cregit-Linux how code gets into the kernel

Release 4.14 arch/m32r/include/asm/uaccess.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_M32R_UACCESS_H

#define _ASM_M32R_UACCESS_H

/*
 *  linux/include/asm-m32r/uaccess.h
 *
 *  M32R version.
 *    Copyright (C) 2004, 2006  Hirokazu Takata <takata at linux-m32r.org>
 */

/*
 * User space memory access functions
 */
#include <asm/page.h>
#include <asm/setup.h>
#include <linux/prefetch.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(s)	((mm_segment_t) { (s) })

#ifdef CONFIG_MMU


#define KERNEL_DS	MAKE_MM_SEG(0xFFFFFFFF)

#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))

#else /* not CONFIG_MMU */


#define KERNEL_DS	MAKE_MM_SEG(0xFFFFFFFF)

#define USER_DS		MAKE_MM_SEG(0xFFFFFFFF)

#define get_ds()	(KERNEL_DS)


static inline mm_segment_t get_fs(void) { return USER_DS; }

Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata12100.00%1100.00%
Total12100.00%1100.00%


static inline void set_fs(mm_segment_t s) { }

Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata9100.00%1100.00%
Total9100.00%1100.00%

#endif /* not CONFIG_MMU */ #define segment_eq(a, b) ((a).seg == (b).seg) #define __addr_ok(addr) \ ((unsigned long)(addr) < (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. * * This is equivalent to the following test: * (u33)addr + (u33)size >= (u33)current->addr_limit.seg * * This needs 33-bit arithmetic. We have a carry... */ #define __range_ok(addr, size) ({ \ unsigned long flag, roksum; \ __chk_user_ptr(addr); \ asm ( \ " cmpu %1, %1 ; clear cbit\n" \ " addx %1, %3 ; set cbit if overflow\n" \ " subx %0, %0\n" \ " cmpu %4, %1\n" \ " subx %0, %5\n" \ : "=&r" (flag), "=r" (roksum) \ : "1" (addr), "r" ((int)(size)), \ "r" (current_thread_info()->addr_limit.seg), "r" (0) \ : "cbit" ); \ flag; }) /** * 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. */ #ifdef CONFIG_MMU #define access_ok(type, addr, size) (likely(__range_ok(addr, size) == 0)) #else
static inline int access_ok(int type, const void *addr, unsigned long size) { unsigned long val = (unsigned long)addr; return ((val >= memory_start) && ((val + size) < memory_end)); }

Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata48100.00%1100.00%
Total48100.00%1100.00%

#endif /* CONFIG_MMU */ #include <asm/extable.h> /* * These are the main single-value transfer routines. They automatically * use the right size if we just have the right pointer type. * * This gets kind of ugly. We want to return _two_ values in "get_user()" * and yet we don't want to do any pointers, because that is too much * of a performance impact. Thus we have a few rather ugly macros here, * and hide all the uglyness from the user. * * The "__xxx" versions of the user access functions are versions that * do not verify the address space, that must have been done previously * with a separate "access_ok()" call (this is used when we do multiple * accesses to the same area of user memory). */ /* Careful: we have to cast the result to the type of the pointer for sign reasons */ /** * 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) \ __get_user_check((x), (ptr), sizeof(*(ptr))) /** * 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) \ __put_user_check((__typeof__(*(ptr)))(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))) #define __get_user_nocheck(x, ptr, size) \ ({ \ long __gu_err = 0; \ unsigned long __gu_val = 0; \ might_fault(); \ __get_user_size(__gu_val, (ptr), (size), __gu_err); \ (x) = (__force __typeof__(*(ptr)))__gu_val; \ __gu_err; \ }) #define __get_user_check(x, ptr, size) \ ({ \ long __gu_err = -EFAULT; \ unsigned long __gu_val = 0; \ const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ might_fault(); \ if (access_ok(VERIFY_READ, __gu_addr, size)) \ __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ (x) = (__force __typeof__(*(ptr)))__gu_val; \ __gu_err; \ }) extern long __get_user_bad(void); #define __get_user_size(x, ptr, size, retval) \ do { \ retval = 0; \ __chk_user_ptr(ptr); \ switch (size) { \ case 1: __get_user_asm(x, ptr, retval, "ub"); break; \ case 2: __get_user_asm(x, ptr, retval, "uh"); break; \ case 4: __get_user_asm(x, ptr, retval, ""); break; \ default: (x) = __get_user_bad(); \ } \ } while (0) #define __get_user_asm(x, addr, err, itype) \ __asm__ __volatile__( \ " .fillinsn\n" \ "1: ld"itype" %1,@%2\n" \ " .fillinsn\n" \ "2:\n" \ ".section .fixup,\"ax\"\n" \ " .balign 4\n" \ "3: ldi %0,%3\n" \ " seth r14,#high(2b)\n" \ " or3 r14,r14,#low(2b)\n" \ " jmp r14\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .balign 4\n" \ " .long 1b,3b\n" \ ".previous" \ : "=&r" (err), "=&r" (x) \ : "r" (addr), "i" (-EFAULT), "0" (err) \ : "r14", "memory") /** * __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((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) #define __put_user_nocheck(x, ptr, size) \ ({ \ long __pu_err; \ might_fault(); \ __put_user_size((x), (ptr), (size), __pu_err); \ __pu_err; \ }) #define __put_user_check(x, ptr, size) \ ({ \ long __pu_err = -EFAULT; \ __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ might_fault(); \ if (access_ok(VERIFY_WRITE, __pu_addr, size)) \ __put_user_size((x), __pu_addr, (size), __pu_err); \ __pu_err; \ }) #if defined(__LITTLE_ENDIAN__) #define __put_user_u64(x, addr, err) \ __asm__ __volatile__( \ " .fillinsn\n" \ "1: st %L1,@%2\n" \ " .fillinsn\n" \ "2: st %H1,@(4,%2)\n" \ " .fillinsn\n" \ "3:\n" \ ".section .fixup,\"ax\"\n" \ " .balign 4\n" \ "4: ldi %0,%3\n" \ " seth r14,#high(3b)\n" \ " or3 r14,r14,#low(3b)\n" \ " jmp r14\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .balign 4\n" \ " .long 1b,4b\n" \ " .long 2b,4b\n" \ ".previous" \ : "=&r" (err) \ : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err) \ : "r14", "memory") #elif defined(__BIG_ENDIAN__) #define __put_user_u64(x, addr, err) \ __asm__ __volatile__( \ " .fillinsn\n" \ "1: st %H1,@%2\n" \ " .fillinsn\n" \ "2: st %L1,@(4,%2)\n" \ " .fillinsn\n" \ "3:\n" \ ".section .fixup,\"ax\"\n" \ " .balign 4\n" \ "4: ldi %0,%3\n" \ " seth r14,#high(3b)\n" \ " or3 r14,r14,#low(3b)\n" \ " jmp r14\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .balign 4\n" \ " .long 1b,4b\n" \ " .long 2b,4b\n" \ ".previous" \ : "=&r" (err) \ : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err) \ : "r14", "memory") #else #error no endian defined #endif extern void __put_user_bad(void); #define __put_user_size(x, ptr, size, retval) \ do { \ retval = 0; \ __chk_user_ptr(ptr); \ switch (size) { \ case 1: __put_user_asm(x, ptr, retval, "b"); break; \ case 2: __put_user_asm(x, ptr, retval, "h"); break; \ case 4: __put_user_asm(x, ptr, retval, ""); break; \ case 8: __put_user_u64((__typeof__(*ptr))(x), ptr, retval); break;\ default: __put_user_bad(); \ } \ } while (0) struct __large_struct { unsigned long buf[100]; }; #define __m(x) (*(struct __large_struct *)(x)) /* * Tell gcc we read from memory instead of writing: this is because * we do not write to any memory gcc knows about, so there are no * aliasing issues. */ #define __put_user_asm(x, addr, err, itype) \ __asm__ __volatile__( \ " .fillinsn\n" \ "1: st"itype" %1,@%2\n" \ " .fillinsn\n" \ "2:\n" \ ".section .fixup,\"ax\"\n" \ " .balign 4\n" \ "3: ldi %0,%3\n" \ " seth r14,#high(2b)\n" \ " or3 r14,r14,#low(2b)\n" \ " jmp r14\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .balign 4\n" \ " .long 1b,3b\n" \ ".previous" \ : "=&r" (err) \ : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err) \ : "r14", "memory") /* * Here we special-case 1, 2 and 4-byte copy_*_user invocations. On a fault * we return the initial request size (1, 2 or 4), as copy_*_user should do. * If a store crosses a page boundary and gets a fault, the m32r will not write * anything, so this is accurate. */ /* * Copy To/From Userspace */ /* Generic arbitrary sized copy. */ /* Return the number of bytes NOT copied. */ #define __copy_user(to, from, size) \ do { \ unsigned long __dst, __src, __c; \ __asm__ __volatile__ ( \ " mv r14, %0\n" \ " or r14, %1\n" \ " beq %0, %1, 9f\n" \ " beqz %2, 9f\n" \ " and3 r14, r14, #3\n" \ " bnez r14, 2f\n" \ " and3 %2, %2, #3\n" \ " beqz %3, 2f\n" \ " addi %0, #-4 ; word_copy \n" \ " .fillinsn\n" \ "0: ld r14, @%1+\n" \ " addi %3, #-1\n" \ " .fillinsn\n" \ "1: st r14, @+%0\n" \ " bnez %3, 0b\n" \ " beqz %2, 9f\n" \ " addi %0, #4\n" \ " .fillinsn\n" \ "2: ldb r14, @%1 ; byte_copy \n" \ " .fillinsn\n" \ "3: stb r14, @%0\n" \ " addi %1, #1\n" \ " addi %2, #-1\n" \ " addi %0, #1\n" \ " bnez %2, 2b\n" \ " .fillinsn\n" \ "9:\n" \ ".section .fixup,\"ax\"\n" \ " .balign 4\n" \ "5: addi %3, #1\n" \ " addi %1, #-4\n" \ " .fillinsn\n" \ "6: slli %3, #2\n" \ " add %2, %3\n" \ " addi %0, #4\n" \ " .fillinsn\n" \ "7: seth r14, #high(9b)\n" \ " or3 r14, r14, #low(9b)\n" \ " jmp r14\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .balign 4\n" \ " .long 0b,6b\n" \ " .long 1b,5b\n" \ " .long 2b,9b\n" \ " .long 3b,9b\n" \ ".previous\n" \ : "=&r" (__dst), "=&r" (__src), "=&r" (size), \ "=&r" (__c) \ : "0" (to), "1" (from), "2" (size), "3" (size / 4) \ : "r14", "memory"); \ } while (0) /* We let the __ versions of copy_from/to_user inline, because they're often * used in fast paths and have only a small space overhead. */
static inline unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) { prefetchw(to); __copy_user(to, from, n); return n; }

Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata3282.05%250.00%
Al Viro717.95%250.00%
Total39100.00%4100.00%


static inline unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) { prefetch(from); __copy_user(to, from, n); return n; }

Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata3384.62%266.67%
Al Viro615.38%133.33%
Total39100.00%3100.00%

long __must_check strncpy_from_user(char *dst, const char __user *src, long count); /** * __clear_user: - Zero a block of memory in user space, with less checking. * @to: Destination address, in user space. * @n: Number of bytes to zero. * * Zero a block of memory in user space. Caller must check * the specified block with access_ok() before calling this function. * * Returns number of bytes that could not be cleared. * On success, this will be zero. */ unsigned long __clear_user(void __user *mem, unsigned long len); /** * clear_user: - Zero a block of memory in user space. * @to: Destination address, in user space. * @n: Number of bytes to zero. * * Zero a block of memory in user space. Caller must check * the specified block with access_ok() before calling this function. * * Returns number of bytes that could not be cleared. * On success, this will be zero. */ unsigned long clear_user(void __user *mem, unsigned long len); long strnlen_user(const char __user *str, long n); #endif /* _ASM_M32R_UACCESS_H */

Overall Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata53893.08%325.00%
Al Viro203.46%433.33%
Michael S. Tsirkin101.73%18.33%
David Hildenbrand50.87%18.33%
Adrian Bunk30.52%18.33%
Greg Kroah-Hartman10.17%18.33%
Tilman Schmidt10.17%18.33%
Total578100.00%12100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.