/usr/share/systemtap/runtime/linux/copy.c is in systemtap-common 2.6-0.2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 | /* -*- linux-c -*-
* Copy from user space functions
* Copyright (C) 2005-2014 Red Hat Inc.
* Copyright (C) 2005 Intel Corporation.
*
* This file is part of systemtap, and is free software. You can
* redistribute it and/or modify it under the terms of the GNU General
* Public License (GPL); either version 2, or (at your option) any
* later version.
*/
#ifndef _STAPLINUX_COPY_C_ /* -*- linux-c -*- */
#define _STAPLINUX_COPY_C_
/** @file copy.c
* @brief Functions to copy from user space.
*/
/** @addtogroup copy Functions to copy from user space.
* Functions to copy from user space.
* None of these functions will sleep (for example to allow pages
* to be swapped in). It is possible (although rare) that the data
* in user space will not present and these functions will return an error.
* @{
*/
#ifdef CONFIG_GENERIC_STRNCPY_FROM_USER
#define __stp_strncpy_from_user(dst,src,count,res) \
do { res = strncpy_from_user(dst, src, count); } while(0)
#else /* !CONFIG_GENERIC_STRNCPY_FROM_USER */
#if defined (__i386__)
#define __stp_strncpy_from_user(dst,src,count,res) \
do { \
int __d0, __d1, __d2; \
__asm__ __volatile__( \
" testl %1,%1\n" \
" jz 2f\n" \
"0: lodsb\n" \
" stosb\n" \
" testb %%al,%%al\n" \
" jz 1f\n" \
" decl %1\n" \
" jnz 0b\n" \
"1: subl %1,%0\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: movl %5,%0\n" \
" jmp 2b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 4\n" \
" .long 0b,3b\n" \
".previous" \
: "=d"(res), "=c"(count), "=&a" (__d0), "=&S" (__d1), \
"=&D" (__d2) \
: "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \
: "memory"); \
} while (0)
#elif defined (__x86_64__)
#define __stp_strncpy_from_user(dst,src,count,res) \
do { \
long __d0, __d1, __d2; \
__asm__ __volatile__( \
" testq %1,%1\n" \
" jz 2f\n" \
"0: lodsb\n" \
" stosb\n" \
" testb %%al,%%al\n" \
" jz 1f\n" \
" decq %1\n" \
" jnz 0b\n" \
"1: subq %1,%0\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: movq %5,%0\n" \
" jmp 2b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 8\n" \
" .quad 0b,3b\n" \
".previous" \
: "=r"(res), "=c"(count), "=&a" (__d0), "=&S" (__d1), \
"=&D" (__d2) \
: "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \
: "memory"); \
} while (0)
#elif defined (__powerpc__) || defined (__arm__)
#define __stp_strncpy_from_user(dst,src,count,res) \
do { res = __strncpy_from_user(dst, src, count); } while(0)
#elif defined (__s390__) || defined (__s390x__)|| defined (__aarch64__)
#define __stp_strncpy_from_user(dst,src,count,res) \
do { res = strncpy_from_user(dst, src, count); } while(0)
#elif defined (__ia64__)
#define __stp_strncpy_from_user(dst,src,count,res) \
do { res = __strncpy_from_user(dst, src, count); } while(0)
#endif
#endif /* !CONFIG_GENERIC_STRNCPY_FROM_USER */
/** Copy a NULL-terminated string from userspace.
* On success, returns the length of the string (not including the trailing
* NULL).
*
* If access to userspace fails, returns -EFAULT (some data may have been
* copied).
* @param dst Destination address, in kernel space. This buffer must be at
* least <i>count</i> bytes long.
* @param src Source address, in user space.
* @param count Maximum number of bytes to copy, including the trailing NULL.
*
* If <i>count</i> is smaller than the length of the string, copies
* <i>count</i> bytes and returns <i>count</i>.
*/
/* XXX: see also kread/uread in loc2c-runtime.h */
static long _stp_strncpy_from_user(char *dst, const char __user *src, long count)
{
long res = -EFAULT;
mm_segment_t _oldfs = get_fs();
set_fs(USER_DS);
pagefault_disable();
if (access_ok(VERIFY_READ, src, count)) /* XXX: bad_addr? */
__stp_strncpy_from_user(dst, src, count, res);
pagefault_enable();
set_fs(_oldfs);
return res;
}
/** Copy a block of data from user space.
*
* If data could not be copied, this function will not modify the
* destination.
*
* @param dst Destination address, in kernel space.
* @param src Source address, in user space.
* @param count Number of bytes to copy.
* @return number of bytes that could not be copied. On success,
* this will be zero.
*
*/
/* XXX: see also kread/uread in loc2c-runtime.h */
static unsigned long _stp_copy_from_user(char *dst, const char __user *src, unsigned long count)
{
if (count) {
mm_segment_t _oldfs = get_fs();
set_fs(USER_DS);
pagefault_disable();
if (access_ok(VERIFY_READ, src, count))
count = __copy_from_user_inatomic(dst, src, count);
else
/* Notice that if we fail, we don't modify
* the destination. In the failure case, we
* can't trust 'count' to be reasonable. */
count = -EFAULT;
pagefault_enable();
set_fs(_oldfs);
}
return count;
}
/** @} */
#endif /* _STAPLINUX_COPY_C_ */
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