/* * linux/fs/proc/base.c * * Copyright (C) 1991, 1992 Linus Torvalds * * proc base directory handling functions * * 1999, Al Viro. Rewritten. Now it covers the whole per-process part. * Instead of using magical inumbers to determine the kind of object * we allocate and fill in-core inodes upon lookup. They don't even * go into icache. We cache the reference to task_struct upon lookup too. * Eventually it should become a filesystem in its own. We don't use the * rest of procfs anymore. */ #include <asm/uaccess.h> #include <linux/config.h> #include <linux/errno.h> #include <linux/time.h> #include <linux/proc_fs.h> #include <linux/stat.h> #include <linux/init.h> #include <linux/file.h> #include <linux/string.h> #include <linux/seq_file.h> #include <linux/namei.h> #include <linux/namespace.h> #include <linux/mm.h> #include <linux/smp_lock.h> #include <linux/kallsyms.h> #include <linux/mount.h> #include <linux/security.h> #include <linux/ptrace.h> /* * For hysterical raisins we keep the same inumbers as in the old procfs. * Feel free to change the macro below - just keep the range distinct from * inumbers of the rest of procfs (currently those are in 0x0000--0xffff). * As soon as we'll get a separate superblock we will be able to forget * about magical ranges too. */ #define fake_ino(pid,ino) (((pid)<<16)|(ino)) enum pid_directory_inos { PROC_TGID_INO = 2, PROC_TGID_TASK, PROC_TGID_STATUS, PROC_TGID_MEM, PROC_TGID_CWD, PROC_TGID_ROOT, PROC_TGID_EXE, PROC_TGID_FD, PROC_TGID_ENVIRON, PROC_TGID_AUXV, PROC_TGID_CMDLINE, PROC_TGID_STAT, PROC_TGID_STATM, PROC_TGID_MAPS, PROC_TGID_MOUNTS, PROC_TGID_WCHAN, #ifdef CONFIG_SECURITY PROC_TGID_ATTR, PROC_TGID_ATTR_CURRENT, PROC_TGID_ATTR_PREV, PROC_TGID_ATTR_EXEC, PROC_TGID_ATTR_FSCREATE, #endif PROC_TGID_FD_DIR, PROC_TID_INO, PROC_TID_STATUS, PROC_TID_MEM, PROC_TID_CWD, PROC_TID_ROOT, PROC_TID_EXE, PROC_TID_FD, PROC_TID_ENVIRON, PROC_TID_AUXV, PROC_TID_CMDLINE, PROC_TID_STAT, PROC_TID_STATM, PROC_TID_MAPS, PROC_TID_MOUNTS, PROC_TID_WCHAN, #ifdef CONFIG_SECURITY PROC_TID_ATTR, PROC_TID_ATTR_CURRENT, PROC_TID_ATTR_PREV, PROC_TID_ATTR_EXEC, PROC_TID_ATTR_FSCREATE, #endif PROC_TID_FD_DIR = 0x8000, /* 0x8000-0xffff */ }; struct pid_entry { int type; int len; char *name; mode_t mode; }; #define E(type,name,mode) {(type),sizeof(name)-1,(name),(mode)} static struct pid_entry tgid_base_stuff[] = { E(PROC_TGID_TASK, "task", S_IFDIR|S_IRUGO|S_IXUGO), E(PROC_TGID_FD, "fd", S_IFDIR|S_IRUSR|S_IXUSR), E(PROC_TGID_ENVIRON, "environ", S_IFREG|S_IRUSR), E(PROC_TGID_AUXV, "auxv", S_IFREG|S_IRUSR), E(PROC_TGID_STATUS, "status", S_IFREG|S_IRUGO), E(PROC_TGID_CMDLINE, "cmdline", S_IFREG|S_IRUGO), E(PROC_TGID_STAT, "stat", S_IFREG|S_IRUGO), E(PROC_TGID_STATM, "statm", S_IFREG|S_IRUGO), E(PROC_TGID_MAPS, "maps", S_IFREG|S_IRUGO), E(PROC_TGID_MEM, "mem", S_IFREG|S_IRUSR|S_IWUSR), E(PROC_TGID_CWD, "cwd", S_IFLNK|S_IRWXUGO), E(PROC_TGID_ROOT, "root", S_IFLNK|S_IRWXUGO), E(PROC_TGID_EXE, "exe", S_IFLNK|S_IRWXUGO), E(PROC_TGID_MOUNTS, "mounts", S_IFREG|S_IRUGO), #ifdef CONFIG_SECURITY E(PROC_TGID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO), #endif #ifdef CONFIG_KALLSYMS E(PROC_TGID_WCHAN, "wchan", S_IFREG|S_IRUGO), #endif {0,0,NULL,0} }; static struct pid_entry tid_base_stuff[] = { E(PROC_TID_FD, "fd", S_IFDIR|S_IRUSR|S_IXUSR), E(PROC_TID_ENVIRON, "environ", S_IFREG|S_IRUSR), E(PROC_TID_AUXV, "auxv", S_IFREG|S_IRUSR), E(PROC_TID_STATUS, "status", S_IFREG|S_IRUGO), E(PROC_TID_CMDLINE, "cmdline", S_IFREG|S_IRUGO), E(PROC_TID_STAT, "stat", S_IFREG|S_IRUGO), E(PROC_TID_STATM, "statm", S_IFREG|S_IRUGO), E(PROC_TID_MAPS, "maps", S_IFREG|S_IRUGO), E(PROC_TID_MEM, "mem", S_IFREG|S_IRUSR|S_IWUSR), E(PROC_TID_CWD, "cwd", S_IFLNK|S_IRWXUGO), E(PROC_TID_ROOT, "root", S_IFLNK|S_IRWXUGO), E(PROC_TID_EXE, "exe", S_IFLNK|S_IRWXUGO), E(PROC_TID_MOUNTS, "mounts", S_IFREG|S_IRUGO), #ifdef CONFIG_SECURITY E(PROC_TID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO), #endif #ifdef CONFIG_KALLSYMS E(PROC_TID_WCHAN, "wchan", S_IFREG|S_IRUGO), #endif {0,0,NULL,0} }; #ifdef CONFIG_SECURITY static struct pid_entry tgid_attr_stuff[] = { E(PROC_TGID_ATTR_CURRENT, "current", S_IFREG|S_IRUGO|S_IWUGO), E(PROC_TGID_ATTR_PREV, "prev", S_IFREG|S_IRUGO), E(PROC_TGID_ATTR_EXEC, "exec", S_IFREG|S_IRUGO|S_IWUGO), E(PROC_TGID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUGO), {0,0,NULL,0} }; static struct pid_entry tid_attr_stuff[] = { E(PROC_TID_ATTR_CURRENT, "current", S_IFREG|S_IRUGO|S_IWUGO), E(PROC_TID_ATTR_PREV, "prev", S_IFREG|S_IRUGO), E(PROC_TID_ATTR_EXEC, "exec", S_IFREG|S_IRUGO|S_IWUGO), E(PROC_TID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUGO), {0,0,NULL,0} }; #endif #undef E static inline struct task_struct *proc_task(struct inode *inode) { return PROC_I(inode)->task; } static inline int proc_type(struct inode *inode) { return PROC_I(inode)->type; } int proc_pid_stat(struct task_struct*,char*); int proc_pid_status(struct task_struct*,char*); int proc_pid_statm(struct task_struct*,char*); int proc_pid_cpu(struct task_struct*,char*); static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt) { struct task_struct *task = proc_task(inode); struct files_struct *files; struct file *file; int fd = proc_type(inode) - PROC_TID_FD_DIR; files = get_files_struct(task); if (files) { spin_lock(&files->file_lock); file = fcheck_files(files, fd); if (file) { *mnt = mntget(file->f_vfsmnt); *dentry = dget(file->f_dentry); spin_unlock(&files->file_lock); put_files_struct(files); return 0; } spin_unlock(&files->file_lock); put_files_struct(files); } return -ENOENT; } static int proc_exe_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt) { struct vm_area_struct * vma; int result = -ENOENT; struct task_struct *task = proc_task(inode); struct mm_struct * mm = get_task_mm(task); if (!mm) goto out; down_read(&mm->mmap_sem); vma = mm->mmap; while (vma) { if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) { *mnt = mntget(vma->vm_file->f_vfsmnt); *dentry = dget(vma->vm_file->f_dentry); result = 0; break; } vma = vma->vm_next; } up_read(&mm->mmap_sem); mmput(mm); out: return result; } static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt) { struct fs_struct *fs; int result = -ENOENT; task_lock(proc_task(inode)); fs = proc_task(inode)->fs; if(fs) atomic_inc(&fs->count); task_unlock(proc_task(inode)); if (fs) { read_lock(&fs->lock); *mnt = mntget(fs->pwdmnt); *dentry = dget(fs->pwd); read_unlock(&fs->lock); result = 0; put_fs_struct(fs); } return result; } static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt) { struct fs_struct *fs; int result = -ENOENT; task_lock(proc_task(inode)); fs = proc_task(inode)->fs; if(fs) atomic_inc(&fs->count); task_unlock(proc_task(inode)); if (fs) { read_lock(&fs->lock); *mnt = mntget(fs->rootmnt); *dentry = dget(fs->root); read_unlock(&fs->lock); result = 0; put_fs_struct(fs); } return result; } #define MAY_PTRACE(task) \ (task == current || \ (task->parent == current && \ (task->ptrace & PT_PTRACED) && task->state == TASK_STOPPED && \ security_ptrace(current,task) == 0)) static int may_ptrace_attach(struct task_struct *task) { int retval = 0; task_lock(task); if (!task->mm) goto out; if (((current->uid != task->euid) || (current->uid != task->suid) || (current->uid != task->uid) || (current->gid != task->egid) || (current->gid != task->sgid) || (current->gid != task->gid)) && !capable(CAP_SYS_PTRACE)) goto out; rmb(); if (!task->mm->dumpable && !capable(CAP_SYS_PTRACE)) goto out; if (security_ptrace(current, task)) goto out; retval = 1; out: task_unlock(task); return retval; } static int proc_pid_environ(struct task_struct *task, char * buffer) { int res = 0; struct mm_struct *mm = get_task_mm(task); if (mm) { unsigned int len = mm->env_end - mm->env_start; if (len > PAGE_SIZE) len = PAGE_SIZE; res = access_process_vm(task, mm->env_start, buffer, len, 0); if (!may_ptrace_attach(task)) res = -ESRCH; mmput(mm); } return res; } static int proc_pid_cmdline(struct task_struct *task, char * buffer) { int res = 0; unsigned int len; struct mm_struct *mm = get_task_mm(task); if (!mm) goto out; len = mm->arg_end - mm->arg_start; if (len > PAGE_SIZE) len = PAGE_SIZE; res = access_process_vm(task, mm->arg_start, buffer, len, 0); // If the nul at the end of args has been overwritten, then // assume application is using setproctitle(3). if (res > 0 && buffer[res-1] != '\0') { len = strnlen(buffer, res); if (len < res) { res = len; } else { len = mm->env_end - mm->env_start; if (len > PAGE_SIZE - res) len = PAGE_SIZE - res; res += access_process_vm(task, mm->env_start, buffer+res, len, 0); res = strnlen(buffer, res); } } mmput(mm); out: return res; } static int proc_pid_auxv(struct task_struct *task, char *buffer) { int res = 0; struct mm_struct *mm = get_task_mm(task); if (mm) { unsigned int nwords = 0; do nwords += 2; while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ res = nwords * sizeof(mm->saved_auxv[0]); if (res > PAGE_SIZE) res = PAGE_SIZE; memcpy(buffer, mm->saved_auxv, res); mmput(mm); } return res; } #ifdef CONFIG_KALLSYMS /* * Provides a wchan file via kallsyms in a proper one-value-per-file format. * Returns the resolved symbol. If that fails, simply return the address. */ static int proc_pid_wchan(struct task_struct *task, char *buffer) { char *modname; const char *sym_name; unsigned long wchan, size, offset; char namebuf[128]; wchan = get_wchan(task); sym_name = kallsyms_lookup(wchan, &size, &offset, &modname, namebuf); if (sym_name) return sprintf(buffer, "%s", sym_name); return sprintf(buffer, "%lu", wchan); } #endif /* CONFIG_KALLSYMS */ /************************************************************************/ /* Here the fs part begins */ /************************************************************************/ /* permission checks */ static int proc_check_root(struct inode *inode) { struct dentry *de, *base, *root; struct vfsmount *our_vfsmnt, *vfsmnt, *mnt; int res = 0; if (proc_root_link(inode, &root, &vfsmnt)) /* Ewww... */ return -ENOENT; read_lock(¤t->fs->lock); our_vfsmnt = mntget(current->fs->rootmnt); base = dget(current->fs->root); read_unlock(¤t->fs->lock); spin_lock(&vfsmount_lock); de = root; mnt = vfsmnt; while (vfsmnt != our_vfsmnt) { if (vfsmnt == vfsmnt->mnt_parent) goto out; de = vfsmnt->mnt_mountpoint; vfsmnt = vfsmnt->mnt_parent; } if (!is_subdir(de, base)) goto out; spin_unlock(&vfsmount_lock); exit: dput(base); mntput(our_vfsmnt); dput(root); mntput(mnt); return res; out: spin_unlock(&vfsmount_lock); res = -EACCES; goto exit; } static int proc_permission(struct inode *inode, int mask, struct nameidata *nd) { if (vfs_permission(inode, mask) != 0) return -EACCES; return proc_check_root(inode); } extern struct seq_operations proc_pid_maps_op; static int maps_open(struct inode *inode, struct file *file) { struct task_struct *task = proc_task(inode); int ret = seq_open(file, &proc_pid_maps_op); if (!ret) { struct seq_file *m = file->private_data; m->private = task; } return ret; } static struct file_operations proc_maps_operations = { .open = maps_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; extern struct seq_operations mounts_op; static int mounts_open(struct inode *inode, struct file *file) { struct task_struct *task = proc_task(inode); int ret = seq_open(file, &mounts_op); if (!ret) { struct seq_file *m = file->private_data; struct namespace *namespace; task_lock(task); namespace = task->namespace; if (namespace) get_namespace(namespace); task_unlock(task); if (namespace) m->private = namespace; else { seq_release(inode, file); ret = -EINVAL; } } return ret; } static int mounts_release(struct inode *inode, struct file *file) { struct seq_file *m = file->private_data; struct namespace *namespace = m->private; put_namespace(namespace); return seq_release(inode, file); } static struct file_operations proc_mounts_operations = { .open = mounts_open, .read = seq_read, .llseek = seq_lseek, .release = mounts_release, }; #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */ static ssize_t proc_info_read(struct file * file, char * buf, size_t count, loff_t *ppos) { struct inode * inode = file->f_dentry->d_inode; unsigned long page; ssize_t length; ssize_t end; struct task_struct *task = proc_task(inode); if (count > PROC_BLOCK_SIZE) count = PROC_BLOCK_SIZE; if (!(page = __get_free_page(GFP_KERNEL))) return -ENOMEM; length = PROC_I(inode)->op.proc_read(task, (char*)page); if (length < 0) { free_page(page); return length; } /* Static 4kB (or whatever) block capacity */ if (*ppos >= length) { free_page(page); return 0; } if (count + *ppos > length) count = length - *ppos; end = count + *ppos; if (copy_to_user(buf, (char *) page + *ppos, count)) count = -EFAULT; else *ppos = end; free_page(page); return count; } static struct file_operations proc_info_file_operations = { .read = proc_info_read, }; static int mem_open(struct inode* inode, struct file* file) { file->private_data = (void*)((long)current->self_exec_id); return 0; } static ssize_t mem_read(struct file * file, char * buf, size_t count, loff_t *ppos) { struct task_struct *task = proc_task(file->f_dentry->d_inode); char *page; unsigned long src = *ppos; int ret = -ESRCH; struct mm_struct *mm; if (!MAY_PTRACE(task) || !may_ptrace_attach(task)) goto out; ret = -ENOMEM; page = (char *)__get_free_page(GFP_USER); if (!page) goto out; ret = 0; mm = get_task_mm(task); if (!mm) goto out_free; ret = -EIO; if (file->private_data != (void*)((long)current->self_exec_id)) goto out_put; ret = 0; while (count > 0) { int this_len, retval; this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; retval = access_process_vm(task, src, page, this_len, 0); if (!retval || !MAY_PTRACE(task) || !may_ptrace_attach(task)) { if (!ret) ret = -EIO; break; } if (copy_to_user(buf, page, retval)) { ret = -EFAULT; break; } ret += retval; src += retval; buf += retval; count -= retval; } *ppos = src; out_put: mmput(mm); out_free: free_page((unsigned long) page); out: return ret; } #define mem_write NULL #ifndef mem_write /* This is a security hazard */ static ssize_t mem_write(struct file * file, const char * buf, size_t count, loff_t *ppos) { int copied = 0; char *page; struct task_struct *task = proc_task(file->f_dentry->d_inode); unsigned long dst = *ppos; if (!MAY_PTRACE(task) || !may_ptrace_attach(task)) return -ESRCH; page = (char *)__get_free_page(GFP_USER); if (!page) return -ENOMEM; while (count > 0) { int this_len, retval; this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; if (copy_from_user(page, buf, this_len)) { copied = -EFAULT; break; } retval = access_process_vm(task, dst, page, this_len, 1); if (!retval) { if (!copied) copied = -EIO; break; } copied += retval; buf += retval; dst += retval; count -= retval; } *ppos = dst; free_page((unsigned long) page); return copied; } #endif static loff_t mem_lseek(struct file * file, loff_t offset, int orig) { switch (orig) { case 0: file->f_pos = offset; break; case 1: file->f_pos += offset; break; default: return -EINVAL; } force_successful_syscall_return(); return file->f_pos; } static struct file_operations proc_mem_operations = { .llseek = mem_lseek, .read = mem_read, .write = mem_write, .open = mem_open, }; static struct inode_operations proc_mem_inode_operations = { .permission = proc_permission, }; static int proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) { struct inode *inode = dentry->d_inode; int error = -EACCES; /* We don't need a base pointer in the /proc filesystem */ path_release(nd); if (current->fsuid != inode->i_uid && !capable(CAP_DAC_OVERRIDE)) goto out; error = proc_check_root(inode); if (error) goto out; error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt); nd->last_type = LAST_BIND; out: return error; } static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt, char *buffer, int buflen) { struct inode * inode; char *tmp = (char*)__get_free_page(GFP_KERNEL), *path; int len; if (!tmp) return -ENOMEM; inode = dentry->d_inode; path = d_path(dentry, mnt, tmp, PAGE_SIZE); len = PTR_ERR(path); if (IS_ERR(path)) goto out; len = tmp + PAGE_SIZE - 1 - path; if (len > buflen) len = buflen; if (copy_to_user(buffer, path, len)) len = -EFAULT; out: free_page((unsigned long)tmp); return len; } static int proc_pid_readlink(struct dentry * dentry, char * buffer, int buflen) { int error = -EACCES; struct inode *inode = dentry->d_inode; struct dentry *de; struct vfsmount *mnt = NULL; lock_kernel(); if (current->fsuid != inode->i_uid && !capable(CAP_DAC_OVERRIDE)) goto out; error = proc_check_root(inode); if (error) goto out; error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt); if (error) goto out; error = do_proc_readlink(de, mnt, buffer, buflen); dput(de); mntput(mnt); out: unlock_kernel(); return error; } static struct inode_operations proc_pid_link_inode_operations = { .readlink = proc_pid_readlink, .follow_link = proc_pid_follow_link }; static int pid_alive(struct task_struct *p) { BUG_ON(p->pids[PIDTYPE_PID].pidptr != &p->pids[PIDTYPE_PID].pid); return atomic_read(&p->pids[PIDTYPE_PID].pid.count); } #define NUMBUF 10 static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir) { struct inode *inode = filp->f_dentry->d_inode; struct task_struct *p = proc_task(inode); unsigned int fd, tid, ino; int retval; char buf[NUMBUF]; struct files_struct * files; retval = -ENOENT; if (!pid_alive(p)) goto out; retval = 0; tid = p->pid; fd = filp->f_pos; switch (fd) { case 0: if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) goto out; filp->f_pos++; case 1: ino = fake_ino(tid, PROC_TID_INO); if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) goto out; filp->f_pos++; default: files = get_files_struct(p); if (!files) goto out; spin_lock(&files->file_lock); for (fd = filp->f_pos-2; fd < files->max_fds; fd++, filp->f_pos++) { unsigned int i,j; if (!fcheck_files(files, fd)) continue; spin_unlock(&files->file_lock); j = NUMBUF; i = fd; do { j--; buf[j] = '0' + (i % 10); i /= 10; } while (i); ino = fake_ino(tid, PROC_TID_FD_DIR + fd); if (filldir(dirent, buf+j, NUMBUF-j, fd+2, ino, DT_LNK) < 0) { spin_lock(&files->file_lock); break; } spin_lock(&files->file_lock); } spin_unlock(&files->file_lock); put_files_struct(files); } out: return retval; } static int proc_pident_readdir(struct file *filp, void *dirent, filldir_t filldir, struct pid_entry *ents, unsigned int nents) { int i; int pid; struct dentry *dentry = filp->f_dentry; struct inode *inode = dentry->d_inode; struct pid_entry *p; ino_t ino; int ret; ret = -ENOENT; if (!pid_alive(proc_task(inode))) goto out; ret = 0; pid = proc_task(inode)->pid; i = filp->f_pos; switch (i) { case 0: ino = inode->i_ino; if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) goto out; i++; filp->f_pos++; /* fall through */ case 1: ino = parent_ino(dentry); if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) goto out; i++; filp->f_pos++; /* fall through */ default: i -= 2; if (i >= nents) { ret = 1; goto out; } p = ents + i; while (p->name) { if (filldir(dirent, p->name, p->len, filp->f_pos, fake_ino(pid, p->type), p->mode >> 12) < 0) goto out; filp->f_pos++; p++; } } ret = 1; out: return ret; } static int proc_tgid_base_readdir(struct file * filp, void * dirent, filldir_t filldir) { return proc_pident_readdir(filp,dirent,filldir, tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); } static int proc_tid_base_readdir(struct file * filp, void * dirent, filldir_t filldir) { return proc_pident_readdir(filp,dirent,filldir, tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); } /* building an inode */ static int task_dumpable(struct task_struct *task) { int dumpable = 0; struct mm_struct *mm; task_lock(task); mm = task->mm; if (mm) dumpable = mm->dumpable; task_unlock(task); return dumpable; } static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task, int ino) { struct inode * inode; struct proc_inode *ei; /* We need a new inode */ inode = new_inode(sb); if (!inode) goto out; /* Common stuff */ ei = PROC_I(inode); ei->task = NULL; inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; inode->i_ino = fake_ino(task->pid, ino); if (!pid_alive(task)) goto out_unlock; /* * grab the reference to task. */ get_task_struct(task); ei->task = task; ei->type = ino; inode->i_uid = 0; inode->i_gid = 0; if (ino == PROC_TGID_INO || ino == PROC_TID_INO || task_dumpable(task)) { inode->i_uid = task->euid; inode->i_gid = task->egid; } security_task_to_inode(task, inode); out: return inode; out_unlock: ei->pde = NULL; iput(inode); return NULL; } /* dentry stuff */ /* * Exceptional case: normally we are not allowed to unhash a busy * directory. In this case, however, we can do it - no aliasing problems * due to the way we treat inodes. * * Rewrite the inode's ownerships here because the owning task may have * performed a setuid(), etc. */ static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) { struct inode *inode = dentry->d_inode; struct task_struct *task = proc_task(inode); if (pid_alive(task)) { if (proc_type(inode) == PROC_TGID_INO || proc_type(inode) == PROC_TID_INO || task_dumpable(task)) { inode->i_uid = task->euid; inode->i_gid = task->egid; } else { inode->i_uid = 0; inode->i_gid = 0; } security_task_to_inode(task, inode); return 1; } d_drop(dentry); return 0; } static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) { struct inode *inode = dentry->d_inode; struct task_struct *task = proc_task(inode); int fd = proc_type(inode) - PROC_TID_FD_DIR; struct files_struct *files; files = get_files_struct(task); if (files) { spin_lock(&files->file_lock); if (fcheck_files(files, fd)) { spin_unlock(&files->file_lock); put_files_struct(files); if (task_dumpable(task)) { inode->i_uid = task->euid; inode->i_gid = task->egid; } else { inode->i_uid = 0; inode->i_gid = 0; } security_task_to_inode(task, inode); return 1; } spin_unlock(&files->file_lock); put_files_struct(files); } d_drop(dentry); return 0; } static void pid_base_iput(struct dentry *dentry, struct inode *inode) { struct task_struct *task = proc_task(inode); spin_lock(&task->proc_lock); if (task->proc_dentry == dentry) task->proc_dentry = NULL; spin_unlock(&task->proc_lock); iput(inode); } static int pid_delete_dentry(struct dentry * dentry) { /* Is the task we represent dead? * If so, then don't put the dentry on the lru list, * kill it immediately. */ return !pid_alive(proc_task(dentry->d_inode)); } static struct dentry_operations tid_fd_dentry_operations = { .d_revalidate = tid_fd_revalidate, .d_delete = pid_delete_dentry, }; static struct dentry_operations pid_dentry_operations = { .d_revalidate = pid_revalidate, .d_delete = pid_delete_dentry, }; static struct dentry_operations pid_base_dentry_operations = { .d_revalidate = pid_revalidate, .d_iput = pid_base_iput, .d_delete = pid_delete_dentry, }; /* Lookups */ static unsigned name_to_int(struct dentry *dentry) { const char *name = dentry->d_name.name; int len = dentry->d_name.len; unsigned n = 0; if (len > 1 && *name == '0') goto out; while (len-- > 0) { unsigned c = *name++ - '0'; if (c > 9) goto out; if (n >= (~0U-9)/10) goto out; n *= 10; n += c; } return n; out: return ~0U; } /* SMP-safe */ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry, struct nameidata *nd) { struct task_struct *task = proc_task(dir); unsigned fd = name_to_int(dentry); struct file * file; struct files_struct * files; struct inode *inode; struct proc_inode *ei; if (fd == ~0U) goto out; if (!pid_alive(task)) goto out; inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_FD_DIR+fd); if (!inode) goto out; ei = PROC_I(inode); files = get_files_struct(task); if (!files) goto out_unlock; inode->i_mode = S_IFLNK; spin_lock(&files->file_lock); file = fcheck_files(files, fd); if (!file) goto out_unlock2; if (file->f_mode & 1) inode->i_mode |= S_IRUSR | S_IXUSR; if (file->f_mode & 2) inode->i_mode |= S_IWUSR | S_IXUSR; spin_unlock(&files->file_lock); put_files_struct(files); inode->i_op = &proc_pid_link_inode_operations; inode->i_size = 64; ei->op.proc_get_link = proc_fd_link; dentry->d_op = &tid_fd_dentry_operations; d_add(dentry, inode); return NULL; out_unlock2: spin_unlock(&files->file_lock); put_files_struct(files); out_unlock: iput(inode); out: return ERR_PTR(-ENOENT); } static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir); static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd); static struct file_operations proc_fd_operations = { .read = generic_read_dir, .readdir = proc_readfd, }; static struct file_operations proc_task_operations = { .read = generic_read_dir, .readdir = proc_task_readdir, }; /* * proc directories can do almost nothing.. */ static struct inode_operations proc_fd_inode_operations = { .lookup = proc_lookupfd, .permission = proc_permission, }; static struct inode_operations proc_task_inode_operations = { .lookup = proc_task_lookup, .permission = proc_permission, }; #ifdef CONFIG_SECURITY static ssize_t proc_pid_attr_read(struct file * file, char * buf, size_t count, loff_t *ppos) { struct inode * inode = file->f_dentry->d_inode; unsigned long page; ssize_t length; ssize_t end; struct task_struct *task = proc_task(inode); if (count > PAGE_SIZE) count = PAGE_SIZE; if (!(page = __get_free_page(GFP_KERNEL))) return -ENOMEM; length = security_getprocattr(task, (char*)file->f_dentry->d_name.name, (void*)page, count); if (length < 0) { free_page(page); return length; } /* Static 4kB (or whatever) block capacity */ if (*ppos >= length) { free_page(page); return 0; } if (count + *ppos > length) count = length - *ppos; end = count + *ppos; if (copy_to_user(buf, (char *) page + *ppos, count)) count = -EFAULT; else *ppos = end; free_page(page); return count; } static ssize_t proc_pid_attr_write(struct file * file, const char * buf, size_t count, loff_t *ppos) { struct inode * inode = file->f_dentry->d_inode; char *page; ssize_t length; struct task_struct *task = proc_task(inode); if (count > PAGE_SIZE) count = PAGE_SIZE; if (*ppos != 0) { /* No partial writes. */ return -EINVAL; } page = (char*)__get_free_page(GFP_USER); if (!page) return -ENOMEM; length = -EFAULT; if (copy_from_user(page, buf, count)) goto out; length = security_setprocattr(task, (char*)file->f_dentry->d_name.name, (void*)page, count); out: free_page((unsigned long) page); return length; } static struct file_operations proc_pid_attr_operations = { .read = proc_pid_attr_read, .write = proc_pid_attr_write, }; static struct file_operations proc_tid_attr_operations; static struct inode_operations proc_tid_attr_inode_operations; static struct file_operations proc_tgid_attr_operations; static struct inode_operations proc_tgid_attr_inode_operations; #endif /* SMP-safe */ static struct dentry *proc_pident_lookup(struct inode *dir, struct dentry *dentry, struct pid_entry *ents) { struct inode *inode; int error; struct task_struct *task = proc_task(dir); struct pid_entry *p; struct proc_inode *ei; error = -ENOENT; inode = NULL; if (!pid_alive(task)) goto out; for (p = ents; p->name; p++) { if (p->len != dentry->d_name.len) continue; if (!memcmp(dentry->d_name.name, p->name, p->len)) break; } if (!p->name) goto out; error = -EINVAL; inode = proc_pid_make_inode(dir->i_sb, task, p->type); if (!inode) goto out; ei = PROC_I(inode); inode->i_mode = p->mode; /* * Yes, it does not scale. And it should not. Don't add * new entries into /proc/<tgid>/ without very good reasons. */ switch(p->type) { case PROC_TGID_TASK: inode->i_nlink = 3; inode->i_op = &proc_task_inode_operations; inode->i_fop = &proc_task_operations; break; case PROC_TID_FD: case PROC_TGID_FD: inode->i_nlink = 2; inode->i_op = &proc_fd_inode_operations; inode->i_fop = &proc_fd_operations; break; case PROC_TID_EXE: case PROC_TGID_EXE: inode->i_op = &proc_pid_link_inode_operations; ei->op.proc_get_link = proc_exe_link; break; case PROC_TID_CWD: case PROC_TGID_CWD: inode->i_op = &proc_pid_link_inode_operations; ei->op.proc_get_link = proc_cwd_link; break; case PROC_TID_ROOT: case PROC_TGID_ROOT: inode->i_op = &proc_pid_link_inode_operations; ei->op.proc_get_link = proc_root_link; break; case PROC_TID_ENVIRON: case PROC_TGID_ENVIRON: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_pid_environ; break; case PROC_TID_AUXV: case PROC_TGID_AUXV: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_pid_auxv; break; case PROC_TID_STATUS: case PROC_TGID_STATUS: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_pid_status; break; case PROC_TID_STAT: case PROC_TGID_STAT: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_pid_stat; break; case PROC_TID_CMDLINE: case PROC_TGID_CMDLINE: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_pid_cmdline; break; case PROC_TID_STATM: case PROC_TGID_STATM: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_pid_statm; break; case PROC_TID_MAPS: case PROC_TGID_MAPS: inode->i_fop = &proc_maps_operations; break; case PROC_TID_MEM: case PROC_TGID_MEM: inode->i_op = &proc_mem_inode_operations; inode->i_fop = &proc_mem_operations; break; case PROC_TID_MOUNTS: case PROC_TGID_MOUNTS: inode->i_fop = &proc_mounts_operations; break; #ifdef CONFIG_SECURITY case PROC_TID_ATTR: inode->i_nlink = 2; inode->i_op = &proc_tid_attr_inode_operations; inode->i_fop = &proc_tid_attr_operations; break; case PROC_TGID_ATTR: inode->i_nlink = 2; inode->i_op = &proc_tgid_attr_inode_operations; inode->i_fop = &proc_tgid_attr_operations; break; case PROC_TID_ATTR_CURRENT: case PROC_TGID_ATTR_CURRENT: case PROC_TID_ATTR_PREV: case PROC_TGID_ATTR_PREV: case PROC_TID_ATTR_EXEC: case PROC_TGID_ATTR_EXEC: case PROC_TID_ATTR_FSCREATE: case PROC_TGID_ATTR_FSCREATE: inode->i_fop = &proc_pid_attr_operations; break; #endif #ifdef CONFIG_KALLSYMS case PROC_TID_WCHAN: case PROC_TGID_WCHAN: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_pid_wchan; break; #endif default: printk("procfs: impossible type (%d)",p->type); iput(inode); return ERR_PTR(-EINVAL); } dentry->d_op = &pid_dentry_operations; d_add(dentry, inode); return NULL; out: return ERR_PTR(error); } static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ return proc_pident_lookup(dir, dentry, tgid_base_stuff); } static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ return proc_pident_lookup(dir, dentry, tid_base_stuff); } static struct file_operations proc_tgid_base_operations = { .read = generic_read_dir, .readdir = proc_tgid_base_readdir, }; static struct file_operations proc_tid_base_operations = { .read = generic_read_dir, .readdir = proc_tid_base_readdir, }; static struct inode_operations proc_tgid_base_inode_operations = { .lookup = proc_tgid_base_lookup, }; static struct inode_operations proc_tid_base_inode_operations = { .lookup = proc_tid_base_lookup, }; #ifdef CONFIG_SECURITY static int proc_tgid_attr_readdir(struct file * filp, void * dirent, filldir_t filldir) { return proc_pident_readdir(filp,dirent,filldir, tgid_attr_stuff,ARRAY_SIZE(tgid_attr_stuff)); } static int proc_tid_attr_readdir(struct file * filp, void * dirent, filldir_t filldir) { return proc_pident_readdir(filp,dirent,filldir, tid_attr_stuff,ARRAY_SIZE(tid_attr_stuff)); } static struct file_operations proc_tgid_attr_operations = { .read = generic_read_dir, .readdir = proc_tgid_attr_readdir, }; static struct file_operations proc_tid_attr_operations = { .read = generic_read_dir, .readdir = proc_tid_attr_readdir, }; static struct dentry *proc_tgid_attr_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { return proc_pident_lookup(dir, dentry, tgid_attr_stuff); } static struct dentry *proc_tid_attr_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { return proc_pident_lookup(dir, dentry, tid_attr_stuff); } static struct inode_operations proc_tgid_attr_inode_operations = { .lookup = proc_tgid_attr_lookup, }; static struct inode_operations proc_tid_attr_inode_operations = { .lookup = proc_tid_attr_lookup, }; #endif /* * /proc/self: */ static int proc_self_readlink(struct dentry *dentry, char *buffer, int buflen) { char tmp[30]; sprintf(tmp, "%d", current->tgid); return vfs_readlink(dentry,buffer,buflen,tmp); } static int proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) { char tmp[30]; sprintf(tmp, "%d", current->tgid); return vfs_follow_link(nd,tmp); } static struct inode_operations proc_self_inode_operations = { .readlink = proc_self_readlink, .follow_link = proc_self_follow_link, }; /** * proc_pid_unhash - Unhash /proc/<pid> entry from the dcache. * @p: task that should be flushed. * * Drops the /proc/<pid> dcache entry from the hash chains. * * Dropping /proc/<pid> entries and detach_pid must be synchroneous, * otherwise e.g. /proc/<pid>/exe might point to the wrong executable, * if the pid value is immediately reused. This is enforced by * - caller must acquire spin_lock(p->proc_lock) * - must be called before detach_pid() * - proc_pid_lookup acquires proc_lock, and checks that * the target is not dead by looking at the attach count * of PIDTYPE_PID. */ struct dentry *proc_pid_unhash(struct task_struct *p) { struct dentry *proc_dentry; proc_dentry = p->proc_dentry; if (proc_dentry != NULL) { spin_lock(&dcache_lock); if (!d_unhashed(proc_dentry)) { dget_locked(proc_dentry); __d_drop(proc_dentry); } else proc_dentry = NULL; spin_unlock(&dcache_lock); } return proc_dentry; } /** * proc_pid_flush - recover memory used by stale /proc/<pid>/x entries * @proc_entry: directoy to prune. * * Shrink the /proc directory that was used by the just killed thread. */ void proc_pid_flush(struct dentry *proc_dentry) { if(proc_dentry != NULL) { shrink_dcache_parent(proc_dentry); dput(proc_dentry); } } /* SMP-safe */ struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) { struct task_struct *task; struct inode *inode; struct proc_inode *ei; unsigned tgid; int died; if (dentry->d_name.len == 4 && !memcmp(dentry->d_name.name,"self",4)) { inode = new_inode(dir->i_sb); if (!inode) return ERR_PTR(-ENOMEM); ei = PROC_I(inode); inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; inode->i_ino = fake_ino(0, PROC_TGID_INO); ei->pde = NULL; inode->i_mode = S_IFLNK|S_IRWXUGO; inode->i_uid = inode->i_gid = 0; inode->i_size = 64; inode->i_op = &proc_self_inode_operations; d_add(dentry, inode); return NULL; } tgid = name_to_int(dentry); if (tgid == ~0U) goto out; read_lock(&tasklist_lock); task = find_task_by_pid(tgid); if (task) get_task_struct(task); read_unlock(&tasklist_lock); if (!task) goto out; inode = proc_pid_make_inode(dir->i_sb, task, PROC_TGID_INO); if (!inode) { put_task_struct(task); goto out; } inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; inode->i_op = &proc_tgid_base_inode_operations; inode->i_fop = &proc_tgid_base_operations; inode->i_nlink = 3; inode->i_flags|=S_IMMUTABLE; dentry->d_op = &pid_base_dentry_operations; died = 0; d_add(dentry, inode); spin_lock(&task->proc_lock); task->proc_dentry = dentry; if (!pid_alive(task)) { dentry = proc_pid_unhash(task); died = 1; } spin_unlock(&task->proc_lock); put_task_struct(task); if (died) { proc_pid_flush(dentry); goto out; } return NULL; out: return ERR_PTR(-ENOENT); } /* SMP-safe */ static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) { struct task_struct *task; struct task_struct *leader = proc_task(dir); struct inode *inode; unsigned tid; tid = name_to_int(dentry); if (tid == ~0U) goto out; read_lock(&tasklist_lock); task = find_task_by_pid(tid); if (task) get_task_struct(task); read_unlock(&tasklist_lock); if (!task) goto out; if (leader->tgid != task->tgid) goto out_drop_task; inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_INO); if (!inode) goto out_drop_task; inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; inode->i_op = &proc_tid_base_inode_operations; inode->i_fop = &proc_tid_base_operations; inode->i_nlink = 3; inode->i_flags|=S_IMMUTABLE; dentry->d_op = &pid_base_dentry_operations; d_add(dentry, inode); put_task_struct(task); return NULL; out_drop_task: put_task_struct(task); out: return ERR_PTR(-ENOENT); } #define PROC_NUMBUF 10 #define PROC_MAXPIDS 20 /* * Get a few tgid's to return for filldir - we need to hold the * tasklist lock while doing this, and we must release it before * we actually do the filldir itself, so we use a temp buffer.. */ static int get_tgid_list(int index, unsigned long version, unsigned int *tgids) { struct task_struct *p; int nr_tgids = 0; index--; read_lock(&tasklist_lock); p = NULL; if (version) { p = find_task_by_pid(version); if (!thread_group_leader(p)) p = NULL; } if (p) index = 0; else p = next_task(&init_task); for ( ; p != &init_task; p = next_task(p)) { int tgid = p->pid; if (!pid_alive(p)) continue; if (--index >= 0) continue; tgids[nr_tgids] = tgid; nr_tgids++; if (nr_tgids >= PROC_MAXPIDS) break; } read_unlock(&tasklist_lock); return nr_tgids; } /* * Get a few tid's to return for filldir - we need to hold the * tasklist lock while doing this, and we must release it before * we actually do the filldir itself, so we use a temp buffer.. */ static int get_tid_list(int index, unsigned int *tids, struct inode *dir) { struct task_struct *leader_task = proc_task(dir); struct task_struct *task = leader_task; int nr_tids = 0; index -= 2; read_lock(&tasklist_lock); /* * The starting point task (leader_task) might be an already * unlinked task, which cannot be used to access the task-list * via next_thread(). */ if (pid_alive(task)) do { int tid = task->pid; if (--index >= 0) continue; tids[nr_tids] = tid; nr_tids++; if (nr_tids >= PROC_MAXPIDS) break; } while ((task = next_thread(task)) != leader_task); read_unlock(&tasklist_lock); return nr_tids; } /* for the /proc/ directory itself, after non-process stuff has been done */ int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) { unsigned int tgid_array[PROC_MAXPIDS]; char buf[PROC_NUMBUF]; unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; unsigned int nr_tgids, i; if (!nr) { ino_t ino = fake_ino(0,PROC_TGID_INO); if (filldir(dirent, "self", 4, filp->f_pos, ino, DT_LNK) < 0) return 0; filp->f_pos++; nr++; } /* * f_version caches the last tgid which was returned from readdir */ nr_tgids = get_tgid_list(nr, filp->f_version, tgid_array); for (i = 0; i < nr_tgids; i++) { int tgid = tgid_array[i]; ino_t ino = fake_ino(tgid,PROC_TGID_INO); unsigned long j = PROC_NUMBUF; do buf[--j] = '0' + (tgid % 10); while (tgid/=10); if (filldir(dirent, buf+j, PROC_NUMBUF-j, filp->f_pos, ino, DT_DIR) < 0) { filp->f_version = tgid; break; } filp->f_pos++; } return 0; } /* for the /proc/TGID/task/ directories */ static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) { unsigned int tid_array[PROC_MAXPIDS]; char buf[PROC_NUMBUF]; unsigned int nr_tids, i; struct dentry *dentry = filp->f_dentry; struct inode *inode = dentry->d_inode; int retval = -ENOENT; ino_t ino; unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */ if (!pid_alive(proc_task(inode))) goto out; retval = 0; switch (pos) { case 0: ino = inode->i_ino; if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0) goto out; pos++; /* fall through */ case 1: ino = parent_ino(dentry); if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0) goto out; pos++; /* fall through */ } nr_tids = get_tid_list(pos, tid_array, inode); for (i = 0; i < nr_tids; i++) { unsigned long j = PROC_NUMBUF; int tid = tid_array[i]; ino = fake_ino(tid,PROC_TID_INO); do buf[--j] = '0' + (tid % 10); while (tid /= 10); if (filldir(dirent, buf+j, PROC_NUMBUF-j, pos, ino, DT_DIR) < 0) break; pos++; } out: filp->f_pos = pos; return retval; }