diff options
Diffstat (limited to 'arch/metag/include/asm/uaccess.h')
| -rw-r--r-- | arch/metag/include/asm/uaccess.h | 116 |
1 files changed, 41 insertions, 75 deletions
diff --git a/arch/metag/include/asm/uaccess.h b/arch/metag/include/asm/uaccess.h index 07238b39638c..9c8fbf8fb5aa 100644 --- a/arch/metag/include/asm/uaccess.h +++ b/arch/metag/include/asm/uaccess.h @@ -4,10 +4,6 @@ /* * User space memory access functions */ -#include <linux/sched.h> - -#define VERIFY_READ 0 -#define VERIFY_WRITE 1 /* * The fs value determines whether argument validity checking should be @@ -28,51 +24,38 @@ #define segment_eq(a, b) ((a).seg == (b).seg) -#define __kernel_ok (segment_eq(get_fs(), KERNEL_DS)) -/* - * 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), \ (unsigned long)(size)) -static inline int verify_area(int type, const void *addr, unsigned long size) -{ - return access_ok(type, addr, size) ? 0 : -EFAULT; -} - -/* - * The exception table consists of pairs of addresses: the first is the - * address of an instruction that is allowed to fault, and the second is - * the address at which the program should continue. No registers are - * modified, so it is entirely up to the continuation code to figure out - * what to do. - * - * All the routines below use bits of fixup code that are out of line - * with the main instruction path. This means when everything is well, - * we don't even have to jump over them. Further, they do not intrude - * on our cache or tlb entries. - */ -struct exception_table_entry { - unsigned long insn, fixup; -}; - -extern int fixup_exception(struct pt_regs *regs); +#include <asm/extable.h> /* * These are the main single-value transfer routines. They automatically @@ -138,7 +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; \ @@ -146,7 +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); \ @@ -157,6 +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 { \ @@ -168,6 +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(); \ } \ @@ -186,8 +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) * @@ -199,35 +192,8 @@ extern long __must_check strnlen_user(const char __user *src, long count); extern unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n); - -static inline unsigned long -copy_from_user(void *to, const void __user *from, unsigned long n) -{ - unsigned long res = n; - if (likely(access_ok(VERIFY_READ, from, n))) - res = raw_copy_from_user(to, from, n); - if (unlikely(res)) - memset(to + (n - res), 0, res); - return res; -} - -#define __copy_from_user(to, from, n) raw_copy_from_user(to, from, n) -#define __copy_from_user_inatomic __copy_from_user - -extern unsigned long __must_check __copy_user(void __user *to, - const void *from, - unsigned long n); - -static inline unsigned long copy_to_user(void __user *to, const void *from, - unsigned long n) -{ - if (access_ok(VERIFY_WRITE, to, n)) - return __copy_user(to, from, n); - return n; -} - -#define __copy_to_user(to, from, n) __copy_user(to, from, n) -#define __copy_to_user_inatomic __copy_to_user +extern unsigned long raw_copy_to_user(void __user *to, const void *from, + unsigned long n); /* * Zero Userspace |