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Diffstat (limited to 'arch/arm/include/asm/uaccess.h')
| -rw-r--r-- | arch/arm/include/asm/uaccess.h | 444 |
1 files changed, 444 insertions, 0 deletions
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h new file mode 100644 index 000000000000..d0f51ff900b5 --- /dev/null +++ b/arch/arm/include/asm/uaccess.h @@ -0,0 +1,444 @@ +/* + * arch/arm/include/asm/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); + +/* + * These two are intentionally not defined anywhere - if the kernel + * code generates any references to them, that's a bug. + */ +extern int __get_user_bad(void); +extern int __put_user_bad(void); + +/* + * Note that this is actually 0x1,0000,0000 + */ +#define KERNEL_DS 0x00000000 +#define get_ds() (KERNEL_DS) + +#ifdef CONFIG_MMU + +#define USER_DS TASK_SIZE +#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, roksum; \ + __chk_user_ptr(addr); \ + __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \ + : "=&r" (flag), "=&r" (roksum) \ + : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \ + : "cc"); \ + flag; }) + +/* + * 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. + */ +extern int __get_user_1(void *); +extern int __get_user_2(void *); +extern int __get_user_4(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) \ + ({ \ + register const typeof(*(p)) __user *__p asm("r0") = (p);\ + register unsigned long __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; \ + }) + +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); + +#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) \ + ({ \ + register const typeof(*(p)) __r2 asm("r2") = (x); \ + register const 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; \ + }) + +#else /* CONFIG_MMU */ + +/* + * uClinux has only one addr space, so has simplified address limits. + */ +#define USER_DS KERNEL_DS + +#define segment_eq(a,b) (1) +#define __addr_ok(addr) (1) +#define __range_ok(addr,size) (0) +#define get_fs() (KERNEL_DS) + +static inline void set_fs(mm_segment_t fs) +{ +} + +#define get_user(x,p) __get_user(x,p) +#define put_user(x,p) __put_user(x,p) + +#endif /* CONFIG_MMU */ + +#define access_ok(type,addr,size) (__range_ok(addr,size) == 0) + +/* + * 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). + */ +#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") + +#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") + + +#ifdef CONFIG_MMU +extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n); +extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n); +extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n); +#else +#define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0) +#define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0) +#define __clear_user(addr,n) (memset((void __force *)addr, 0, n), 0) +#endif + +extern unsigned long __must_check __strncpy_from_user(char *to, const char __user *from, unsigned long count); +extern unsigned long __must_check __strnlen_user(const char __user *s, long n); + +static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n) +{ + if (access_ok(VERIFY_READ, from, n)) + n = __copy_from_user(to, from, n); + else /* security hole - plug it */ + memzero(to, n); + return n; +} + +static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n) +{ + if (access_ok(VERIFY_WRITE, to, n)) + n = __copy_to_user(to, from, n); + return n; +} + +#define __copy_to_user_inatomic __copy_to_user +#define __copy_from_user_inatomic __copy_from_user + +static inline unsigned long __must_check clear_user(void __user *to, unsigned long n) +{ + if (access_ok(VERIFY_WRITE, to, n)) + n = __clear_user(to, n); + return n; +} + +static inline long __must_check strncpy_from_user(char *dst, const char __user *src, long count) +{ + long res = -EFAULT; + if (access_ok(VERIFY_READ, src, 1)) + res = __strncpy_from_user(dst, src, count); + return res; +} + +#define strlen_user(s) strnlen_user(s, ~0UL >> 1) + +static inline long __must_check strnlen_user(const char __user *s, long n) +{ + unsigned long res = 0; + + if (__addr_ok(s)) + res = __strnlen_user(s, n); + + return res; +} + +#endif /* _ASMARM_UACCESS_H */ |