2 * Copyright (C) 2002 - 2003 Jeff Dike (jdike@addtoit.com)
3 * Licensed under the GPL
6 #include "linux/compiler.h"
7 #include "linux/stddef.h"
8 #include "linux/kernel.h"
9 #include "linux/string.h"
11 #include "linux/highmem.h"
13 #include "asm/pgtable.h"
14 #include "asm/uaccess.h"
15 #include "kern_util.h"
16 #include "user_util.h"
18 extern void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
21 static unsigned long maybe_map(unsigned long virt, int is_write)
26 void *phys = um_virt_to_phys(current, virt, &pte);
29 if(IS_ERR(phys) || (is_write && !pte_write(pte))){
30 err = handle_page_fault(virt, 0, is_write, 1, &dummy_code);
33 phys = um_virt_to_phys(current, virt, NULL);
35 return((unsigned long) phys);
38 static int do_op(unsigned long addr, int len, int is_write,
39 int (*op)(unsigned long addr, int len, void *arg), void *arg)
44 addr = maybe_map(addr, is_write);
48 page = phys_to_page(addr);
49 addr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
50 n = (*op)(addr, len, arg);
56 static void do_buffer_op(void *jmpbuf, void *arg_ptr)
60 int len, is_write, size, remain, n;
61 int (*op)(unsigned long, int, void *);
65 va_copy(args, *(va_list *)arg_ptr);
66 addr = va_arg(args, unsigned long);
67 len = va_arg(args, int);
68 is_write = va_arg(args, int);
69 op = va_arg(args, void *);
70 arg = va_arg(args, void *);
71 res = va_arg(args, int *);
73 size = min(PAGE_ALIGN(addr) - addr, (unsigned long) len);
76 current->thread.fault_catcher = jmpbuf;
77 n = do_op(addr, size, is_write, op, arg);
79 *res = (n < 0 ? remain : 0);
90 while(addr < ((addr + remain) & PAGE_MASK)){
91 n = do_op(addr, PAGE_SIZE, is_write, op, arg);
93 *res = (n < 0 ? remain : 0);
105 n = do_op(addr, remain, is_write, op, arg);
107 *res = (n < 0 ? remain : 0);
110 current->thread.fault_catcher = NULL;
113 static int buffer_op(unsigned long addr, int len, int is_write,
114 int (*op)(unsigned long addr, int len, void *arg),
119 faulted = setjmp_wrapper(do_buffer_op, addr, len, is_write, op, arg,
124 return(addr + len - (unsigned long) current->thread.fault_addr);
127 static int copy_chunk_from_user(unsigned long from, int len, void *arg)
129 unsigned long *to_ptr = arg, to = *to_ptr;
131 memcpy((void *) to, (void *) from, len);
136 int copy_from_user_skas(void *to, const void __user *from, int n)
138 if(segment_eq(get_fs(), KERNEL_DS)){
139 memcpy(to, (__force void*)from, n);
143 return(access_ok_skas(VERIFY_READ, from, n) ?
144 buffer_op((unsigned long) from, n, 0, copy_chunk_from_user, &to):
148 static int copy_chunk_to_user(unsigned long to, int len, void *arg)
150 unsigned long *from_ptr = arg, from = *from_ptr;
152 memcpy((void *) to, (void *) from, len);
157 int copy_to_user_skas(void __user *to, const void *from, int n)
159 if(segment_eq(get_fs(), KERNEL_DS)){
160 memcpy((__force void*)to, from, n);
164 return(access_ok_skas(VERIFY_WRITE, to, n) ?
165 buffer_op((unsigned long) to, n, 1, copy_chunk_to_user, &from) :
169 static int strncpy_chunk_from_user(unsigned long from, int len, void *arg)
171 char **to_ptr = arg, *to = *to_ptr;
174 strncpy(to, (void *) from, len);
175 n = strnlen(to, len);
183 int strncpy_from_user_skas(char *dst, const char __user *src, int count)
188 if(segment_eq(get_fs(), KERNEL_DS)){
189 strncpy(dst, (__force void*)src, count);
190 return(strnlen(dst, count));
193 if(!access_ok_skas(VERIFY_READ, src, 1))
196 n = buffer_op((unsigned long) src, count, 0, strncpy_chunk_from_user,
200 return(strnlen(dst, count));
203 static int clear_chunk(unsigned long addr, int len, void *unused)
205 memset((void *) addr, 0, len);
209 int __clear_user_skas(void __user *mem, int len)
211 return(buffer_op((unsigned long) mem, len, 1, clear_chunk, NULL));
214 int clear_user_skas(void __user *mem, int len)
216 if(segment_eq(get_fs(), KERNEL_DS)){
217 memset((__force void*)mem, 0, len);
221 return(access_ok_skas(VERIFY_WRITE, mem, len) ?
222 buffer_op((unsigned long) mem, len, 1, clear_chunk, NULL) : len);
225 static int strnlen_chunk(unsigned long str, int len, void *arg)
227 int *len_ptr = arg, n;
229 n = strnlen((void *) str, len);
237 int strnlen_user_skas(const void __user *str, int len)
241 if(segment_eq(get_fs(), KERNEL_DS))
242 return(strnlen((__force char*)str, len) + 1);
244 n = buffer_op((unsigned long) str, len, 0, strnlen_chunk, &count);
251 * Overrides for Emacs so that we follow Linus's tabbing style.
252 * Emacs will notice this stuff at the end of the file and automatically
253 * adjust the settings for this buffer only. This must remain at the end
255 * ---------------------------------------------------------------------------
257 * c-file-style: "linux"