diff options
Diffstat (limited to 'arch/x86/include/asm/uaccess_32.h')
| -rw-r--r-- | arch/x86/include/asm/uaccess_32.h | 29 |
1 files changed, 27 insertions, 2 deletions
diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h index 5e06259e90e5..0c9825e97f36 100644 --- a/arch/x86/include/asm/uaccess_32.h +++ b/arch/x86/include/asm/uaccess_32.h @@ -33,7 +33,7 @@ unsigned long __must_check __copy_from_user_ll_nocache_nozero * Copy data from kernel space to user space. Caller must check * the specified block with access_ok() before calling this function. * The caller should also make sure he pins the user space address - * so that the we don't result in page fault and sleep. + * so that we don't result in page fault and sleep. * * Here we special-case 1, 2 and 4-byte copy_*_user invocations. On a fault * we return the initial request size (1, 2 or 4), as copy_*_user should do. @@ -187,9 +187,34 @@ __copy_from_user_inatomic_nocache(void *to, const void __user *from, unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n); -unsigned long __must_check copy_from_user(void *to, +unsigned long __must_check _copy_from_user(void *to, const void __user *from, unsigned long n); + + +extern void copy_from_user_overflow(void) +#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS + __compiletime_error("copy_from_user() buffer size is not provably correct") +#else + __compiletime_warning("copy_from_user() buffer size is not provably correct") +#endif +; + +static inline unsigned long __must_check copy_from_user(void *to, + const void __user *from, + unsigned long n) +{ + int sz = __compiletime_object_size(to); + int ret = -EFAULT; + + if (likely(sz == -1 || sz >= n)) + ret = _copy_from_user(to, from, n); + else + copy_from_user_overflow(); + + return ret; +} + long __must_check strncpy_from_user(char *dst, const char __user *src, long count); long __must_check __strncpy_from_user(char *dst, |