| /* |
| * 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/string.h> |
| #include <asm/memory.h> |
| #include <asm/domain.h> |
| #include <asm/unified.h> |
| #include <asm/compiler.h> |
| |
| #include <asm/extable.h> |
| |
| /* |
| * These two functions allow hooking accesses to userspace to increase |
| * system integrity by ensuring that the kernel can not inadvertantly |
| * perform such accesses (eg, via list poison values) which could then |
| * be exploited for priviledge escalation. |
| */ |
| static inline unsigned int uaccess_save_and_enable(void) |
| { |
| #ifdef CONFIG_CPU_SW_DOMAIN_PAN |
| unsigned int old_domain = get_domain(); |
| |
| /* Set the current domain access to permit user accesses */ |
| set_domain((old_domain & ~domain_mask(DOMAIN_USER)) | |
| domain_val(DOMAIN_USER, DOMAIN_CLIENT)); |
| |
| return old_domain; |
| #else |
| return 0; |
| #endif |
| } |
| |
| static inline void uaccess_restore(unsigned int flags) |
| { |
| #ifdef CONFIG_CPU_SW_DOMAIN_PAN |
| /* Restore the user access mask */ |
| set_domain(flags); |
| #endif |
| } |
| |
| /* |
| * 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)) |
| |
| /* 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 *); |
| extern int __get_user_32t_8(void *); |
| extern int __get_user_8(void *); |
| extern int __get_user_64t_1(void *); |
| extern int __get_user_64t_2(void *); |
| extern int __get_user_64t_4(void *); |
| |
| #define __GUP_CLOBBER_1 "lr", "cc" |
| #ifdef CONFIG_CPU_USE_DOMAINS |
| #define __GUP_CLOBBER_2 "ip", "lr", "cc" |
| #else |
| #define __GUP_CLOBBER_2 "lr", "cc" |
| #endif |
| #define __GUP_CLOBBER_4 "lr", "cc" |
| #define __GUP_CLOBBER_32t_8 "lr", "cc" |
| #define __GUP_CLOBBER_8 "lr", "cc" |
| |
| #define __get_user_x(__r2, __p, __e, __l, __s) \ |
| __asm__ __volatile__ ( \ |
| __asmeq("%0", "r0") __asmeq("%1", "r2") \ |
| __asmeq("%3", "r1") \ |
| "bl __get_user_" #__s \ |
| : "=&r" (__e), "=r" (__r2) \ |
| : "0" (__p), "r" (__l) \ |
| : __GUP_CLOBBER_##__s) |
| |
| /* narrowing a double-word get into a single 32bit word register: */ |
| #ifdef __ARMEB__ |
| #define __get_user_x_32t(__r2, __p, __e, __l, __s) \ |
| __get_user_x(__r2, __p, __e, __l, 32t_8) |
| #else |
| #define __get_user_x_32t __get_user_x |
| #endif |
| |
| /* |
| * storing result into proper least significant word of 64bit target var, |
| * different only for big endian case where 64 bit __r2 lsw is r3: |
| */ |
| #ifdef __ARMEB__ |
| #define __get_user_x_64t(__r2, __p, __e, __l, __s) \ |
| __asm__ __volatile__ ( \ |
| __asmeq("%0", "r0") __asmeq("%1", "r2") \ |
| __asmeq("%3", "r1") \ |
| "bl __get_user_64t_" #__s \ |
| : "=&r" (__e), "=r" (__r2) \ |
| : "0" (__p), "r" (__l) \ |
| : __GUP_CLOBBER_##__s) |
| #else |
| #define __get_user_x_64t __get_user_x |
| #endif |
| |
| |
| #define __get_user_check(x, p) \ |
| ({ \ |
| unsigned long __limit = current_thread_info()->addr_limit - 1; \ |
| register const typeof(*(p)) __user *__p asm("r0") = (p);\ |
| register typeof(x) __r2 asm("r2"); \ |
| register unsigned long __l asm("r1") = __limit; \ |
| register int __e asm("r0"); \ |
| unsigned int __ua_flags = uaccess_save_and_enable(); \ |
| switch (sizeof(*(__p))) { \ |
| case 1: \ |
| if (sizeof((x)) >= 8) \ |
| __get_user_x_64t(__r2, __p, __e, __l, 1); \ |
| else \ |
| __get_user_x(__r2, __p, __e, __l, 1); \ |
| break; \ |
| case 2: \ |
| if (sizeof((x)) >= 8) \ |
| __get_user_x_64t(__r2, __p, __e, __l, 2); \ |
| else \ |
| __get_user_x(__r2, __p, __e, __l, 2); \ |
| break; \ |
| case 4: \ |
| if (sizeof((x)) >= 8) \ |
| __get_user_x_64t(__r2, __p, __e, __l, 4); \ |
| else \ |
| __get_user_x(__r2, __p, __e, __l, 4); \ |
| break; \ |
| case 8: \ |
| if (sizeof((x)) < 8) \ |
| __get_user_x_32t(__r2, __p, __e, __l, 4); \ |
| else \ |
| __get_user_x(__r2, __p, __e, __l, 8); \ |
| break; \ |
| default: __e = __get_user_bad(); break; \ |
| } \ |
| uaccess_restore(__ua_flags); \ |
| x = (typeof(*(p))) __r2; \ |
| __e; \ |
| }) |
| |
| #define get_user(x, p) \ |
| ({ \ |
| might_fault(); \ |
| __get_user_check(x, p); \ |
| }) |
| |
| 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_check(__pu_val, __ptr, __err, __s) \ |
| ({ \ |
| unsigned long __limit = current_thread_info()->addr_limit - 1; \ |
| register typeof(__pu_val) __r2 asm("r2") = __pu_val; \ |
| register const void __user *__p asm("r0") = __ptr; \ |
| register unsigned long __l asm("r1") = __limit; \ |
| register int __e asm("r0"); \ |
| __asm__ __volatile__ ( \ |
| __asmeq("%0", "r0") __asmeq("%2", "r2") \ |
| __asmeq("%3", "r1") \ |
| "bl __put_user_" #__s \ |
| : "=&r" (__e) \ |
| : "0" (__p), "r" (__r2), "r" (__l) \ |
| : "ip", "lr", "cc"); \ |
| __err = __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) ((void)(addr), 1) |
| #define __range_ok(addr, size) ((void)(addr), 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_check __put_user_nocheck |
| |
| #endif /* CONFIG_MMU */ |
| |
| #define access_ok(type, addr, size) (__range_ok(addr, size) == 0) |
| |
| #define user_addr_max() \ |
| (uaccess_kernel() ? ~0UL : get_fs()) |
| |
| /* |
| * 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; \ |
| unsigned int __ua_flags; \ |
| __chk_user_ptr(ptr); \ |
| might_fault(); \ |
| __ua_flags = uaccess_save_and_enable(); \ |
| 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(); \ |
| } \ |
| uaccess_restore(__ua_flags); \ |
| (x) = (__typeof__(*(ptr)))__gu_val; \ |
| } while (0) |
| |
| #define __get_user_asm(x, addr, err, instr) \ |
| __asm__ __volatile__( \ |
| "1: " TUSER(instr) " %1, [%2], #0\n" \ |
| "2:\n" \ |
| " .pushsection .text.fixup,\"ax\"\n" \ |
| " .align 2\n" \ |
| "3: mov %0, %3\n" \ |
| " mov %1, #0\n" \ |
| " b 2b\n" \ |
| " .popsection\n" \ |
| " .pushsection __ex_table,\"a\"\n" \ |
| " .align 3\n" \ |
| " .long 1b, 3b\n" \ |
| " .popsection" \ |
| : "+r" (err), "=&r" (x) \ |
| : "r" (addr), "i" (-EFAULT) \ |
| : "cc") |
| |
| #define __get_user_asm_byte(x, addr, err) \ |
| __get_user_asm(x, addr, err, ldrb) |
| |
| #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) \ |
| __get_user_asm(x, addr, err, ldr) |
| |
| |
| #define __put_user_switch(x, ptr, __err, __fn) \ |
| do { \ |
| const __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \ |
| __typeof__(*(ptr)) __pu_val = (x); \ |
| unsigned int __ua_flags; \ |
| might_fault(); \ |
| __ua_flags = uaccess_save_and_enable(); \ |
| switch (sizeof(*(ptr))) { \ |
| case 1: __fn(__pu_val, __pu_ptr, __err, 1); break; \ |
| case 2: __fn(__pu_val, __pu_ptr, __err, 2); break; \ |
| case 4: __fn(__pu_val, __pu_ptr, __err, 4); break; \ |
| case 8: __fn(__pu_val, __pu_ptr, __err, 8); break; \ |
| default: __err = __put_user_bad(); break; \ |
| } \ |
| uaccess_restore(__ua_flags); \ |
| } while (0) |
| |
| #define put_user(x, ptr) \ |
| ({ \ |
| int __pu_err = 0; \ |
| __put_user_switch((x), (ptr), __pu_err, __put_user_check); \ |
| __pu_err; \ |
| }) |
| |
| #define __put_user(x, ptr) \ |
| ({ \ |
| long __pu_err = 0; \ |
| __put_user_switch((x), (ptr), __pu_err, __put_user_nocheck); \ |
| __pu_err; \ |
| }) |
| |
| #define __put_user_error(x, ptr, err) \ |
| ({ \ |
| __put_user_switch((x), (ptr), (err), __put_user_nocheck); \ |
| (void) 0; \ |
| }) |
| |
| #define __put_user_nocheck(x, __pu_ptr, __err, __size) \ |
| do { \ |
| unsigned long __pu_addr = (unsigned long)__pu_ptr; \ |
| __put_user_nocheck_##__size(x, __pu_addr, __err); \ |
| } while (0) |
| |
| #define __put_user_nocheck_1 __put_user_asm_byte |
| #define __put_user_nocheck_2 __put_user_asm_half |
| #define __put_user_nocheck_4 __put_user_asm_word |
| #define __put_user_nocheck_8 __put_user_asm_dword |
| |
| #define __put_user_asm(x, __pu_addr, err, instr) \ |
| __asm__ __volatile__( \ |
| "1: " TUSER(instr) " %1, [%2], #0\n" \ |
| "2:\n" \ |
| " .pushsection .text.fixup,\"ax\"\n" \ |
| " .align 2\n" \ |
| "3: mov %0, %3\n" \ |
| " b 2b\n" \ |
| " .popsection\n" \ |
| " .pushsection __ex_table,\"a\"\n" \ |
| " .align 3\n" \ |
| " .long 1b, 3b\n" \ |
| " .popsection" \ |
| : "+r" (err) \ |
| : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \ |
| : "cc") |
| |
| #define __put_user_asm_byte(x, __pu_addr, err) \ |
| __put_user_asm(x, __pu_addr, err, strb) |
| |
| #ifndef __ARMEB__ |
| #define __put_user_asm_half(x, __pu_addr, err) \ |
| ({ \ |
| unsigned long __temp = (__force 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 = (__force 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) \ |
| __put_user_asm(x, __pu_addr, err, str) |
| |
| #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__( \ |
| ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \ |
| ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \ |
| THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \ |
| THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \ |
| "3:\n" \ |
| " .pushsection .text.fixup,\"ax\"\n" \ |
| " .align 2\n" \ |
| "4: mov %0, %3\n" \ |
| " b 3b\n" \ |
| " .popsection\n" \ |
| " .pushsection __ex_table,\"a\"\n" \ |
| " .align 3\n" \ |
| " .long 1b, 4b\n" \ |
| " .long 2b, 4b\n" \ |
| " .popsection" \ |
| : "+r" (err), "+r" (__pu_addr) \ |
| : "r" (x), "i" (-EFAULT) \ |
| : "cc") |
| |
| |
| #ifdef CONFIG_MMU |
| extern unsigned long __must_check |
| arm_copy_from_user(void *to, const void __user *from, unsigned long n); |
| |
| static inline unsigned long __must_check |
| raw_copy_from_user(void *to, const void __user *from, unsigned long n) |
| { |
| unsigned int __ua_flags; |
| |
| __ua_flags = uaccess_save_and_enable(); |
| n = arm_copy_from_user(to, from, n); |
| uaccess_restore(__ua_flags); |
| return n; |
| } |
| |
| extern unsigned long __must_check |
| arm_copy_to_user(void __user *to, const void *from, unsigned long n); |
| extern unsigned long __must_check |
| __copy_to_user_std(void __user *to, const void *from, unsigned long n); |
| |
| static inline unsigned long __must_check |
| raw_copy_to_user(void __user *to, const void *from, unsigned long n) |
| { |
| #ifndef CONFIG_UACCESS_WITH_MEMCPY |
| unsigned int __ua_flags; |
| __ua_flags = uaccess_save_and_enable(); |
| n = arm_copy_to_user(to, from, n); |
| uaccess_restore(__ua_flags); |
| return n; |
| #else |
| return arm_copy_to_user(to, from, n); |
| #endif |
| } |
| |
| extern unsigned long __must_check |
| arm_clear_user(void __user *addr, unsigned long n); |
| extern unsigned long __must_check |
| __clear_user_std(void __user *addr, unsigned long n); |
| |
| static inline unsigned long __must_check |
| __clear_user(void __user *addr, unsigned long n) |
| { |
| unsigned int __ua_flags = uaccess_save_and_enable(); |
| n = arm_clear_user(addr, n); |
| uaccess_restore(__ua_flags); |
| return n; |
| } |
| |
| #else |
| static inline unsigned long |
| raw_copy_from_user(void *to, const void __user *from, unsigned long n) |
| { |
| memcpy(to, (const void __force *)from, n); |
| return 0; |
| } |
| static inline unsigned long |
| raw_copy_to_user(void __user *to, const void *from, unsigned long n) |
| { |
| memcpy((void __force *)to, from, n); |
| return 0; |
| } |
| #define __clear_user(addr, n) (memset((void __force *)addr, 0, n), 0) |
| #endif |
| #define INLINE_COPY_TO_USER |
| #define INLINE_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; |
| } |
| |
| /* These are from lib/ code, and use __get_user() and friends */ |
| extern long strncpy_from_user(char *dest, const char __user *src, long count); |
| |
| extern __must_check long strnlen_user(const char __user *str, long n); |
| |
| #endif /* _ASMARM_UACCESS_H */ |