diff options
Diffstat (limited to 'arch/metag/include/asm/uaccess.h')
-rw-r--r-- | arch/metag/include/asm/uaccess.h | 58 |
1 files changed, 38 insertions, 20 deletions
diff --git a/arch/metag/include/asm/uaccess.h b/arch/metag/include/asm/uaccess.h index 5ebc285..9c8fbf8 100644 --- a/arch/metag/include/asm/uaccess.h +++ b/arch/metag/include/asm/uaccess.h @@ -24,24 +24,32 @@ #define segment_eq(a, b) ((a).seg == (b).seg) -#define __kernel_ok (uaccess_kernel()) -/* - * Explicitly allow NULL pointers here. Parts of the kernel such - * as readv/writev use access_ok to validate pointers, but want - * to allow NULL pointers for various reasons. NULL pointers are - * safe to allow through because the first page is not mappable on - * Meta. - * - * We also wish to avoid letting user code access the system area - * and the kernel half of the address space. - */ -#define __user_bad(addr, size) (((addr) > 0 && (addr) < META_MEMORY_BASE) || \ - ((addr) > PAGE_OFFSET && \ - (addr) < LINCORE_BASE)) - static inline int __access_ok(unsigned long addr, unsigned long size) { - return __kernel_ok || !__user_bad(addr, size); + /* + * Allow access to the user mapped memory area, but not the system area + * before it. The check extends to the top of the address space when + * kernel access is allowed (there's no real reason to user copy to the + * system area in any case). + */ + if (likely(addr >= META_MEMORY_BASE && addr < get_fs().seg && + size <= get_fs().seg - addr)) + return true; + /* + * Explicitly allow NULL pointers here. Parts of the kernel such + * as readv/writev use access_ok to validate pointers, but want + * to allow NULL pointers for various reasons. NULL pointers are + * safe to allow through because the first page is not mappable on + * Meta. + */ + if (!addr) + return true; + /* Allow access to core code memory area... */ + if (addr >= LINCORE_CODE_BASE && addr <= LINCORE_CODE_LIMIT && + size <= LINCORE_CODE_LIMIT + 1 - addr) + return true; + /* ... but no other areas. */ + return false; } #define access_ok(type, addr, size) __access_ok((unsigned long)(addr), \ @@ -113,7 +121,8 @@ extern long __get_user_bad(void); #define __get_user_nocheck(x, ptr, size) \ ({ \ - long __gu_err, __gu_val; \ + long __gu_err; \ + long long __gu_val; \ __get_user_size(__gu_val, (ptr), (size), __gu_err); \ (x) = (__force __typeof__(*(ptr)))__gu_val; \ __gu_err; \ @@ -121,7 +130,8 @@ extern long __get_user_bad(void); #define __get_user_check(x, ptr, size) \ ({ \ - long __gu_err = -EFAULT, __gu_val = 0; \ + long __gu_err = -EFAULT; \ + long long __gu_val = 0; \ const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ if (access_ok(VERIFY_READ, __gu_addr, size)) \ __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ @@ -132,6 +142,7 @@ extern long __get_user_bad(void); extern unsigned char __get_user_asm_b(const void __user *addr, long *err); extern unsigned short __get_user_asm_w(const void __user *addr, long *err); extern unsigned int __get_user_asm_d(const void __user *addr, long *err); +extern unsigned long long __get_user_asm_l(const void __user *addr, long *err); #define __get_user_size(x, ptr, size, retval) \ do { \ @@ -143,6 +154,8 @@ do { \ x = __get_user_asm_w(ptr, &retval); break; \ case 4: \ x = __get_user_asm_d(ptr, &retval); break; \ + case 8: \ + x = __get_user_asm_l(ptr, &retval); break; \ default: \ (x) = __get_user_bad(); \ } \ @@ -161,8 +174,13 @@ do { \ extern long __must_check __strncpy_from_user(char *dst, const char __user *src, long count); -#define strncpy_from_user(dst, src, count) __strncpy_from_user(dst, src, count) - +static inline long +strncpy_from_user(char *dst, const char __user *src, long count) +{ + if (!access_ok(VERIFY_READ, src, 1)) + return -EFAULT; + return __strncpy_from_user(dst, src, count); +} /* * Return the size of a string (including the ending 0) * |