| /* |
| * 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 */ |
| }; |