| /* |
| * This file is subject to the terms and conditions of the GNU General Public |
| * License. See the file "COPYING" in the main directory of this archive |
| * for more details. |
| * |
| * Copyright (C) 1996, 1997, 1998, 1999, 2000, 03, 04 by Ralf Baechle |
| * Copyright (C) 1999, 2000 Silicon Graphics, Inc. |
| * Copyright (C) 2007 Maciej W. Rozycki |
| * Copyright (C) 2014, Imagination Technologies Ltd. |
| */ |
| #ifndef _ASM_UACCESS_H |
| #define _ASM_UACCESS_H |
| |
| #include <linux/kernel.h> |
| #include <linux/string.h> |
| #include <asm/asm-eva.h> |
| #include <asm/extable.h> |
| |
| /* |
| * 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. |
| */ |
| #ifdef CONFIG_32BIT |
| |
| #ifdef CONFIG_KVM_GUEST |
| #define __UA_LIMIT 0x40000000UL |
| #else |
| #define __UA_LIMIT 0x80000000UL |
| #endif |
| |
| #define __UA_ADDR ".word" |
| #define __UA_LA "la" |
| #define __UA_t0 "$8" |
| |
| #endif /* CONFIG_32BIT */ |
| |
| #ifdef CONFIG_64BIT |
| |
| extern u64 __ua_limit; |
| |
| #define __UA_LIMIT __ua_limit |
| |
| #define __UA_ADDR ".dword" |
| #define __UA_LA "dla" |
| #define __UA_t0 "$12" |
| |
| #endif /* CONFIG_64BIT */ |
| |
| /* |
| * USER_DS is a bitmask that has the bits set that may not be set in a valid |
| * userspace address. Note that we limit 32-bit userspace to 0x7fff8000 but |
| * the arithmetic we're doing only works if the limit is a power of two, so |
| * we use 0x80000000 here on 32-bit kernels. If a process passes an invalid |
| * address in this range it's the process's problem, not ours :-) |
| */ |
| |
| #ifdef CONFIG_KVM_GUEST |
| #define KERNEL_DS ((mm_segment_t) { 0x80000000UL }) |
| #define USER_DS ((mm_segment_t) { 0xC0000000UL }) |
| #else |
| #define KERNEL_DS ((mm_segment_t) { 0UL }) |
| #define USER_DS ((mm_segment_t) { __UA_LIMIT }) |
| #endif |
| |
| #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) |
| |
| /* |
| * eva_kernel_access() - determine whether kernel memory access on an EVA system |
| * |
| * Determines whether memory accesses should be performed to kernel memory |
| * on a system using Extended Virtual Addressing (EVA). |
| * |
| * Return: true if a kernel memory access on an EVA system, else false. |
| */ |
| static inline bool eva_kernel_access(void) |
| { |
| if (!IS_ENABLED(CONFIG_EVA)) |
| return false; |
| |
| return uaccess_kernel(); |
| } |
| |
| /* |
| * Is a address valid? This does a straightforward calculation rather |
| * than tests. |
| * |
| * Address valid if: |
| * - "addr" doesn't have any high-bits set |
| * - AND "size" doesn't have any high-bits set |
| * - AND "addr+size" doesn't have any high-bits set |
| * - OR we are in kernel mode. |
| * |
| * __ua_size() is a trick to avoid runtime checking of positive constant |
| * sizes; for those we already know at compile time that the size is ok. |
| */ |
| #define __ua_size(size) \ |
| ((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size)) |
| |
| /* |
| * access_ok: - Checks if a user space pointer is valid |
| * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that |
| * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe |
| * to write to a block, it is always safe to read from it. |
| * @addr: User space pointer to start of block to check |
| * @size: Size of block to check |
| * |
| * Context: User context only. This function may sleep if pagefaults are |
| * enabled. |
| * |
| * Checks if a pointer to a block of memory in user space is valid. |
| * |
| * Returns true (nonzero) if the memory block may be valid, false (zero) |
| * if it is definitely invalid. |
| * |
| * Note that, depending on architecture, this function probably just |
| * checks that the pointer is in the user space range - after calling |
| * this function, memory access functions may still return -EFAULT. |
| */ |
| |
| static inline int __access_ok(const void __user *p, unsigned long size) |
| { |
| unsigned long addr = (unsigned long)p; |
| return (get_fs().seg & (addr | (addr + size) | __ua_size(size))) == 0; |
| } |
| |
| #define access_ok(type, addr, size) \ |
| likely(__access_ok((addr), (size))) |
| |
| /* |
| * put_user: - Write a simple value into user space. |
| * @x: Value to copy to user space. |
| * @ptr: Destination address, in user space. |
| * |
| * Context: User context only. This function may sleep if pagefaults are |
| * enabled. |
| * |
| * This macro copies a single simple value from kernel space to user |
| * space. It supports simple types like char and int, but not larger |
| * data types like structures or arrays. |
| * |
| * @ptr must have pointer-to-simple-variable type, and @x must be assignable |
| * to the result of dereferencing @ptr. |
| * |
| * Returns zero on success, or -EFAULT on error. |
| */ |
| #define put_user(x, ptr) \ |
| ({ \ |
| void __user *__p = (ptr); \ |
| might_fault(); \ |
| access_ok(VERIFY_WRITE, __p, sizeof(*ptr)) ? \ |
| __put_user((x), ((__typeof__(*(ptr)) __user *)__p)) : \ |
| -EFAULT; \ |
| }) |
| |
| /* |
| * get_user: - Get a simple variable from user space. |
| * @x: Variable to store result. |
| * @ptr: Source address, in user space. |
| * |
| * Context: User context only. This function may sleep if pagefaults are |
| * enabled. |
| * |
| * This macro copies a single simple variable from user space to kernel |
| * space. It supports simple types like char and int, but not larger |
| * data types like structures or arrays. |
| * |
| * @ptr must have pointer-to-simple-variable type, and the result of |
| * dereferencing @ptr must be assignable to @x without a cast. |
| * |
| * Returns zero on success, or -EFAULT on error. |
| * On error, the variable @x is set to zero. |
| */ |
| #define get_user(x, ptr) \ |
| ({ \ |
| const void __user *__p = (ptr); \ |
| might_fault(); \ |
| access_ok(VERIFY_READ, __p, sizeof(*ptr)) ? \ |
| __get_user((x), (__typeof__(*(ptr)) __user *)__p) :\ |
| ((x) = (__typeof__(*(ptr)))0,-EFAULT); \ |
| }) |
| |
| /* |
| * __put_user: - Write a simple value into user space, with less checking. |
| * @x: Value to copy to user space. |
| * @ptr: Destination address, in user space. |
| * |
| * Context: User context only. This function may sleep if pagefaults are |
| * enabled. |
| * |
| * This macro copies a single simple value from kernel space to user |
| * space. It supports simple types like char and int, but not larger |
| * data types like structures or arrays. |
| * |
| * @ptr must have pointer-to-simple-variable type, and @x must be assignable |
| * to the result of dereferencing @ptr. |
| * |
| * Caller must check the pointer with access_ok() before calling this |
| * function. |
| * |
| * Returns zero on success, or -EFAULT on error. |
| */ |
| #define __put_user(x,ptr) \ |
| __put_user_nocheck((x), (ptr), sizeof(*(ptr))) |
| |
| /* |
| * __get_user: - Get a simple variable from user space, with less checking. |
| * @x: Variable to store result. |
| * @ptr: Source address, in user space. |
| * |
| * Context: User context only. This function may sleep if pagefaults are |
| * enabled. |
| * |
| * This macro copies a single simple variable from user space to kernel |
| * space. It supports simple types like char and int, but not larger |
| * data types like structures or arrays. |
| * |
| * @ptr must have pointer-to-simple-variable type, and the result of |
| * dereferencing @ptr must be assignable to @x without a cast. |
| * |
| * Caller must check the pointer with access_ok() before calling this |
| * function. |
| * |
| * Returns zero on success, or -EFAULT on error. |
| * On error, the variable @x is set to zero. |
| */ |
| #define __get_user(x,ptr) \ |
| __get_user_nocheck((x), (ptr), sizeof(*(ptr))) |
| |
| struct __large_struct { unsigned long buf[100]; }; |
| #define __m(x) (*(struct __large_struct __user *)(x)) |
| |
| /* |
| * Yuck. We need two variants, one for 64bit operation and one |
| * for 32 bit mode and old iron. |
| */ |
| #ifndef CONFIG_EVA |
| #define __get_kernel_common(val, size, ptr) __get_user_common(val, size, ptr) |
| #else |
| #define __get_kernel_common(val, size, ptr) \ |
| do { \ |
| switch (size) { \ |
| case 1: __get_data_asm(val, kernel_lb, ptr); break; \ |
| case 2: __get_data_asm(val, kernel_lh, ptr); break; \ |
| case 4: __get_data_asm(val, kernel_lw, ptr); break; \ |
| case 8: __GET_DW(val, kernel_ld, ptr); break; \ |
| default: __get_user_unknown(); break; \ |
| } \ |
| } while (0) |
| #endif |
| |
| #ifdef CONFIG_32BIT |
| #define __GET_DW(val, insn, ptr) __get_data_asm_ll32(val, insn, ptr) |
| #endif |
| #ifdef CONFIG_64BIT |
| #define __GET_DW(val, insn, ptr) __get_data_asm(val, insn, ptr) |
| #endif |
| |
| extern void __get_user_unknown(void); |
| |
| #define __get_user_common(val, size, ptr) \ |
| do { \ |
| switch (size) { \ |
| case 1: __get_data_asm(val, user_lb, ptr); break; \ |
| case 2: __get_data_asm(val, user_lh, ptr); break; \ |
| case 4: __get_data_asm(val, user_lw, ptr); break; \ |
| case 8: __GET_DW(val, user_ld, ptr); break; \ |
| default: __get_user_unknown(); break; \ |
| } \ |
| } while (0) |
| |
| #define __get_user_nocheck(x, ptr, size) \ |
| ({ \ |
| int __gu_err; \ |
| \ |
| if (eva_kernel_access()) { \ |
| __get_kernel_common((x), size, ptr); \ |
| } else { \ |
| __chk_user_ptr(ptr); \ |
| __get_user_common((x), size, ptr); \ |
| } \ |
| __gu_err; \ |
| }) |
| |
| #define __get_data_asm(val, insn, addr) \ |
| { \ |
| long __gu_tmp; \ |
| \ |
| __asm__ __volatile__( \ |
| "1: "insn("%1", "%3")" \n" \ |
| "2: \n" \ |
| " .insn \n" \ |
| " .section .fixup,\"ax\" \n" \ |
| "3: li %0, %4 \n" \ |
| " move %1, $0 \n" \ |
| " j 2b \n" \ |
| " .previous \n" \ |
| " .section __ex_table,\"a\" \n" \ |
| " "__UA_ADDR "\t1b, 3b \n" \ |
| " .previous \n" \ |
| : "=r" (__gu_err), "=r" (__gu_tmp) \ |
| : "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \ |
| \ |
| (val) = (__typeof__(*(addr))) __gu_tmp; \ |
| } |
| |
| /* |
| * Get a long long 64 using 32 bit registers. |
| */ |
| #define __get_data_asm_ll32(val, insn, addr) \ |
| { \ |
| union { \ |
| unsigned long long l; \ |
| __typeof__(*(addr)) t; \ |
| } __gu_tmp; \ |
| \ |
| __asm__ __volatile__( \ |
| "1: " insn("%1", "(%3)")" \n" \ |
| "2: " insn("%D1", "4(%3)")" \n" \ |
| "3: \n" \ |
| " .insn \n" \ |
| " .section .fixup,\"ax\" \n" \ |
| "4: li %0, %4 \n" \ |
| " move %1, $0 \n" \ |
| " move %D1, $0 \n" \ |
| " j 3b \n" \ |
| " .previous \n" \ |
| " .section __ex_table,\"a\" \n" \ |
| " " __UA_ADDR " 1b, 4b \n" \ |
| " " __UA_ADDR " 2b, 4b \n" \ |
| " .previous \n" \ |
| : "=r" (__gu_err), "=&r" (__gu_tmp.l) \ |
| : "0" (0), "r" (addr), "i" (-EFAULT)); \ |
| \ |
| (val) = __gu_tmp.t; \ |
| } |
| |
| #ifndef CONFIG_EVA |
| #define __put_kernel_common(ptr, size) __put_user_common(ptr, size) |
| #else |
| #define __put_kernel_common(ptr, size) \ |
| do { \ |
| switch (size) { \ |
| case 1: __put_data_asm(kernel_sb, ptr); break; \ |
| case 2: __put_data_asm(kernel_sh, ptr); break; \ |
| case 4: __put_data_asm(kernel_sw, ptr); break; \ |
| case 8: __PUT_DW(kernel_sd, ptr); break; \ |
| default: __put_user_unknown(); break; \ |
| } \ |
| } while(0) |
| #endif |
| |
| /* |
| * Yuck. We need two variants, one for 64bit operation and one |
| * for 32 bit mode and old iron. |
| */ |
| #ifdef CONFIG_32BIT |
| #define __PUT_DW(insn, ptr) __put_data_asm_ll32(insn, ptr) |
| #endif |
| #ifdef CONFIG_64BIT |
| #define __PUT_DW(insn, ptr) __put_data_asm(insn, ptr) |
| #endif |
| |
| #define __put_user_common(ptr, size) \ |
| do { \ |
| switch (size) { \ |
| case 1: __put_data_asm(user_sb, ptr); break; \ |
| case 2: __put_data_asm(user_sh, ptr); break; \ |
| case 4: __put_data_asm(user_sw, ptr); break; \ |
| case 8: __PUT_DW(user_sd, ptr); break; \ |
| default: __put_user_unknown(); break; \ |
| } \ |
| } while (0) |
| |
| #define __put_user_nocheck(x, ptr, size) \ |
| ({ \ |
| __typeof__(*(ptr)) __pu_val; \ |
| int __pu_err = 0; \ |
| \ |
| __pu_val = (x); \ |
| if (eva_kernel_access()) { \ |
| __put_kernel_common(ptr, size); \ |
| } else { \ |
| __chk_user_ptr(ptr); \ |
| __put_user_common(ptr, size); \ |
| } \ |
| __pu_err; \ |
| }) |
| |
| #define __put_data_asm(insn, ptr) \ |
| { \ |
| __asm__ __volatile__( \ |
| "1: "insn("%z2", "%3")" # __put_data_asm \n" \ |
| "2: \n" \ |
| " .insn \n" \ |
| " .section .fixup,\"ax\" \n" \ |
| "3: li %0, %4 \n" \ |
| " j 2b \n" \ |
| " .previous \n" \ |
| " .section __ex_table,\"a\" \n" \ |
| " " __UA_ADDR " 1b, 3b \n" \ |
| " .previous \n" \ |
| : "=r" (__pu_err) \ |
| : "0" (0), "Jr" (__pu_val), "o" (__m(ptr)), \ |
| "i" (-EFAULT)); \ |
| } |
| |
| #define __put_data_asm_ll32(insn, ptr) \ |
| { \ |
| __asm__ __volatile__( \ |
| "1: "insn("%2", "(%3)")" # __put_data_asm_ll32 \n" \ |
| "2: "insn("%D2", "4(%3)")" \n" \ |
| "3: \n" \ |
| " .insn \n" \ |
| " .section .fixup,\"ax\" \n" \ |
| "4: li %0, %4 \n" \ |
| " j 3b \n" \ |
| " .previous \n" \ |
| " .section __ex_table,\"a\" \n" \ |
| " " __UA_ADDR " 1b, 4b \n" \ |
| " " __UA_ADDR " 2b, 4b \n" \ |
| " .previous" \ |
| : "=r" (__pu_err) \ |
| : "0" (0), "r" (__pu_val), "r" (ptr), \ |
| "i" (-EFAULT)); \ |
| } |
| |
| extern void __put_user_unknown(void); |
| |
| /* |
| * We're generating jump to subroutines which will be outside the range of |
| * jump instructions |
| */ |
| #ifdef MODULE |
| #define __MODULE_JAL(destination) \ |
| ".set\tnoat\n\t" \ |
| __UA_LA "\t$1, " #destination "\n\t" \ |
| "jalr\t$1\n\t" \ |
| ".set\tat\n\t" |
| #else |
| #define __MODULE_JAL(destination) \ |
| "jal\t" #destination "\n\t" |
| #endif |
| |
| extern size_t mips_copy_user(void *__to, const void *__from, size_t __n); |
| extern size_t mips_copy_from_user(void *__to, const void *__from, size_t __n); |
| extern size_t mips_copy_to_user(void *__to, const void *__from, size_t __n); |
| |
| static inline unsigned long |
| raw_copy_to_user(void __user *to, const void *from, unsigned long n) |
| { |
| if (eva_kernel_access()) { |
| memcpy(to, from, n); |
| return 0; |
| } |
| |
| return mips_copy_to_user(to, from, n); |
| } |
| |
| static inline unsigned long |
| raw_copy_from_user(void *to, const void __user *from, unsigned long n) |
| { |
| if (eva_kernel_access()) { |
| memcpy(to, from, n); |
| return 0; |
| } |
| |
| return mips_copy_from_user(to, from, n); |
| } |
| |
| #define INLINE_COPY_FROM_USER |
| #define INLINE_COPY_TO_USER |
| |
| static inline unsigned long |
| raw_copy_in_user(void __user*to, const void __user *from, unsigned long n) |
| { |
| if (eva_kernel_access()) { |
| memcpy(to, from, n); |
| return 0; |
| } |
| |
| return mips_copy_user(to, from, n); |
| } |
| |
| extern __must_check unsigned long __clear_user(void __user *to, unsigned long n); |
| |
| #define clear_user(addr,n) \ |
| ({ \ |
| void __user * __cl_addr = (addr); \ |
| unsigned long __cl_size = (n); \ |
| if (__cl_size && access_ok(VERIFY_WRITE, \ |
| __cl_addr, __cl_size)) \ |
| __cl_size = __clear_user(__cl_addr, __cl_size); \ |
| __cl_size; \ |
| }) |
| |
| extern long __strncpy_from_kernel_asm(char *__to, const char __user *__from, long __len); |
| extern long __strncpy_from_user_asm(char *__to, const char __user *__from, long __len); |
| |
| /* |
| * strncpy_from_user: - Copy a NUL terminated string from userspace. |
| * @dst: Destination address, in kernel space. This buffer must be at |
| * least @count bytes long. |
| * @src: Source address, in user space. |
| * @count: Maximum number of bytes to copy, including the trailing NUL. |
| * |
| * Copies a NUL-terminated string from userspace to kernel space. |
| * |
| * On success, returns the length of the string (not including the trailing |
| * NUL). |
| * |
| * If access to userspace fails, returns -EFAULT (some data may have been |
| * copied). |
| * |
| * If @count is smaller than the length of the string, copies @count bytes |
| * and returns @count. |
| */ |
| static inline long |
| strncpy_from_user(char *__to, const char __user *__from, long __len) |
| { |
| long res; |
| |
| if (eva_kernel_access()) { |
| __asm__ __volatile__( |
| "move\t$4, %1\n\t" |
| "move\t$5, %2\n\t" |
| "move\t$6, %3\n\t" |
| __MODULE_JAL(__strncpy_from_kernel_asm) |
| "move\t%0, $2" |
| : "=r" (res) |
| : "r" (__to), "r" (__from), "r" (__len) |
| : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory"); |
| } else { |
| might_fault(); |
| __asm__ __volatile__( |
| "move\t$4, %1\n\t" |
| "move\t$5, %2\n\t" |
| "move\t$6, %3\n\t" |
| __MODULE_JAL(__strncpy_from_user_asm) |
| "move\t%0, $2" |
| : "=r" (res) |
| : "r" (__to), "r" (__from), "r" (__len) |
| : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory"); |
| } |
| |
| return res; |
| } |
| |
| extern long __strnlen_kernel_asm(const char __user *s, long n); |
| extern long __strnlen_user_asm(const char __user *s, long n); |
| |
| /* |
| * strnlen_user: - Get the size of a string in user space. |
| * @str: The string to measure. |
| * |
| * Context: User context only. This function may sleep if pagefaults are |
| * enabled. |
| * |
| * Get the size of a NUL-terminated string in user space. |
| * |
| * Returns the size of the string INCLUDING the terminating NUL. |
| * On exception, returns 0. |
| * If the string is too long, returns a value greater than @n. |
| */ |
| static inline long strnlen_user(const char __user *s, long n) |
| { |
| long res; |
| |
| might_fault(); |
| if (eva_kernel_access()) { |
| __asm__ __volatile__( |
| "move\t$4, %1\n\t" |
| "move\t$5, %2\n\t" |
| __MODULE_JAL(__strnlen_kernel_asm) |
| "move\t%0, $2" |
| : "=r" (res) |
| : "r" (s), "r" (n) |
| : "$2", "$4", "$5", __UA_t0, "$31"); |
| } else { |
| __asm__ __volatile__( |
| "move\t$4, %1\n\t" |
| "move\t$5, %2\n\t" |
| __MODULE_JAL(__strnlen_user_asm) |
| "move\t%0, $2" |
| : "=r" (res) |
| : "r" (s), "r" (n) |
| : "$2", "$4", "$5", __UA_t0, "$31"); |
| } |
| |
| return res; |
| } |
| |
| #endif /* _ASM_UACCESS_H */ |