diff options
Diffstat (limited to 'arch/arm64/include/asm/uaccess.h')
| -rw-r--r-- | arch/arm64/include/asm/uaccess.h | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h new file mode 100644 index 000000000000..008f8481da65 --- /dev/null +++ b/arch/arm64/include/asm/uaccess.h @@ -0,0 +1,297 @@ +/* + * Based on arch/arm/include/asm/uaccess.h + * + * Copyright (C) 2012 ARM Ltd. + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#ifndef __ASM_UACCESS_H +#define __ASM_UACCESS_H + +/* + * User space memory access functions + */ +#include <linux/string.h> +#include <linux/thread_info.h> + +#include <asm/ptrace.h> +#include <asm/errno.h> +#include <asm/memory.h> +#include <asm/compiler.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); + +#define KERNEL_DS (-1UL) +#define get_ds() (KERNEL_DS) + +#define USER_DS TASK_SIZE_64 +#define get_fs() (current_thread_info()->addr_limit) + +static inline void set_fs(mm_segment_t fs) +{ + current_thread_info()->addr_limit = fs; +} + +#define segment_eq(a,b) ((a) == (b)) + +/* + * Return 1 if addr < current->addr_limit, 0 otherwise. + */ +#define __addr_ok(addr) \ +({ \ + unsigned long flag; \ + asm("cmp %1, %0; cset %0, lo" \ + : "=&r" (flag) \ + : "r" (addr), "0" (current_thread_info()->addr_limit) \ + : "cc"); \ + flag; \ +}) + +/* + * Test whether a block of memory is a valid user space address. + * Returns 1 if the range is valid, 0 otherwise. + * + * This is equivalent to the following test: + * (u65)addr + (u65)size < (u65)current->addr_limit + * + * This needs 65-bit arithmetic. + */ +#define __range_ok(addr, size) \ +({ \ + unsigned long flag, roksum; \ + __chk_user_ptr(addr); \ + asm("adds %1, %1, %3; ccmp %1, %4, #2, cc; cset %0, cc" \ + : "=&r" (flag), "=&r" (roksum) \ + : "1" (addr), "Ir" (size), \ + "r" (current_thread_info()->addr_limit) \ + : "cc"); \ + flag; \ +}) + +#define access_ok(type, addr, size) __range_ok(addr, size) + +/* + * 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. + */ +#define __get_user_asm(instr, reg, x, addr, err) \ + asm volatile( \ + "1: " instr " " reg "1, [%2]\n" \ + "2:\n" \ + " .section .fixup, \"ax\"\n" \ + " .align 2\n" \ + "3: mov %w0, %3\n" \ + " mov %1, #0\n" \ + " b 2b\n" \ + " .previous\n" \ + " .section __ex_table,\"a\"\n" \ + " .align 3\n" \ + " .quad 1b, 3b\n" \ + " .previous" \ + : "+r" (err), "=&r" (x) \ + : "r" (addr), "i" (-EFAULT)) + +#define __get_user_err(x, ptr, err) \ +do { \ + unsigned long __gu_val; \ + __chk_user_ptr(ptr); \ + switch (sizeof(*(ptr))) { \ + case 1: \ + __get_user_asm("ldrb", "%w", __gu_val, (ptr), (err)); \ + break; \ + case 2: \ + __get_user_asm("ldrh", "%w", __gu_val, (ptr), (err)); \ + break; \ + case 4: \ + __get_user_asm("ldr", "%w", __gu_val, (ptr), (err)); \ + break; \ + case 8: \ + __get_user_asm("ldr", "%", __gu_val, (ptr), (err)); \ + break; \ + default: \ + BUILD_BUG(); \ + } \ + (x) = (__typeof__(*(ptr)))__gu_val; \ +} while (0) + +#define __get_user(x, ptr) \ +({ \ + int __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_unaligned __get_user + +#define get_user(x, ptr) \ +({ \ + might_sleep(); \ + access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) ? \ + __get_user((x), (ptr)) : \ + ((x) = 0, -EFAULT); \ +}) + +#define __put_user_asm(instr, reg, x, addr, err) \ + asm volatile( \ + "1: " instr " " reg "1, [%2]\n" \ + "2:\n" \ + " .section .fixup,\"ax\"\n" \ + " .align 2\n" \ + "3: mov %w0, %3\n" \ + " b 2b\n" \ + " .previous\n" \ + " .section __ex_table,\"a\"\n" \ + " .align 3\n" \ + " .quad 1b, 3b\n" \ + " .previous" \ + : "+r" (err) \ + : "r" (x), "r" (addr), "i" (-EFAULT)) + +#define __put_user_err(x, ptr, err) \ +do { \ + __typeof__(*(ptr)) __pu_val = (x); \ + __chk_user_ptr(ptr); \ + switch (sizeof(*(ptr))) { \ + case 1: \ + __put_user_asm("strb", "%w", __pu_val, (ptr), (err)); \ + break; \ + case 2: \ + __put_user_asm("strh", "%w", __pu_val, (ptr), (err)); \ + break; \ + case 4: \ + __put_user_asm("str", "%w", __pu_val, (ptr), (err)); \ + break; \ + case 8: \ + __put_user_asm("str", "%", __pu_val, (ptr), (err)); \ + break; \ + default: \ + BUILD_BUG(); \ + } \ +} while (0) + +#define __put_user(x, ptr) \ +({ \ + int __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_unaligned __put_user + +#define put_user(x, ptr) \ +({ \ + might_sleep(); \ + access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) ? \ + __put_user((x), (ptr)) : \ + -EFAULT; \ +}) + +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 __copy_in_user(void __user *to, const void __user *from, unsigned long n); +extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n); + +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 */ + memset(to, 0, 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; +} + +static inline unsigned long __must_check copy_in_user(void __user *to, const void __user *from, unsigned long n) +{ + if (access_ok(VERIFY_READ, from, n) && access_ok(VERIFY_WRITE, to, n)) + n = __copy_in_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 /* __ASM_UACCESS_H */ |