diff options
Diffstat (limited to 'fs/proc')
| -rw-r--r-- | fs/proc/Kconfig | 4 | ||||
| -rw-r--r-- | fs/proc/array.c | 12 | ||||
| -rw-r--r-- | fs/proc/base.c | 207 | ||||
| -rw-r--r-- | fs/proc/generic.c | 23 | ||||
| -rw-r--r-- | fs/proc/inode.c | 4 | ||||
| -rw-r--r-- | fs/proc/internal.h | 6 | ||||
| -rw-r--r-- | fs/proc/proc_sysctl.c | 37 | ||||
| -rw-r--r-- | fs/proc/root.c | 9 |
8 files changed, 284 insertions, 18 deletions
diff --git a/fs/proc/Kconfig b/fs/proc/Kconfig index 2183fcf41d59..d751fcb637bb 100644 --- a/fs/proc/Kconfig +++ b/fs/proc/Kconfig @@ -71,3 +71,7 @@ config PROC_PAGE_MONITOR /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap, /proc/kpagecount, and /proc/kpageflags. Disabling these interfaces will reduce the size of the kernel by approximately 4kb. + +config PROC_CHILDREN + bool "Include /proc/<pid>/task/<tid>/children file" + default n diff --git a/fs/proc/array.c b/fs/proc/array.c index fd02a9ebfc30..ce065cf3104f 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -126,6 +126,14 @@ static inline const char *get_task_state(struct task_struct *tsk) { unsigned int state = (tsk->state | tsk->exit_state) & TASK_REPORT; + /* + * Parked tasks do not run; they sit in __kthread_parkme(). + * Without this check, we would report them as running, which is + * clearly wrong, so we report them as sleeping instead. + */ + if (tsk->state == TASK_PARKED) + state = TASK_INTERRUPTIBLE; + BUILD_BUG_ON(1 + ilog2(TASK_REPORT) != ARRAY_SIZE(task_state_array)-1); return task_state_array[fls(state)]; @@ -569,7 +577,7 @@ int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns, return 0; } -#ifdef CONFIG_CHECKPOINT_RESTORE +#ifdef CONFIG_PROC_CHILDREN static struct pid * get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos) { @@ -692,4 +700,4 @@ const struct file_operations proc_tid_children_operations = { .llseek = seq_lseek, .release = children_seq_release, }; -#endif /* CONFIG_CHECKPOINT_RESTORE */ +#endif /* CONFIG_PROC_CHILDREN */ diff --git a/fs/proc/base.c b/fs/proc/base.c index ad63fa3306df..87782e874b6a 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -196,18 +196,205 @@ static int proc_root_link(struct dentry *dentry, struct path *path) return result; } -static int proc_pid_cmdline(struct seq_file *m, struct pid_namespace *ns, - struct pid *pid, struct task_struct *task) +static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, + size_t _count, loff_t *pos) { + struct task_struct *tsk; + struct mm_struct *mm; + char *page; + unsigned long count = _count; + unsigned long arg_start, arg_end, env_start, env_end; + unsigned long len1, len2, len; + unsigned long p; + char c; + ssize_t rv; + + BUG_ON(*pos < 0); + + tsk = get_proc_task(file_inode(file)); + if (!tsk) + return -ESRCH; + mm = get_task_mm(tsk); + put_task_struct(tsk); + if (!mm) + return 0; + /* Check if process spawned far enough to have cmdline. */ + if (!mm->env_end) { + rv = 0; + goto out_mmput; + } + + page = (char *)__get_free_page(GFP_TEMPORARY); + if (!page) { + rv = -ENOMEM; + goto out_mmput; + } + + down_read(&mm->mmap_sem); + arg_start = mm->arg_start; + arg_end = mm->arg_end; + env_start = mm->env_start; + env_end = mm->env_end; + up_read(&mm->mmap_sem); + + BUG_ON(arg_start > arg_end); + BUG_ON(env_start > env_end); + + len1 = arg_end - arg_start; + len2 = env_end - env_start; + /* - * Rely on struct seq_operations::show() being called once - * per internal buffer allocation. See single_open(), traverse(). + * Inherently racy -- command line shares address space + * with code and data. */ - BUG_ON(m->size < PAGE_SIZE); - m->count += get_cmdline(task, m->buf, PAGE_SIZE); - return 0; + rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0); + if (rv <= 0) + goto out_free_page; + + rv = 0; + + if (c == '\0') { + /* Command line (set of strings) occupies whole ARGV. */ + if (len1 <= *pos) + goto out_free_page; + + p = arg_start + *pos; + len = len1 - *pos; + while (count > 0 && len > 0) { + unsigned int _count; + int nr_read; + + _count = min3(count, len, PAGE_SIZE); + nr_read = access_remote_vm(mm, p, page, _count, 0); + if (nr_read < 0) + rv = nr_read; + if (nr_read <= 0) + goto out_free_page; + + if (copy_to_user(buf, page, nr_read)) { + rv = -EFAULT; + goto out_free_page; + } + + p += nr_read; + len -= nr_read; + buf += nr_read; + count -= nr_read; + rv += nr_read; + } + } else { + /* + * Command line (1 string) occupies ARGV and maybe + * extends into ENVP. + */ + if (len1 + len2 <= *pos) + goto skip_argv_envp; + if (len1 <= *pos) + goto skip_argv; + + p = arg_start + *pos; + len = len1 - *pos; + while (count > 0 && len > 0) { + unsigned int _count, l; + int nr_read; + bool final; + + _count = min3(count, len, PAGE_SIZE); + nr_read = access_remote_vm(mm, p, page, _count, 0); + if (nr_read < 0) + rv = nr_read; + if (nr_read <= 0) + goto out_free_page; + + /* + * Command line can be shorter than whole ARGV + * even if last "marker" byte says it is not. + */ + final = false; + l = strnlen(page, nr_read); + if (l < nr_read) { + nr_read = l; + final = true; + } + + if (copy_to_user(buf, page, nr_read)) { + rv = -EFAULT; + goto out_free_page; + } + + p += nr_read; + len -= nr_read; + buf += nr_read; + count -= nr_read; + rv += nr_read; + + if (final) + goto out_free_page; + } +skip_argv: + /* + * Command line (1 string) occupies ARGV and + * extends into ENVP. + */ + if (len1 <= *pos) { + p = env_start + *pos - len1; + len = len1 + len2 - *pos; + } else { + p = env_start; + len = len2; + } + while (count > 0 && len > 0) { + unsigned int _count, l; + int nr_read; + bool final; + + _count = min3(count, len, PAGE_SIZE); + nr_read = access_remote_vm(mm, p, page, _count, 0); + if (nr_read < 0) + rv = nr_read; + if (nr_read <= 0) + goto out_free_page; + + /* Find EOS. */ + final = false; + l = strnlen(page, nr_read); + if (l < nr_read) { + nr_read = l; + final = true; + } + + if (copy_to_user(buf, page, nr_read)) { + rv = -EFAULT; + goto out_free_page; + } + + p += nr_read; + len -= nr_read; + buf += nr_read; + count -= nr_read; + rv += nr_read; + + if (final) + goto out_free_page; + } +skip_argv_envp: + ; + } + +out_free_page: + free_page((unsigned long)page); +out_mmput: + mmput(mm); + if (rv > 0) + *pos += rv; + return rv; } +static const struct file_operations proc_pid_cmdline_ops = { + .read = proc_pid_cmdline_read, + .llseek = generic_file_llseek, +}; + static int proc_pid_auxv(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *task) { @@ -2575,7 +2762,7 @@ static const struct pid_entry tgid_base_stuff[] = { #ifdef CONFIG_HAVE_ARCH_TRACEHOOK ONE("syscall", S_IRUSR, proc_pid_syscall), #endif - ONE("cmdline", S_IRUGO, proc_pid_cmdline), + REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), ONE("stat", S_IRUGO, proc_tgid_stat), ONE("statm", S_IRUGO, proc_pid_statm), REG("maps", S_IRUGO, proc_pid_maps_operations), @@ -2921,11 +3108,11 @@ static const struct pid_entry tid_base_stuff[] = { #ifdef CONFIG_HAVE_ARCH_TRACEHOOK ONE("syscall", S_IRUSR, proc_pid_syscall), #endif - ONE("cmdline", S_IRUGO, proc_pid_cmdline), + REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), ONE("stat", S_IRUGO, proc_tid_stat), ONE("statm", S_IRUGO, proc_pid_statm), REG("maps", S_IRUGO, proc_tid_maps_operations), -#ifdef CONFIG_CHECKPOINT_RESTORE +#ifdef CONFIG_PROC_CHILDREN REG("children", S_IRUGO, proc_tid_children_operations), #endif #ifdef CONFIG_NUMA diff --git a/fs/proc/generic.c b/fs/proc/generic.c index df6327a2b865..e5dee5c3188e 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -373,6 +373,10 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent, WARN(1, "create '/proc/%s' by hand\n", qstr.name); return NULL; } + if (is_empty_pde(*parent)) { + WARN(1, "attempt to add to permanently empty directory"); + return NULL; + } ent = kzalloc(sizeof(struct proc_dir_entry) + qstr.len + 1, GFP_KERNEL); if (!ent) @@ -455,6 +459,25 @@ struct proc_dir_entry *proc_mkdir(const char *name, } EXPORT_SYMBOL(proc_mkdir); +struct proc_dir_entry *proc_create_mount_point(const char *name) +{ + umode_t mode = S_IFDIR | S_IRUGO | S_IXUGO; + struct proc_dir_entry *ent, *parent = NULL; + + ent = __proc_create(&parent, name, mode, 2); + if (ent) { + ent->data = NULL; + ent->proc_fops = NULL; + ent->proc_iops = NULL; + if (proc_register(parent, ent) < 0) { + kfree(ent); + parent->nlink--; + ent = NULL; + } + } + return ent; +} + struct proc_dir_entry *proc_create_data(const char *name, umode_t mode, struct proc_dir_entry *parent, const struct file_operations *proc_fops, diff --git a/fs/proc/inode.c b/fs/proc/inode.c index afe232b9df6e..bd95b9fdebb0 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -422,6 +422,10 @@ struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de) inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; PROC_I(inode)->pde = de; + if (is_empty_pde(de)) { + make_empty_dir_inode(inode); + return inode; + } if (de->mode) { inode->i_mode = de->mode; inode->i_uid = de->uid; diff --git a/fs/proc/internal.h b/fs/proc/internal.h index c835b94c0cd3..aa2781095bd1 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -191,6 +191,12 @@ static inline struct proc_dir_entry *pde_get(struct proc_dir_entry *pde) } extern void pde_put(struct proc_dir_entry *); +static inline bool is_empty_pde(const struct proc_dir_entry *pde) +{ + return S_ISDIR(pde->mode) && !pde->proc_iops; +} +struct proc_dir_entry *proc_create_mount_point(const char *name); + /* * inode.c */ diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index fea2561d773b..fdda62e6115e 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -19,6 +19,28 @@ static const struct inode_operations proc_sys_inode_operations; static const struct file_operations proc_sys_dir_file_operations; static const struct inode_operations proc_sys_dir_operations; +/* Support for permanently empty directories */ + +struct ctl_table sysctl_mount_point[] = { + { } +}; + +static bool is_empty_dir(struct ctl_table_header *head) +{ + return head->ctl_table[0].child == sysctl_mount_point; +} + +static void set_empty_dir(struct ctl_dir *dir) +{ + dir->header.ctl_table[0].child = sysctl_mount_point; +} + +static void clear_empty_dir(struct ctl_dir *dir) + +{ + dir->header.ctl_table[0].child = NULL; +} + void proc_sys_poll_notify(struct ctl_table_poll *poll) { if (!poll) @@ -187,6 +209,17 @@ static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header) struct ctl_table *entry; int err; + /* Is this a permanently empty directory? */ + if (is_empty_dir(&dir->header)) + return -EROFS; + + /* Am I creating a permanently empty directory? */ + if (header->ctl_table == sysctl_mount_point) { + if (!RB_EMPTY_ROOT(&dir->root)) + return -EINVAL; + set_empty_dir(dir); + } + dir->header.nreg++; header->parent = dir; err = insert_links(header); @@ -202,6 +235,8 @@ fail: erase_header(header); put_links(header); fail_links: + if (header->ctl_table == sysctl_mount_point) + clear_empty_dir(dir); header->parent = NULL; drop_sysctl_table(&dir->header); return err; @@ -419,6 +454,8 @@ static struct inode *proc_sys_make_inode(struct super_block *sb, inode->i_mode |= S_IFDIR; inode->i_op = &proc_sys_dir_operations; inode->i_fop = &proc_sys_dir_file_operations; + if (is_empty_dir(head)) + make_empty_dir_inode(inode); } out: return inode; diff --git a/fs/proc/root.c b/fs/proc/root.c index b7fa4bfe896a..68feb0f70e63 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -112,9 +112,6 @@ static struct dentry *proc_mount(struct file_system_type *fs_type, ns = task_active_pid_ns(current); options = data; - if (!capable(CAP_SYS_ADMIN) && !fs_fully_visible(fs_type)) - return ERR_PTR(-EPERM); - /* Does the mounter have privilege over the pid namespace? */ if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN)) return ERR_PTR(-EPERM); @@ -159,7 +156,7 @@ static struct file_system_type proc_fs_type = { .name = "proc", .mount = proc_mount, .kill_sb = proc_kill_sb, - .fs_flags = FS_USERNS_MOUNT, + .fs_flags = FS_USERNS_VISIBLE | FS_USERNS_MOUNT, }; void __init proc_root_init(void) @@ -182,10 +179,10 @@ void __init proc_root_init(void) #endif proc_mkdir("fs", NULL); proc_mkdir("driver", NULL); - proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */ + proc_create_mount_point("fs/nfsd"); /* somewhere for the nfsd filesystem to be mounted */ #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE) /* just give it a mountpoint */ - proc_mkdir("openprom", NULL); + proc_create_mount_point("openprom"); #endif proc_tty_init(); proc_mkdir("bus", NULL); |