  	return n;
d597580d373774 Al Viro        2017-03-20  146  }
d597580d373774 Al Viro        2017-03-20  147
:::::: 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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