Loading...
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 | /* * linux/fs/proc/mem.c * * Copyright (C) 1991, 1992 Linus Torvalds */ #include <linux/types.h> #include <linux/errno.h> #include <linux/sched.h> #include <linux/kernel.h> #include <asm/segment.h> #include <asm/io.h> /* * mem_write isn't really a good idea right now. It needs * to check a lot more: if the process we try to write to * dies in the middle right now, mem_write will overwrite * kernel memory.. This disables it altogether. */ #define mem_write NULL static int mem_read(struct inode * inode, struct file * file,char * buf, int count) { unsigned long addr, pid, cr3; char *tmp; unsigned long pte, page; int i; if (count < 0) return -EINVAL; pid = inode->i_ino; pid >>= 16; cr3 = 0; for (i = 1 ; i < NR_TASKS ; i++) if (task[i] && task[i]->pid == pid) { cr3 = task[i]->tss.cr3; break; } if (!cr3) return -EACCES; addr = file->f_pos; tmp = buf; while (count > 0) { if (current->signal & ~current->blocked) break; pte = *PAGE_DIR_OFFSET(cr3,addr); if (!(pte & PAGE_PRESENT)) break; pte &= PAGE_MASK; pte += PAGE_PTR(addr); page = *(unsigned long *) pte; if (!(page & 1)) break; page &= PAGE_MASK; page += addr & ~PAGE_MASK; i = PAGE_SIZE-(addr & ~PAGE_MASK); if (i > count) i = count; memcpy_tofs(tmp,(void *) page,i); addr += i; tmp += i; count -= i; } file->f_pos = addr; return tmp-buf; } #ifndef mem_write static int mem_write(struct inode * inode, struct file * file,char * buf, int count) { unsigned long addr, pid, cr3; char *tmp; unsigned long pte, page; int i; if (count < 0) return -EINVAL; addr = file->f_pos; pid = inode->i_ino; pid >>= 16; cr3 = 0; for (i = 1 ; i < NR_TASKS ; i++) if (task[i] && task[i]->pid == pid) { cr3 = task[i]->tss.cr3; break; } if (!cr3) return -EACCES; tmp = buf; while (count > 0) { if (current->signal & ~current->blocked) break; pte = *PAGE_DIR_OFFSET(cr3,addr); if (!(pte & PAGE_PRESENT)) break; pte &= PAGE_MASK; pte += PAGE_PTR(addr); page = *(unsigned long *) pte; if (!(page & PAGE_PRESENT)) break; if (!(page & 2)) { do_wp_page(0,addr,current,0); continue; } page &= PAGE_MASK; page += addr & ~PAGE_MASK; i = PAGE_SIZE-(addr & ~PAGE_MASK); if (i > count) i = count; memcpy_fromfs((void *) page,tmp,i); addr += i; tmp += i; count -= i; } file->f_pos = addr; if (tmp != buf) return tmp-buf; if (current->signal & ~current->blocked) return -ERESTARTSYS; return 0; } #endif static int mem_lseek(struct inode * inode, struct file * file, off_t offset, int orig) { switch (orig) { case 0: file->f_pos = offset; return file->f_pos; case 1: file->f_pos += offset; return file->f_pos; default: return -EINVAL; } } static struct file_operations proc_mem_operations = { mem_lseek, mem_read, mem_write, NULL, /* mem_readdir */ NULL, /* mem_select */ NULL, /* mem_ioctl */ NULL, /* mmap */ NULL, /* no special open code */ NULL, /* no special release code */ NULL /* can't fsync */ }; struct inode_operations proc_mem_inode_operations = { &proc_mem_operations, /* default base directory file-ops */ NULL, /* create */ NULL, /* lookup */ NULL, /* link */ NULL, /* unlink */ NULL, /* symlink */ NULL, /* mkdir */ NULL, /* rmdir */ NULL, /* mknod */ NULL, /* rename */ NULL, /* readlink */ NULL, /* follow_link */ NULL, /* bmap */ NULL, /* truncate */ NULL /* permission */ }; |