/* * linux/include/asm-arm/uaccess.h * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #ifndef _ASMARM_UACCESS_H #define _ASMARM_UACCESS_H /* * User space memory access functions */ #include <linux/sched.h> #include <asm/errno.h> #include <asm/memory.h> #include <asm/domain.h> #include <asm/system.h> #define VERIFY_READ 0 #define VERIFY_WRITE 1 /* * 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); /* * Note that this is actually 0x1,0000,0000 */ #define KERNEL_DS 0x00000000 #define USER_DS TASK_SIZE #define get_ds() (KERNEL_DS) #define get_fs() (current_thread_info()->addr_limit) static inline void set_fs (mm_segment_t fs) { current_thread_info()->addr_limit = fs; modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER); } #define segment_eq(a,b) ((a) == (b)) #define __addr_ok(addr) ({ \ unsigned long flag; \ __asm__("cmp %2, %0; movlo %0, #0" \ : "=&r" (flag) \ : "0" (current_thread_info()->addr_limit), "r" (addr) \ : "cc"); \ (flag == 0); }) /* We use 33-bit arithmetic here... */ #define __range_ok(addr,size) ({ \ unsigned long flag, sum; \ __chk_user_ptr(addr); \ __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \ : "=&r" (flag), "=&r" (sum) \ : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \ : "cc"); \ flag; }) #define access_ok(type,addr,size) (__range_ok(addr,size) == 0) /* * Single-value transfer routines. They automatically use the right * size if we just have the right pointer type. Note that the functions * which read from user space (*get_*) need to take care not to leak * kernel data even if the calling code is buggy and fails to check * the return value. This means zeroing out the destination variable * or buffer on error. Normally this is done out of line by the * fixup code, but there are a few places where it intrudes on the * main code path. When we only write to user space, there is no * problem. * * The "__xxx" versions of the user access functions do not verify the * address space - it must have been done previously with a separate * "access_ok()" call. * * The "xxx_error" versions set the third argument to EFAULT if an * error occurs, and leave it unchanged on success. Note that these * versions are void (ie, don't return a value as such). */ extern int __get_user_1(void *); extern int __get_user_2(void *); extern int __get_user_4(void *); extern int __get_user_bad(void); #define __get_user_x(__r2,__p,__e,__s,__i...) \ __asm__ __volatile__ ( \ __asmeq("%0", "r0") __asmeq("%1", "r2") \ "bl __get_user_" #__s \ : "=&r" (__e), "=r" (__r2) \ : "0" (__p) \ : __i, "cc") #define get_user(x,p) \ ({ \ const register typeof(*(p)) __user *__p asm("r0") = (p);\ register unsigned int __r2 asm("r2"); \ register int __e asm("r0"); \ switch (sizeof(*(__p))) { \ case 1: \ __get_user_x(__r2, __p, __e, 1, "lr"); \ break; \ case 2: \ __get_user_x(__r2, __p, __e, 2, "r3", "lr"); \ break; \ case 4: \ __get_user_x(__r2, __p, __e, 4, "lr"); \ break; \ default: __e = __get_user_bad(); break; \ } \ x = (typeof(*(p))) __r2; \ __e; \ }) #define __get_user(x,ptr) \ ({ \ long __gu_err = 0; \ __get_user_err((x),(ptr),__gu_err); \ __gu_err; \ }) #define __get_user_error(x,ptr,err) \ ({ \ __get_user_err((x),(ptr),err); \ (void) 0; \ }) #define __get_user_err(x,ptr,err) \ do { \ unsigned long __gu_addr = (unsigned long)(ptr); \ unsigned long __gu_val; \ __chk_user_ptr(ptr); \ switch (sizeof(*(ptr))) { \ case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \ case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \ case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \ default: (__gu_val) = __get_user_bad(); \ } \ (x) = (__typeof__(*(ptr)))__gu_val; \ } while (0) #define __get_user_asm_byte(x,addr,err) \ __asm__ __volatile__( \ "1: ldrbt %1,[%2],#0\n" \ "2:\n" \ " .section .fixup,\"ax\"\n" \ " .align 2\n" \ "3: mov %0, %3\n" \ " mov %1, #0\n" \ " b 2b\n" \ " .previous\n" \ " .section __ex_table,\"a\"\n" \ " .align 3\n" \ " .long 1b, 3b\n" \ " .previous" \ : "+r" (err), "=&r" (x) \ : "r" (addr), "i" (-EFAULT) \ : "cc") #ifndef __ARMEB__ #define __get_user_asm_half(x,__gu_addr,err) \ ({ \ unsigned long __b1, __b2; \ __get_user_asm_byte(__b1, __gu_addr, err); \ __get_user_asm_byte(__b2, __gu_addr + 1, err); \ (x) = __b1 | (__b2 << 8); \ }) #else #define __get_user_asm_half(x,__gu_addr,err) \ ({ \ unsigned long __b1, __b2; \ __get_user_asm_byte(__b1, __gu_addr, err); \ __get_user_asm_byte(__b2, __gu_addr + 1, err); \ (x) = (__b1 << 8) | __b2; \ }) #endif #define __get_user_asm_word(x,addr,err) \ __asm__ __volatile__( \ "1: ldrt %1,[%2],#0\n" \ "2:\n" \ " .section .fixup,\"ax\"\n" \ " .align 2\n" \ "3: mov %0, %3\n" \ " mov %1, #0\n" \ " b 2b\n" \ " .previous\n" \ " .section __ex_table,\"a\"\n" \ " .align 3\n" \ " .long 1b, 3b\n" \ " .previous" \ : "+r" (err), "=&r" (x) \ : "r" (addr), "i" (-EFAULT) \ : "cc") extern int __put_user_1(void *, unsigned int); extern int __put_user_2(void *, unsigned int); extern int __put_user_4(void *, unsigned int); extern int __put_user_8(void *, unsigned long long); extern int __put_user_bad(void); #define __put_user_x(__r2,__p,__e,__s) \ __asm__ __volatile__ ( \ __asmeq("%0", "r0") __asmeq("%2", "r2") \ "bl __put_user_" #__s \ : "=&r" (__e) \ : "0" (__p), "r" (__r2) \ : "ip", "lr", "cc") #define put_user(x,p) \ ({ \ const register typeof(*(p)) __r2 asm("r2") = (x); \ const register typeof(*(p)) __user *__p asm("r0") = (p);\ register int __e asm("r0"); \ switch (sizeof(*(__p))) { \ case 1: \ __put_user_x(__r2, __p, __e, 1); \ break; \ case 2: \ __put_user_x(__r2, __p, __e, 2); \ break; \ case 4: \ __put_user_x(__r2, __p, __e, 4); \ break; \ case 8: \ __put_user_x(__r2, __p, __e, 8); \ break; \ default: __e = __put_user_bad(); break; \ } \ __e; \ }) #define __put_user(x,ptr) \ ({ \ long __pu_err = 0; \ __put_user_err((x),(ptr),__pu_err); \ __pu_err; \ }) #define __put_user_error(x,ptr,err) \ ({ \ __put_user_err((x),(ptr),err); \ (void) 0; \ }) #define __put_user_err(x,ptr,err) \ do { \ unsigned long __pu_addr = (unsigned long)(ptr); \ __typeof__(*(ptr)) __pu_val = (x); \ __chk_user_ptr(ptr); \ switch (sizeof(*(ptr))) { \ case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \ case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \ case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \ case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \ default: __put_user_bad(); \ } \ } while (0) #define __put_user_asm_byte(x,__pu_addr,err) \ __asm__ __volatile__( \ "1: strbt %1,[%2],#0\n" \ "2:\n" \ " .section .fixup,\"ax\"\n" \ " .align 2\n" \ "3: mov %0, %3\n" \ " b 2b\n" \ " .previous\n" \ " .section __ex_table,\"a\"\n" \ " .align 3\n" \ " .long 1b, 3b\n" \ " .previous" \ : "+r" (err) \ : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \ : "cc") #ifndef __ARMEB__ #define __put_user_asm_half(x,__pu_addr,err) \ ({ \ unsigned long __temp = (unsigned long)(x); \ __put_user_asm_byte(__temp, __pu_addr, err); \ __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \ }) #else #define __put_user_asm_half(x,__pu_addr,err) \ ({ \ unsigned long __temp = (unsigned long)(x); \ __put_user_asm_byte(__temp >> 8, __pu_addr, err); \ __put_user_asm_byte(__temp, __pu_addr + 1, err); \ }) #endif #define __put_user_asm_word(x,__pu_addr,err) \ __asm__ __volatile__( \ "1: strt %1,[%2],#0\n" \ "2:\n" \ " .section .fixup,\"ax\"\n" \ " .align 2\n" \ "3: mov %0, %3\n" \ " b 2b\n" \ " .previous\n" \ " .section __ex_table,\"a\"\n" \ " .align 3\n" \ " .long 1b, 3b\n" \ " .previous" \ : "+r" (err) \ : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \ : "cc") #ifndef __ARMEB__ #define __reg_oper0 "%R2" #define __reg_oper1 "%Q2" #else #define __reg_oper0 "%Q2" #define __reg_oper1 "%R2" #endif #define __put_user_asm_dword(x,__pu_addr,err) \ __asm__ __volatile__( \ "1: strt " __reg_oper1 ", [%1], #4\n" \ "2: strt " __reg_oper0 ", [%1], #0\n" \ "3:\n" \ " .section .fixup,\"ax\"\n" \ " .align 2\n" \ "4: mov %0, %3\n" \ " b 3b\n" \ " .previous\n" \ " .section __ex_table,\"a\"\n" \ " .align 3\n" \ " .long 1b, 4b\n" \ " .long 2b, 4b\n" \ " .previous" \ : "+r" (err), "+r" (__pu_addr) \ : "r" (x), "i" (-EFAULT) \ : "cc") extern unsigned long __arch_copy_from_user(void *to, const void __user *from, unsigned long n); extern unsigned long __arch_copy_to_user(void __user *to, const void *from, unsigned long n); extern unsigned long __arch_clear_user(void __user *addr, unsigned long n); extern unsigned long __arch_strncpy_from_user(char *to, const char __user *from, unsigned long count); extern unsigned long __arch_strnlen_user(const char __user *s, 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)) n = __arch_copy_from_user(to, from, n); else /* security hole - plug it */ memzero(to, n); return n; } static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n) { return __arch_copy_from_user(to, from, n); } static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n) { if (access_ok(VERIFY_WRITE, to, n)) n = __arch_copy_to_user(to, from, n); return n; } static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n) { return __arch_copy_to_user(to, from, n); } #define __copy_to_user_inatomic __copy_to_user #define __copy_from_user_inatomic __copy_from_user static inline unsigned long clear_user (void __user *to, unsigned long n) { if (access_ok(VERIFY_WRITE, to, n)) n = __arch_clear_user(to, n); return n; } static inline unsigned long __clear_user (void __user *to, unsigned long n) { return __arch_clear_user(to, n); } static inline long strncpy_from_user (char *dst, const char __user *src, long count) { long res = -EFAULT; if (access_ok(VERIFY_READ, src, 1)) res = __arch_strncpy_from_user(dst, src, count); return res; } static inline long __strncpy_from_user (char *dst, const char __user *src, long count) { return __arch_strncpy_from_user(dst, src, count); } #define strlen_user(s) strnlen_user(s, ~0UL >> 1) static inline long strnlen_user(const char __user *s, long n) { unsigned long res = 0; if (__addr_ok(s)) res = __arch_strnlen_user(s, n); return res; } #endif /* _ASMARM_UACCESS_H */