diff options
Diffstat (limited to 'arch/x86/include/asm/uaccess.h')
| -rw-r--r-- | arch/x86/include/asm/uaccess.h | 25 |
1 files changed, 3 insertions, 22 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 79c4869ccdd6..a59ba2578e64 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -16,33 +16,14 @@ * Test whether a block of memory is a valid user space address. * Returns 0 if the range is valid, nonzero otherwise. */ -static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size) +static inline bool __access_ok(void __user *ptr, unsigned long size) { unsigned long limit = TASK_SIZE_MAX; + unsigned long addr = ptr; - /* - * If we have used "sizeof()" for the size, - * we know it won't overflow the limit (but - * it might overflow the 'addr', so it's - * important to subtract the size from the - * limit, not add it to the address). - */ - if (__builtin_constant_p(size)) - return unlikely(addr > limit - size); - - /* Arbitrary sizes? Be careful about overflow */ - addr += size; - if (unlikely(addr < size)) - return true; - return unlikely(addr > limit); + return (size <= limit) && (addr <= (limit - size)); } -#define __access_ok(addr, size) \ -({ \ - __chk_user_ptr(addr); \ - !__chk_range_not_ok((unsigned long __force)(addr), size); \ -}) - #ifdef CONFIG_DEBUG_ATOMIC_SLEEP static inline bool pagefault_disabled(void); # define WARN_ON_IN_IRQ() \ |