From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/metag/include/asm/uaccess.h | 246 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 246 insertions(+) create mode 100644 arch/metag/include/asm/uaccess.h (limited to 'arch/metag/include/asm/uaccess.h') diff --git a/arch/metag/include/asm/uaccess.h b/arch/metag/include/asm/uaccess.h new file mode 100644 index 000000000..8282cbce7 --- /dev/null +++ b/arch/metag/include/asm/uaccess.h @@ -0,0 +1,246 @@ +#ifndef __METAG_UACCESS_H +#define __METAG_UACCESS_H + +/* + * User space memory access functions + */ +#include + +#define VERIFY_READ 0 +#define VERIFY_WRITE 1 + +/* + * The fs value determines whether argument validity checking should be + * performed or not. If get_fs() == USER_DS, checking is performed, with + * get_fs() == KERNEL_DS, checking is bypassed. + * + * For historical reasons, these macros are grossly misnamed. + */ + +#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) + +#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF) +#define USER_DS MAKE_MM_SEG(PAGE_OFFSET) + +#define get_ds() (KERNEL_DS) +#define get_fs() (current_thread_info()->addr_limit) +#define set_fs(x) (current_thread_info()->addr_limit = (x)) + +#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); +} + +#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); + +/* + * These are the main single-value transfer routines. They automatically + * use the right size if we just have the right pointer type. + */ + +#define put_user(x, ptr) \ + __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) +#define __put_user(x, ptr) \ + __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) + +extern void __put_user_bad(void); + +#define __put_user_nocheck(x, ptr, size) \ +({ \ + long __pu_err; \ + __put_user_size((x), (ptr), (size), __pu_err); \ + __pu_err; \ +}) + +#define __put_user_check(x, ptr, size) \ +({ \ + long __pu_err = -EFAULT; \ + __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ + if (access_ok(VERIFY_WRITE, __pu_addr, size)) \ + __put_user_size((x), __pu_addr, (size), __pu_err); \ + __pu_err; \ +}) + +extern long __put_user_asm_b(unsigned int x, void __user *addr); +extern long __put_user_asm_w(unsigned int x, void __user *addr); +extern long __put_user_asm_d(unsigned int x, void __user *addr); +extern long __put_user_asm_l(unsigned long long x, void __user *addr); + +#define __put_user_size(x, ptr, size, retval) \ +do { \ + retval = 0; \ + switch (size) { \ + case 1: \ + retval = __put_user_asm_b((__force unsigned int)x, ptr);\ + break; \ + case 2: \ + retval = __put_user_asm_w((__force unsigned int)x, ptr);\ + break; \ + case 4: \ + retval = __put_user_asm_d((__force unsigned int)x, ptr);\ + break; \ + case 8: \ + retval = __put_user_asm_l((__force unsigned long long)x,\ + ptr); \ + break; \ + default: \ + __put_user_bad(); \ + } \ +} while (0) + +#define get_user(x, ptr) \ + __get_user_check((x), (ptr), sizeof(*(ptr))) +#define __get_user(x, ptr) \ + __get_user_nocheck((x), (ptr), sizeof(*(ptr))) + +extern long __get_user_bad(void); + +#define __get_user_nocheck(x, ptr, size) \ +({ \ + long __gu_err, __gu_val; \ + __get_user_size(__gu_val, (ptr), (size), __gu_err); \ + (x) = (__force __typeof__(*(ptr)))__gu_val; \ + __gu_err; \ +}) + +#define __get_user_check(x, ptr, size) \ +({ \ + long __gu_err = -EFAULT, __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); \ + (x) = (__force __typeof__(*(ptr)))__gu_val; \ + __gu_err; \ +}) + +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); + +#define __get_user_size(x, ptr, size, retval) \ +do { \ + retval = 0; \ + switch (size) { \ + case 1: \ + x = __get_user_asm_b(ptr, &retval); break; \ + case 2: \ + x = __get_user_asm_w(ptr, &retval); break; \ + case 4: \ + x = __get_user_asm_d(ptr, &retval); break; \ + default: \ + (x) = __get_user_bad(); \ + } \ +} while (0) + +/* + * Copy a null terminated string from userspace. + * + * Must return: + * -EFAULT for an exception + * count if we hit the buffer limit + * bytes copied if we hit a null byte + * (without the null byte) + */ + +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) + +/* + * Return the size of a string (including the ending 0) + * + * Return 0 on exception, a value greater than N if too long + */ +extern long __must_check strnlen_user(const char __user *src, long count); + +#define strlen_user(str) strnlen_user(str, 32767) + +extern unsigned long __must_check __copy_user_zeroing(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) +{ + if (access_ok(VERIFY_READ, from, n)) + return __copy_user_zeroing(to, from, n); + return n; +} + +#define __copy_from_user(to, from, n) __copy_user_zeroing(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 + +/* + * Zero Userspace + */ + +extern unsigned long __must_check __do_clear_user(void __user *to, + unsigned long n); + +static inline unsigned long clear_user(void __user *to, unsigned long n) +{ + if (access_ok(VERIFY_WRITE, to, n)) + return __do_clear_user(to, n); + return n; +} + +#define __clear_user(to, n) __do_clear_user(to, n) + +#endif /* _METAG_UACCESS_H */ -- cgit v1.2.3-54-g00ecf