diff options
Diffstat (limited to 'arch/x86/include/asm/uaccess.h')
| -rw-r--r-- | arch/x86/include/asm/uaccess.h | 128 |
1 files changed, 49 insertions, 79 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 0328c2ccc..2131c4ce7 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -29,12 +29,12 @@ #define USER_DS MAKE_MM_SEG(TASK_SIZE_MAX) #define get_ds() (KERNEL_DS) -#define get_fs() (current_thread_info()->addr_limit) -#define set_fs(x) (current_thread_info()->addr_limit = (x)) +#define get_fs() (current->thread.addr_limit) +#define set_fs(x) (current->thread.addr_limit = (x)) #define segment_eq(a, b) ((a).seg == (b).seg) -#define user_addr_max() (current_thread_info()->addr_limit.seg) +#define user_addr_max() (current->thread.addr_limit.seg) #define __addr_ok(addr) \ ((unsigned long __force)(addr) < user_addr_max()) @@ -342,7 +342,26 @@ do { \ } while (0) #ifdef CONFIG_X86_32 -#define __get_user_asm_u64(x, ptr, retval, errret) (x) = __get_user_bad() +#define __get_user_asm_u64(x, ptr, retval, errret) \ +({ \ + __typeof__(ptr) __ptr = (ptr); \ + asm volatile(ASM_STAC "\n" \ + "1: movl %2,%%eax\n" \ + "2: movl %3,%%edx\n" \ + "3: " ASM_CLAC "\n" \ + ".section .fixup,\"ax\"\n" \ + "4: mov %4,%0\n" \ + " xorl %%eax,%%eax\n" \ + " xorl %%edx,%%edx\n" \ + " jmp 3b\n" \ + ".previous\n" \ + _ASM_EXTABLE(1b, 4b) \ + _ASM_EXTABLE(2b, 4b) \ + : "=r" (retval), "=A"(x) \ + : "m" (__m(__ptr)), "m" __m(((u32 *)(__ptr)) + 1), \ + "i" (errret), "0" (retval)); \ +}) + #define __get_user_asm_ex_u64(x, ptr) (x) = __get_user_bad() #else #define __get_user_asm_u64(x, ptr, retval, errret) \ @@ -433,7 +452,7 @@ do { \ #define __get_user_nocheck(x, ptr, size) \ ({ \ int __gu_err; \ - unsigned long __gu_val; \ + __inttype(*(ptr)) __gu_val; \ __uaccess_begin(); \ __get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT); \ __uaccess_end(); \ @@ -472,13 +491,13 @@ struct __large_struct { unsigned long buf[100]; }; * uaccess_try and catch */ #define uaccess_try do { \ - current_thread_info()->uaccess_err = 0; \ + current->thread.uaccess_err = 0; \ __uaccess_begin(); \ barrier(); #define uaccess_catch(err) \ __uaccess_end(); \ - (err) |= (current_thread_info()->uaccess_err ? -EFAULT : 0); \ + (err) |= (current->thread.uaccess_err ? -EFAULT : 0); \ } while (0) /** @@ -682,44 +701,15 @@ unsigned long __must_check _copy_from_user(void *to, const void __user *from, unsigned long __must_check _copy_to_user(void __user *to, const void *from, unsigned n); -#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS -# define copy_user_diag __compiletime_error -#else -# define copy_user_diag __compiletime_warning -#endif - -extern void copy_user_diag("copy_from_user() buffer size is too small") -copy_from_user_overflow(void); -extern void copy_user_diag("copy_to_user() buffer size is too small") -copy_to_user_overflow(void) __asm__("copy_from_user_overflow"); - -#undef copy_user_diag - -#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS - -extern void -__compiletime_warning("copy_from_user() buffer size is not provably correct") -__copy_from_user_overflow(void) __asm__("copy_from_user_overflow"); -#define __copy_from_user_overflow(size, count) __copy_from_user_overflow() +extern void __compiletime_error("usercopy buffer size is too small") +__bad_copy_user(void); -extern void -__compiletime_warning("copy_to_user() buffer size is not provably correct") -__copy_to_user_overflow(void) __asm__("copy_from_user_overflow"); -#define __copy_to_user_overflow(size, count) __copy_to_user_overflow() - -#else - -static inline void -__copy_from_user_overflow(int size, unsigned long count) +static inline void copy_user_overflow(int size, unsigned long count) { WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); } -#define __copy_to_user_overflow __copy_from_user_overflow - -#endif - -static inline unsigned long __must_check +static __always_inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n) { int sz = __compiletime_object_size(to); @@ -728,35 +718,18 @@ copy_from_user(void *to, const void __user *from, unsigned long n) kasan_check_write(to, n); - /* - * While we would like to have the compiler do the checking for us - * even in the non-constant size case, any false positives there are - * a problem (especially when DEBUG_STRICT_USER_COPY_CHECKS, but even - * without - the [hopefully] dangerous looking nature of the warning - * would make people go look at the respecitive call sites over and - * over again just to find that there's no problem). - * - * And there are cases where it's just not realistic for the compiler - * to prove the count to be in range. For example when multiple call - * sites of a helper function - perhaps in different source files - - * all doing proper range checking, yet the helper function not doing - * so again. - * - * Therefore limit the compile time checking to the constant size - * case, and do only runtime checking for non-constant sizes. - */ - - if (likely(sz < 0 || sz >= n)) + if (likely(sz < 0 || sz >= n)) { + check_object_size(to, n, false); n = _copy_from_user(to, from, n); - else if(__builtin_constant_p(n)) - copy_from_user_overflow(); + } else if (!__builtin_constant_p(n)) + copy_user_overflow(sz, n); else - __copy_from_user_overflow(sz, n); + __bad_copy_user(); return n; } -static inline unsigned long __must_check +static __always_inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n) { int sz = __compiletime_object_size(from); @@ -765,20 +738,17 @@ copy_to_user(void __user *to, const void *from, unsigned long n) might_fault(); - /* See the comment in copy_from_user() above. */ - if (likely(sz < 0 || sz >= n)) + if (likely(sz < 0 || sz >= n)) { + check_object_size(from, n, true); n = _copy_to_user(to, from, n); - else if(__builtin_constant_p(n)) - copy_to_user_overflow(); + } else if (!__builtin_constant_p(n)) + copy_user_overflow(sz, n); else - __copy_to_user_overflow(sz, n); + __bad_copy_user(); return n; } -#undef __copy_from_user_overflow -#undef __copy_to_user_overflow - /* * We rely on the nested NMI work to allow atomic faults from the NMI path; the * nested NMI paths are careful to preserve CR2. @@ -797,21 +767,21 @@ copy_to_user(void __user *to, const void *from, unsigned long n) #define user_access_begin() __uaccess_begin() #define user_access_end() __uaccess_end() -#define unsafe_put_user(x, ptr) \ -({ \ +#define unsafe_put_user(x, ptr, err_label) \ +do { \ int __pu_err; \ __put_user_size((x), (ptr), sizeof(*(ptr)), __pu_err, -EFAULT); \ - __builtin_expect(__pu_err, 0); \ -}) + if (unlikely(__pu_err)) goto err_label; \ +} while (0) -#define unsafe_get_user(x, ptr) \ -({ \ +#define unsafe_get_user(x, ptr, err_label) \ +do { \ int __gu_err; \ unsigned long __gu_val; \ __get_user_size(__gu_val, (ptr), sizeof(*(ptr)), __gu_err, -EFAULT); \ (x) = (__force __typeof__(*(ptr)))__gu_val; \ - __builtin_expect(__gu_err, 0); \ -}) + if (unlikely(__gu_err)) goto err_label; \ +} while (0) #endif /* _ASM_X86_UACCESS_H */ |