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Diffstat (limited to '')
| -rw-r--r-- | fs/proc/base.c | 3663 |
1 files changed, 3663 insertions, 0 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c new file mode 100644 index 000000000..e3f10c110 --- /dev/null +++ b/fs/proc/base.c @@ -0,0 +1,3663 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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. + * + * + * Changelog: + * 17-Jan-2005 + * Allan Bezerra + * Bruna Moreira <bruna.moreira@indt.org.br> + * Edjard Mota <edjard.mota@indt.org.br> + * Ilias Biris <ilias.biris@indt.org.br> + * Mauricio Lin <mauricio.lin@indt.org.br> + * + * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT + * + * A new process specific entry (smaps) included in /proc. It shows the + * size of rss for each memory area. The maps entry lacks information + * about physical memory size (rss) for each mapped file, i.e., + * rss information for executables and library files. + * This additional information is useful for any tools that need to know + * about physical memory consumption for a process specific library. + * + * Changelog: + * 21-Feb-2005 + * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT + * Pud inclusion in the page table walking. + * + * ChangeLog: + * 10-Mar-2005 + * 10LE Instituto Nokia de Tecnologia - INdT: + * A better way to walks through the page table as suggested by Hugh Dickins. + * + * Simo Piiroinen <simo.piiroinen@nokia.com>: + * Smaps information related to shared, private, clean and dirty pages. + * + * Paul Mundt <paul.mundt@nokia.com>: + * Overall revision about smaps. + */ + +#include <linux/uaccess.h> + +#include <linux/errno.h> +#include <linux/time.h> +#include <linux/proc_fs.h> +#include <linux/stat.h> +#include <linux/task_io_accounting_ops.h> +#include <linux/init.h> +#include <linux/capability.h> +#include <linux/file.h> +#include <linux/fdtable.h> +#include <linux/string.h> +#include <linux/seq_file.h> +#include <linux/namei.h> +#include <linux/mnt_namespace.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/rcupdate.h> +#include <linux/kallsyms.h> +#include <linux/stacktrace.h> +#include <linux/resource.h> +#include <linux/module.h> +#include <linux/mount.h> +#include <linux/security.h> +#include <linux/ptrace.h> +#include <linux/tracehook.h> +#include <linux/printk.h> +#include <linux/cache.h> +#include <linux/cgroup.h> +#include <linux/cpuset.h> +#include <linux/audit.h> +#include <linux/poll.h> +#include <linux/nsproxy.h> +#include <linux/oom.h> +#include <linux/elf.h> +#include <linux/pid_namespace.h> +#include <linux/user_namespace.h> +#include <linux/fs_struct.h> +#include <linux/slab.h> +#include <linux/sched/autogroup.h> +#include <linux/sched/mm.h> +#include <linux/sched/coredump.h> +#include <linux/sched/debug.h> +#include <linux/sched/stat.h> +#include <linux/flex_array.h> +#include <linux/posix-timers.h> +#include <trace/events/oom.h> +#include "internal.h" +#include "fd.h" + +#include "../../lib/kstrtox.h" + +/* NOTE: + * Implementing inode permission operations in /proc is almost + * certainly an error. Permission checks need to happen during + * each system call not at open time. The reason is that most of + * what we wish to check for permissions in /proc varies at runtime. + * + * The classic example of a problem is opening file descriptors + * in /proc for a task before it execs a suid executable. + */ + +static u8 nlink_tid __ro_after_init; +static u8 nlink_tgid __ro_after_init; + +struct pid_entry { + const char *name; + unsigned int len; + umode_t mode; + const struct inode_operations *iop; + const struct file_operations *fop; + union proc_op op; +}; + +#define NOD(NAME, MODE, IOP, FOP, OP) { \ + .name = (NAME), \ + .len = sizeof(NAME) - 1, \ + .mode = MODE, \ + .iop = IOP, \ + .fop = FOP, \ + .op = OP, \ +} + +#define DIR(NAME, MODE, iops, fops) \ + NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) +#define LNK(NAME, get_link) \ + NOD(NAME, (S_IFLNK|S_IRWXUGO), \ + &proc_pid_link_inode_operations, NULL, \ + { .proc_get_link = get_link } ) +#define REG(NAME, MODE, fops) \ + NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) +#define ONE(NAME, MODE, show) \ + NOD(NAME, (S_IFREG|(MODE)), \ + NULL, &proc_single_file_operations, \ + { .proc_show = show } ) + +/* + * Count the number of hardlinks for the pid_entry table, excluding the . + * and .. links. + */ +static unsigned int __init pid_entry_nlink(const struct pid_entry *entries, + unsigned int n) +{ + unsigned int i; + unsigned int count; + + count = 2; + for (i = 0; i < n; ++i) { + if (S_ISDIR(entries[i].mode)) + ++count; + } + + return count; +} + +static int get_task_root(struct task_struct *task, struct path *root) +{ + int result = -ENOENT; + + task_lock(task); + if (task->fs) { + get_fs_root(task->fs, root); + result = 0; + } + task_unlock(task); + return result; +} + +static int proc_cwd_link(struct dentry *dentry, struct path *path) +{ + struct task_struct *task = get_proc_task(d_inode(dentry)); + int result = -ENOENT; + + if (task) { + task_lock(task); + if (task->fs) { + get_fs_pwd(task->fs, path); + result = 0; + } + task_unlock(task); + put_task_struct(task); + } + return result; +} + +static int proc_root_link(struct dentry *dentry, struct path *path) +{ + struct task_struct *task = get_proc_task(d_inode(dentry)); + int result = -ENOENT; + + if (task) { + result = get_task_root(task, path); + put_task_struct(task); + } + return result; +} + +/* + * If the user used setproctitle(), we just get the string from + * user space at arg_start, and limit it to a maximum of one page. + */ +static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf, + size_t count, unsigned long pos, + unsigned long arg_start) +{ + char *page; + int ret, got; + + if (pos >= PAGE_SIZE) + return 0; + + page = (char *)__get_free_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + + ret = 0; + got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON); + if (got > 0) { + int len = strnlen(page, got); + + /* Include the NUL character if it was found */ + if (len < got) + len++; + + if (len > pos) { + len -= pos; + if (len > count) + len = count; + len -= copy_to_user(buf, page+pos, len); + if (!len) + len = -EFAULT; + ret = len; + } + } + free_page((unsigned long)page); + return ret; +} + +static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned long arg_start, arg_end, env_start, env_end; + unsigned long pos, len; + char *page, c; + + /* Check if process spawned far enough to have cmdline. */ + if (!mm->env_end) + return 0; + + spin_lock(&mm->arg_lock); + arg_start = mm->arg_start; + arg_end = mm->arg_end; + env_start = mm->env_start; + env_end = mm->env_end; + spin_unlock(&mm->arg_lock); + + if (arg_start >= arg_end) + return 0; + + /* + * We allow setproctitle() to overwrite the argument + * strings, and overflow past the original end. But + * only when it overflows into the environment area. + */ + if (env_start != arg_end || env_end < env_start) + env_start = env_end = arg_end; + len = env_end - arg_start; + + /* We're not going to care if "*ppos" has high bits set */ + pos = *ppos; + if (pos >= len) + return 0; + if (count > len - pos) + count = len - pos; + if (!count) + return 0; + + /* + * Magical special case: if the argv[] end byte is not + * zero, the user has overwritten it with setproctitle(3). + * + * Possible future enhancement: do this only once when + * pos is 0, and set a flag in the 'struct file'. + */ + if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c) + return get_mm_proctitle(mm, buf, count, pos, arg_start); + + /* + * For the non-setproctitle() case we limit things strictly + * to the [arg_start, arg_end[ range. + */ + pos += arg_start; + if (pos < arg_start || pos >= arg_end) + return 0; + if (count > arg_end - pos) + count = arg_end - pos; + + page = (char *)__get_free_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + + len = 0; + while (count) { + int got; + size_t size = min_t(size_t, PAGE_SIZE, count); + + got = access_remote_vm(mm, pos, page, size, FOLL_ANON); + if (got <= 0) + break; + got -= copy_to_user(buf, page, got); + if (unlikely(!got)) { + if (!len) + len = -EFAULT; + break; + } + pos += got; + buf += got; + len += got; + count -= got; + } + + free_page((unsigned long)page); + return len; +} + +static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf, + size_t count, loff_t *pos) +{ + struct mm_struct *mm; + ssize_t ret; + + mm = get_task_mm(tsk); + if (!mm) + return 0; + + ret = get_mm_cmdline(mm, buf, count, pos); + mmput(mm); + return ret; +} + +static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, + size_t count, loff_t *pos) +{ + struct task_struct *tsk; + ssize_t ret; + + BUG_ON(*pos < 0); + + tsk = get_proc_task(file_inode(file)); + if (!tsk) + return -ESRCH; + ret = get_task_cmdline(tsk, buf, count, pos); + put_task_struct(tsk); + if (ret > 0) + *pos += ret; + return ret; +} + +static const struct file_operations proc_pid_cmdline_ops = { + .read = proc_pid_cmdline_read, + .llseek = generic_file_llseek, +}; + +#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 seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) +{ + unsigned long wchan; + char symname[KSYM_NAME_LEN]; + + if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) + goto print0; + + wchan = get_wchan(task); + if (wchan && !lookup_symbol_name(wchan, symname)) { + seq_puts(m, symname); + return 0; + } + +print0: + seq_putc(m, '0'); + return 0; +} +#endif /* CONFIG_KALLSYMS */ + +static int lock_trace(struct task_struct *task) +{ + int err = mutex_lock_killable(&task->signal->cred_guard_mutex); + if (err) + return err; + if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) { + mutex_unlock(&task->signal->cred_guard_mutex); + return -EPERM; + } + return 0; +} + +static void unlock_trace(struct task_struct *task) +{ + mutex_unlock(&task->signal->cred_guard_mutex); +} + +#ifdef CONFIG_STACKTRACE + +#define MAX_STACK_TRACE_DEPTH 64 + +static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) +{ + struct stack_trace trace; + unsigned long *entries; + int err; + + /* + * The ability to racily run the kernel stack unwinder on a running task + * and then observe the unwinder output is scary; while it is useful for + * debugging kernel issues, it can also allow an attacker to leak kernel + * stack contents. + * Doing this in a manner that is at least safe from races would require + * some work to ensure that the remote task can not be scheduled; and + * even then, this would still expose the unwinder as local attack + * surface. + * Therefore, this interface is restricted to root. + */ + if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) + return -EACCES; + + entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries), + GFP_KERNEL); + if (!entries) + return -ENOMEM; + + trace.nr_entries = 0; + trace.max_entries = MAX_STACK_TRACE_DEPTH; + trace.entries = entries; + trace.skip = 0; + + err = lock_trace(task); + if (!err) { + unsigned int i; + + save_stack_trace_tsk(task, &trace); + + for (i = 0; i < trace.nr_entries; i++) { + seq_printf(m, "[<0>] %pB\n", (void *)entries[i]); + } + unlock_trace(task); + } + kfree(entries); + + return err; +} +#endif + +#ifdef CONFIG_SCHED_INFO +/* + * Provides /proc/PID/schedstat + */ +static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) +{ + if (unlikely(!sched_info_on())) + seq_printf(m, "0 0 0\n"); + else + seq_printf(m, "%llu %llu %lu\n", + (unsigned long long)task->se.sum_exec_runtime, + (unsigned long long)task->sched_info.run_delay, + task->sched_info.pcount); + + return 0; +} +#endif + +#ifdef CONFIG_LATENCYTOP +static int lstats_show_proc(struct seq_file *m, void *v) +{ + int i; + struct inode *inode = m->private; + struct task_struct *task = get_proc_task(inode); + + if (!task) + return -ESRCH; + seq_puts(m, "Latency Top version : v0.1\n"); + for (i = 0; i < LT_SAVECOUNT; i++) { + struct latency_record *lr = &task->latency_record[i]; + if (lr->backtrace[0]) { + int q; + seq_printf(m, "%i %li %li", + lr->count, lr->time, lr->max); + for (q = 0; q < LT_BACKTRACEDEPTH; q++) { + unsigned long bt = lr->backtrace[q]; + if (!bt) + break; + if (bt == ULONG_MAX) + break; + seq_printf(m, " %ps", (void *)bt); + } + seq_putc(m, '\n'); + } + + } + put_task_struct(task); + return 0; +} + +static int lstats_open(struct inode *inode, struct file *file) +{ + return single_open(file, lstats_show_proc, inode); +} + +static ssize_t lstats_write(struct file *file, const char __user *buf, + size_t count, loff_t *offs) +{ + struct task_struct *task = get_proc_task(file_inode(file)); + + if (!task) + return -ESRCH; + clear_all_latency_tracing(task); + put_task_struct(task); + + return count; +} + +static const struct file_operations proc_lstats_operations = { + .open = lstats_open, + .read = seq_read, + .write = lstats_write, + .llseek = seq_lseek, + .release = single_release, +}; + +#endif + +static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) +{ + unsigned long totalpages = totalram_pages + total_swap_pages; + unsigned long points = 0; + + points = oom_badness(task, NULL, NULL, totalpages) * + 1000 / totalpages; + seq_printf(m, "%lu\n", points); + + return 0; +} + +struct limit_names { + const char *name; + const char *unit; +}; + +static const struct limit_names lnames[RLIM_NLIMITS] = { + [RLIMIT_CPU] = {"Max cpu time", "seconds"}, + [RLIMIT_FSIZE] = {"Max file size", "bytes"}, + [RLIMIT_DATA] = {"Max data size", "bytes"}, + [RLIMIT_STACK] = {"Max stack size", "bytes"}, + [RLIMIT_CORE] = {"Max core file size", "bytes"}, + [RLIMIT_RSS] = {"Max resident set", "bytes"}, + [RLIMIT_NPROC] = {"Max processes", "processes"}, + [RLIMIT_NOFILE] = {"Max open files", "files"}, + [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, + [RLIMIT_AS] = {"Max address space", "bytes"}, + [RLIMIT_LOCKS] = {"Max file locks", "locks"}, + [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, + [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, + [RLIMIT_NICE] = {"Max nice priority", NULL}, + [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, + [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, +}; + +/* Display limits for a process */ +static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) +{ + unsigned int i; + unsigned long flags; + + struct rlimit rlim[RLIM_NLIMITS]; + + if (!lock_task_sighand(task, &flags)) + return 0; + memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); + unlock_task_sighand(task, &flags); + + /* + * print the file header + */ + seq_printf(m, "%-25s %-20s %-20s %-10s\n", + "Limit", "Soft Limit", "Hard Limit", "Units"); + + for (i = 0; i < RLIM_NLIMITS; i++) { + if (rlim[i].rlim_cur == RLIM_INFINITY) + seq_printf(m, "%-25s %-20s ", + lnames[i].name, "unlimited"); + else + seq_printf(m, "%-25s %-20lu ", + lnames[i].name, rlim[i].rlim_cur); + + if (rlim[i].rlim_max == RLIM_INFINITY) + seq_printf(m, "%-20s ", "unlimited"); + else + seq_printf(m, "%-20lu ", rlim[i].rlim_max); + + if (lnames[i].unit) + seq_printf(m, "%-10s\n", lnames[i].unit); + else + seq_putc(m, '\n'); + } + + return 0; +} + +#ifdef CONFIG_HAVE_ARCH_TRACEHOOK +static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) +{ + long nr; + unsigned long args[6], sp, pc; + int res; + + res = lock_trace(task); + if (res) + return res; + + if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) + seq_puts(m, "running\n"); + else if (nr < 0) + seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc); + else + seq_printf(m, + "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", + nr, + args[0], args[1], args[2], args[3], args[4], args[5], + sp, pc); + unlock_trace(task); + + return 0; +} +#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ + +/************************************************************************/ +/* Here the fs part begins */ +/************************************************************************/ + +/* permission checks */ +static int proc_fd_access_allowed(struct inode *inode) +{ + struct task_struct *task; + int allowed = 0; + /* Allow access to a task's file descriptors if it is us or we + * may use ptrace attach to the process and find out that + * information. + */ + task = get_proc_task(inode); + if (task) { + allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); + put_task_struct(task); + } + return allowed; +} + +int proc_setattr(struct dentry *dentry, struct iattr *attr) +{ + int error; + struct inode *inode = d_inode(dentry); + + if (attr->ia_valid & ATTR_MODE) + return -EPERM; + + error = setattr_prepare(dentry, attr); + if (error) + return error; + + setattr_copy(inode, attr); + mark_inode_dirty(inode); + return 0; +} + +/* + * May current process learn task's sched/cmdline info (for hide_pid_min=1) + * or euid/egid (for hide_pid_min=2)? + */ +static bool has_pid_permissions(struct pid_namespace *pid, + struct task_struct *task, + int hide_pid_min) +{ + if (pid->hide_pid < hide_pid_min) + return true; + if (in_group_p(pid->pid_gid)) + return true; + return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); +} + + +static int proc_pid_permission(struct inode *inode, int mask) +{ + struct pid_namespace *pid = proc_pid_ns(inode); + struct task_struct *task; + bool has_perms; + + task = get_proc_task(inode); + if (!task) + return -ESRCH; + has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS); + put_task_struct(task); + + if (!has_perms) { + if (pid->hide_pid == HIDEPID_INVISIBLE) { + /* + * Let's make getdents(), stat(), and open() + * consistent with each other. If a process + * may not stat() a file, it shouldn't be seen + * in procfs at all. + */ + return -ENOENT; + } + + return -EPERM; + } + return generic_permission(inode, mask); +} + + + +static const struct inode_operations proc_def_inode_operations = { + .setattr = proc_setattr, +}; + +static int proc_single_show(struct seq_file *m, void *v) +{ + struct inode *inode = m->private; + struct pid_namespace *ns = proc_pid_ns(inode); + struct pid *pid = proc_pid(inode); + struct task_struct *task; + int ret; + + task = get_pid_task(pid, PIDTYPE_PID); + if (!task) + return -ESRCH; + + ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); + + put_task_struct(task); + return ret; +} + +static int proc_single_open(struct inode *inode, struct file *filp) +{ + return single_open(filp, proc_single_show, inode); +} + +static const struct file_operations proc_single_file_operations = { + .open = proc_single_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + + +struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) +{ + struct task_struct *task = get_proc_task(inode); + struct mm_struct *mm = ERR_PTR(-ESRCH); + + if (task) { + mm = mm_access(task, mode | PTRACE_MODE_FSCREDS); + put_task_struct(task); + + if (!IS_ERR_OR_NULL(mm)) { + /* ensure this mm_struct can't be freed */ + mmgrab(mm); + /* but do not pin its memory */ + mmput(mm); + } + } + + return mm; +} + +static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) +{ + struct mm_struct *mm = proc_mem_open(inode, mode); + + if (IS_ERR(mm)) + return PTR_ERR(mm); + + file->private_data = mm; + return 0; +} + +static int mem_open(struct inode *inode, struct file *file) +{ + int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH); + + /* OK to pass negative loff_t, we can catch out-of-range */ + file->f_mode |= FMODE_UNSIGNED_OFFSET; + + return ret; +} + +static ssize_t mem_rw(struct file *file, char __user *buf, + size_t count, loff_t *ppos, int write) +{ + struct mm_struct *mm = file->private_data; + unsigned long addr = *ppos; + ssize_t copied; + char *page; + unsigned int flags; + + if (!mm) + return 0; + + page = (char *)__get_free_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + + copied = 0; + if (!mmget_not_zero(mm)) + goto free; + + flags = FOLL_FORCE | (write ? FOLL_WRITE : 0); + + while (count > 0) { + size_t this_len = min_t(size_t, count, PAGE_SIZE); + + if (write && copy_from_user(page, buf, this_len)) { + copied = -EFAULT; + break; + } + + this_len = access_remote_vm(mm, addr, page, this_len, flags); + if (!this_len) { + if (!copied) + copied = -EIO; + break; + } + + if (!write && copy_to_user(buf, page, this_len)) { + copied = -EFAULT; + break; + } + + buf += this_len; + addr += this_len; + copied += this_len; + count -= this_len; + } + *ppos = addr; + + mmput(mm); +free: + free_page((unsigned long) page); + return copied; +} + +static ssize_t mem_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + return mem_rw(file, buf, count, ppos, 0); +} + +static ssize_t mem_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + return mem_rw(file, (char __user*)buf, count, ppos, 1); +} + +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 int mem_release(struct inode *inode, struct file *file) +{ + struct mm_struct *mm = file->private_data; + if (mm) + mmdrop(mm); + return 0; +} + +static const struct file_operations proc_mem_operations = { + .llseek = mem_lseek, + .read = mem_read, + .write = mem_write, + .open = mem_open, + .release = mem_release, +}; + +static int environ_open(struct inode *inode, struct file *file) +{ + return __mem_open(inode, file, PTRACE_MODE_READ); +} + +static ssize_t environ_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + char *page; + unsigned long src = *ppos; + int ret = 0; + struct mm_struct *mm = file->private_data; + unsigned long env_start, env_end; + + /* Ensure the process spawned far enough to have an environment. */ + if (!mm || !mm->env_end) + return 0; + + page = (char *)__get_free_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + + ret = 0; + if (!mmget_not_zero(mm)) + goto free; + + spin_lock(&mm->arg_lock); + env_start = mm->env_start; + env_end = mm->env_end; + spin_unlock(&mm->arg_lock); + + while (count > 0) { + size_t this_len, max_len; + int retval; + + if (src >= (env_end - env_start)) + break; + + this_len = env_end - (env_start + src); + + max_len = min_t(size_t, PAGE_SIZE, count); + this_len = min(max_len, this_len); + + retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON); + + if (retval <= 0) { + ret = retval; + break; + } + + if (copy_to_user(buf, page, retval)) { + ret = -EFAULT; + break; + } + + ret += retval; + src += retval; + buf += retval; + count -= retval; + } + *ppos = src; + mmput(mm); + +free: + free_page((unsigned long) page); + return ret; +} + +static const struct file_operations proc_environ_operations = { + .open = environ_open, + .read = environ_read, + .llseek = generic_file_llseek, + .release = mem_release, +}; + +static int auxv_open(struct inode *inode, struct file *file) +{ + return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS); +} + +static ssize_t auxv_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct mm_struct *mm = file->private_data; + unsigned int nwords = 0; + + if (!mm) + return 0; + do { + nwords += 2; + } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ + return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv, + nwords * sizeof(mm->saved_auxv[0])); +} + +static const struct file_operations proc_auxv_operations = { + .open = auxv_open, + .read = auxv_read, + .llseek = generic_file_llseek, + .release = mem_release, +}; + +static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count, + loff_t *ppos) +{ + struct task_struct *task = get_proc_task(file_inode(file)); + char buffer[PROC_NUMBUF]; + int oom_adj = OOM_ADJUST_MIN; + size_t len; + + if (!task) + return -ESRCH; + if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) + oom_adj = OOM_ADJUST_MAX; + else + oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) / + OOM_SCORE_ADJ_MAX; + put_task_struct(task); + len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj); + return simple_read_from_buffer(buf, count, ppos, buffer, len); +} + +static int __set_oom_adj(struct file *file, int oom_adj, bool legacy) +{ + struct mm_struct *mm = NULL; + struct task_struct *task; + int err = 0; + + task = get_proc_task(file_inode(file)); + if (!task) + return -ESRCH; + + mutex_lock(&oom_adj_mutex); + if (legacy) { + if (oom_adj < task->signal->oom_score_adj && + !capable(CAP_SYS_RESOURCE)) { + err = -EACCES; + goto err_unlock; + } + /* + * /proc/pid/oom_adj is provided for legacy purposes, ask users to use + * /proc/pid/oom_score_adj instead. + */ + pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", + current->comm, task_pid_nr(current), task_pid_nr(task), + task_pid_nr(task)); + } else { + if ((short)oom_adj < task->signal->oom_score_adj_min && + !capable(CAP_SYS_RESOURCE)) { + err = -EACCES; + goto err_unlock; + } + } + + /* + * Make sure we will check other processes sharing the mm if this is + * not vfrok which wants its own oom_score_adj. + * pin the mm so it doesn't go away and get reused after task_unlock + */ + if (!task->vfork_done) { + struct task_struct *p = find_lock_task_mm(task); + + if (p) { + if (test_bit(MMF_MULTIPROCESS, &p->mm->flags)) { + mm = p->mm; + mmgrab(mm); + } + task_unlock(p); + } + } + + task->signal->oom_score_adj = oom_adj; + if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) + task->signal->oom_score_adj_min = (short)oom_adj; + trace_oom_score_adj_update(task); + + if (mm) { + struct task_struct *p; + + rcu_read_lock(); + for_each_process(p) { + if (same_thread_group(task, p)) + continue; + + /* do not touch kernel threads or the global init */ + if (p->flags & PF_KTHREAD || is_global_init(p)) + continue; + + task_lock(p); + if (!p->vfork_done && process_shares_mm(p, mm)) { + p->signal->oom_score_adj = oom_adj; + if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) + p->signal->oom_score_adj_min = (short)oom_adj; + } + task_unlock(p); + } + rcu_read_unlock(); + mmdrop(mm); + } +err_unlock: + mutex_unlock(&oom_adj_mutex); + put_task_struct(task); + return err; +} + +/* + * /proc/pid/oom_adj exists solely for backwards compatibility with previous + * kernels. The effective policy is defined by oom_score_adj, which has a + * different scale: oom_adj grew exponentially and oom_score_adj grows linearly. + * Values written to oom_adj are simply mapped linearly to oom_score_adj. + * Processes that become oom disabled via oom_adj will still be oom disabled + * with this implementation. + * + * oom_adj cannot be removed since existing userspace binaries use it. + */ +static ssize_t oom_adj_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char buffer[PROC_NUMBUF]; + int oom_adj; + int err; + + memset(buffer, 0, sizeof(buffer)); + if (count > sizeof(buffer) - 1) + count = sizeof(buffer) - 1; + if (copy_from_user(buffer, buf, count)) { + err = -EFAULT; + goto out; + } + + err = kstrtoint(strstrip(buffer), 0, &oom_adj); + if (err) + goto out; + if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) && + oom_adj != OOM_DISABLE) { + err = -EINVAL; + goto out; + } + + /* + * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum + * value is always attainable. + */ + if (oom_adj == OOM_ADJUST_MAX) + oom_adj = OOM_SCORE_ADJ_MAX; + else + oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; + + err = __set_oom_adj(file, oom_adj, true); +out: + return err < 0 ? err : count; +} + +static const struct file_operations proc_oom_adj_operations = { + .read = oom_adj_read, + .write = oom_adj_write, + .llseek = generic_file_llseek, +}; + +static ssize_t oom_score_adj_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct task_struct *task = get_proc_task(file_inode(file)); + char buffer[PROC_NUMBUF]; + short oom_score_adj = OOM_SCORE_ADJ_MIN; + size_t len; + + if (!task) + return -ESRCH; + oom_score_adj = task->signal->oom_score_adj; + put_task_struct(task); + len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj); + return simple_read_from_buffer(buf, count, ppos, buffer, len); +} + +static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char buffer[PROC_NUMBUF]; + int oom_score_adj; + int err; + + memset(buffer, 0, sizeof(buffer)); + if (count > sizeof(buffer) - 1) + count = sizeof(buffer) - 1; + if (copy_from_user(buffer, buf, count)) { + err = -EFAULT; + goto out; + } + + err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); + if (err) + goto out; + if (oom_score_adj < OOM_SCORE_ADJ_MIN || + oom_score_adj > OOM_SCORE_ADJ_MAX) { + err = -EINVAL; + goto out; + } + + err = __set_oom_adj(file, oom_score_adj, false); +out: + return err < 0 ? err : count; +} + +static const struct file_operations proc_oom_score_adj_operations = { + .read = oom_score_adj_read, + .write = oom_score_adj_write, + .llseek = default_llseek, +}; + +#ifdef CONFIG_AUDITSYSCALL +#define TMPBUFLEN 11 +static ssize_t proc_loginuid_read(struct file * file, char __user * buf, + size_t count, loff_t *ppos) +{ + struct inode * inode = file_inode(file); + struct task_struct *task = get_proc_task(inode); + ssize_t length; + char tmpbuf[TMPBUFLEN]; + + if (!task) + return -ESRCH; + length = scnprintf(tmpbuf, TMPBUFLEN, "%u", + from_kuid(file->f_cred->user_ns, + audit_get_loginuid(task))); + put_task_struct(task); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, + size_t count, loff_t *ppos) +{ + struct inode * inode = file_inode(file); + uid_t loginuid; + kuid_t kloginuid; + int rv; + + rcu_read_lock(); + if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { + rcu_read_unlock(); + return -EPERM; + } + rcu_read_unlock(); + + if (*ppos != 0) { + /* No partial writes. */ + return -EINVAL; + } + + rv = kstrtou32_from_user(buf, count, 10, &loginuid); + if (rv < 0) + return rv; + + /* is userspace tring to explicitly UNSET the loginuid? */ + if (loginuid == AUDIT_UID_UNSET) { + kloginuid = INVALID_UID; + } else { + kloginuid = make_kuid(file->f_cred->user_ns, loginuid); + if (!uid_valid(kloginuid)) + return -EINVAL; + } + + rv = audit_set_loginuid(kloginuid); + if (rv < 0) + return rv; + return count; +} + +static const struct file_operations proc_loginuid_operations = { + .read = proc_loginuid_read, + .write = proc_loginuid_write, + .llseek = generic_file_llseek, +}; + +static ssize_t proc_sessionid_read(struct file * file, char __user * buf, + size_t count, loff_t *ppos) +{ + struct inode * inode = file_inode(file); + struct task_struct *task = get_proc_task(inode); + ssize_t length; + char tmpbuf[TMPBUFLEN]; + + if (!task) + return -ESRCH; + length = scnprintf(tmpbuf, TMPBUFLEN, "%u", + audit_get_sessionid(task)); + put_task_struct(task); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static const struct file_operations proc_sessionid_operations = { + .read = proc_sessionid_read, + .llseek = generic_file_llseek, +}; +#endif + +#ifdef CONFIG_FAULT_INJECTION +static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, + size_t count, loff_t *ppos) +{ + struct task_struct *task = get_proc_task(file_inode(file)); + char buffer[PROC_NUMBUF]; + size_t len; + int make_it_fail; + + if (!task) + return -ESRCH; + make_it_fail = task->make_it_fail; + put_task_struct(task); + + len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); + + return simple_read_from_buffer(buf, count, ppos, buffer, len); +} + +static ssize_t proc_fault_inject_write(struct file * file, + const char __user * buf, size_t count, loff_t *ppos) +{ + struct task_struct *task; + char buffer[PROC_NUMBUF]; + int make_it_fail; + int rv; + + if (!capable(CAP_SYS_RESOURCE)) + return -EPERM; + memset(buffer, 0, sizeof(buffer)); + if (count > sizeof(buffer) - 1) + count = sizeof(buffer) - 1; + if (copy_from_user(buffer, buf, count)) + return -EFAULT; + rv = kstrtoint(strstrip(buffer), 0, &make_it_fail); + if (rv < 0) + return rv; + if (make_it_fail < 0 || make_it_fail > 1) + return -EINVAL; + + task = get_proc_task(file_inode(file)); + if (!task) + return -ESRCH; + task->make_it_fail = make_it_fail; + put_task_struct(task); + + return count; +} + +static const struct file_operations proc_fault_inject_operations = { + .read = proc_fault_inject_read, + .write = proc_fault_inject_write, + .llseek = generic_file_llseek, +}; + +static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct task_struct *task; + int err; + unsigned int n; + + err = kstrtouint_from_user(buf, count, 0, &n); + if (err) + return err; + + task = get_proc_task(file_inode(file)); + if (!task) + return -ESRCH; + task->fail_nth = n; + put_task_struct(task); + + return count; +} + +static ssize_t proc_fail_nth_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct task_struct *task; + char numbuf[PROC_NUMBUF]; + ssize_t len; + + task = get_proc_task(file_inode(file)); + if (!task) + return -ESRCH; + len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth); + put_task_struct(task); + return simple_read_from_buffer(buf, count, ppos, numbuf, len); +} + +static const struct file_operations proc_fail_nth_operations = { + .read = proc_fail_nth_read, + .write = proc_fail_nth_write, +}; +#endif + + +#ifdef CONFIG_SCHED_DEBUG +/* + * Print out various scheduling related per-task fields: + */ +static int sched_show(struct seq_file *m, void *v) +{ + struct inode *inode = m->private; + struct pid_namespace *ns = proc_pid_ns(inode); + struct task_struct *p; + + p = get_proc_task(inode); + if (!p) + return -ESRCH; + proc_sched_show_task(p, ns, m); + + put_task_struct(p); + + return 0; +} + +static ssize_t +sched_write(struct file *file, const char __user *buf, + size_t count, loff_t *offset) +{ + struct inode *inode = file_inode(file); + struct task_struct *p; + + p = get_proc_task(inode); + if (!p) + return -ESRCH; + proc_sched_set_task(p); + + put_task_struct(p); + + return count; +} + +static int sched_open(struct inode *inode, struct file *filp) +{ + return single_open(filp, sched_show, inode); +} + +static const struct file_operations proc_pid_sched_operations = { + .open = sched_open, + .read = seq_read, + .write = sched_write, + .llseek = seq_lseek, + .release = single_release, +}; + +#endif + +#ifdef CONFIG_SCHED_AUTOGROUP +/* + * Print out autogroup related information: + */ +static int sched_autogroup_show(struct seq_file *m, void *v) +{ + struct inode *inode = m->private; + struct task_struct *p; + + p = get_proc_task(inode); + if (!p) + return -ESRCH; + proc_sched_autogroup_show_task(p, m); + + put_task_struct(p); + + return 0; +} + +static ssize_t +sched_autogroup_write(struct file *file, const char __user *buf, + size_t count, loff_t *offset) +{ + struct inode *inode = file_inode(file); + struct task_struct *p; + char buffer[PROC_NUMBUF]; + int nice; + int err; + + memset(buffer, 0, sizeof(buffer)); + if (count > sizeof(buffer) - 1) + count = sizeof(buffer) - 1; + if (copy_from_user(buffer, buf, count)) + return -EFAULT; + + err = kstrtoint(strstrip(buffer), 0, &nice); + if (err < 0) + return err; + + p = get_proc_task(inode); + if (!p) + return -ESRCH; + + err = proc_sched_autogroup_set_nice(p, nice); + if (err) + count = err; + + put_task_struct(p); + + return count; +} + +static int sched_autogroup_open(struct inode *inode, struct file *filp) +{ + int ret; + + ret = single_open(filp, sched_autogroup_show, NULL); + if (!ret) { + struct seq_file *m = filp->private_data; + + m->private = inode; + } + return ret; +} + +static const struct file_operations proc_pid_sched_autogroup_operations = { + .open = sched_autogroup_open, + .read = seq_read, + .write = sched_autogroup_write, + .llseek = seq_lseek, + .release = single_release, +}; + +#endif /* CONFIG_SCHED_AUTOGROUP */ + +static ssize_t comm_write(struct file *file, const char __user *buf, + size_t count, loff_t *offset) +{ + struct inode *inode = file_inode(file); + struct task_struct *p; + char buffer[TASK_COMM_LEN]; + const size_t maxlen = sizeof(buffer) - 1; + + memset(buffer, 0, sizeof(buffer)); + if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count)) + return -EFAULT; + + p = get_proc_task(inode); + if (!p) + return -ESRCH; + + if (same_thread_group(current, p)) + set_task_comm(p, buffer); + else + count = -EINVAL; + + put_task_struct(p); + + return count; +} + +static int comm_show(struct seq_file *m, void *v) +{ + struct inode *inode = m->private; + struct task_struct *p; + + p = get_proc_task(inode); + if (!p) + return -ESRCH; + + proc_task_name(m, p, false); + seq_putc(m, '\n'); + + put_task_struct(p); + + return 0; +} + +static int comm_open(struct inode *inode, struct file *filp) +{ + return single_open(filp, comm_show, inode); +} + +static const struct file_operations proc_pid_set_comm_operations = { + .open = comm_open, + .read = seq_read, + .write = comm_write, + .llseek = seq_lseek, + .release = single_release, +}; + +static int proc_exe_link(struct dentry *dentry, struct path *exe_path) +{ + struct task_struct *task; + struct file *exe_file; + + task = get_proc_task(d_inode(dentry)); + if (!task) + return -ENOENT; + exe_file = get_task_exe_file(task); + put_task_struct(task); + if (exe_file) { + *exe_path = exe_file->f_path; + path_get(&exe_file->f_path); + fput(exe_file); + return 0; + } else + return -ENOENT; +} + +static const char *proc_pid_get_link(struct dentry *dentry, + struct inode *inode, + struct delayed_call *done) +{ + struct path path; + int error = -EACCES; + + if (!dentry) + return ERR_PTR(-ECHILD); + + /* Are we allowed to snoop on the tasks file descriptors? */ + if (!proc_fd_access_allowed(inode)) + goto out; + + error = PROC_I(inode)->op.proc_get_link(dentry, &path); + if (error) + goto out; + + nd_jump_link(&path); + return NULL; +out: + return ERR_PTR(error); +} + +static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) +{ + char *tmp = (char *)__get_free_page(GFP_KERNEL); + char *pathname; + int len; + + if (!tmp) + return -ENOMEM; + + pathname = d_path(path, tmp, PAGE_SIZE); + len = PTR_ERR(pathname); + if (IS_ERR(pathname)) + goto out; + len = tmp + PAGE_SIZE - 1 - pathname; + + if (len > buflen) + len = buflen; + if (copy_to_user(buffer, pathname, len)) + len = -EFAULT; + out: + free_page((unsigned long)tmp); + return len; +} + +static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) +{ + int error = -EACCES; + struct inode *inode = d_inode(dentry); + struct path path; + + /* Are we allowed to snoop on the tasks file descriptors? */ + if (!proc_fd_access_allowed(inode)) + goto out; + + error = PROC_I(inode)->op.proc_get_link(dentry, &path); + if (error) + goto out; + + error = do_proc_readlink(&path, buffer, buflen); + path_put(&path); +out: + return error; +} + +const struct inode_operations proc_pid_link_inode_operations = { + .readlink = proc_pid_readlink, + .get_link = proc_pid_get_link, + .setattr = proc_setattr, +}; + + +/* building an inode */ + +void task_dump_owner(struct task_struct *task, umode_t mode, + kuid_t *ruid, kgid_t *rgid) +{ + /* Depending on the state of dumpable compute who should own a + * proc file for a task. + */ + const struct cred *cred; + kuid_t uid; + kgid_t gid; + + if (unlikely(task->flags & PF_KTHREAD)) { + *ruid = GLOBAL_ROOT_UID; + *rgid = GLOBAL_ROOT_GID; + return; + } + + /* Default to the tasks effective ownership */ + rcu_read_lock(); + cred = __task_cred(task); + uid = cred->euid; + gid = cred->egid; + rcu_read_unlock(); + + /* + * Before the /proc/pid/status file was created the only way to read + * the effective uid of a /process was to stat /proc/pid. Reading + * /proc/pid/status is slow enough that procps and other packages + * kept stating /proc/pid. To keep the rules in /proc simple I have + * made this apply to all per process world readable and executable + * directories. + */ + if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) { + struct mm_struct *mm; + task_lock(task); + mm = task->mm; + /* Make non-dumpable tasks owned by some root */ + if (mm) { + if (get_dumpable(mm) != SUID_DUMP_USER) { + struct user_namespace *user_ns = mm->user_ns; + + uid = make_kuid(user_ns, 0); + if (!uid_valid(uid)) + uid = GLOBAL_ROOT_UID; + + gid = make_kgid(user_ns, 0); + if (!gid_valid(gid)) + gid = GLOBAL_ROOT_GID; + } + } else { + uid = GLOBAL_ROOT_UID; + gid = GLOBAL_ROOT_GID; + } + task_unlock(task); + } + *ruid = uid; + *rgid = gid; +} + +struct inode *proc_pid_make_inode(struct super_block * sb, + struct task_struct *task, umode_t mode) +{ + 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); + inode->i_mode = mode; + inode->i_ino = get_next_ino(); + inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); + inode->i_op = &proc_def_inode_operations; + + /* + * grab the reference to task. + */ + ei->pid = get_task_pid(task, PIDTYPE_PID); + if (!ei->pid) + goto out_unlock; + + task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); + security_task_to_inode(task, inode); + +out: + return inode; + +out_unlock: + iput(inode); + return NULL; +} + +int pid_getattr(const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int query_flags) +{ + struct inode *inode = d_inode(path->dentry); + struct pid_namespace *pid = proc_pid_ns(inode); + struct task_struct *task; + + generic_fillattr(inode, stat); + + stat->uid = GLOBAL_ROOT_UID; + stat->gid = GLOBAL_ROOT_GID; + rcu_read_lock(); + task = pid_task(proc_pid(inode), PIDTYPE_PID); + if (task) { + if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) { + rcu_read_unlock(); + /* + * This doesn't prevent learning whether PID exists, + * it only makes getattr() consistent with readdir(). + */ + return -ENOENT; + } + task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid); + } + rcu_read_unlock(); + return 0; +} + +/* dentry stuff */ + +/* + * Set <pid>/... inode ownership (can change due to setuid(), etc.) + */ +void pid_update_inode(struct task_struct *task, struct inode *inode) +{ + task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid); + + inode->i_mode &= ~(S_ISUID | S_ISGID); + security_task_to_inode(task, inode); +} + +/* + * Rewrite the inode's ownerships here because the owning task may have + * performed a setuid(), etc. + * + */ +static int pid_revalidate(struct dentry *dentry, unsigned int flags) +{ + struct inode *inode; + struct task_struct *task; + + if (flags & LOOKUP_RCU) + return -ECHILD; + + inode = d_inode(dentry); + task = get_proc_task(inode); + + if (task) { + pid_update_inode(task, inode); + put_task_struct(task); + return 1; + } + return 0; +} + +static inline bool proc_inode_is_dead(struct inode *inode) +{ + return !proc_pid(inode)->tasks[PIDTYPE_PID].first; +} + +int pid_delete_dentry(const 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 proc_inode_is_dead(d_inode(dentry)); +} + +const struct dentry_operations pid_dentry_operations = +{ + .d_revalidate = pid_revalidate, + .d_delete = pid_delete_dentry, +}; + +/* Lookups */ + +/* + * Fill a directory entry. + * + * If possible create the dcache entry and derive our inode number and + * file type from dcache entry. + * + * Since all of the proc inode numbers are dynamically generated, the inode + * numbers do not exist until the inode is cache. This means creating the + * the dcache entry in readdir is necessary to keep the inode numbers + * reported by readdir in sync with the inode numbers reported + * by stat. + */ +bool proc_fill_cache(struct file *file, struct dir_context *ctx, + const char *name, unsigned int len, + instantiate_t instantiate, struct task_struct *task, const void *ptr) +{ + struct dentry *child, *dir = file->f_path.dentry; + struct qstr qname = QSTR_INIT(name, len); + struct inode *inode; + unsigned type = DT_UNKNOWN; + ino_t ino = 1; + + child = d_hash_and_lookup(dir, &qname); + if (!child) { + DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + child = d_alloc_parallel(dir, &qname, &wq); + if (IS_ERR(child)) + goto end_instantiate; + if (d_in_lookup(child)) { + struct dentry *res; + res = instantiate(child, task, ptr); + d_lookup_done(child); + if (unlikely(res)) { + dput(child); + child = res; + if (IS_ERR(child)) + goto end_instantiate; + } + } + } + inode = d_inode(child); + ino = inode->i_ino; + type = inode->i_mode >> 12; + dput(child); +end_instantiate: + return dir_emit(ctx, name, len, ino, type); +} + +/* + * dname_to_vma_addr - maps a dentry name into two unsigned longs + * which represent vma start and end addresses. + */ +static int dname_to_vma_addr(struct dentry *dentry, + unsigned long *start, unsigned long *end) +{ + const char *str = dentry->d_name.name; + unsigned long long sval, eval; + unsigned int len; + + if (str[0] == '0' && str[1] != '-') + return -EINVAL; + len = _parse_integer(str, 16, &sval); + if (len & KSTRTOX_OVERFLOW) + return -EINVAL; + if (sval != (unsigned long)sval) + return -EINVAL; + str += len; + + if (*str != '-') + return -EINVAL; + str++; + + if (str[0] == '0' && str[1]) + return -EINVAL; + len = _parse_integer(str, 16, &eval); + if (len & KSTRTOX_OVERFLOW) + return -EINVAL; + if (eval != (unsigned long)eval) + return -EINVAL; + str += len; + + if (*str != '\0') + return -EINVAL; + + *start = sval; + *end = eval; + + return 0; +} + +static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) +{ + unsigned long vm_start, vm_end; + bool exact_vma_exists = false; + struct mm_struct *mm = NULL; + struct task_struct *task; + struct inode *inode; + int status = 0; + + if (flags & LOOKUP_RCU) + return -ECHILD; + + inode = d_inode(dentry); + task = get_proc_task(inode); + if (!task) + goto out_notask; + + mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); + if (IS_ERR_OR_NULL(mm)) + goto out; + + if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { + status = down_read_killable(&mm->mmap_sem); + if (!status) { + exact_vma_exists = !!find_exact_vma(mm, vm_start, + vm_end); + up_read(&mm->mmap_sem); + } + } + + mmput(mm); + + if (exact_vma_exists) { + task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); + + security_task_to_inode(task, inode); + status = 1; + } + +out: + put_task_struct(task); + +out_notask: + return status; +} + +static const struct dentry_operations tid_map_files_dentry_operations = { + .d_revalidate = map_files_d_revalidate, + .d_delete = pid_delete_dentry, +}; + +static int map_files_get_link(struct dentry *dentry, struct path *path) +{ + unsigned long vm_start, vm_end; + struct vm_area_struct *vma; + struct task_struct *task; + struct mm_struct *mm; + int rc; + + rc = -ENOENT; + task = get_proc_task(d_inode(dentry)); + if (!task) + goto out; + + mm = get_task_mm(task); + put_task_struct(task); + if (!mm) + goto out; + + rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); + if (rc) + goto out_mmput; + + rc = down_read_killable(&mm->mmap_sem); + if (rc) + goto out_mmput; + + rc = -ENOENT; + vma = find_exact_vma(mm, vm_start, vm_end); + if (vma && vma->vm_file) { + *path = vma->vm_file->f_path; + path_get(path); + rc = 0; + } + up_read(&mm->mmap_sem); + +out_mmput: + mmput(mm); +out: + return rc; +} + +struct map_files_info { + unsigned long start; + unsigned long end; + fmode_t mode; +}; + +/* + * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the + * symlinks may be used to bypass permissions on ancestor directories in the + * path to the file in question. + */ +static const char * +proc_map_files_get_link(struct dentry *dentry, + struct inode *inode, + struct delayed_call *done) +{ + if (!capable(CAP_SYS_ADMIN)) + return ERR_PTR(-EPERM); + + return proc_pid_get_link(dentry, inode, done); +} + +/* + * Identical to proc_pid_link_inode_operations except for get_link() + */ +static const struct inode_operations proc_map_files_link_inode_operations = { + .readlink = proc_pid_readlink, + .get_link = proc_map_files_get_link, + .setattr = proc_setattr, +}; + +static struct dentry * +proc_map_files_instantiate(struct dentry *dentry, + struct task_struct *task, const void *ptr) +{ + fmode_t mode = (fmode_t)(unsigned long)ptr; + struct proc_inode *ei; + struct inode *inode; + + inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK | + ((mode & FMODE_READ ) ? S_IRUSR : 0) | + ((mode & FMODE_WRITE) ? S_IWUSR : 0)); + if (!inode) + return ERR_PTR(-ENOENT); + + ei = PROC_I(inode); + ei->op.proc_get_link = map_files_get_link; + + inode->i_op = &proc_map_files_link_inode_operations; + inode->i_size = 64; + + d_set_d_op(dentry, &tid_map_files_dentry_operations); + return d_splice_alias(inode, dentry); +} + +static struct dentry *proc_map_files_lookup(struct inode *dir, + struct dentry *dentry, unsigned int flags) +{ + unsigned long vm_start, vm_end; + struct vm_area_struct *vma; + struct task_struct *task; + struct dentry *result; + struct mm_struct *mm; + + result = ERR_PTR(-ENOENT); + task = get_proc_task(dir); + if (!task) + goto out; + + result = ERR_PTR(-EACCES); + if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) + goto out_put_task; + + result = ERR_PTR(-ENOENT); + if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) + goto out_put_task; + + mm = get_task_mm(task); + if (!mm) + goto out_put_task; + + result = ERR_PTR(-EINTR); + if (down_read_killable(&mm->mmap_sem)) + goto out_put_mm; + + result = ERR_PTR(-ENOENT); + vma = find_exact_vma(mm, vm_start, vm_end); + if (!vma) + goto out_no_vma; + + if (vma->vm_file) + result = proc_map_files_instantiate(dentry, task, + (void *)(unsigned long)vma->vm_file->f_mode); + +out_no_vma: + up_read(&mm->mmap_sem); +out_put_mm: + mmput(mm); +out_put_task: + put_task_struct(task); +out: + return result; +} + +static const struct inode_operations proc_map_files_inode_operations = { + .lookup = proc_map_files_lookup, + .permission = proc_fd_permission, + .setattr = proc_setattr, +}; + +static int +proc_map_files_readdir(struct file *file, struct dir_context *ctx) +{ + struct vm_area_struct *vma; + struct task_struct *task; + struct mm_struct *mm; + unsigned long nr_files, pos, i; + struct flex_array *fa = NULL; + struct map_files_info info; + struct map_files_info *p; + int ret; + + ret = -ENOENT; + task = get_proc_task(file_inode(file)); + if (!task) + goto out; + + ret = -EACCES; + if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) + goto out_put_task; + + ret = 0; + if (!dir_emit_dots(file, ctx)) + goto out_put_task; + + mm = get_task_mm(task); + if (!mm) + goto out_put_task; + + ret = down_read_killable(&mm->mmap_sem); + if (ret) { + mmput(mm); + goto out_put_task; + } + + nr_files = 0; + + /* + * We need two passes here: + * + * 1) Collect vmas of mapped files with mmap_sem taken + * 2) Release mmap_sem and instantiate entries + * + * otherwise we get lockdep complained, since filldir() + * routine might require mmap_sem taken in might_fault(). + */ + + for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { + if (vma->vm_file && ++pos > ctx->pos) + nr_files++; + } + + if (nr_files) { + fa = flex_array_alloc(sizeof(info), nr_files, + GFP_KERNEL); + if (!fa || flex_array_prealloc(fa, 0, nr_files, + GFP_KERNEL)) { + ret = -ENOMEM; + if (fa) + flex_array_free(fa); + up_read(&mm->mmap_sem); + mmput(mm); + goto out_put_task; + } + for (i = 0, vma = mm->mmap, pos = 2; vma; + vma = vma->vm_next) { + if (!vma->vm_file) + continue; + if (++pos <= ctx->pos) + continue; + + info.start = vma->vm_start; + info.end = vma->vm_end; + info.mode = vma->vm_file->f_mode; + if (flex_array_put(fa, i++, &info, GFP_KERNEL)) + BUG(); + } + } + up_read(&mm->mmap_sem); + mmput(mm); + + for (i = 0; i < nr_files; i++) { + char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */ + unsigned int len; + + p = flex_array_get(fa, i); + len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end); + if (!proc_fill_cache(file, ctx, + buf, len, + proc_map_files_instantiate, + task, + (void *)(unsigned long)p->mode)) + break; + ctx->pos++; + } + if (fa) + flex_array_free(fa); + +out_put_task: + put_task_struct(task); +out: + return ret; +} + +static const struct file_operations proc_map_files_operations = { + .read = generic_read_dir, + .iterate_shared = proc_map_files_readdir, + .llseek = generic_file_llseek, +}; + +#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) +struct timers_private { + struct pid *pid; + struct task_struct *task; + struct sighand_struct *sighand; + struct pid_namespace *ns; + unsigned long flags; +}; + +static void *timers_start(struct seq_file *m, loff_t *pos) +{ + struct timers_private *tp = m->private; + + tp->task = get_pid_task(tp->pid, PIDTYPE_PID); + if (!tp->task) + return ERR_PTR(-ESRCH); + + tp->sighand = lock_task_sighand(tp->task, &tp->flags); + if (!tp->sighand) + return ERR_PTR(-ESRCH); + + return seq_list_start(&tp->task->signal->posix_timers, *pos); +} + +static void *timers_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct timers_private *tp = m->private; + return seq_list_next(v, &tp->task->signal->posix_timers, pos); +} + +static void timers_stop(struct seq_file *m, void *v) +{ + struct timers_private *tp = m->private; + + if (tp->sighand) { + unlock_task_sighand(tp->task, &tp->flags); + tp->sighand = NULL; + } + + if (tp->task) { + put_task_struct(tp->task); + tp->task = NULL; + } +} + +static int show_timer(struct seq_file *m, void *v) +{ + struct k_itimer *timer; + struct timers_private *tp = m->private; + int notify; + static const char * const nstr[] = { + [SIGEV_SIGNAL] = "signal", + [SIGEV_NONE] = "none", + [SIGEV_THREAD] = "thread", + }; + + timer = list_entry((struct list_head *)v, struct k_itimer, list); + notify = timer->it_sigev_notify; + + seq_printf(m, "ID: %d\n", timer->it_id); + seq_printf(m, "signal: %d/%px\n", + timer->sigq->info.si_signo, + timer->sigq->info.si_value.sival_ptr); + seq_printf(m, "notify: %s/%s.%d\n", + nstr[notify & ~SIGEV_THREAD_ID], + (notify & SIGEV_THREAD_ID) ? "tid" : "pid", + pid_nr_ns(timer->it_pid, tp->ns)); + seq_printf(m, "ClockID: %d\n", timer->it_clock); + + return 0; +} + +static const struct seq_operations proc_timers_seq_ops = { + .start = timers_start, + .next = timers_next, + .stop = timers_stop, + .show = show_timer, +}; + +static int proc_timers_open(struct inode *inode, struct file *file) +{ + struct timers_private *tp; + + tp = __seq_open_private(file, &proc_timers_seq_ops, + sizeof(struct timers_private)); + if (!tp) + return -ENOMEM; + + tp->pid = proc_pid(inode); + tp->ns = proc_pid_ns(inode); + return 0; +} + +static const struct file_operations proc_timers_operations = { + .open = proc_timers_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_private, +}; +#endif + +static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, + size_t count, loff_t *offset) +{ + struct inode *inode = file_inode(file); + struct task_struct *p; + u64 slack_ns; + int err; + + err = kstrtoull_from_user(buf, count, 10, &slack_ns); + if (err < 0) + return err; + + p = get_proc_task(inode); + if (!p) + return -ESRCH; + + if (p != current) { + if (!capable(CAP_SYS_NICE)) { + count = -EPERM; + goto out; + } + + err = security_task_setscheduler(p); + if (err) { + count = err; + goto out; + } + } + + task_lock(p); + if (slack_ns == 0) + p->timer_slack_ns = p->default_timer_slack_ns; + else + p->timer_slack_ns = slack_ns; + task_unlock(p); + +out: + put_task_struct(p); + + return count; +} + +static int timerslack_ns_show(struct seq_file *m, void *v) +{ + struct inode *inode = m->private; + struct task_struct *p; + int err = 0; + + p = get_proc_task(inode); + if (!p) + return -ESRCH; + + if (p != current) { + + if (!capable(CAP_SYS_NICE)) { + err = -EPERM; + goto out; + } + err = security_task_getscheduler(p); + if (err) + goto out; + } + + task_lock(p); + seq_printf(m, "%llu\n", p->timer_slack_ns); + task_unlock(p); + +out: + put_task_struct(p); + + return err; +} + +static int timerslack_ns_open(struct inode *inode, struct file *filp) +{ + return single_open(filp, timerslack_ns_show, inode); +} + +static const struct file_operations proc_pid_set_timerslack_ns_operations = { + .open = timerslack_ns_open, + .read = seq_read, + .write = timerslack_ns_write, + .llseek = seq_lseek, + .release = single_release, +}; + +static struct dentry *proc_pident_instantiate(struct dentry *dentry, + struct task_struct *task, const void *ptr) +{ + const struct pid_entry *p = ptr; + struct inode *inode; + struct proc_inode *ei; + + inode = proc_pid_make_inode(dentry->d_sb, task, p->mode); + if (!inode) + return ERR_PTR(-ENOENT); + + ei = PROC_I(inode); + if (S_ISDIR(inode->i_mode)) + set_nlink(inode, 2); /* Use getattr to fix if necessary */ + if (p->iop) + inode->i_op = p->iop; + if (p->fop) + inode->i_fop = p->fop; + ei->op = p->op; + pid_update_inode(task, inode); + d_set_d_op(dentry, &pid_dentry_operations); + return d_splice_alias(inode, dentry); +} + +static struct dentry *proc_pident_lookup(struct inode *dir, + struct dentry *dentry, + const struct pid_entry *ents, + unsigned int nents) +{ + struct task_struct *task = get_proc_task(dir); + const struct pid_entry *p, *last; + struct dentry *res = ERR_PTR(-ENOENT); + + if (!task) + goto out_no_task; + + /* + * Yes, it does not scale. And it should not. Don't add + * new entries into /proc/<tgid>/ without very good reasons. + */ + last = &ents[nents]; + for (p = ents; p < last; p++) { + if (p->len != dentry->d_name.len) + continue; + if (!memcmp(dentry->d_name.name, p->name, p->len)) { + res = proc_pident_instantiate(dentry, task, p); + break; + } + } + put_task_struct(task); +out_no_task: + return res; +} + +static int proc_pident_readdir(struct file *file, struct dir_context *ctx, + const struct pid_entry *ents, unsigned int nents) +{ + struct task_struct *task = get_proc_task(file_inode(file)); + const struct pid_entry *p; + + if (!task) + return -ENOENT; + + if (!dir_emit_dots(file, ctx)) + goto out; + + if (ctx->pos >= nents + 2) + goto out; + + for (p = ents + (ctx->pos - 2); p < ents + nents; p++) { + if (!proc_fill_cache(file, ctx, p->name, p->len, + proc_pident_instantiate, task, p)) + break; + ctx->pos++; + } +out: + put_task_struct(task); + return 0; +} + +#ifdef CONFIG_SECURITY +static int proc_pid_attr_open(struct inode *inode, struct file *file) +{ + file->private_data = NULL; + __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS); + return 0; +} + +static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, + size_t count, loff_t *ppos) +{ + struct inode * inode = file_inode(file); + char *p = NULL; + ssize_t length; + struct task_struct *task = get_proc_task(inode); + + if (!task) + return -ESRCH; + + length = security_getprocattr(task, + (char*)file->f_path.dentry->d_name.name, + &p); + put_task_struct(task); + if (length > 0) + length = simple_read_from_buffer(buf, count, ppos, p, length); + kfree(p); + return length; +} + +static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, + size_t count, loff_t *ppos) +{ + struct inode * inode = file_inode(file); + struct task_struct *task; + void *page; + int rv; + + /* A task may only write when it was the opener. */ + if (file->private_data != current->mm) + return -EPERM; + + rcu_read_lock(); + task = pid_task(proc_pid(inode), PIDTYPE_PID); + if (!task) { + rcu_read_unlock(); + return -ESRCH; + } + /* A task may only write its own attributes. */ + if (current != task) { + rcu_read_unlock(); + return -EACCES; + } + /* Prevent changes to overridden credentials. */ + if (current_cred() != current_real_cred()) { + rcu_read_unlock(); + return -EBUSY; + } + rcu_read_unlock(); + + if (count > PAGE_SIZE) + count = PAGE_SIZE; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user(buf, count); + if (IS_ERR(page)) { + rv = PTR_ERR(page); + goto out; + } + + /* Guard against adverse ptrace interaction */ + rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex); + if (rv < 0) + goto out_free; + + rv = security_setprocattr(file->f_path.dentry->d_name.name, page, count); + mutex_unlock(¤t->signal->cred_guard_mutex); +out_free: + kfree(page); +out: + return rv; +} + +static const struct file_operations proc_pid_attr_operations = { + .open = proc_pid_attr_open, + .read = proc_pid_attr_read, + .write = proc_pid_attr_write, + .llseek = generic_file_llseek, + .release = mem_release, +}; + +static const struct pid_entry attr_dir_stuff[] = { + REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), + REG("prev", S_IRUGO, proc_pid_attr_operations), + REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), + REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), + REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), + REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), +}; + +static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx) +{ + return proc_pident_readdir(file, ctx, + attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); +} + +static const struct file_operations proc_attr_dir_operations = { + .read = generic_read_dir, + .iterate_shared = proc_attr_dir_readdir, + .llseek = generic_file_llseek, +}; + +static struct dentry *proc_attr_dir_lookup(struct inode *dir, + struct dentry *dentry, unsigned int flags) +{ + return proc_pident_lookup(dir, dentry, + attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); +} + +static const struct inode_operations proc_attr_dir_inode_operations = { + .lookup = proc_attr_dir_lookup, + .getattr = pid_getattr, + .setattr = proc_setattr, +}; + +#endif + +#ifdef CONFIG_ELF_CORE +static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct task_struct *task = get_proc_task(file_inode(file)); + struct mm_struct *mm; + char buffer[PROC_NUMBUF]; + size_t len; + int ret; + + if (!task) + return -ESRCH; + + ret = 0; + mm = get_task_mm(task); + if (mm) { + len = snprintf(buffer, sizeof(buffer), "%08lx\n", + ((mm->flags & MMF_DUMP_FILTER_MASK) >> + MMF_DUMP_FILTER_SHIFT)); + mmput(mm); + ret = simple_read_from_buffer(buf, count, ppos, buffer, len); + } + + put_task_struct(task); + + return ret; +} + +static ssize_t proc_coredump_filter_write(struct file *file, + const char __user *buf, + size_t count, + loff_t *ppos) +{ + struct task_struct *task; + struct mm_struct *mm; + unsigned int val; + int ret; + int i; + unsigned long mask; + + ret = kstrtouint_from_user(buf, count, 0, &val); + if (ret < 0) + return ret; + + ret = -ESRCH; + task = get_proc_task(file_inode(file)); + if (!task) + goto out_no_task; + + mm = get_task_mm(task); + if (!mm) + goto out_no_mm; + ret = 0; + + for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { + if (val & mask) + set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); + else + clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); + } + + mmput(mm); + out_no_mm: + put_task_struct(task); + out_no_task: + if (ret < 0) + return ret; + return count; +} + +static const struct file_operations proc_coredump_filter_operations = { + .read = proc_coredump_filter_read, + .write = proc_coredump_filter_write, + .llseek = generic_file_llseek, +}; +#endif + +#ifdef CONFIG_TASK_IO_ACCOUNTING +static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole) +{ + struct task_io_accounting acct = task->ioac; + unsigned long flags; + int result; + + result = mutex_lock_killable(&task->signal->cred_guard_mutex); + if (result) + return result; + + if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { + result = -EACCES; + goto out_unlock; + } + + if (whole && lock_task_sighand(task, &flags)) { + struct task_struct *t = task; + + task_io_accounting_add(&acct, &task->signal->ioac); + while_each_thread(task, t) + task_io_accounting_add(&acct, &t->ioac); + + unlock_task_sighand(task, &flags); + } + seq_printf(m, + "rchar: %llu\n" + "wchar: %llu\n" + "syscr: %llu\n" + "syscw: %llu\n" + "read_bytes: %llu\n" + "write_bytes: %llu\n" + "cancelled_write_bytes: %llu\n", + (unsigned long long)acct.rchar, + (unsigned long long)acct.wchar, + (unsigned long long)acct.syscr, + (unsigned long long)acct.syscw, + (unsigned long long)acct.read_bytes, + (unsigned long long)acct.write_bytes, + (unsigned long long)acct.cancelled_write_bytes); + result = 0; + +out_unlock: + mutex_unlock(&task->signal->cred_guard_mutex); + return result; +} + +static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) +{ + return do_io_accounting(task, m, 0); +} + +static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) +{ + return do_io_accounting(task, m, 1); +} +#endif /* CONFIG_TASK_IO_ACCOUNTING */ + +#ifdef CONFIG_USER_NS +static int proc_id_map_open(struct inode *inode, struct file *file, + const struct seq_operations *seq_ops) +{ + struct user_namespace *ns = NULL; + struct task_struct *task; + struct seq_file *seq; + int ret = -EINVAL; + + task = get_proc_task(inode); + if (task) { + rcu_read_lock(); + ns = get_user_ns(task_cred_xxx(task, user_ns)); + rcu_read_unlock(); + put_task_struct(task); + } + if (!ns) + goto err; + + ret = seq_open(file, seq_ops); + if (ret) + goto err_put_ns; + + seq = file->private_data; + seq->private = ns; + + return 0; +err_put_ns: + put_user_ns(ns); +err: + return ret; +} + +static int proc_id_map_release(struct inode *inode, struct file *file) +{ + struct seq_file *seq = file->private_data; + struct user_namespace *ns = seq->private; + put_user_ns(ns); + return seq_release(inode, file); +} + +static int proc_uid_map_open(struct inode *inode, struct file *file) +{ + return proc_id_map_open(inode, file, &proc_uid_seq_operations); +} + +static int proc_gid_map_open(struct inode *inode, struct file *file) +{ + return proc_id_map_open(inode, file, &proc_gid_seq_operations); +} + +static int proc_projid_map_open(struct inode *inode, struct file *file) +{ + return proc_id_map_open(inode, file, &proc_projid_seq_operations); +} + +static const struct file_operations proc_uid_map_operations = { + .open = proc_uid_map_open, + .write = proc_uid_map_write, + .read = seq_read, + .llseek = seq_lseek, + .release = proc_id_map_release, +}; + +static const struct file_operations proc_gid_map_operations = { + .open = proc_gid_map_open, + .write = proc_gid_map_write, + .read = seq_read, + .llseek = seq_lseek, + .release = proc_id_map_release, +}; + +static const struct file_operations proc_projid_map_operations = { + .open = proc_projid_map_open, + .write = proc_projid_map_write, + .read = seq_read, + .llseek = seq_lseek, + .release = proc_id_map_release, +}; + +static int proc_setgroups_open(struct inode *inode, struct file *file) +{ + struct user_namespace *ns = NULL; + struct task_struct *task; + int ret; + + ret = -ESRCH; + task = get_proc_task(inode); + if (task) { + rcu_read_lock(); + ns = get_user_ns(task_cred_xxx(task, user_ns)); + rcu_read_unlock(); + put_task_struct(task); + } + if (!ns) + goto err; + + if (file->f_mode & FMODE_WRITE) { + ret = -EACCES; + if (!ns_capable(ns, CAP_SYS_ADMIN)) + goto err_put_ns; + } + + ret = single_open(file, &proc_setgroups_show, ns); + if (ret) + goto err_put_ns; + + return 0; +err_put_ns: + put_user_ns(ns); +err: + return ret; +} + +static int proc_setgroups_release(struct inode *inode, struct file *file) +{ + struct seq_file *seq = file->private_data; + struct user_namespace *ns = seq->private; + int ret = single_release(inode, file); + put_user_ns(ns); + return ret; +} + +static const struct file_operations proc_setgroups_operations = { + .open = proc_setgroups_open, + .write = proc_setgroups_write, + .read = seq_read, + .llseek = seq_lseek, + .release = proc_setgroups_release, +}; +#endif /* CONFIG_USER_NS */ + +static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) +{ + int err = lock_trace(task); + if (!err) { + seq_printf(m, "%08x\n", task->personality); + unlock_trace(task); + } + return err; +} + +#ifdef CONFIG_LIVEPATCH +static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) +{ + seq_printf(m, "%d\n", task->patch_state); + return 0; +} +#endif /* CONFIG_LIVEPATCH */ + +/* + * Thread groups + */ +static const struct file_operations proc_task_operations; +static const struct inode_operations proc_task_inode_operations; + +static const struct pid_entry tgid_base_stuff[] = { + DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), + DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), + DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), + DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), + DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), +#ifdef CONFIG_NET + DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), +#endif + REG("environ", S_IRUSR, proc_environ_operations), + REG("auxv", S_IRUSR, proc_auxv_operations), + ONE("status", S_IRUGO, proc_pid_status), + ONE("personality", S_IRUSR, proc_pid_personality), + ONE("limits", S_IRUGO, proc_pid_limits), +#ifdef CONFIG_SCHED_DEBUG + REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), +#endif +#ifdef CONFIG_SCHED_AUTOGROUP + REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), +#endif + REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), +#ifdef CONFIG_HAVE_ARCH_TRACEHOOK + ONE("syscall", S_IRUSR, proc_pid_syscall), +#endif + 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), +#ifdef CONFIG_NUMA + REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), +#endif + REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), + LNK("cwd", proc_cwd_link), + LNK("root", proc_root_link), + LNK("exe", proc_exe_link), + REG("mounts", S_IRUGO, proc_mounts_operations), + REG("mountinfo", S_IRUGO, proc_mountinfo_operations), + REG("mountstats", S_IRUSR, proc_mountstats_operations), +#ifdef CONFIG_PROC_PAGE_MONITOR + REG("clear_refs", S_IWUSR, proc_clear_refs_operations), + REG("smaps", S_IRUGO, proc_pid_smaps_operations), + REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations), + REG("pagemap", S_IRUSR, proc_pagemap_operations), +#endif +#ifdef CONFIG_SECURITY + DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), +#endif +#ifdef CONFIG_KALLSYMS + ONE("wchan", S_IRUGO, proc_pid_wchan), +#endif +#ifdef CONFIG_STACKTRACE + ONE("stack", S_IRUSR, proc_pid_stack), +#endif +#ifdef CONFIG_SCHED_INFO + ONE("schedstat", S_IRUGO, proc_pid_schedstat), +#endif +#ifdef CONFIG_LATENCYTOP + REG("latency", S_IRUGO, proc_lstats_operations), +#endif +#ifdef CONFIG_PROC_PID_CPUSET + ONE("cpuset", S_IRUGO, proc_cpuset_show), +#endif +#ifdef CONFIG_CGROUPS + ONE("cgroup", S_IRUGO, proc_cgroup_show), +#endif + ONE("oom_score", S_IRUGO, proc_oom_score), + REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), + REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), +#ifdef CONFIG_AUDITSYSCALL + REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), + REG("sessionid", S_IRUGO, proc_sessionid_operations), +#endif +#ifdef CONFIG_FAULT_INJECTION + REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), + REG("fail-nth", 0644, proc_fail_nth_operations), +#endif +#ifdef CONFIG_ELF_CORE + REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), +#endif +#ifdef CONFIG_TASK_IO_ACCOUNTING + ONE("io", S_IRUSR, proc_tgid_io_accounting), +#endif +#ifdef CONFIG_USER_NS + REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), + REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), + REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), + REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), +#endif +#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) + REG("timers", S_IRUGO, proc_timers_operations), +#endif + REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations), +#ifdef CONFIG_LIVEPATCH + ONE("patch_state", S_IRUSR, proc_pid_patch_state), +#endif +}; + +static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) +{ + return proc_pident_readdir(file, ctx, + tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); +} + +static const struct file_operations proc_tgid_base_operations = { + .read = generic_read_dir, + .iterate_shared = proc_tgid_base_readdir, + .llseek = generic_file_llseek, +}; + +static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) +{ + return proc_pident_lookup(dir, dentry, + tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); +} + +static const struct inode_operations proc_tgid_base_inode_operations = { + .lookup = proc_tgid_base_lookup, + .getattr = pid_getattr, + .setattr = proc_setattr, + .permission = proc_pid_permission, +}; + +static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) +{ + struct dentry *dentry, *leader, *dir; + char buf[10 + 1]; + struct qstr name; + + name.name = buf; + name.len = snprintf(buf, sizeof(buf), "%u", pid); + /* no ->d_hash() rejects on procfs */ + dentry = d_hash_and_lookup(mnt->mnt_root, &name); + if (dentry) { + d_invalidate(dentry); + dput(dentry); + } + + if (pid == tgid) + return; + + name.name = buf; + name.len = snprintf(buf, sizeof(buf), "%u", tgid); + leader = d_hash_and_lookup(mnt->mnt_root, &name); + if (!leader) + goto out; + + name.name = "task"; + name.len = strlen(name.name); + dir = d_hash_and_lookup(leader, &name); + if (!dir) + goto out_put_leader; + + name.name = buf; + name.len = snprintf(buf, sizeof(buf), "%u", pid); + dentry = d_hash_and_lookup(dir, &name); + if (dentry) { + d_invalidate(dentry); + dput(dentry); + } + + dput(dir); +out_put_leader: + dput(leader); +out: + return; +} + +/** + * proc_flush_task - Remove dcache entries for @task from the /proc dcache. + * @task: task that should be flushed. + * + * When flushing dentries from proc, one needs to flush them from global + * proc (proc_mnt) and from all the namespaces' procs this task was seen + * in. This call is supposed to do all of this job. + * + * Looks in the dcache for + * /proc/@pid + * /proc/@tgid/task/@pid + * if either directory is present flushes it and all of it'ts children + * from the dcache. + * + * It is safe and reasonable to cache /proc entries for a task until + * that task exits. After that they just clog up the dcache with + * useless entries, possibly causing useful dcache entries to be + * flushed instead. This routine is proved to flush those useless + * dcache entries at process exit time. + * + * NOTE: This routine is just an optimization so it does not guarantee + * that no dcache entries will exist at process exit time it + * just makes it very unlikely that any will persist. + */ + +void proc_flush_task(struct task_struct *task) +{ + int i; + struct pid *pid, *tgid; + struct upid *upid; + + pid = task_pid(task); + tgid = task_tgid(task); + + for (i = 0; i <= pid->level; i++) { + upid = &pid->numbers[i]; + proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, + tgid->numbers[i].nr); + } +} + +static struct dentry *proc_pid_instantiate(struct dentry * dentry, + struct task_struct *task, const void *ptr) +{ + struct inode *inode; + + inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); + if (!inode) + return ERR_PTR(-ENOENT); + + inode->i_op = &proc_tgid_base_inode_operations; + inode->i_fop = &proc_tgid_base_operations; + inode->i_flags|=S_IMMUTABLE; + + set_nlink(inode, nlink_tgid); + pid_update_inode(task, inode); + + d_set_d_op(dentry, &pid_dentry_operations); + return d_splice_alias(inode, dentry); +} + +struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) +{ + struct task_struct *task; + unsigned tgid; + struct pid_namespace *ns; + struct dentry *result = ERR_PTR(-ENOENT); + + tgid = name_to_int(&dentry->d_name); + if (tgid == ~0U) + goto out; + + ns = dentry->d_sb->s_fs_info; + rcu_read_lock(); + task = find_task_by_pid_ns(tgid, ns); + if (task) + get_task_struct(task); + rcu_read_unlock(); + if (!task) + goto out; + + result = proc_pid_instantiate(dentry, task, NULL); + put_task_struct(task); +out: + return result; +} + +/* + * Find the first task with tgid >= tgid + * + */ +struct tgid_iter { + unsigned int tgid; + struct task_struct *task; +}; +static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) +{ + struct pid *pid; + + if (iter.task) + put_task_struct(iter.task); + rcu_read_lock(); +retry: + iter.task = NULL; + pid = find_ge_pid(iter.tgid, ns); + if (pid) { + iter.tgid = pid_nr_ns(pid, ns); + iter.task = pid_task(pid, PIDTYPE_PID); + /* What we to know is if the pid we have find is the + * pid of a thread_group_leader. Testing for task + * being a thread_group_leader is the obvious thing + * todo but there is a window when it fails, due to + * the pid transfer logic in de_thread. + * + * So we perform the straight forward test of seeing + * if the pid we have found is the pid of a thread + * group leader, and don't worry if the task we have + * found doesn't happen to be a thread group leader. + * As we don't care in the case of readdir. + */ + if (!iter.task || !has_group_leader_pid(iter.task)) { + iter.tgid += 1; + goto retry; + } + get_task_struct(iter.task); + } + rcu_read_unlock(); + return iter; +} + +#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) + +/* for the /proc/ directory itself, after non-process stuff has been done */ +int proc_pid_readdir(struct file *file, struct dir_context *ctx) +{ + struct tgid_iter iter; + struct pid_namespace *ns = proc_pid_ns(file_inode(file)); + loff_t pos = ctx->pos; + + if (pos >= PID_MAX_LIMIT + TGID_OFFSET) + return 0; + + if (pos == TGID_OFFSET - 2) { + struct inode *inode = d_inode(ns->proc_self); + if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) + return 0; + ctx->pos = pos = pos + 1; + } + if (pos == TGID_OFFSET - 1) { + struct inode *inode = d_inode(ns->proc_thread_self); + if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) + return 0; + ctx->pos = pos = pos + 1; + } + iter.tgid = pos - TGID_OFFSET; + iter.task = NULL; + for (iter = next_tgid(ns, iter); + iter.task; + iter.tgid += 1, iter = next_tgid(ns, iter)) { + char name[10 + 1]; + unsigned int len; + + cond_resched(); + if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE)) + continue; + + len = snprintf(name, sizeof(name), "%u", iter.tgid); + ctx->pos = iter.tgid + TGID_OFFSET; + if (!proc_fill_cache(file, ctx, name, len, + proc_pid_instantiate, iter.task, NULL)) { + put_task_struct(iter.task); + return 0; + } + } + ctx->pos = PID_MAX_LIMIT + TGID_OFFSET; + return 0; +} + +/* + * proc_tid_comm_permission is a special permission function exclusively + * used for the node /proc/<pid>/task/<tid>/comm. + * It bypasses generic permission checks in the case where a task of the same + * task group attempts to access the node. + * The rationale behind this is that glibc and bionic access this node for + * cross thread naming (pthread_set/getname_np(!self)). However, if + * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0, + * which locks out the cross thread naming implementation. + * This function makes sure that the node is always accessible for members of + * same thread group. + */ +static int proc_tid_comm_permission(struct inode *inode, int mask) +{ + bool is_same_tgroup; + struct task_struct *task; + + task = get_proc_task(inode); + if (!task) + return -ESRCH; + is_same_tgroup = same_thread_group(current, task); + put_task_struct(task); + + if (likely(is_same_tgroup && !(mask & MAY_EXEC))) { + /* This file (/proc/<pid>/task/<tid>/comm) can always be + * read or written by the members of the corresponding + * thread group. + */ + return 0; + } + + return generic_permission(inode, mask); +} + +static const struct inode_operations proc_tid_comm_inode_operations = { + .permission = proc_tid_comm_permission, +}; + +/* + * Tasks + */ +static const struct pid_entry tid_base_stuff[] = { + DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), + DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), + DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), +#ifdef CONFIG_NET + DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), +#endif + REG("environ", S_IRUSR, proc_environ_operations), + REG("auxv", S_IRUSR, proc_auxv_operations), + ONE("status", S_IRUGO, proc_pid_status), + ONE("personality", S_IRUSR, proc_pid_personality), + ONE("limits", S_IRUGO, proc_pid_limits), +#ifdef CONFIG_SCHED_DEBUG + REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), +#endif + NOD("comm", S_IFREG|S_IRUGO|S_IWUSR, + &proc_tid_comm_inode_operations, + &proc_pid_set_comm_operations, {}), +#ifdef CONFIG_HAVE_ARCH_TRACEHOOK + ONE("syscall", S_IRUSR, proc_pid_syscall), +#endif + 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_pid_maps_operations), +#ifdef CONFIG_PROC_CHILDREN + REG("children", S_IRUGO, proc_tid_children_operations), +#endif +#ifdef CONFIG_NUMA + REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), +#endif + REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), + LNK("cwd", proc_cwd_link), + LNK("root", proc_root_link), + LNK("exe", proc_exe_link), + REG("mounts", S_IRUGO, proc_mounts_operations), + REG("mountinfo", S_IRUGO, proc_mountinfo_operations), +#ifdef CONFIG_PROC_PAGE_MONITOR + REG("clear_refs", S_IWUSR, proc_clear_refs_operations), + REG("smaps", S_IRUGO, proc_pid_smaps_operations), + REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations), + REG("pagemap", S_IRUSR, proc_pagemap_operations), +#endif +#ifdef CONFIG_SECURITY + DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), +#endif +#ifdef CONFIG_KALLSYMS + ONE("wchan", S_IRUGO, proc_pid_wchan), +#endif +#ifdef CONFIG_STACKTRACE + ONE("stack", S_IRUSR, proc_pid_stack), +#endif +#ifdef CONFIG_SCHED_INFO + ONE("schedstat", S_IRUGO, proc_pid_schedstat), +#endif +#ifdef CONFIG_LATENCYTOP + REG("latency", S_IRUGO, proc_lstats_operations), +#endif +#ifdef CONFIG_PROC_PID_CPUSET + ONE("cpuset", S_IRUGO, proc_cpuset_show), +#endif +#ifdef CONFIG_CGROUPS + ONE("cgroup", S_IRUGO, proc_cgroup_show), +#endif + ONE("oom_score", S_IRUGO, proc_oom_score), + REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), + REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), +#ifdef CONFIG_AUDITSYSCALL + REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), + REG("sessionid", S_IRUGO, proc_sessionid_operations), +#endif +#ifdef CONFIG_FAULT_INJECTION + REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), + REG("fail-nth", 0644, proc_fail_nth_operations), +#endif +#ifdef CONFIG_TASK_IO_ACCOUNTING + ONE("io", S_IRUSR, proc_tid_io_accounting), +#endif +#ifdef CONFIG_USER_NS + REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), + REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), + REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), + REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), +#endif +#ifdef CONFIG_LIVEPATCH + ONE("patch_state", S_IRUSR, proc_pid_patch_state), +#endif +}; + +static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) +{ + return proc_pident_readdir(file, ctx, + tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); +} + +static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) +{ + return proc_pident_lookup(dir, dentry, + tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); +} + +static const struct file_operations proc_tid_base_operations = { + .read = generic_read_dir, + .iterate_shared = proc_tid_base_readdir, + .llseek = generic_file_llseek, +}; + +static const struct inode_operations proc_tid_base_inode_operations = { + .lookup = proc_tid_base_lookup, + .getattr = pid_getattr, + .setattr = proc_setattr, +}; + +static struct dentry *proc_task_instantiate(struct dentry *dentry, + struct task_struct *task, const void *ptr) +{ + struct inode *inode; + inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); + if (!inode) + return ERR_PTR(-ENOENT); + + inode->i_op = &proc_tid_base_inode_operations; + inode->i_fop = &proc_tid_base_operations; + inode->i_flags |= S_IMMUTABLE; + + set_nlink(inode, nlink_tid); + pid_update_inode(task, inode); + + d_set_d_op(dentry, &pid_dentry_operations); + return d_splice_alias(inode, dentry); +} + +static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) +{ + struct task_struct *task; + struct task_struct *leader = get_proc_task(dir); + unsigned tid; + struct pid_namespace *ns; + struct dentry *result = ERR_PTR(-ENOENT); + + if (!leader) + goto out_no_task; + + tid = name_to_int(&dentry->d_name); + if (tid == ~0U) + goto out; + + ns = dentry->d_sb->s_fs_info; + rcu_read_lock(); + task = find_task_by_pid_ns(tid, ns); + if (task) + get_task_struct(task); + rcu_read_unlock(); + if (!task) + goto out; + if (!same_thread_group(leader, task)) + goto out_drop_task; + + result = proc_task_instantiate(dentry, task, NULL); +out_drop_task: + put_task_struct(task); +out: + put_task_struct(leader); +out_no_task: + return result; +} + +/* + * Find the first tid of a thread group to return to user space. + * + * Usually this is just the thread group leader, but if the users + * buffer was too small or there was a seek into the middle of the + * directory we have more work todo. + * + * In the case of a short read we start with find_task_by_pid. + * + * In the case of a seek we start with the leader and walk nr + * threads past it. + */ +static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, + struct pid_namespace *ns) +{ + struct task_struct *pos, *task; + unsigned long nr = f_pos; + + if (nr != f_pos) /* 32bit overflow? */ + return NULL; + + rcu_read_lock(); + task = pid_task(pid, PIDTYPE_PID); + if (!task) + goto fail; + + /* Attempt to start with the tid of a thread */ + if (tid && nr) { + pos = find_task_by_pid_ns(tid, ns); + if (pos && same_thread_group(pos, task)) + goto found; + } + + /* If nr exceeds the number of threads there is nothing todo */ + if (nr >= get_nr_threads(task)) + goto fail; + + /* If we haven't found our starting place yet start + * with the leader and walk nr threads forward. + */ + pos = task = task->group_leader; + do { + if (!nr--) + goto found; + } while_each_thread(task, pos); +fail: + pos = NULL; + goto out; +found: + get_task_struct(pos); +out: + rcu_read_unlock(); + return pos; +} + +/* + * Find the next thread in the thread list. + * Return NULL if there is an error or no next thread. + * + * The reference to the input task_struct is released. + */ +static struct task_struct *next_tid(struct task_struct *start) +{ + struct task_struct *pos = NULL; + rcu_read_lock(); + if (pid_alive(start)) { + pos = next_thread(start); + if (thread_group_leader(pos)) + pos = NULL; + else + get_task_struct(pos); + } + rcu_read_unlock(); + put_task_struct(start); + return pos; +} + +/* for the /proc/TGID/task/ directories */ +static int proc_task_readdir(struct file *file, struct dir_context *ctx) +{ + struct inode *inode = file_inode(file); + struct task_struct *task; + struct pid_namespace *ns; + int tid; + + if (proc_inode_is_dead(inode)) + return -ENOENT; + + if (!dir_emit_dots(file, ctx)) + return 0; + + /* f_version caches the tgid value that the last readdir call couldn't + * return. lseek aka telldir automagically resets f_version to 0. + */ + ns = proc_pid_ns(inode); + tid = (int)file->f_version; + file->f_version = 0; + for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); + task; + task = next_tid(task), ctx->pos++) { + char name[10 + 1]; + unsigned int len; + tid = task_pid_nr_ns(task, ns); + len = snprintf(name, sizeof(name), "%u", tid); + if (!proc_fill_cache(file, ctx, name, len, + proc_task_instantiate, task, NULL)) { + /* returning this tgid failed, save it as the first + * pid for the next readir call */ + file->f_version = (u64)tid; + put_task_struct(task); + break; + } + } + + return 0; +} + +static int proc_task_getattr(const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int query_flags) +{ + struct inode *inode = d_inode(path->dentry); + struct task_struct *p = get_proc_task(inode); + generic_fillattr(inode, stat); + + if (p) { + stat->nlink += get_nr_threads(p); + put_task_struct(p); + } + + return 0; +} + +static const struct inode_operations proc_task_inode_operations = { + .lookup = proc_task_lookup, + .getattr = proc_task_getattr, + .setattr = proc_setattr, + .permission = proc_pid_permission, +}; + +static const struct file_operations proc_task_operations = { + .read = generic_read_dir, + .iterate_shared = proc_task_readdir, + .llseek = generic_file_llseek, +}; + +void __init set_proc_pid_nlink(void) +{ + nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); + nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); +} |