Messages in this thread Patch in this message | | | From | "Kirill A. Shutemov" <> | Subject | [PATCH 2/2] x86/mm: Fix sparse warnings in untagged_ptr() | Date | Wed, 16 Nov 2022 03:43:53 +0300 |
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Linear Address Masking patchset triggered a lot of sparse warnings.
The root cause is that casting pointer to '__typeof__(*(ptr)) *' will strip all sparse tags. The type has to be defined based on the pointer type, not based on what the pointer points to.
Fix cast in untagged_ptr() and avoid __typeof__() usage in get/put_user().
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: kernel test robot <lkp@intel.com> --- arch/x86/include/asm/uaccess.h | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 1d2c79246681..bd92e1ee1c1a 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -43,7 +43,7 @@ DECLARE_STATIC_KEY_FALSE(tagged_addr_key); #define untagged_ptr(mm, ptr) ({ \ u64 __ptrval = (__force u64)(ptr); \ __ptrval = untagged_addr(mm, __ptrval); \ - (__force __typeof__(*(ptr)) *)__ptrval; \ + (__force __typeof__(ptr))__ptrval; \ }) #else #define untagged_addr(mm, addr) (addr) @@ -158,10 +158,8 @@ extern int __get_user_bad(void); */ #define get_user(x,ptr) \ ({ \ - __typeof__(*(ptr)) __user *__ptr_clean; \ - __ptr_clean = untagged_ptr(current->mm, ptr); \ might_fault(); \ - do_get_user_call(get_user,x,__ptr_clean); \ + do_get_user_call(get_user,x,untagged_ptr(current->mm, ptr)); \ }) /** @@ -263,10 +261,8 @@ extern void __put_user_nocheck_8(void); * Return: zero on success, or -EFAULT on error. */ #define put_user(x, ptr) ({ \ - __typeof__(*(ptr)) __user *__ptr_clean; \ - __ptr_clean = untagged_ptr(current->mm, ptr); \ might_fault(); \ - do_put_user_call(put_user,x,__ptr_clean); \ + do_put_user_call(put_user,x,untagged_ptr(current->mm, ptr)); \ }) /** -- 2.38.0
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