cregit-Linux how code gets into the kernel

Release 4.14 arch/tile/include/asm/uaccess.h

/*
 * Copyright 2010 Tilera Corporation. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation, version 2.
 *
 *   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, GOOD TITLE or
 *   NON INFRINGEMENT.  See the GNU General Public License for
 *   more details.
 */

#ifndef _ASM_TILE_UACCESS_H

#define _ASM_TILE_UACCESS_H

/*
 * User space memory access functions
 */
#include <linux/mm.h>
#include <asm/processor.h>
#include <asm/page.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.
 */

#define MAKE_MM_SEG(a)  ((mm_segment_t) { (a) })


#define KERNEL_DS	MAKE_MM_SEG(-1UL)

#define USER_DS		MAKE_MM_SEG(PAGE_OFFSET)


#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)

#ifndef __tilegx__
/*
 * We could allow mapping all 16 MB at 0xfc000000, but we set up a
 * special hack in arch_setup_additional_pages() to auto-create a mapping
 * for the first 16 KB, and it would seem strange to have different
 * user-accessible semantics for memory at 0xfc000000 and above 0xfc004000.
 */

static inline int is_arch_mappable_range(unsigned long addr, unsigned long size) { return (addr >= MEM_USER_INTRPT && addr < (MEM_USER_INTRPT + INTRPT_SIZE) && size <= (MEM_USER_INTRPT + INTRPT_SIZE) - addr); }

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Chris Metcalf40100.00%1100.00%
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#define is_arch_mappable_range is_arch_mappable_range #else #define is_arch_mappable_range(addr, size) 0 #endif /* * Note that using this definition ignores is_arch_mappable_range(), * so on tilepro code that uses user_addr_max() is constrained not * to reference the tilepro user-interrupt region. */ #define user_addr_max() (current_thread_info()->addr_limit.seg) /* * Test whether a block of memory is a valid user space address. * Returns 0 if the range is valid, nonzero otherwise. */ int __range_ok(unsigned long addr, unsigned long 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. */ #define access_ok(type, addr, size) ({ \ __chk_user_ptr(addr); \ likely(__range_ok((unsigned long)(addr), (size)) == 0); \ }) #include <asm/extable.h> /* * This is a type: either unsigned long, if the argument fits into * that type, or otherwise unsigned long long. */ #define __inttype(x) \ __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) /* * Support macros for __get_user(). * Note that __get_user() and __put_user() assume proper alignment. */ #ifdef __LP64__ #define _ASM_PTR ".quad" #define _ASM_ALIGN ".align 8" #else #define _ASM_PTR ".long" #define _ASM_ALIGN ".align 4" #endif #define __get_user_asm(OP, x, ptr, ret) \ asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n" \ ".pushsection .fixup,\"ax\"\n" \ "0: { movei %1, 0; movei %0, %3 }\n" \ "j 9f\n" \ ".section __ex_table,\"a\"\n" \ _ASM_ALIGN "\n" \ _ASM_PTR " 1b, 0b\n" \ ".popsection\n" \ "9:" \ : "=r" (ret), "=r" (x) \ : "r" (ptr), "i" (-EFAULT)) #ifdef __tilegx__ #define __get_user_1(x, ptr, ret) __get_user_asm(ld1u, x, ptr, ret) #define __get_user_2(x, ptr, ret) __get_user_asm(ld2u, x, ptr, ret) #define __get_user_4(x, ptr, ret) __get_user_asm(ld4s, x, ptr, ret) #define __get_user_8(x, ptr, ret) __get_user_asm(ld, x, ptr, ret) #else #define __get_user_1(x, ptr, ret) __get_user_asm(lb_u, x, ptr, ret) #define __get_user_2(x, ptr, ret) __get_user_asm(lh_u, x, ptr, ret) #define __get_user_4(x, ptr, ret) __get_user_asm(lw, x, ptr, ret) #ifdef __LITTLE_ENDIAN #define __lo32(a, b) a #define __hi32(a, b) b #else #define __lo32(a, b) b #define __hi32(a, b) a #endif #define __get_user_8(x, ptr, ret) \ ({ \ unsigned int __a, __b; \ asm volatile("1: { lw %1, %3; addi %2, %3, 4 }\n" \ "2: { lw %2, %2; movei %0, 0 }\n" \ ".pushsection .fixup,\"ax\"\n" \ "0: { movei %1, 0; movei %2, 0 }\n" \ "{ movei %0, %4; j 9f }\n" \ ".section __ex_table,\"a\"\n" \ ".align 4\n" \ ".word 1b, 0b\n" \ ".word 2b, 0b\n" \ ".popsection\n" \ "9:" \ : "=r" (ret), "=r" (__a), "=&r" (__b) \ : "r" (ptr), "i" (-EFAULT)); \ (x) = (__force __typeof(x))(__inttype(x)) \ (((u64)__hi32(__a, __b) << 32) | \ __lo32(__a, __b)); \ }) #endif extern int __get_user_bad(void) __attribute__((warning("sizeof __get_user argument not 1, 2, 4 or 8"))); /** * __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. * * Returns zero on success, or -EFAULT on error. * On error, the variable @x is set to zero. * * Caller must check the pointer with access_ok() before calling this * function. */ #define __get_user(x, ptr) \ ({ \ int __ret; \ typeof(x) _x; \ __chk_user_ptr(ptr); \ switch (sizeof(*(ptr))) { \ case 1: __get_user_1(_x, ptr, __ret); break; \ case 2: __get_user_2(_x, ptr, __ret); break; \ case 4: __get_user_4(_x, ptr, __ret); break; \ case 8: __get_user_8(_x, ptr, __ret); break; \ default: __ret = __get_user_bad(); break; \ } \ (x) = (typeof(*(ptr))) _x; \ __ret; \ }) /* Support macros for __put_user(). */ #define __put_user_asm(OP, x, ptr, ret) \ asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n" \ ".pushsection .fixup,\"ax\"\n" \ "0: { movei %0, %3; j 9f }\n" \ ".section __ex_table,\"a\"\n" \ _ASM_ALIGN "\n" \ _ASM_PTR " 1b, 0b\n" \ ".popsection\n" \ "9:" \ : "=r" (ret) \ : "r" (ptr), "r" (x), "i" (-EFAULT)) #ifdef __tilegx__ #define __put_user_1(x, ptr, ret) __put_user_asm(st1, x, ptr, ret) #define __put_user_2(x, ptr, ret) __put_user_asm(st2, x, ptr, ret) #define __put_user_4(x, ptr, ret) __put_user_asm(st4, x, ptr, ret) #define __put_user_8(x, ptr, ret) __put_user_asm(st, x, ptr, ret) #else #define __put_user_1(x, ptr, ret) __put_user_asm(sb, x, ptr, ret) #define __put_user_2(x, ptr, ret) __put_user_asm(sh, x, ptr, ret) #define __put_user_4(x, ptr, ret) __put_user_asm(sw, x, ptr, ret) #define __put_user_8(x, ptr, ret) \ ({ \ u64 __x = (__force __inttype(x))(x); \ int __lo = (int) __x, __hi = (int) (__x >> 32); \ asm volatile("1: { sw %1, %2; addi %0, %1, 4 }\n" \ "2: { sw %0, %3; movei %0, 0 }\n" \ ".pushsection .fixup,\"ax\"\n" \ "0: { movei %0, %4; j 9f }\n" \ ".section __ex_table,\"a\"\n" \ ".align 4\n" \ ".word 1b, 0b\n" \ ".word 2b, 0b\n" \ ".popsection\n" \ "9:" \ : "=&r" (ret) \ : "r" (ptr), "r" (__lo32(__lo, __hi)), \ "r" (__hi32(__lo, __hi)), "i" (-EFAULT)); \ }) #endif extern int __put_user_bad(void) __attribute__((warning("sizeof __put_user argument not 1, 2, 4 or 8"))); /** * __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) \ ({ \ int __ret; \ typeof(*(ptr)) _x = (x); \ __chk_user_ptr(ptr); \ switch (sizeof(*(ptr))) { \ case 1: __put_user_1(_x, ptr, __ret); break; \ case 2: __put_user_2(_x, ptr, __ret); break; \ case 4: __put_user_4(_x, ptr, __ret); break; \ case 8: __put_user_8(_x, ptr, __ret); break; \ default: __ret = __put_user_bad(); break; \ } \ __ret; \ }) /* * The versions of get_user and put_user without initial underscores * check the address of their arguments to make sure they are not * in kernel space. */ #define put_user(x, ptr) \ ({ \ __typeof__(*(ptr)) __user *__Pu_addr = (ptr); \ access_ok(VERIFY_WRITE, (__Pu_addr), sizeof(*(__Pu_addr))) ? \ __put_user((x), (__Pu_addr)) : \ -EFAULT; \ }) #define get_user(x, ptr) \ ({ \ __typeof__(*(ptr)) const __user *__Gu_addr = (ptr); \ access_ok(VERIFY_READ, (__Gu_addr), sizeof(*(__Gu_addr))) ? \ __get_user((x), (__Gu_addr)) : \ ((x) = 0, -EFAULT); \ }) extern unsigned long __must_check raw_copy_to_user(void __user *to, const void *from, unsigned long n); extern unsigned long __must_check raw_copy_from_user(void *to, const void __user *from, unsigned long n); #define INLINE_COPY_FROM_USER #define INLINE_COPY_TO_USER #ifdef __tilegx__ extern unsigned long raw_copy_in_user( void __user *to, const void __user *from, unsigned long n); #endif extern long strnlen_user(const char __user *str, long n); extern long strncpy_from_user(char *dst, const char __user *src, long); /** * clear_user: - Zero a block of memory in user space. * @mem: Destination address, in user space. * @len: Number of bytes to zero. * * Zero a block of memory in user space. * * Returns number of bytes that could not be cleared. * On success, this will be zero. */ extern unsigned long clear_user_asm(void __user *mem, unsigned long len);
static inline unsigned long __must_check __clear_user( void __user *mem, unsigned long len) { might_fault(); return clear_user_asm(mem, len); }

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static inline unsigned long __must_check clear_user( void __user *mem, unsigned long len) { if (access_ok(VERIFY_WRITE, mem, len)) return __clear_user(mem, len); return len; }

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Chris Metcalf40100.00%1100.00%
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/** * flush_user: - Flush a block of memory in user space from cache. * @mem: Destination address, in user space. * @len: Number of bytes to flush. * * Returns number of bytes that could not be flushed. * On success, this will be zero. */ extern unsigned long flush_user_asm(void __user *mem, unsigned long len);
static inline unsigned long __must_check __flush_user( void __user *mem, unsigned long len) { int retval; might_fault(); retval = flush_user_asm(mem, len); mb_incoherent(); return retval; }

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Chris Metcalf39100.00%1100.00%
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static inline unsigned long __must_check flush_user( void __user *mem, unsigned long len) { if (access_ok(VERIFY_WRITE, mem, len)) return __flush_user(mem, len); return len; }

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Chris Metcalf40100.00%1100.00%
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/** * finv_user: - Flush-inval a block of memory in user space from cache. * @mem: Destination address, in user space. * @len: Number of bytes to invalidate. * * Returns number of bytes that could not be flush-invalidated. * On success, this will be zero. */ extern unsigned long finv_user_asm(void __user *mem, unsigned long len);
static inline unsigned long __must_check __finv_user( void __user *mem, unsigned long len) { int retval; might_fault(); retval = finv_user_asm(mem, len); mb_incoherent(); return retval; }

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static inline unsigned long __must_check finv_user( void __user *mem, unsigned long len) { if (access_ok(VERIFY_WRITE, mem, len)) return __finv_user(mem, len); return len; }

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#endif /* _ASM_TILE_UACCESS_H */

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Chris Metcalf88898.34%872.73%
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