cregit-Linux how code gets into the kernel

Release 4.14 arch/mn10300/include/asm/uaccess.h

/* MN10300 userspace access functions
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */
#ifndef _ASM_UACCESS_H

#define _ASM_UACCESS_H

/*
 * User space memory access functions
 */
#include <linux/kernel.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(s)	((mm_segment_t) { (s) })


#define KERNEL_XDS	MAKE_MM_SEG(0xBFFFFFFF)

#define KERNEL_DS	MAKE_MM_SEG(0x9FFFFFFF)

#define USER_DS		MAKE_MM_SEG(TASK_SIZE)


#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)


#define __addr_ok(addr) \
	((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))

/*
 * check that a range of addresses falls within the current address limit
 */

static inline int ___range_ok(unsigned long addr, unsigned int size) { int flag = 1, tmp; asm(" add %3,%1 \n" /* set C-flag if addr + size > 4Gb */ " bcs 0f \n" " cmp %4,%1 \n" /* jump if addr+size>limit (error) */ " bhi 0f \n" " clr %0 \n" /* mark okay */ "0: \n" : "=r"(flag), "=&r"(tmp) : "1"(addr), "ir"(size), "r"(current_thread_info()->addr_limit.seg), "0"(flag) : "cc" ); return flag; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells32100.00%1100.00%
Total32100.00%1100.00%

#define __range_ok(addr, size) ___range_ok((unsigned long)(addr), (u32)(size)) #define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0) #define __access_ok(addr, size) (__range_ok((addr), (size)) == 0) #include <asm/extable.h> #define put_user(x, ptr) __put_user_check((x), (ptr), sizeof(*(ptr))) #define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(ptr))) /* * The "__xxx" versions do not do address space checking, useful when * doing multiple accesses to the same area (the user has to do the * checks by hand with "access_ok()") */ #define __put_user(x, ptr) __put_user_nocheck((x), (ptr), sizeof(*(ptr))) #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 *)(x)) #define __get_user_nocheck(x, ptr, size) \ ({ \ unsigned long __gu_addr; \ int __gu_err; \ __gu_addr = (unsigned long) (ptr); \ switch (size) { \ case 1: { \ unsigned char __gu_val; \ __get_user_asm("bu"); \ (x) = *(__force __typeof__(*(ptr))*) &__gu_val; \ break; \ } \ case 2: { \ unsigned short __gu_val; \ __get_user_asm("hu"); \ (x) = *(__force __typeof__(*(ptr))*) &__gu_val; \ break; \ } \ case 4: { \ unsigned int __gu_val; \ __get_user_asm(""); \ (x) = *(__force __typeof__(*(ptr))*) &__gu_val; \ break; \ } \ default: \ __get_user_unknown(); \ break; \ } \ __gu_err; \ }) #define __get_user_check(x, ptr, size) \ ({ \ const __typeof__(*(ptr))* __guc_ptr = (ptr); \ int _e; \ if (likely(__access_ok((unsigned long) __guc_ptr, (size)))) \ _e = __get_user_nocheck((x), __guc_ptr, (size)); \ else { \ _e = -EFAULT; \ (x) = (__typeof__(x))0; \ } \ _e; \ }) #define __get_user_asm(INSN) \ ({ \ asm volatile( \ "1:\n" \ " mov"INSN" %2,%1\n" \ " mov 0,%0\n" \ "2:\n" \ " .section .fixup,\"ax\"\n" \ "3:\n\t" \ " mov 0,%1\n" \ " mov %3,%0\n" \ " jmp 2b\n" \ " .previous\n" \ " .section __ex_table,\"a\"\n" \ " .balign 4\n" \ " .long 1b, 3b\n" \ " .previous" \ : "=&r" (__gu_err), "=&r" (__gu_val) \ : "m" (__m(__gu_addr)), "i" (-EFAULT)); \ }) extern int __get_user_unknown(void); #define __put_user_nocheck(x, ptr, size) \ ({ \ union { \ __typeof__(*(ptr)) val; \ u32 bits[2]; \ } __pu_val; \ unsigned long __pu_addr; \ int __pu_err; \ __pu_val.val = (x); \ __pu_addr = (unsigned long) (ptr); \ switch (size) { \ case 1: __put_user_asm("bu"); break; \ case 2: __put_user_asm("hu"); break; \ case 4: __put_user_asm("" ); break; \ case 8: __put_user_asm8(); break; \ default: __pu_err = __put_user_unknown(); break; \ } \ __pu_err; \ }) #define __put_user_check(x, ptr, size) \ ({ \ union { \ __typeof__(*(ptr)) val; \ u32 bits[2]; \ } __pu_val; \ unsigned long __pu_addr; \ int __pu_err; \ __pu_val.val = (x); \ __pu_addr = (unsigned long) (ptr); \ if (likely(__access_ok(__pu_addr, size))) { \ switch (size) { \ case 1: __put_user_asm("bu"); break; \ case 2: __put_user_asm("hu"); break; \ case 4: __put_user_asm("" ); break; \ case 8: __put_user_asm8(); break; \ default: __pu_err = __put_user_unknown(); break; \ } \ } \ else { \ __pu_err = -EFAULT; \ } \ __pu_err; \ }) #define __put_user_asm(INSN) \ ({ \ asm volatile( \ "1:\n" \ " mov"INSN" %1,%2\n" \ " mov 0,%0\n" \ "2:\n" \ " .section .fixup,\"ax\"\n" \ "3:\n" \ " mov %3,%0\n" \ " jmp 2b\n" \ " .previous\n" \ " .section __ex_table,\"a\"\n" \ " .balign 4\n" \ " .long 1b, 3b\n" \ " .previous" \ : "=&r" (__pu_err) \ : "r" (__pu_val.val), "m" (__m(__pu_addr)), \ "i" (-EFAULT) \ ); \ }) #define __put_user_asm8() \ ({ \ asm volatile( \ "1: mov %1,%3 \n" \ "2: mov %2,%4 \n" \ " mov 0,%0 \n" \ "3: \n" \ " .section .fixup,\"ax\" \n" \ "4: \n" \ " mov %5,%0 \n" \ " jmp 3b \n" \ " .previous \n" \ " .section __ex_table,\"a\"\n" \ " .balign 4 \n" \ " .long 1b, 4b \n" \ " .long 2b, 4b \n" \ " .previous \n" \ : "=&r" (__pu_err) \ : "r" (__pu_val.bits[0]), "r" (__pu_val.bits[1]), \ "m" (__m(__pu_addr)), "m" (__m(__pu_addr+4)), \ "i" (-EFAULT) \ ); \ }) extern int __put_user_unknown(void); /* * Copy To/From Userspace */ /* Generic arbitrary sized copy. */ #define __copy_user(to, from, size) \ do { \ if (size) { \ void *__to = to; \ const void *__from = from; \ int w; \ asm volatile( \ "0: movbu (%0),%3;\n" \ "1: movbu %3,(%1);\n" \ " inc %0;\n" \ " inc %1;\n" \ " add -1,%2;\n" \ " bne 0b;\n" \ "2:\n" \ " .section .fixup,\"ax\"\n" \ "3: jmp 2b\n" \ " .previous\n" \ " .section __ex_table,\"a\"\n" \ " .balign 4\n" \ " .long 0b,3b\n" \ " .long 1b,3b\n" \ " .previous\n" \ : "=a"(__from), "=a"(__to), "=r"(size), "=&r"(w)\ : "0"(__from), "1"(__to), "2"(size) \ : "cc", "memory"); \ } \ } while (0)
static inline unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) { __copy_user(to, from, n); return n; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells3191.18%133.33%
Al Viro38.82%266.67%
Total34100.00%3100.00%


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

Contributors

PersonTokensPropCommitsCommitProp
David Howells3294.12%133.33%
Al Viro25.88%266.67%
Total34100.00%3100.00%

extern long strncpy_from_user(char *dst, const char __user *src, long count); extern long strnlen_user(const char __user *str, long n); extern unsigned long clear_user(void __user *mem, unsigned long len); extern unsigned long __clear_user(void __user *mem, unsigned long len); #endif /* _ASM_UACCESS_H */

Overall Contributors

PersonTokensPropCommitsCommitProp
David Howells40796.90%220.00%
Al Viro92.14%440.00%
Akira Takeuchi20.48%220.00%
Mark Salter20.48%220.00%
Total420100.00%10100.00%
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