/* * 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 <asm/uaccess.h> #include <linux/errno.h> #include <linux/time.h> #include <linux/proc_fs.h> #include <linux/stat.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/rcupdate.h> #include <linux/kallsyms.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/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 "internal.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. */ struct pid_entry { char *name; int len; mode_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, OTYPE) \ NOD(NAME, (S_IFDIR|(MODE)), \ &proc_##OTYPE##_inode_operations, &proc_##OTYPE##_operations, \ {} ) #define LNK(NAME, OTYPE) \ NOD(NAME, (S_IFLNK|S_IRWXUGO), \ &proc_pid_link_inode_operations, NULL, \ { .proc_get_link = &proc_##OTYPE##_link } ) #define REG(NAME, MODE, OTYPE) \ NOD(NAME, (S_IFREG|(MODE)), NULL, \ &proc_##OTYPE##_operations, {}) #define INF(NAME, MODE, OTYPE) \ NOD(NAME, (S_IFREG|(MODE)), \ NULL, &proc_info_file_operations, \ { .proc_read = &proc_##OTYPE } ) #define ONE(NAME, MODE, OTYPE) \ NOD(NAME, (S_IFREG|(MODE)), \ NULL, &proc_single_file_operations, \ { .proc_show = &proc_##OTYPE } ) /* * Count the number of hardlinks for the pid_entry table, excluding the . * and .. links. */ static unsigned int pid_entry_count_dirs(const struct pid_entry *entries, unsigned int n) { unsigned int i; unsigned int count; count = 0; for (i = 0; i < n; ++i) { if (S_ISDIR(entries[i].mode)) ++count; } return count; } int maps_protect; EXPORT_SYMBOL(maps_protect); static struct fs_struct *get_fs_struct(struct task_struct *task) { struct fs_struct *fs; task_lock(task); fs = task->fs; if(fs) atomic_inc(&fs->count); task_unlock(task); return fs; } static int get_nr_threads(struct task_struct *tsk) { /* Must be called with the rcu_read_lock held */ unsigned long flags; int count = 0; if (lock_task_sighand(tsk, &flags)) { count = atomic_read(&tsk->signal->count); unlock_task_sighand(tsk, &flags); } return count; } static int proc_cwd_link(struct inode *inode, struct path *path) { struct task_struct *task = get_proc_task(inode); struct fs_struct *fs = NULL; int result = -ENOENT; if (task) { fs = get_fs_struct(task); put_task_struct(task); } if (fs) { read_lock(&fs->lock); *path = fs->pwd; path_get(&fs->pwd); read_unlock(&fs->lock); result = 0; put_fs_struct(fs); } return result; } static int proc_root_link(struct inode *inode, struct path *path) { struct task_struct *task = get_proc_task(inode); struct fs_struct *fs = NULL; int result = -ENOENT; if (task) { fs = get_fs_struct(task); put_task_struct(task); } if (fs) { read_lock(&fs->lock); *path = fs->root; path_get(&fs->root); read_unlock(&fs->lock); result = 0; put_fs_struct(fs); } return result; } /* * Return zero if current may access user memory in @task, -error if not. */ static int check_mem_permission(struct task_struct *task) { /* * A task can always look at itself, in case it chooses * to use system calls instead of load instructions. */ if (task == current) return 0; /* * If current is actively ptrace'ing, and would also be * permitted to freshly attach with ptrace now, permit it. */ if (task_is_stopped_or_traced(task)) { int match; rcu_read_lock(); match = (tracehook_tracer_task(task) == current); rcu_read_unlock(); if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH)) return 0; } /* * Noone else is allowed. */ return -EPERM; } struct mm_struct *mm_for_maps(struct task_struct *task) { struct mm_struct *mm = get_task_mm(task); if (!mm) return NULL; down_read(&mm->mmap_sem); task_lock(task); if (task->mm != mm) goto out; if (task->mm != current->mm && __ptrace_may_access(task, PTRACE_MODE_READ) < 0) goto out; task_unlock(task); return mm; out: task_unlock(task); up_read(&mm->mmap_sem); mmput(mm); return NULL; } static int proc_pid_cmdline(struct task_struct *task, char * buffer) { int res = 0; unsigned int len; struct mm_struct *mm = get_task_mm(task); if (!mm) goto out; if (!mm->arg_end) goto out_mm; /* Shh! No looking before we're done */ len = mm->arg_end - mm->arg_start; if (len > PAGE_SIZE) len = PAGE_SIZE; res = access_process_vm(task, mm->arg_start, buffer, len, 0); // If the nul at the end of args has been overwritten, then // assume application is using setproctitle(3). if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) { len = strnlen(buffer, res); if (len < res) { res = len; } else { len = mm->env_end - mm->env_start; if (len > PAGE_SIZE - res) len = PAGE_SIZE - res; res += access_process_vm(task, mm->env_start, buffer+res, len, 0); res = strnlen(buffer, res); } } out_mm: mmput(mm); out: return res; } static int proc_pid_auxv(struct task_struct *task, char *buffer) { int res = 0; struct mm_struct *mm = get_task_mm(task); if (mm) { unsigned int nwords = 0; do nwords += 2; while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ res = nwords * sizeof(mm->saved_auxv[0]); if (res > PAGE_SIZE) res = PAGE_SIZE; memcpy(buffer, mm->saved_auxv, res); mmput(mm); } return res; } #ifdef CONFIG_KALLSYMS /* * Provides a wchan file via kallsyms in a proper one-value-per-file format. * Returns the resolved symbol. If that fails, simply return the address. */ static int proc_pid_wchan(struct task_struct *task, char *buffer) { unsigned long wchan; char symname[KSYM_NAME_LEN]; wchan = get_wchan(task); if (lookup_symbol_name(wchan, symname) < 0) return sprintf(buffer, "%lu", wchan); else return sprintf(buffer, "%s", symname); } #endif /* CONFIG_KALLSYMS */ #ifdef CONFIG_SCHEDSTATS /* * Provides /proc/PID/schedstat */ static int proc_pid_schedstat(struct task_struct *task, char *buffer) { return sprintf(buffer, "%llu %llu %lu\n", task->sched_info.cpu_time, task->sched_info.run_delay, task->sched_info.pcount); } #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 < 32; i++) { if (task->latency_record[i].backtrace[0]) { int q; seq_printf(m, "%i %li %li ", task->latency_record[i].count, task->latency_record[i].time, task->latency_record[i].max); for (q = 0; q < LT_BACKTRACEDEPTH; q++) { char sym[KSYM_NAME_LEN]; char *c; if (!task->latency_record[i].backtrace[q]) break; if (task->latency_record[i].backtrace[q] == ULONG_MAX) break; sprint_symbol(sym, task->latency_record[i].backtrace[q]); c = strchr(sym, '+'); if (c) *c = 0; seq_printf(m, "%s ", sym); } seq_printf(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->f_dentry->d_inode); 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 /* The badness from the OOM killer */ unsigned long badness(struct task_struct *p, unsigned long uptime); static int proc_oom_score(struct task_struct *task, char *buffer) { unsigned long points; struct timespec uptime; do_posix_clock_monotonic_gettime(&uptime); read_lock(&tasklist_lock); points = badness(task, uptime.tv_sec); read_unlock(&tasklist_lock); return sprintf(buffer, "%lu\n", points); } struct limit_names { char *name; char *unit; }; static const struct limit_names lnames[RLIM_NLIMITS] = { [RLIMIT_CPU] = {"Max cpu time", "ms"}, [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 task_struct *task, char *buffer) { unsigned int i; int count = 0; unsigned long flags; char *bufptr = buffer; struct rlimit rlim[RLIM_NLIMITS]; rcu_read_lock(); if (!lock_task_sighand(task,&flags)) { rcu_read_unlock(); return 0; } memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); unlock_task_sighand(task, &flags); rcu_read_unlock(); /* * print the file header */ count += sprintf(&bufptr[count], "%-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) count += sprintf(&bufptr[count], "%-25s %-20s ", lnames[i].name, "unlimited"); else count += sprintf(&bufptr[count], "%-25s %-20lu ", lnames[i].name, rlim[i].rlim_cur); if (rlim[i].rlim_max == RLIM_INFINITY) count += sprintf(&bufptr[count], "%-20s ", "unlimited"); else count += sprintf(&bufptr[count], "%-20lu ", rlim[i].rlim_max); if (lnames[i].unit) count += sprintf(&bufptr[count], "%-10s\n", lnames[i].unit); else count += sprintf(&bufptr[count], "\n"); } return count; } #ifdef CONFIG_HAVE_ARCH_TRACEHOOK static int proc_pid_syscall(struct task_struct *task, char *buffer) { long nr; unsigned long args[6], sp, pc; if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) return sprintf(buffer, "running\n"); if (nr < 0) return sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc); return sprintf(buffer, "%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); } #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); put_task_struct(task); } return allowed; } static int proc_setattr(struct dentry *dentry, struct iattr *attr) { int error; struct inode *inode = dentry->d_inode; if (attr->ia_valid & ATTR_MODE) return -EPERM; error = inode_change_ok(inode, attr); if (!error) error = inode_setattr(inode, attr); return error; } static const struct inode_operations proc_def_inode_operations = { .setattr = proc_setattr, }; static int mounts_open_common(struct inode *inode, struct file *file, const struct seq_operations *op) { struct task_struct *task = get_proc_task(inode); struct nsproxy *nsp; struct mnt_namespace *ns = NULL; struct fs_struct *fs = NULL; struct path root; struct proc_mounts *p; int ret = -EINVAL; if (task) { rcu_read_lock(); nsp = task_nsproxy(task); if (nsp) { ns = nsp->mnt_ns; if (ns) get_mnt_ns(ns); } rcu_read_unlock(); if (ns) fs = get_fs_struct(task); put_task_struct(task); } if (!ns) goto err; if (!fs) goto err_put_ns; read_lock(&fs->lock); root = fs->root; path_get(&root); read_unlock(&fs->lock); put_fs_struct(fs); ret = -ENOMEM; p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); if (!p) goto err_put_path; file->private_data = &p->m; ret = seq_open(file, op); if (ret) goto err_free; p->m.private = p; p->ns = ns; p->root = root; p->event = ns->event; return 0; err_free: kfree(p); err_put_path: path_put(&root); err_put_ns: put_mnt_ns(ns); err: return ret; } static int mounts_release(struct inode *inode, struct file *file) { struct proc_mounts *p = file->private_data; path_put(&p->root); put_mnt_ns(p->ns); return seq_release(inode, file); } static unsigned mounts_poll(struct file *file, poll_table *wait) { struct proc_mounts *p = file->private_data; struct mnt_namespace *ns = p->ns; unsigned res = 0; poll_wait(file, &ns->poll, wait); spin_lock(&vfsmount_lock); if (p->event != ns->event) { p->event = ns->event; res = POLLERR; } spin_unlock(&vfsmount_lock); return res; } static int mounts_open(struct inode *inode, struct file *file) { return mounts_open_common(inode, file, &mounts_op); } static const struct file_operations proc_mounts_operations = { .open = mounts_open, .read = seq_read, .llseek = seq_lseek, .release = mounts_release, .poll = mounts_poll, }; static int mountinfo_open(struct inode *inode, struct file *file) { return mounts_open_common(inode, file, &mountinfo_op); } static const struct file_operations proc_mountinfo_operations = { .open = mountinfo_open, .read = seq_read, .llseek = seq_lseek, .release = mounts_release, .poll = mounts_poll, }; static int mountstats_open(struct inode *inode, struct file *file) { return mounts_open_common(inode, file, &mountstats_op); } static const struct file_operations proc_mountstats_operations = { .open = mountstats_open, .read = seq_read, .llseek = seq_lseek, .release = mounts_release, }; #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */ static ssize_t proc_info_read(struct file * file, char __user * buf, size_t count, loff_t *ppos) { struct inode * inode = file->f_path.dentry->d_inode; unsigned long page; ssize_t length; struct task_struct *task = get_proc_task(inode); length = -ESRCH; if (!task) goto out_no_task; if (count > PROC_BLOCK_SIZE) count = PROC_BLOCK_SIZE; length = -ENOMEM; if (!(page = __get_free_page(GFP_TEMPORARY))) goto out; length = PROC_I(inode)->op.proc_read(task, (char*)page); if (length >= 0) length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); free_page(page); out: put_task_struct(task); out_no_task: return length; } static const struct file_operations proc_info_file_operations = { .read = proc_info_read, }; static int proc_single_show(struct seq_file *m, void *v) { struct inode *inode = m->private; struct pid_namespace *ns; struct pid *pid; struct task_struct *task; int ret; ns = inode->i_sb->s_fs_info; pid = proc_pid(inode); 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) { int ret; ret = single_open(filp, proc_single_show, NULL); if (!ret) { struct seq_file *m = filp->private_data; m->private = inode; } return ret; } static const struct file_operations proc_single_file_operations = { .open = proc_single_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; static int mem_open(struct inode* inode, struct file* file) { file->private_data = (void*)((long)current->self_exec_id); return 0; } static ssize_t mem_read(struct file * file, char __user * buf, size_t count, loff_t *ppos) { struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); char *page; unsigned long src = *ppos; int ret = -ESRCH; struct mm_struct *mm; if (!task) goto out_no_task; if (check_mem_permission(task)) goto out; ret = -ENOMEM; page = (char *)__get_free_page(GFP_TEMPORARY); if (!page) goto out; ret = 0; mm = get_task_mm(task); if (!mm) goto out_free; ret = -EIO; if (file->private_data != (void*)((long)current->self_exec_id)) goto out_put; ret = 0; while (count > 0) { int this_len, retval; this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; retval = access_process_vm(task, src, page, this_len, 0); if (!retval || check_mem_permission(task)) { if (!ret) ret = -EIO; break; } if (copy_to_user(buf, page, retval)) { ret = -EFAULT; break; } ret += retval; src += retval; buf += retval; count -= retval; } *ppos = src; out_put: mmput(mm); out_free: free_page((unsigned long) page); out: put_task_struct(task); out_no_task: return ret; } #define mem_write NULL #ifndef mem_write /* This is a security hazard */ static ssize_t mem_write(struct file * file, const char __user *buf, size_t count, loff_t *ppos) { int copied; char *page; struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); unsigned long dst = *ppos; copied = -ESRCH; if (!task) goto out_no_task; if (check_mem_permission(task)) goto out; copied = -ENOMEM; page = (char *)__get_free_page(GFP_TEMPORARY); if (!page) goto out; copied = 0; while (count > 0) { int this_len, retval; this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; if (copy_from_user(page, buf, this_len)) { copied = -EFAULT; break; } retval = access_process_vm(task, dst, page, this_len, 1); if (!retval) { if (!copied) copied = -EIO; break; } copied += retval; buf += retval; dst += retval; count -= retval; } *ppos = dst; free_page((unsigned long) page); out: put_task_struct(task); out_no_task: return copied; } #endif 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 const struct file_operations proc_mem_operations = { .llseek = mem_lseek, .read = mem_read, .write = mem_write, .open = mem_open, }; static ssize_t environ_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { struct task_struct *task = get_proc_task(file->f_dentry->d_inode); char *page; unsigned long src = *ppos; int ret = -ESRCH; struct mm_struct *mm; if (!task) goto out_no_task; if (!ptrace_may_access(task, PTRACE_MODE_READ)) goto out; ret = -ENOMEM; page = (char *)__get_free_page(GFP_TEMPORARY); if (!page) goto out; ret = 0; mm = get_task_mm(task); if (!mm) goto out_free; while (count > 0) { int this_len, retval, max_len; this_len = mm->env_end - (mm->env_start + src); if (this_len <= 0) break; max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; this_len = (this_len > max_len) ? max_len : this_len; retval = access_process_vm(task, (mm->env_start + src), page, this_len, 0); 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); out_free: free_page((unsigned long) page); out: put_task_struct(task); out_no_task: return ret; } static const struct file_operations proc_environ_operations = { .read = environ_read, }; static ssize_t oom_adjust_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); char buffer[PROC_NUMBUF]; size_t len; int oom_adjust; if (!task) return -ESRCH; oom_adjust = task->oomkilladj; put_task_struct(task); len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); return simple_read_from_buffer(buf, count, ppos, buffer, len); } static ssize_t oom_adjust_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct task_struct *task; char buffer[PROC_NUMBUF], *end; int oom_adjust; memset(buffer, 0, sizeof(buffer)); if (count > sizeof(buffer) - 1) count = sizeof(buffer) - 1; if (copy_from_user(buffer, buf, count)) return -EFAULT; oom_adjust = simple_strtol(buffer, &end, 0); if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && oom_adjust != OOM_DISABLE) return -EINVAL; if (*end == '\n') end++; task = get_proc_task(file->f_path.dentry->d_inode); if (!task) return -ESRCH; if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) { put_task_struct(task); return -EACCES; } task->oomkilladj = oom_adjust; put_task_struct(task); if (end - buffer == 0) return -EIO; return end - buffer; } static const struct file_operations proc_oom_adjust_operations = { .read = oom_adjust_read, .write = oom_adjust_write, }; #ifdef CONFIG_AUDITSYSCALL #define TMPBUFLEN 21 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, size_t count, loff_t *ppos) { struct inode * inode = file->f_path.dentry->d_inode; 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_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->f_path.dentry->d_inode; char *page, *tmp; ssize_t length; uid_t loginuid; if (!capable(CAP_AUDIT_CONTROL)) return -EPERM; if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) return -EPERM; if (count >= PAGE_SIZE) count = PAGE_SIZE - 1; if (*ppos != 0) { /* No partial writes. */ return -EINVAL; } page = (char*)__get_free_page(GFP_TEMPORARY); if (!page) return -ENOMEM; length = -EFAULT; if (copy_from_user(page, buf, count)) goto out_free_page; page[count] = '\0'; loginuid = simple_strtoul(page, &tmp, 10); if (tmp == page) { length = -EINVAL; goto out_free_page; } length = audit_set_loginuid(current, loginuid); if (likely(length == 0)) length = count; out_free_page: free_page((unsigned long) page); return length; } static const struct file_operations proc_loginuid_operations = { .read = proc_loginuid_read, .write = proc_loginuid_write, }; static ssize_t proc_sessionid_read(struct file * file, char __user * buf, size_t count, loff_t *ppos) { struct inode * inode = file->f_path.dentry->d_inode; 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, }; #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->f_dentry->d_inode); 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], *end; int make_it_fail; 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; make_it_fail = simple_strtol(buffer, &end, 0); if (*end == '\n') end++; task = get_proc_task(file->f_dentry->d_inode); if (!task) return -ESRCH; task->make_it_fail = make_it_fail; put_task_struct(task); if (end - buffer == 0) return -EIO; return end - buffer; } static const struct file_operations proc_fault_inject_operations = { .read = proc_fault_inject_read, .write = proc_fault_inject_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 task_struct *p; WARN_ON(!inode); p = get_proc_task(inode); if (!p) return -ESRCH; proc_sched_show_task(p, 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->f_path.dentry->d_inode; struct task_struct *p; WARN_ON(!inode); 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) { int ret; ret = single_open(filp, sched_show, NULL); if (!ret) { struct seq_file *m = filp->private_data; m->private = inode; } return ret; } 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 /* * We added or removed a vma mapping the executable. The vmas are only mapped * during exec and are not mapped with the mmap system call. * Callers must hold down_write() on the mm's mmap_sem for these */ void added_exe_file_vma(struct mm_struct *mm) { mm->num_exe_file_vmas++; } void removed_exe_file_vma(struct mm_struct *mm) { mm->num_exe_file_vmas--; if ((mm->num_exe_file_vmas == 0) && mm->exe_file){ fput(mm->exe_file); mm->exe_file = NULL; } } void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) { if (new_exe_file) get_file(new_exe_file); if (mm->exe_file) fput(mm->exe_file); mm->exe_file = new_exe_file; mm->num_exe_file_vmas = 0; } struct file *get_mm_exe_file(struct mm_struct *mm) { struct file *exe_file; /* We need mmap_sem to protect against races with removal of * VM_EXECUTABLE vmas */ down_read(&mm->mmap_sem); exe_file = mm->exe_file; if (exe_file) get_file(exe_file); up_read(&mm->mmap_sem); return exe_file; } void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm) { /* It's safe to write the exe_file pointer without exe_file_lock because * this is called during fork when the task is not yet in /proc */ newmm->exe_file = get_mm_exe_file(oldmm); } static int proc_exe_link(struct inode *inode, struct path *exe_path) { struct task_struct *task; struct mm_struct *mm; struct file *exe_file; task = get_proc_task(inode); if (!task) return -ENOENT; mm = get_task_mm(task); put_task_struct(task); if (!mm) return -ENOENT; exe_file = get_mm_exe_file(mm); mmput(mm); if (exe_file) { *exe_path = exe_file->f_path; path_get(&exe_file->f_path); fput(exe_file); return 0; } else return -ENOENT; } static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) { struct inode *inode = dentry->d_inode; int error = -EACCES; /* We don't need a base pointer in the /proc filesystem */ path_put(&nd->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(inode, &nd->path); nd->last_type = LAST_BIND; 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_TEMPORARY); 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 = dentry->d_inode; 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(inode, &path); if (error) goto out; error = do_proc_readlink(&path, buffer, buflen); path_put(&path); out: return error; } static const struct inode_operations proc_pid_link_inode_operations = { .readlink = proc_pid_readlink, .follow_link = proc_pid_follow_link, .setattr = proc_setattr, }; /* building an inode */ static int task_dumpable(struct task_struct *task) { int dumpable = 0; struct mm_struct *mm; task_lock(task); mm = task->mm; if (mm) dumpable = get_dumpable(mm); task_unlock(task); if(dumpable == 1) return 1; return 0; } static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) { 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_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 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; inode->i_uid = 0; inode->i_gid = 0; if (task_dumpable(task)) { inode->i_uid = task->euid; inode->i_gid = task->egid; } security_task_to_inode(task, inode); out: return inode; out_unlock: iput(inode); return NULL; } static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) { struct inode *inode = dentry->d_inode; struct task_struct *task; generic_fillattr(inode, stat); rcu_read_lock(); stat->uid = 0; stat->gid = 0; task = pid_task(proc_pid(inode), PIDTYPE_PID); if (task) { if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || task_dumpable(task)) { stat->uid = task->euid; stat->gid = task->egid; } } rcu_read_unlock(); return 0; } /* dentry stuff */ /* * Exceptional case: normally we are not allowed to unhash a busy * directory. In this case, however, we can do it - no aliasing problems * due to the way we treat inodes. * * Rewrite the inode's ownerships here because the owning task may have * performed a setuid(), etc. * * 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. */ static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) { struct inode *inode = dentry->d_inode; struct task_struct *task = get_proc_task(inode); if (task) { if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || task_dumpable(task)) { inode->i_uid = task->euid; inode->i_gid = task->egid; } else { inode->i_uid = 0; inode->i_gid = 0; } inode->i_mode &= ~(S_ISUID | S_ISGID); security_task_to_inode(task, inode); put_task_struct(task); return 1; } d_drop(dentry); return 0; } static int pid_delete_dentry(struct dentry * dentry) { /* Is the task we represent dead? * If so, then don't put the dentry on the lru list, * kill it immediately. */ return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; } static struct dentry_operations pid_dentry_operations = { .d_revalidate = pid_revalidate, .d_delete = pid_delete_dentry, }; /* Lookups */ typedef struct dentry *instantiate_t(struct inode *, struct dentry *, struct task_struct *, const void *); /* * 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. */ static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, char *name, int len, instantiate_t instantiate, struct task_struct *task, const void *ptr) { struct dentry *child, *dir = filp->f_path.dentry; struct inode *inode; struct qstr qname; ino_t ino = 0; unsigned type = DT_UNKNOWN; qname.name = name; qname.len = len; qname.hash = full_name_hash(name, len); child = d_lookup(dir, &qname); if (!child) { struct dentry *new; new = d_alloc(dir, &qname); if (new) { child = instantiate(dir->d_inode, new, task, ptr); if (child) dput(new); else child = new; } } if (!child || IS_ERR(child) || !child->d_inode) goto end_instantiate; inode = child->d_inode; if (inode) { ino = inode->i_ino; type = inode->i_mode >> 12; } dput(child); end_instantiate: if (!ino) ino = find_inode_number(dir, &qname); if (!ino) ino = 1; return filldir(dirent, name, len, filp->f_pos, ino, type); } static unsigned name_to_int(struct dentry *dentry) { const char *name = dentry->d_name.name; int len = dentry->d_name.len; unsigned n = 0; if (len > 1 && *name == '0') goto out; while (len-- > 0) { unsigned c = *name++ - '0'; if (c > 9) goto out; if (n >= (~0U-9)/10) goto out; n *= 10; n += c; } return n; out: return ~0U; } #define PROC_FDINFO_MAX 64 static int proc_fd_info(struct inode *inode, struct path *path, char *info) { struct task_struct *task = get_proc_task(inode); struct files_struct *files = NULL; struct file *file; int fd = proc_fd(inode); if (task) { files = get_files_struct(task); put_task_struct(task); } if (files) { /* * We are not taking a ref to the file structure, so we must * hold ->file_lock. */ spin_lock(&files->file_lock); file = fcheck_files(files, fd); if (file) { if (path) { *path = file->f_path; path_get(&file->f_path); } if (info) snprintf(info, PROC_FDINFO_MAX, "pos:\t%lli\n" "flags:\t0%o\n", (long long) file->f_pos, file->f_flags); spin_unlock(&files->file_lock); put_files_struct(files); return 0; } spin_unlock(&files->file_lock); put_files_struct(files); } return -ENOENT; } static int proc_fd_link(struct inode *inode, struct path *path) { return proc_fd_info(inode, path, NULL); } static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) { struct inode *inode = dentry->d_inode; struct task_struct *task = get_proc_task(inode); int fd = proc_fd(inode); struct files_struct *files; if (task) { files = get_files_struct(task); if (files) { rcu_read_lock(); if (fcheck_files(files, fd)) { rcu_read_unlock(); put_files_struct(files); if (task_dumpable(task)) { inode->i_uid = task->euid; inode->i_gid = task->egid; } else { inode->i_uid = 0; inode->i_gid = 0; } inode->i_mode &= ~(S_ISUID | S_ISGID); security_task_to_inode(task, inode); put_task_struct(task); return 1; } rcu_read_unlock(); put_files_struct(files); } put_task_struct(task); } d_drop(dentry); return 0; } static struct dentry_operations tid_fd_dentry_operations = { .d_revalidate = tid_fd_revalidate, .d_delete = pid_delete_dentry, }; static struct dentry *proc_fd_instantiate(struct inode *dir, struct dentry *dentry, struct task_struct *task, const void *ptr) { unsigned fd = *(const unsigned *)ptr; struct file *file; struct files_struct *files; struct inode *inode; struct proc_inode *ei; struct dentry *error = ERR_PTR(-ENOENT); inode = proc_pid_make_inode(dir->i_sb, task); if (!inode) goto out; ei = PROC_I(inode); ei->fd = fd; files = get_files_struct(task); if (!files) goto out_iput; inode->i_mode = S_IFLNK; /* * We are not taking a ref to the file structure, so we must * hold ->file_lock. */ spin_lock(&files->file_lock); file = fcheck_files(files, fd); if (!file) goto out_unlock; if (file->f_mode & 1) inode->i_mode |= S_IRUSR | S_IXUSR; if (file->f_mode & 2) inode->i_mode |= S_IWUSR | S_IXUSR; spin_unlock(&files->file_lock); put_files_struct(files); inode->i_op = &proc_pid_link_inode_operations; inode->i_size = 64; ei->op.proc_get_link = proc_fd_link; dentry->d_op = &tid_fd_dentry_operations; d_add(dentry, inode); /* Close the race of the process dying before we return the dentry */ if (tid_fd_revalidate(dentry, NULL)) error = NULL; out: return error; out_unlock: spin_unlock(&files->file_lock); put_files_struct(files); out_iput: iput(inode); goto out; } static struct dentry *proc_lookupfd_common(struct inode *dir, struct dentry *dentry, instantiate_t instantiate) { struct task_struct *task = get_proc_task(dir); unsigned fd = name_to_int(dentry); struct dentry *result = ERR_PTR(-ENOENT); if (!task) goto out_no_task; if (fd == ~0U) goto out; result = instantiate(dir, dentry, task, &fd); out: put_task_struct(task); out_no_task: return result; } static int proc_readfd_common(struct file * filp, void * dirent, filldir_t filldir, instantiate_t instantiate) { struct dentry *dentry = filp->f_path.dentry; struct inode *inode = dentry->d_inode; struct task_struct *p = get_proc_task(inode); unsigned int fd, ino; int retval; struct files_struct * files; retval = -ENOENT; if (!p) goto out_no_task; retval = 0; fd = filp->f_pos; switch (fd) { case 0: if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) goto out; filp->f_pos++; case 1: ino = parent_ino(dentry); if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) goto out; filp->f_pos++; default: files = get_files_struct(p); if (!files) goto out; rcu_read_lock(); for (fd = filp->f_pos-2; fd < files_fdtable(files)->max_fds; fd++, filp->f_pos++) { char name[PROC_NUMBUF]; int len; if (!fcheck_files(files, fd)) continue; rcu_read_unlock(); len = snprintf(name, sizeof(name), "%d", fd); if (proc_fill_cache(filp, dirent, filldir, name, len, instantiate, p, &fd) < 0) { rcu_read_lock(); break; } rcu_read_lock(); } rcu_read_unlock(); put_files_struct(files); } out: put_task_struct(p); out_no_task: return retval; } static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); } static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) { return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); } static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, size_t len, loff_t *ppos) { char tmp[PROC_FDINFO_MAX]; int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); if (!err) err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); return err; } static const struct file_operations proc_fdinfo_file_operations = { .open = nonseekable_open, .read = proc_fdinfo_read, }; static const struct file_operations proc_fd_operations = { .read = generic_read_dir, .readdir = proc_readfd, }; /* * /proc/pid/fd needs a special permission handler so that a process can still * access /proc/self/fd after it has executed a setuid(). */ static int proc_fd_permission(struct inode *inode, int mask) { int rv; rv = generic_permission(inode, mask, NULL); if (rv == 0) return 0; if (task_pid(current) == proc_pid(inode)) rv = 0; return rv; } /* * proc directories can do almost nothing.. */ static const struct inode_operations proc_fd_inode_operations = { .lookup = proc_lookupfd, .permission = proc_fd_permission, .setattr = proc_setattr, }; static struct dentry *proc_fdinfo_instantiate(struct inode *dir, struct dentry *dentry, struct task_struct *task, const void *ptr) { unsigned fd = *(unsigned *)ptr; struct inode *inode; struct proc_inode *ei; struct dentry *error = ERR_PTR(-ENOENT); inode = proc_pid_make_inode(dir->i_sb, task); if (!inode) goto out; ei = PROC_I(inode); ei->fd = fd; inode->i_mode = S_IFREG | S_IRUSR; inode->i_fop = &proc_fdinfo_file_operations; dentry->d_op = &tid_fd_dentry_operations; d_add(dentry, inode); /* Close the race of the process dying before we return the dentry */ if (tid_fd_revalidate(dentry, NULL)) error = NULL; out: return error; } static struct dentry *proc_lookupfdinfo(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); } static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) { return proc_readfd_common(filp, dirent, filldir, proc_fdinfo_instantiate); } static const struct file_operations proc_fdinfo_operations = { .read = generic_read_dir, .readdir = proc_readfdinfo, }; /* * proc directories can do almost nothing.. */ static const struct inode_operations proc_fdinfo_inode_operations = { .lookup = proc_lookupfdinfo, .setattr = proc_setattr, }; static struct dentry *proc_pident_instantiate(struct inode *dir, struct dentry *dentry, struct task_struct *task, const void *ptr) { const struct pid_entry *p = ptr; struct inode *inode; struct proc_inode *ei; struct dentry *error = ERR_PTR(-EINVAL); inode = proc_pid_make_inode(dir->i_sb, task); if (!inode) goto out; ei = PROC_I(inode); inode->i_mode = p->mode; if (S_ISDIR(inode->i_mode)) inode->i_nlink = 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; dentry->d_op = &pid_dentry_operations; d_add(dentry, inode); /* Close the race of the process dying before we return the dentry */ if (pid_revalidate(dentry, NULL)) error = NULL; out: return error; } static struct dentry *proc_pident_lookup(struct inode *dir, struct dentry *dentry, const struct pid_entry *ents, unsigned int nents) { struct inode *inode; struct dentry *error; struct task_struct *task = get_proc_task(dir); const struct pid_entry *p, *last; error = ERR_PTR(-ENOENT); inode = NULL; 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 - 1]; for (p = ents; p <= last; p++) { if (p->len != dentry->d_name.len) continue; if (!memcmp(dentry->d_name.name, p->name, p->len)) break; } if (p > last) goto out; error = proc_pident_instantiate(dir, dentry, task, p); out: put_task_struct(task); out_no_task: return error; } static int proc_pident_fill_cache(struct file *filp, void *dirent, filldir_t filldir, struct task_struct *task, const struct pid_entry *p) { return proc_fill_cache(filp, dirent, filldir, p->name, p->len, proc_pident_instantiate, task, p); } static int proc_pident_readdir(struct file *filp, void *dirent, filldir_t filldir, const struct pid_entry *ents, unsigned int nents) { int i; struct dentry *dentry = filp->f_path.dentry; struct inode *inode = dentry->d_inode; struct task_struct *task = get_proc_task(inode); const struct pid_entry *p, *last; ino_t ino; int ret; ret = -ENOENT; if (!task) goto out_no_task; ret = 0; i = filp->f_pos; switch (i) { case 0: ino = inode->i_ino; if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) goto out; i++; filp->f_pos++; /* fall through */ case 1: ino = parent_ino(dentry); if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) goto out; i++; filp->f_pos++; /* fall through */ default: i -= 2; if (i >= nents) { ret = 1; goto out; } p = ents + i; last = &ents[nents - 1]; while (p <= last) { if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) goto out; filp->f_pos++; p++; } } ret = 1; out: put_task_struct(task); out_no_task: return ret; } #ifdef CONFIG_SECURITY static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, size_t count, loff_t *ppos) { struct inode * inode = file->f_path.dentry->d_inode; 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->f_path.dentry->d_inode; char *page; ssize_t length; struct task_struct *task = get_proc_task(inode); length = -ESRCH; if (!task) goto out_no_task; if (count > PAGE_SIZE) count = PAGE_SIZE; /* No partial writes. */ length = -EINVAL; if (*ppos != 0) goto out; length = -ENOMEM; page = (char*)__get_free_page(GFP_TEMPORARY); if (!page) goto out; length = -EFAULT; if (copy_from_user(page, buf, count)) goto out_free; length = security_setprocattr(task, (char*)file->f_path.dentry->d_name.name, (void*)page, count); out_free: free_page((unsigned long) page); out: put_task_struct(task); out_no_task: return length; } static const struct file_operations proc_pid_attr_operations = { .read = proc_pid_attr_read, .write = proc_pid_attr_write, }; static const struct pid_entry attr_dir_stuff[] = { REG("current", S_IRUGO|S_IWUGO, pid_attr), REG("prev", S_IRUGO, pid_attr), REG("exec", S_IRUGO|S_IWUGO, pid_attr), REG("fscreate", S_IRUGO|S_IWUGO, pid_attr), REG("keycreate", S_IRUGO|S_IWUGO, pid_attr), REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr), }; static int proc_attr_dir_readdir(struct file * filp, void * dirent, filldir_t filldir) { return proc_pident_readdir(filp,dirent,filldir, attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); } static const struct file_operations proc_attr_dir_operations = { .read = generic_read_dir, .readdir = proc_attr_dir_readdir, }; static struct dentry *proc_attr_dir_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { 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 #if defined(USE_ELF_CORE_DUMP) && defined(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->f_dentry->d_inode); 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; char buffer[PROC_NUMBUF], *end; unsigned int val; int ret; int i; unsigned long mask; ret = -EFAULT; memset(buffer, 0, sizeof(buffer)); if (count > sizeof(buffer) - 1) count = sizeof(buffer) - 1; if (copy_from_user(buffer, buf, count)) goto out_no_task; ret = -EINVAL; val = (unsigned int)simple_strtoul(buffer, &end, 0); if (*end == '\n') end++; if (end - buffer == 0) goto out_no_task; ret = -ESRCH; task = get_proc_task(file->f_dentry->d_inode); if (!task) goto out_no_task; ret = end - buffer; mm = get_task_mm(task); if (!mm) goto out_no_mm; 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: return ret; } static const struct file_operations proc_coredump_filter_operations = { .read = proc_coredump_filter_read, .write = proc_coredump_filter_write, }; #endif /* * /proc/self: */ static int proc_self_readlink(struct dentry *dentry, char __user *buffer, int buflen) { struct pid_namespace *ns = dentry->d_sb->s_fs_info; pid_t tgid = task_tgid_nr_ns(current, ns); char tmp[PROC_NUMBUF]; if (!tgid) return -ENOENT; sprintf(tmp, "%d", tgid); return vfs_readlink(dentry,buffer,buflen,tmp); } static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) { struct pid_namespace *ns = dentry->d_sb->s_fs_info; pid_t tgid = task_tgid_nr_ns(current, ns); char tmp[PROC_NUMBUF]; if (!tgid) return ERR_PTR(-ENOENT); sprintf(tmp, "%d", task_tgid_nr_ns(current, ns)); return ERR_PTR(vfs_follow_link(nd,tmp)); } static const struct inode_operations proc_self_inode_operations = { .readlink = proc_self_readlink, .follow_link = proc_self_follow_link, }; /* * proc base * * These are the directory entries in the root directory of /proc * that properly belong to the /proc filesystem, as they describe * describe something that is process related. */ static const struct pid_entry proc_base_stuff[] = { NOD("self", S_IFLNK|S_IRWXUGO, &proc_self_inode_operations, NULL, {}), }; /* * Exceptional case: normally we are not allowed to unhash a busy * directory. In this case, however, we can do it - no aliasing problems * due to the way we treat inodes. */ static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) { struct inode *inode = dentry->d_inode; struct task_struct *task = get_proc_task(inode); if (task) { put_task_struct(task); return 1; } d_drop(dentry); return 0; } static struct dentry_operations proc_base_dentry_operations = { .d_revalidate = proc_base_revalidate, .d_delete = pid_delete_dentry, }; static struct dentry *proc_base_instantiate(struct inode *dir, struct dentry *dentry, struct task_struct *task, const void *ptr) { const struct pid_entry *p = ptr; struct inode *inode; struct proc_inode *ei; struct dentry *error = ERR_PTR(-EINVAL); /* Allocate the inode */ error = ERR_PTR(-ENOMEM); inode = new_inode(dir->i_sb); if (!inode) goto out; /* Initialize the inode */ ei = PROC_I(inode); inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; /* * grab the reference to the task. */ ei->pid = get_task_pid(task, PIDTYPE_PID); if (!ei->pid) goto out_iput; inode->i_uid = 0; inode->i_gid = 0; inode->i_mode = p->mode; if (S_ISDIR(inode->i_mode)) inode->i_nlink = 2; if (S_ISLNK(inode->i_mode)) inode->i_size = 64; if (p->iop) inode->i_op = p->iop; if (p->fop) inode->i_fop = p->fop; ei->op = p->op; dentry->d_op = &proc_base_dentry_operations; d_add(dentry, inode); error = NULL; out: return error; out_iput: iput(inode); goto out; } static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) { struct dentry *error; struct task_struct *task = get_proc_task(dir); const struct pid_entry *p, *last; error = ERR_PTR(-ENOENT); if (!task) goto out_no_task; /* Lookup the directory entry */ last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; for (p = proc_base_stuff; p <= last; p++) { if (p->len != dentry->d_name.len) continue; if (!memcmp(dentry->d_name.name, p->name, p->len)) break; } if (p > last) goto out; error = proc_base_instantiate(dir, dentry, task, p); out: put_task_struct(task); out_no_task: return error; } static int proc_base_fill_cache(struct file *filp, void *dirent, filldir_t filldir, struct task_struct *task, const struct pid_entry *p) { return proc_fill_cache(filp, dirent, filldir, p->name, p->len, proc_base_instantiate, task, p); } #ifdef CONFIG_TASK_IO_ACCOUNTING static int do_io_accounting(struct task_struct *task, char *buffer, int whole) { u64 rchar, wchar, syscr, syscw; struct task_io_accounting ioac; if (!whole) { rchar = task->rchar; wchar = task->wchar; syscr = task->syscr; syscw = task->syscw; memcpy(&ioac, &task->ioac, sizeof(ioac)); } else { unsigned long flags; struct task_struct *t = task; rchar = wchar = syscr = syscw = 0; memset(&ioac, 0, sizeof(ioac)); rcu_read_lock(); do { rchar += t->rchar; wchar += t->wchar; syscr += t->syscr; syscw += t->syscw; ioac.read_bytes += t->ioac.read_bytes; ioac.write_bytes += t->ioac.write_bytes; ioac.cancelled_write_bytes += t->ioac.cancelled_write_bytes; t = next_thread(t); } while (t != task); rcu_read_unlock(); if (lock_task_sighand(task, &flags)) { struct signal_struct *sig = task->signal; rchar += sig->rchar; wchar += sig->wchar; syscr += sig->syscr; syscw += sig->syscw; ioac.read_bytes += sig->ioac.read_bytes; ioac.write_bytes += sig->ioac.write_bytes; ioac.cancelled_write_bytes += sig->ioac.cancelled_write_bytes; unlock_task_sighand(task, &flags); } } return sprintf(buffer, "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)rchar, (unsigned long long)wchar, (unsigned long long)syscr, (unsigned long long)syscw, (unsigned long long)ioac.read_bytes, (unsigned long long)ioac.write_bytes, (unsigned long long)ioac.cancelled_write_bytes); } static int proc_tid_io_accounting(struct task_struct *task, char *buffer) { return do_io_accounting(task, buffer, 0); } static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) { return do_io_accounting(task, buffer, 1); } #endif /* CONFIG_TASK_IO_ACCOUNTING */ /* * 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, task), DIR("fd", S_IRUSR|S_IXUSR, fd), DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), #ifdef CONFIG_NET DIR("net", S_IRUGO|S_IXUGO, net), #endif REG("environ", S_IRUSR, environ), INF("auxv", S_IRUSR, pid_auxv), ONE("status", S_IRUGO, pid_status), INF("limits", S_IRUSR, pid_limits), #ifdef CONFIG_SCHED_DEBUG REG("sched", S_IRUGO|S_IWUSR, pid_sched), #endif #ifdef CONFIG_HAVE_ARCH_TRACEHOOK INF("syscall", S_IRUSR, pid_syscall), #endif INF("cmdline", S_IRUGO, pid_cmdline), ONE("stat", S_IRUGO, tgid_stat), ONE("statm", S_IRUGO, pid_statm), REG("maps", S_IRUGO, maps), #ifdef CONFIG_NUMA REG("numa_maps", S_IRUGO, numa_maps), #endif REG("mem", S_IRUSR|S_IWUSR, mem), LNK("cwd", cwd), LNK("root", root), LNK("exe", exe), REG("mounts", S_IRUGO, mounts), REG("mountinfo", S_IRUGO, mountinfo), REG("mountstats", S_IRUSR, mountstats), #ifdef CONFIG_PROC_PAGE_MONITOR REG("clear_refs", S_IWUSR, clear_refs), REG("smaps", S_IRUGO, smaps), REG("pagemap", S_IRUSR, pagemap), #endif #ifdef CONFIG_SECURITY DIR("attr", S_IRUGO|S_IXUGO, attr_dir), #endif #ifdef CONFIG_KALLSYMS INF("wchan", S_IRUGO, pid_wchan), #endif #ifdef CONFIG_SCHEDSTATS INF("schedstat", S_IRUGO, pid_schedstat), #endif #ifdef CONFIG_LATENCYTOP REG("latency", S_IRUGO, lstats), #endif #ifdef CONFIG_PROC_PID_CPUSET REG("cpuset", S_IRUGO, cpuset), #endif #ifdef CONFIG_CGROUPS REG("cgroup", S_IRUGO, cgroup), #endif INF("oom_score", S_IRUGO, oom_score), REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), #ifdef CONFIG_AUDITSYSCALL REG("loginuid", S_IWUSR|S_IRUGO, loginuid), REG("sessionid", S_IRUGO, sessionid), #endif #ifdef CONFIG_FAULT_INJECTION REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), #endif #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter), #endif #ifdef CONFIG_TASK_IO_ACCOUNTING INF("io", S_IRUGO, tgid_io_accounting), #endif }; static int proc_tgid_base_readdir(struct file * filp, void * dirent, filldir_t filldir) { return proc_pident_readdir(filp,dirent,filldir, tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); } static const struct file_operations proc_tgid_base_operations = { .read = generic_read_dir, .readdir = proc_tgid_base_readdir, }; static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ return proc_pident_lookup(dir, dentry, tgid_base_stuff, 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, }; static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) { struct dentry *dentry, *leader, *dir; char buf[PROC_NUMBUF]; struct qstr name; name.name = buf; name.len = snprintf(buf, sizeof(buf), "%d", pid); dentry = d_hash_and_lookup(mnt->mnt_root, &name); if (dentry) { if (!(current->flags & PF_EXITING)) shrink_dcache_parent(dentry); d_drop(dentry); dput(dentry); } if (tgid == 0) goto out; name.name = buf; name.len = snprintf(buf, sizeof(buf), "%d", 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), "%d", pid); dentry = d_hash_and_lookup(dir, &name); if (dentry) { shrink_dcache_parent(dentry); d_drop(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 = NULL; struct upid *upid; pid = task_pid(task); if (thread_group_leader(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 ? tgid->numbers[i].nr : 0); } upid = &pid->numbers[pid->level]; if (upid->nr == 1) pid_ns_release_proc(upid->ns); } static struct dentry *proc_pid_instantiate(struct inode *dir, struct dentry * dentry, struct task_struct *task, const void *ptr) { struct dentry *error = ERR_PTR(-ENOENT); struct inode *inode; inode = proc_pid_make_inode(dir->i_sb, task); if (!inode) goto out; inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; inode->i_op = &proc_tgid_base_inode_operations; inode->i_fop = &proc_tgid_base_operations; inode->i_flags|=S_IMMUTABLE; inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); dentry->d_op = &pid_dentry_operations; d_add(dentry, inode); /* Close the race of the process dying before we return the dentry */ if (pid_revalidate(dentry, NULL)) error = NULL; out: return error; } struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) { struct dentry *result = ERR_PTR(-ENOENT); struct task_struct *task; unsigned tgid; struct pid_namespace *ns; result = proc_base_lookup(dir, dentry); if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) goto out; tgid = name_to_int(dentry); 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(dir, 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 + ARRAY_SIZE(proc_base_stuff)) static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, struct tgid_iter iter) { char name[PROC_NUMBUF]; int len = snprintf(name, sizeof(name), "%d", iter.tgid); return proc_fill_cache(filp, dirent, filldir, name, len, proc_pid_instantiate, iter.task, NULL); } /* for the /proc/ directory itself, after non-process stuff has been done */ int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) { unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); struct tgid_iter iter; struct pid_namespace *ns; if (!reaper) goto out_no_task; for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { const struct pid_entry *p = &proc_base_stuff[nr]; if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) goto out; } ns = filp->f_dentry->d_sb->s_fs_info; iter.task = NULL; iter.tgid = filp->f_pos - TGID_OFFSET; for (iter = next_tgid(ns, iter); iter.task; iter.tgid += 1, iter = next_tgid(ns, iter)) { filp->f_pos = iter.tgid + TGID_OFFSET; if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) { put_task_struct(iter.task); goto out; } } filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; out: put_task_struct(reaper); out_no_task: return 0; } /* * Tasks */ static const struct pid_entry tid_base_stuff[] = { DIR("fd", S_IRUSR|S_IXUSR, fd), DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), REG("environ", S_IRUSR, environ), INF("auxv", S_IRUSR, pid_auxv), ONE("status", S_IRUGO, pid_status), INF("limits", S_IRUSR, pid_limits), #ifdef CONFIG_SCHED_DEBUG REG("sched", S_IRUGO|S_IWUSR, pid_sched), #endif #ifdef CONFIG_HAVE_ARCH_TRACEHOOK INF("syscall", S_IRUSR, pid_syscall), #endif INF("cmdline", S_IRUGO, pid_cmdline), ONE("stat", S_IRUGO, tid_stat), ONE("statm", S_IRUGO, pid_statm), REG("maps", S_IRUGO, maps), #ifdef CONFIG_NUMA REG("numa_maps", S_IRUGO, numa_maps), #endif REG("mem", S_IRUSR|S_IWUSR, mem), LNK("cwd", cwd), LNK("root", root), LNK("exe", exe), REG("mounts", S_IRUGO, mounts), REG("mountinfo", S_IRUGO, mountinfo), #ifdef CONFIG_PROC_PAGE_MONITOR REG("clear_refs", S_IWUSR, clear_refs), REG("smaps", S_IRUGO, smaps), REG("pagemap", S_IRUSR, pagemap), #endif #ifdef CONFIG_SECURITY DIR("attr", S_IRUGO|S_IXUGO, attr_dir), #endif #ifdef CONFIG_KALLSYMS INF("wchan", S_IRUGO, pid_wchan), #endif #ifdef CONFIG_SCHEDSTATS INF("schedstat", S_IRUGO, pid_schedstat), #endif #ifdef CONFIG_LATENCYTOP REG("latency", S_IRUGO, lstats), #endif #ifdef CONFIG_PROC_PID_CPUSET REG("cpuset", S_IRUGO, cpuset), #endif #ifdef CONFIG_CGROUPS REG("cgroup", S_IRUGO, cgroup), #endif INF("oom_score", S_IRUGO, oom_score), REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), #ifdef CONFIG_AUDITSYSCALL REG("loginuid", S_IWUSR|S_IRUGO, loginuid), REG("sessionid", S_IRUSR, sessionid), #endif #ifdef CONFIG_FAULT_INJECTION REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), #endif #ifdef CONFIG_TASK_IO_ACCOUNTING INF("io", S_IRUGO, tid_io_accounting), #endif }; static int proc_tid_base_readdir(struct file * filp, void * dirent, filldir_t filldir) { return proc_pident_readdir(filp,dirent,filldir, tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); } static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ return proc_pident_lookup(dir, dentry, tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); } static const struct file_operations proc_tid_base_operations = { .read = generic_read_dir, .readdir = proc_tid_base_readdir, }; 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 inode *dir, struct dentry *dentry, struct task_struct *task, const void *ptr) { struct dentry *error = ERR_PTR(-ENOENT); struct inode *inode; inode = proc_pid_make_inode(dir->i_sb, task); if (!inode) goto out; inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; inode->i_op = &proc_tid_base_inode_operations; inode->i_fop = &proc_tid_base_operations; inode->i_flags|=S_IMMUTABLE; inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); dentry->d_op = &pid_dentry_operations; d_add(dentry, inode); /* Close the race of the process dying before we return the dentry */ if (pid_revalidate(dentry, NULL)) error = NULL; out: return error; } static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) { struct dentry *result = ERR_PTR(-ENOENT); struct task_struct *task; struct task_struct *leader = get_proc_task(dir); unsigned tid; struct pid_namespace *ns; if (!leader) goto out_no_task; tid = name_to_int(dentry); 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(dir, 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 task_struct *leader, int tid, int nr, struct pid_namespace *ns) { struct task_struct *pos; rcu_read_lock(); /* Attempt to start with the pid of a thread */ if (tid && (nr > 0)) { pos = find_task_by_pid_ns(tid, ns); if (pos && (pos->group_leader == leader)) goto found; } /* If nr exceeds the number of threads there is nothing todo */ pos = NULL; if (nr && nr >= get_nr_threads(leader)) goto out; /* If we haven't found our starting place yet start * with the leader and walk nr threads forward. */ for (pos = leader; nr > 0; --nr) { pos = next_thread(pos); if (pos == leader) { 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; } static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, struct task_struct *task, int tid) { char name[PROC_NUMBUF]; int len = snprintf(name, sizeof(name), "%d", tid); return proc_fill_cache(filp, dirent, filldir, name, len, proc_task_instantiate, task, NULL); } /* for the /proc/TGID/task/ directories */ static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) { struct dentry *dentry = filp->f_path.dentry; struct inode *inode = dentry->d_inode; struct task_struct *leader = NULL; struct task_struct *task; int retval = -ENOENT; ino_t ino; int tid; unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */ struct pid_namespace *ns; task = get_proc_task(inode); if (!task) goto out_no_task; rcu_read_lock(); if (pid_alive(task)) { leader = task->group_leader; get_task_struct(leader); } rcu_read_unlock(); put_task_struct(task); if (!leader) goto out_no_task; retval = 0; switch (pos) { case 0: ino = inode->i_ino; if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0) goto out; pos++; /* fall through */ case 1: ino = parent_ino(dentry); if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0) goto out; pos++; /* fall through */ } /* f_version caches the tgid value that the last readdir call couldn't * return. lseek aka telldir automagically resets f_version to 0. */ ns = filp->f_dentry->d_sb->s_fs_info; tid = (int)filp->f_version; filp->f_version = 0; for (task = first_tid(leader, tid, pos - 2, ns); task; task = next_tid(task), pos++) { tid = task_pid_nr_ns(task, ns); if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { /* returning this tgid failed, save it as the first * pid for the next readir call */ filp->f_version = (u64)tid; put_task_struct(task); break; } } out: filp->f_pos = pos; put_task_struct(leader); out_no_task: return retval; } static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) { struct inode *inode = dentry->d_inode; struct task_struct *p = get_proc_task(inode); generic_fillattr(inode, stat); if (p) { rcu_read_lock(); stat->nlink += get_nr_threads(p); rcu_read_unlock(); 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, }; static const struct file_operations proc_task_operations = { .read = generic_read_dir, .readdir = proc_task_readdir, };