find / -name foo as root results in: find: WARNING: Hard link count is wrong for /proc: this may be a bug in your filesystem driver. Automatically turning on find's -noleaf option. Earlier results may have failed to include directories that should have been searched. I' ve searched for this issue at google and I found out, that it has something to do with either the kernel or the findutils. The page says that the kernel seems to count a 3 instead of a 5 which he is actually supposed to. Please refer to: http://forums.gentoo.org/viewtopic-p-2213058.html#2213058 Reproducible: Always Steps to Reproduce: 1. su - 2. find / -name foo OR 1. login as root 2. find / -name foo Actual Results: find: WARNING: Hard link count is wrong for /proc: this may be a bug in your filesystem driver. Automatically turning on find's -noleaf option. Earlier results may have failed to include directories that should have been searched. Expected Results: regular find results.
Sorry for the delay, and thanks for looking into it on the forums. This should fix it: http://www.reactivated.net/patches/linux-kernel/2.6.12/procfs-hardlinks.patch I'll see what upstream says.
Andrew Morton has accepted it. Will be included in next gentoo-sources release.
The patch did acutally not help though I did apply it (manually). ~ # cd /usr/src/linux/fs/proc ~ # nano -w base.c // in order to apply the patch ~ # cd /usr/src/linux ~ # make clean ~ # make ~ # cp arch/i386/boot/bzImage /boot/kernel-2.6.11.4 ~ # cp System.map /boot/System.map ~ # reboot ~ # find / -name lol find: WARNING: Hard link count is wrong for /: this may be a bug in your filesystem driver. Automatically turning on find's -noleaf option. Earlier results may have failed to include directories that should have been searched. #####CTRL+C##### ~ # updatedb //Maybe that' s the point, though find should acutally not be affected. ~ # reboot ~ # find / -name lol find: WARNING: Hard link count is wrong for /: this may be a bug in your filesystem driver. Automatically turning on find's -noleaf option. Earlier results may have failed to include directories that should have been searched. #####CTRL+C##### ~ # ~ # find / -name lol #####CTRL+C##### ~ # ~ # find / -name lol find: WARNING: Hard link count is wrong for /: this may be a bug in your filesystem driver. Automatically turning on find's -noleaf option. Earlier results may have failed to include directories that should have been searched. #####CTRL+C##### ~ # find / -name lol find: WARNING: Hard link count is wrong for /: this may be a bug in your filesystem driver. Automatically turning on find's -noleaf option. Earlier results may have failed to include directories that should have been searched. #####CTRL+C##### ~ # find / -name Search /usr/lib/perl5/5.8.6/Search /usr/share/doc/perl-5.8.6-r4/html/lib/Search #####CTRL+C##### ~ # find / -name Search /usr/lib/perl5/5.8.6/Search /usr/share/doc/perl-5.8.6-r4/html/lib/Search #####CTRL+C##### ~ # find / -name lol #####CTRL+C##### ~ # find / -name lol #####CTRL+C##### ~ # Perhaps I did something wrong? ----------------------------base.c------------------------------ /* * linux/fs/proc/base.c * * Copyright (C) 1991, 1992 Linus Torvalds * * proc base directory handling functions * * 1999, Al Viro. Rewritten. Now it covers the whole per-process part. * Instead of using magical inumbers to determine the kind of object * we allocate and fill in-core inodes upon lookup. They don't even * go into icache. We cache the reference to task_struct upon lookup too. * Eventually it should become a filesystem in its own. We don't use the * rest of procfs anymore. */ #include <asm/uaccess.h> #include <linux/config.h> #include <linux/errno.h> #include <linux/time.h> #include <linux/proc_fs.h> #include <linux/stat.h> #include <linux/init.h> #include <linux/file.h> #include <linux/string.h> #include <linux/seq_file.h> #include <linux/namei.h> #include <linux/namespace.h> #include <linux/mm.h> #include <linux/smp_lock.h> #include <linux/kallsyms.h> #include <linux/mount.h> #include <linux/security.h> #include <linux/ptrace.h> #include "internal.h" /* * For hysterical raisins we keep the same inumbers as in the old procfs. * Feel free to change the macro below - just keep the range distinct from * inumbers of the rest of procfs (currently those are in 0x0000--0xffff). * As soon as we'll get a separate superblock we will be able to forget * about magical ranges too. */ #define fake_ino(pid,ino) (((pid)<<16)|(ino)) enum pid_directory_inos { PROC_TGID_INO = 2, PROC_TGID_TASK, PROC_TGID_STATUS, PROC_TGID_MEM, PROC_TGID_CWD, PROC_TGID_ROOT, PROC_TGID_EXE, PROC_TGID_FD, PROC_TGID_ENVIRON, PROC_TGID_AUXV, PROC_TGID_CMDLINE, PROC_TGID_STAT, PROC_TGID_STATM, PROC_TGID_MAPS, PROC_TGID_MOUNTS, PROC_TGID_WCHAN, #ifdef CONFIG_SCHEDSTATS PROC_TGID_SCHEDSTAT, #endif #ifdef CONFIG_SECURITY PROC_TGID_ATTR, PROC_TGID_ATTR_CURRENT, PROC_TGID_ATTR_PREV, PROC_TGID_ATTR_EXEC, PROC_TGID_ATTR_FSCREATE, #endif #ifdef CONFIG_AUDITSYSCALL PROC_TGID_LOGINUID, #endif PROC_TGID_FD_DIR, PROC_TGID_OOM_SCORE, PROC_TGID_OOM_ADJUST, PROC_TID_INO, PROC_TID_STATUS, PROC_TID_MEM, PROC_TID_CWD, PROC_TID_ROOT, PROC_TID_EXE, PROC_TID_FD, PROC_TID_ENVIRON, PROC_TID_AUXV, PROC_TID_CMDLINE, PROC_TID_STAT, PROC_TID_STATM, PROC_TID_MAPS, PROC_TID_MOUNTS, PROC_TID_WCHAN, #ifdef CONFIG_SCHEDSTATS PROC_TID_SCHEDSTAT, #endif #ifdef CONFIG_SECURITY PROC_TID_ATTR, PROC_TID_ATTR_CURRENT, PROC_TID_ATTR_PREV, PROC_TID_ATTR_EXEC, PROC_TID_ATTR_FSCREATE, #endif #ifdef CONFIG_AUDITSYSCALL PROC_TID_LOGINUID, #endif PROC_TID_FD_DIR = 0x8000, /* 0x8000-0xffff */ PROC_TID_OOM_SCORE, PROC_TID_OOM_ADJUST, }; struct pid_entry { int type; int len; char *name; mode_t mode; }; #define E(type,name,mode) {(type),sizeof(name)-1,(name),(mode)} static struct pid_entry tgid_base_stuff[] = { E(PROC_TGID_TASK, "task", S_IFDIR|S_IRUGO|S_IXUGO), E(PROC_TGID_FD, "fd", S_IFDIR|S_IRUSR|S_IXUSR), E(PROC_TGID_ENVIRON, "environ", S_IFREG|S_IRUSR), E(PROC_TGID_AUXV, "auxv", S_IFREG|S_IRUSR), E(PROC_TGID_STATUS, "status", S_IFREG|S_IRUGO), E(PROC_TGID_CMDLINE, "cmdline", S_IFREG|S_IRUGO), E(PROC_TGID_STAT, "stat", S_IFREG|S_IRUGO), E(PROC_TGID_STATM, "statm", S_IFREG|S_IRUGO), E(PROC_TGID_MAPS, "maps", S_IFREG|S_IRUGO), E(PROC_TGID_MEM, "mem", S_IFREG|S_IRUSR|S_IWUSR), E(PROC_TGID_CWD, "cwd", S_IFLNK|S_IRWXUGO), E(PROC_TGID_ROOT, "root", S_IFLNK|S_IRWXUGO), E(PROC_TGID_EXE, "exe", S_IFLNK|S_IRWXUGO), E(PROC_TGID_MOUNTS, "mounts", S_IFREG|S_IRUGO), #ifdef CONFIG_SECURITY E(PROC_TGID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO), #endif #ifdef CONFIG_KALLSYMS E(PROC_TGID_WCHAN, "wchan", S_IFREG|S_IRUGO), #endif #ifdef CONFIG_SCHEDSTATS E(PROC_TGID_SCHEDSTAT, "schedstat", S_IFREG|S_IRUGO), #endif E(PROC_TGID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO), E(PROC_TGID_OOM_ADJUST,"oom_adj", S_IFREG|S_IRUGO|S_IWUSR), #ifdef CONFIG_AUDITSYSCALL E(PROC_TGID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO), #endif {0,0,NULL,0} }; static struct pid_entry tid_base_stuff[] = { E(PROC_TID_FD, "fd", S_IFDIR|S_IRUSR|S_IXUSR), E(PROC_TID_ENVIRON, "environ", S_IFREG|S_IRUSR), E(PROC_TID_AUXV, "auxv", S_IFREG|S_IRUSR), E(PROC_TID_STATUS, "status", S_IFREG|S_IRUGO), E(PROC_TID_CMDLINE, "cmdline", S_IFREG|S_IRUGO), E(PROC_TID_STAT, "stat", S_IFREG|S_IRUGO), E(PROC_TID_STATM, "statm", S_IFREG|S_IRUGO), E(PROC_TID_MAPS, "maps", S_IFREG|S_IRUGO), E(PROC_TID_MEM, "mem", S_IFREG|S_IRUSR|S_IWUSR), E(PROC_TID_CWD, "cwd", S_IFLNK|S_IRWXUGO), E(PROC_TID_ROOT, "root", S_IFLNK|S_IRWXUGO), E(PROC_TID_EXE, "exe", S_IFLNK|S_IRWXUGO), E(PROC_TID_MOUNTS, "mounts", S_IFREG|S_IRUGO), #ifdef CONFIG_SECURITY E(PROC_TID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO), #endif #ifdef CONFIG_KALLSYMS E(PROC_TID_WCHAN, "wchan", S_IFREG|S_IRUGO), #endif #ifdef CONFIG_SCHEDSTATS E(PROC_TID_SCHEDSTAT, "schedstat",S_IFREG|S_IRUGO), #endif E(PROC_TID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO), E(PROC_TID_OOM_ADJUST, "oom_adj", S_IFREG|S_IRUGO|S_IWUSR), #ifdef CONFIG_AUDITSYSCALL E(PROC_TID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO), #endif {0,0,NULL,0} }; #ifdef CONFIG_SECURITY static struct pid_entry tgid_attr_stuff[] = { E(PROC_TGID_ATTR_CURRENT, "current", S_IFREG|S_IRUGO|S_IWUGO), E(PROC_TGID_ATTR_PREV, "prev", S_IFREG|S_IRUGO), E(PROC_TGID_ATTR_EXEC, "exec", S_IFREG|S_IRUGO|S_IWUGO), E(PROC_TGID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUGO), {0,0,NULL,0} }; static struct pid_entry tid_attr_stuff[] = { E(PROC_TID_ATTR_CURRENT, "current", S_IFREG|S_IRUGO|S_IWUGO), E(PROC_TID_ATTR_PREV, "prev", S_IFREG|S_IRUGO), E(PROC_TID_ATTR_EXEC, "exec", S_IFREG|S_IRUGO|S_IWUGO), E(PROC_TID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUGO), {0,0,NULL,0} }; #endif #undef E static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt) { struct task_struct *task = proc_task(inode); struct files_struct *files; struct file *file; int fd = proc_type(inode) - PROC_TID_FD_DIR; files = get_files_struct(task); if (files) { spin_lock(&files->file_lock); file = fcheck_files(files, fd); if (file) { *mnt = mntget(file->f_vfsmnt); *dentry = dget(file->f_dentry); spin_unlock(&files->file_lock); put_files_struct(files); return 0; } spin_unlock(&files->file_lock); put_files_struct(files); } return -ENOENT; } static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt) { struct fs_struct *fs; int result = -ENOENT; task_lock(proc_task(inode)); fs = proc_task(inode)->fs; if(fs) atomic_inc(&fs->count); task_unlock(proc_task(inode)); if (fs) { read_lock(&fs->lock); *mnt = mntget(fs->pwdmnt); *dentry = dget(fs->pwd); read_unlock(&fs->lock); result = 0; put_fs_struct(fs); } return result; } static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt) { struct fs_struct *fs; int result = -ENOENT; task_lock(proc_task(inode)); fs = proc_task(inode)->fs; if(fs) atomic_inc(&fs->count); task_unlock(proc_task(inode)); if (fs) { read_lock(&fs->lock); *mnt = mntget(fs->rootmnt); *dentry = dget(fs->root); read_unlock(&fs->lock); result = 0; put_fs_struct(fs); } return result; } #define MAY_PTRACE(task) \ (task == current || \ (task->parent == current && \ (task->ptrace & PT_PTRACED) && \ (task->state == TASK_STOPPED || task->state == TASK_TRACED) && \ security_ptrace(current,task) == 0)) static int may_ptrace_attach(struct task_struct *task) { int retval = 0; task_lock(task); if (!task->mm) goto out; if (((current->uid != task->euid) || (current->uid != task->suid) || (current->uid != task->uid) || (current->gid != task->egid) || (current->gid != task->sgid) || (current->gid != task->gid)) && !capable(CAP_SYS_PTRACE)) goto out; rmb(); if (!task->mm->dumpable && !capable(CAP_SYS_PTRACE)) goto out; if (security_ptrace(current, task)) goto out; retval = 1; out: task_unlock(task); return retval; } static int proc_pid_environ(struct task_struct *task, char * buffer) { int res = 0; struct mm_struct *mm = get_task_mm(task); if (mm) { unsigned int len = mm->env_end - mm->env_start; if (len > PAGE_SIZE) len = PAGE_SIZE; res = access_process_vm(task, mm->env_start, buffer, len, 0); if (!may_ptrace_attach(task)) res = -ESRCH; mmput(mm); } return res; } static int proc_pid_cmdline(struct task_struct *task, char * buffer) { int res = 0; unsigned int len; struct mm_struct *mm = get_task_mm(task); if (!mm) goto out; 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) { char *modname; const char *sym_name; unsigned long wchan, size, offset; char namebuf[KSYM_NAME_LEN+1]; wchan = get_wchan(task); sym_name = kallsyms_lookup(wchan, &size, &offset, &modname, namebuf); if (sym_name) return sprintf(buffer, "%s", sym_name); return sprintf(buffer, "%lu", wchan); } #endif /* CONFIG_KALLSYMS */ #ifdef CONFIG_SCHEDSTATS /* * Provides /proc/PID/schedstat */ static int proc_pid_schedstat(struct task_struct *task, char *buffer) { return sprintf(buffer, "%lu %lu %lu\n", task->sched_info.cpu_time, task->sched_info.run_delay, task->sched_info.pcnt); } #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); points = badness(task, uptime.tv_sec); return sprintf(buffer, "%lu\n", points); } /************************************************************************/ /* Here the fs part begins */ /************************************************************************/ /* permission checks */ static int proc_check_root(struct inode *inode) { struct dentry *de, *base, *root; struct vfsmount *our_vfsmnt, *vfsmnt, *mnt; int res = 0; if (proc_root_link(inode, &root, &vfsmnt)) /* Ewww... */ return -ENOENT; read_lock(¤t->fs->lock); our_vfsmnt = mntget(current->fs->rootmnt); base = dget(current->fs->root); read_unlock(¤t->fs->lock); spin_lock(&vfsmount_lock); de = root; mnt = vfsmnt; while (vfsmnt != our_vfsmnt) { if (vfsmnt == vfsmnt->mnt_parent) goto out; de = vfsmnt->mnt_mountpoint; vfsmnt = vfsmnt->mnt_parent; } if (!is_subdir(de, base)) goto out; spin_unlock(&vfsmount_lock); exit: dput(base); mntput(our_vfsmnt); dput(root); mntput(mnt); return res; out: spin_unlock(&vfsmount_lock); res = -EACCES; goto exit; } static int proc_permission(struct inode *inode, int mask, struct nameidata *nd) { if (generic_permission(inode, mask, NULL) != 0) return -EACCES; return proc_check_root(inode); } extern struct seq_operations proc_pid_maps_op; static int maps_open(struct inode *inode, struct file *file) { struct task_struct *task = proc_task(inode); int ret = seq_open(file, &proc_pid_maps_op); if (!ret) { struct seq_file *m = file->private_data; m->private = task; } return ret; } static struct file_operations proc_maps_operations = { .open = maps_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; extern struct seq_operations mounts_op; static int mounts_open(struct inode *inode, struct file *file) { struct task_struct *task = proc_task(inode); int ret = seq_open(file, &mounts_op); if (!ret) { struct seq_file *m = file->private_data; struct namespace *namespace; task_lock(task); namespace = task->namespace; if (namespace) get_namespace(namespace); task_unlock(task); if (namespace) m->private = namespace; else { seq_release(inode, file); ret = -EINVAL; } } return ret; } static int mounts_release(struct inode *inode, struct file *file) { struct seq_file *m = file->private_data; struct namespace *namespace = m->private; put_namespace(namespace); return seq_release(inode, file); } static struct file_operations proc_mounts_operations = { .open = mounts_open, .read = seq_read, .llseek = seq_lseek, .release = mounts_release, }; #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */ static ssize_t proc_info_read(struct file * file, char __user * buf, size_t count, loff_t *ppos) { struct inode * inode = file->f_dentry->d_inode; unsigned long page; ssize_t length; struct task_struct *task = proc_task(inode); if (count > PROC_BLOCK_SIZE) count = PROC_BLOCK_SIZE; if (!(page = __get_free_page(GFP_KERNEL))) return -ENOMEM; length = PROC_I(inode)->op.proc_read(task, (char*)page); if (length >= 0) length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); free_page(page); return length; } static struct file_operations proc_info_file_operations = { .read = proc_info_read, }; static int mem_open(struct inode* inode, struct file* file) { file->private_data = (void*)((long)current->self_exec_id); return 0; } static ssize_t mem_read(struct file * file, char __user * buf, size_t count, loff_t *ppos) { struct task_struct *task = proc_task(file->f_dentry->d_inode); char *page; unsigned long src = *ppos; int ret = -ESRCH; struct mm_struct *mm; if (!MAY_PTRACE(task) || !may_ptrace_attach(task)) goto out; ret = -ENOMEM; page = (char *)__get_free_page(GFP_USER); if (!page) goto out; ret = 0; mm = get_task_mm(task); if (!mm) goto out_free; ret = -EIO; if (file->private_data != (void*)((long)current->self_exec_id)) goto out_put; ret = 0; while (count > 0) { int this_len, retval; this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; retval = access_process_vm(task, src, page, this_len, 0); if (!retval || !MAY_PTRACE(task) || !may_ptrace_attach(task)) { if (!ret) ret = -EIO; break; } if (copy_to_user(buf, page, retval)) { ret = -EFAULT; break; } ret += retval; src += retval; buf += retval; count -= retval; } *ppos = src; out_put: mmput(mm); out_free: free_page((unsigned long) page); out: return ret; } #define mem_write NULL #ifndef mem_write /* This is a security hazard */ static ssize_t mem_write(struct file * file, const char * buf, size_t count, loff_t *ppos) { int copied = 0; char *page; struct task_struct *task = proc_task(file->f_dentry->d_inode); unsigned long dst = *ppos; if (!MAY_PTRACE(task) || !may_ptrace_attach(task)) return -ESRCH; page = (char *)__get_free_page(GFP_USER); if (!page) return -ENOMEM; while (count > 0) { int this_len, retval; this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; if (copy_from_user(page, buf, this_len)) { copied = -EFAULT; break; } retval = access_process_vm(task, dst, page, this_len, 1); if (!retval) { if (!copied) copied = -EIO; break; } copied += retval; buf += retval; dst += retval; count -= retval; } *ppos = dst; free_page((unsigned long) page); return copied; } #endif static loff_t mem_lseek(struct file * file, loff_t offset, int orig) { switch (orig) { case 0: file->f_pos = offset; break; case 1: file->f_pos += offset; break; default: return -EINVAL; } force_successful_syscall_return(); return file->f_pos; } static struct file_operations proc_mem_operations = { .llseek = mem_lseek, .read = mem_read, .write = mem_write, .open = mem_open, }; static ssize_t oom_adjust_read(struct file *file, char *buf, size_t count, loff_t *ppos) { struct task_struct *task = proc_task(file->f_dentry->d_inode); char buffer[8]; size_t len; int oom_adjust = task->oomkilladj; loff_t __ppos = *ppos; len = sprintf(buffer, "%i\n", oom_adjust); if (__ppos >= len) return 0; if (count > len-__ppos) count = len-__ppos; if (copy_to_user(buf, buffer + __ppos, count)) return -EFAULT; *ppos = __ppos + count; return count; } static ssize_t oom_adjust_write(struct file *file, const char *buf, size_t count, loff_t *ppos) { struct task_struct *task = proc_task(file->f_dentry->d_inode); char buffer[8], *end; int oom_adjust; if (!capable(CAP_SYS_RESOURCE)) return -EPERM; memset(buffer, 0, 8); if (count > 6) count = 6; if (copy_from_user(buffer, buf, count)) return -EFAULT; oom_adjust = simple_strtol(buffer, &end, 0); if (oom_adjust < -16 || oom_adjust > 15) return -EINVAL; if (*end == '\n') end++; task->oomkilladj = oom_adjust; if (end - buffer == 0) return -EIO; return end - buffer; } static struct file_operations proc_oom_adjust_operations = { read: oom_adjust_read, write: oom_adjust_write, }; static struct inode_operations proc_mem_inode_operations = { .permission = proc_permission, }; #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_dentry->d_inode; struct task_struct *task = proc_task(inode); ssize_t length; char tmpbuf[TMPBUFLEN]; length = scnprintf(tmpbuf, TMPBUFLEN, "%u", audit_get_loginuid(task->audit_context)); 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_dentry->d_inode; char *page, *tmp; ssize_t length; struct task_struct *task = proc_task(inode); uid_t loginuid; if (!capable(CAP_AUDIT_CONTROL)) return -EPERM; if (current != task) return -EPERM; if (count > PAGE_SIZE) count = PAGE_SIZE; if (*ppos != 0) { /* No partial writes. */ return -EINVAL; } page = (char*)__get_free_page(GFP_USER); if (!page) return -ENOMEM; length = -EFAULT; if (copy_from_user(page, buf, count)) goto out_free_page; loginuid = simple_strtoul(page, &tmp, 10); if (tmp == page) { length = -EINVAL; goto out_free_page; } length = audit_set_loginuid(task->audit_context, loginuid); if (likely(length == 0)) length = count; out_free_page: free_page((unsigned long) page); return length; } static struct file_operations proc_loginuid_operations = { .read = proc_loginuid_read, .write = proc_loginuid_write, }; #endif static int proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) { struct inode *inode = dentry->d_inode; int error = -EACCES; /* We don't need a base pointer in the /proc filesystem */ path_release(nd); if (current->fsuid != inode->i_uid && !capable(CAP_DAC_OVERRIDE)) goto out; error = proc_check_root(inode); if (error) goto out; error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt); nd->last_type = LAST_BIND; out: return error; } static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt, char __user *buffer, int buflen) { struct inode * inode; char *tmp = (char*)__get_free_page(GFP_KERNEL), *path; int len; if (!tmp) return -ENOMEM; inode = dentry->d_inode; path = d_path(dentry, mnt, tmp, PAGE_SIZE); len = PTR_ERR(path); if (IS_ERR(path)) goto out; len = tmp + PAGE_SIZE - 1 - path; if (len > buflen) len = buflen; if (copy_to_user(buffer, path, len)) len = -EFAULT; out: free_page((unsigned long)tmp); return len; } static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) { int error = -EACCES; struct inode *inode = dentry->d_inode; struct dentry *de; struct vfsmount *mnt = NULL; lock_kernel(); if (current->fsuid != inode->i_uid && !capable(CAP_DAC_OVERRIDE)) goto out; error = proc_check_root(inode); if (error) goto out; error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt); if (error) goto out; error = do_proc_readlink(de, mnt, buffer, buflen); dput(de); mntput(mnt); out: unlock_kernel(); return error; } static struct inode_operations proc_pid_link_inode_operations = { .readlink = proc_pid_readlink, .follow_link = proc_pid_follow_link }; #define NUMBUF 10 static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir) { struct inode *inode = filp->f_dentry->d_inode; struct task_struct *p = proc_task(inode); unsigned int fd, tid, ino; int retval; char buf[NUMBUF]; struct files_struct * files; retval = -ENOENT; if (!pid_alive(p)) goto out; retval = 0; tid = p->pid; fd = filp->f_pos; switch (fd) { case 0: if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) goto out; filp->f_pos++; case 1: ino = fake_ino(tid, PROC_TID_INO); if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) goto out; filp->f_pos++; default: files = get_files_struct(p); if (!files) goto out; spin_lock(&files->file_lock); for (fd = filp->f_pos-2; fd < files->max_fds; fd++, filp->f_pos++) { unsigned int i,j; if (!fcheck_files(files, fd)) continue; spin_unlock(&files->file_lock); j = NUMBUF; i = fd; do { j--; buf[j] = '0' + (i % 10); i /= 10; } while (i); ino = fake_ino(tid, PROC_TID_FD_DIR + fd); if (filldir(dirent, buf+j, NUMBUF-j, fd+2, ino, DT_LNK) < 0) { spin_lock(&files->file_lock); break; } spin_lock(&files->file_lock); } spin_unlock(&files->file_lock); put_files_struct(files); } out: return retval; } static int proc_pident_readdir(struct file *filp, void *dirent, filldir_t filldir, struct pid_entry *ents, unsigned int nents) { int i; int pid; struct dentry *dentry = filp->f_dentry; struct inode *inode = dentry->d_inode; struct pid_entry *p; ino_t ino; int ret; ret = -ENOENT; if (!pid_alive(proc_task(inode))) goto out; ret = 0; pid = proc_task(inode)->pid; i = filp->f_pos; switch (i) { case 0: ino = inode->i_ino; if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) goto out; i++; filp->f_pos++; /* fall through */ case 1: ino = parent_ino(dentry); if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) goto out; i++; filp->f_pos++; /* fall through */ default: i -= 2; if (i >= nents) { ret = 1; goto out; } p = ents + i; while (p->name) { if (filldir(dirent, p->name, p->len, filp->f_pos, fake_ino(pid, p->type), p->mode >> 12) < 0) goto out; filp->f_pos++; p++; } } ret = 1; out: return ret; } static int proc_tgid_base_readdir(struct file * filp, void * dirent, filldir_t filldir) { return proc_pident_readdir(filp,dirent,filldir, tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); } static int proc_tid_base_readdir(struct file * filp, void * dirent, filldir_t filldir) { return proc_pident_readdir(filp,dirent,filldir, tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); } /* building an inode */ static int task_dumpable(struct task_struct *task) { int dumpable = 0; struct mm_struct *mm; task_lock(task); mm = task->mm; if (mm) dumpable = mm->dumpable; task_unlock(task); return dumpable; } static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task, int ino) { struct inode * inode; struct proc_inode *ei; /* We need a new inode */ inode = new_inode(sb); if (!inode) goto out; /* Common stuff */ ei = PROC_I(inode); ei->task = NULL; inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; inode->i_ino = fake_ino(task->pid, ino); if (!pid_alive(task)) goto out_unlock; /* * grab the reference to task. */ get_task_struct(task); ei->task = task; ei->type = ino; inode->i_uid = 0; inode->i_gid = 0; if (ino == PROC_TGID_INO || ino == PROC_TID_INO || task_dumpable(task)) { inode->i_uid = task->euid; inode->i_gid = task->egid; } security_task_to_inode(task, inode); out: return inode; out_unlock: ei->pde = NULL; iput(inode); return NULL; } /* dentry stuff */ /* * Exceptional case: normally we are not allowed to unhash a busy * directory. In this case, however, we can do it - no aliasing problems * due to the way we treat inodes. * * Rewrite the inode's ownerships here because the owning task may have * performed a setuid(), etc. */ static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) { struct inode *inode = dentry->d_inode; struct task_struct *task = proc_task(inode); if (pid_alive(task)) { if (proc_type(inode) == PROC_TGID_INO || proc_type(inode) == PROC_TID_INO || task_dumpable(task)) { inode->i_uid = task->euid; inode->i_gid = task->egid; } else { inode->i_uid = 0; inode->i_gid = 0; } security_task_to_inode(task, inode); return 1; } d_drop(dentry); return 0; } static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) { struct inode *inode = dentry->d_inode; struct task_struct *task = proc_task(inode); int fd = proc_type(inode) - PROC_TID_FD_DIR; struct files_struct *files; files = get_files_struct(task); if (files) { spin_lock(&files->file_lock); if (fcheck_files(files, fd)) { spin_unlock(&files->file_lock); put_files_struct(files); if (task_dumpable(task)) { inode->i_uid = task->euid; inode->i_gid = task->egid; } else { inode->i_uid = 0; inode->i_gid = 0; } security_task_to_inode(task, inode); return 1; } spin_unlock(&files->file_lock); put_files_struct(files); } d_drop(dentry); return 0; } static void pid_base_iput(struct dentry *dentry, struct inode *inode) { struct task_struct *task = proc_task(inode); spin_lock(&task->proc_lock); if (task->proc_dentry == dentry) task->proc_dentry = NULL; spin_unlock(&task->proc_lock); iput(inode); } static int pid_delete_dentry(struct dentry * dentry) { /* Is the task we represent dead? * If so, then don't put the dentry on the lru list, * kill it immediately. */ return !pid_alive(proc_task(dentry->d_inode)); } static struct dentry_operations tid_fd_dentry_operations = { .d_revalidate = tid_fd_revalidate, .d_delete = pid_delete_dentry, }; static struct dentry_operations pid_dentry_operations = { .d_revalidate = pid_revalidate, .d_delete = pid_delete_dentry, }; static struct dentry_operations pid_base_dentry_operations = { .d_revalidate = pid_revalidate, .d_iput = pid_base_iput, .d_delete = pid_delete_dentry, }; /* Lookups */ static unsigned name_to_int(struct dentry *dentry) { const char *name = dentry->d_name.name; int len = dentry->d_name.len; unsigned n = 0; if (len > 1 && *name == '0') goto out; while (len-- > 0) { unsigned c = *name++ - '0'; if (c > 9) goto out; if (n >= (~0U-9)/10) goto out; n *= 10; n += c; } return n; out: return ~0U; } /* SMP-safe */ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry, struct nameidata *nd) { struct task_struct *task = proc_task(dir); unsigned fd = name_to_int(dentry); struct file * file; struct files_struct * files; struct inode *inode; struct proc_inode *ei; if (fd == ~0U) goto out; if (!pid_alive(task)) goto out; inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_FD_DIR+fd); if (!inode) goto out; ei = PROC_I(inode); files = get_files_struct(task); if (!files) goto out_unlock; inode->i_mode = S_IFLNK; spin_lock(&files->file_lock); file = fcheck_files(files, fd); if (!file) goto out_unlock2; if (file->f_mode & 1) inode->i_mode |= S_IRUSR | S_IXUSR; if (file->f_mode & 2) inode->i_mode |= S_IWUSR | S_IXUSR; spin_unlock(&files->file_lock); put_files_struct(files); inode->i_op = &proc_pid_link_inode_operations; inode->i_size = 64; ei->op.proc_get_link = proc_fd_link; dentry->d_op = &tid_fd_dentry_operations; d_add(dentry, inode); return NULL; out_unlock2: spin_unlock(&files->file_lock); put_files_struct(files); out_unlock: iput(inode); out: return ERR_PTR(-ENOENT); } static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir); static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd); static struct file_operations proc_fd_operations = { .read = generic_read_dir, .readdir = proc_readfd, }; static struct file_operations proc_task_operations = { .read = generic_read_dir, .readdir = proc_task_readdir, }; /* * proc directories can do almost nothing.. */ static struct inode_operations proc_fd_inode_operations = { .lookup = proc_lookupfd, .permission = proc_permission, }; static struct inode_operations proc_task_inode_operations = { .lookup = proc_task_lookup, .permission = proc_permission, }; #ifdef CONFIG_SECURITY static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, size_t count, loff_t *ppos) { struct inode * inode = file->f_dentry->d_inode; unsigned long page; ssize_t length; struct task_struct *task = proc_task(inode); if (count > PAGE_SIZE) count = PAGE_SIZE; if (!(page = __get_free_page(GFP_KERNEL))) return -ENOMEM; length = security_getprocattr(task, (char*)file->f_dentry->d_name.name, (void*)page, count); if (length >= 0) length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); free_page(page); 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_dentry->d_inode; char *page; ssize_t length; struct task_struct *task = proc_task(inode); if (count > PAGE_SIZE) count = PAGE_SIZE; if (*ppos != 0) { /* No partial writes. */ return -EINVAL; } page = (char*)__get_free_page(GFP_USER); if (!page) return -ENOMEM; length = -EFAULT; if (copy_from_user(page, buf, count)) goto out; length = security_setprocattr(task, (char*)file->f_dentry->d_name.name, (void*)page, count); out: free_page((unsigned long) page); return length; } static struct file_operations proc_pid_attr_operations = { .read = proc_pid_attr_read, .write = proc_pid_attr_write, }; static struct file_operations proc_tid_attr_operations; static struct inode_operations proc_tid_attr_inode_operations; static struct file_operations proc_tgid_attr_operations; static struct inode_operations proc_tgid_attr_inode_operations; #endif /* SMP-safe */ static struct dentry *proc_pident_lookup(struct inode *dir, struct dentry *dentry, struct pid_entry *ents) { struct inode *inode; int error; struct task_struct *task = proc_task(dir); struct pid_entry *p; struct proc_inode *ei; error = -ENOENT; inode = NULL; if (!pid_alive(task)) goto out; for (p = ents; p->name; p++) { if (p->len != dentry->d_name.len) continue; if (!memcmp(dentry->d_name.name, p->name, p->len)) break; } if (!p->name) goto out; error = -EINVAL; inode = proc_pid_make_inode(dir->i_sb, task, p->type); if (!inode) goto out; ei = PROC_I(inode); inode->i_mode = p->mode; /* * Yes, it does not scale. And it should not. Don't add * new entries into /proc/<tgid>/ without very good reasons. */ switch(p->type) { case PROC_TGID_TASK: inode->i_nlink = 3; inode->i_op = &proc_task_inode_operations; inode->i_fop = &proc_task_operations; break; case PROC_TID_FD: case PROC_TGID_FD: inode->i_nlink = 2; inode->i_op = &proc_fd_inode_operations; inode->i_fop = &proc_fd_operations; break; case PROC_TID_EXE: case PROC_TGID_EXE: inode->i_op = &proc_pid_link_inode_operations; ei->op.proc_get_link = proc_exe_link; break; case PROC_TID_CWD: case PROC_TGID_CWD: inode->i_op = &proc_pid_link_inode_operations; ei->op.proc_get_link = proc_cwd_link; break; case PROC_TID_ROOT: case PROC_TGID_ROOT: inode->i_op = &proc_pid_link_inode_operations; ei->op.proc_get_link = proc_root_link; break; case PROC_TID_ENVIRON: case PROC_TGID_ENVIRON: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_pid_environ; break; case PROC_TID_AUXV: case PROC_TGID_AUXV: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_pid_auxv; break; case PROC_TID_STATUS: case PROC_TGID_STATUS: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_pid_status; break; case PROC_TID_STAT: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_tid_stat; break; case PROC_TGID_STAT: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_tgid_stat; break; case PROC_TID_CMDLINE: case PROC_TGID_CMDLINE: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_pid_cmdline; break; case PROC_TID_STATM: case PROC_TGID_STATM: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_pid_statm; break; case PROC_TID_MAPS: case PROC_TGID_MAPS: inode->i_fop = &proc_maps_operations; break; case PROC_TID_MEM: case PROC_TGID_MEM: inode->i_op = &proc_mem_inode_operations; inode->i_fop = &proc_mem_operations; break; case PROC_TID_MOUNTS: case PROC_TGID_MOUNTS: inode->i_fop = &proc_mounts_operations; break; #ifdef CONFIG_SECURITY case PROC_TID_ATTR: inode->i_nlink = 2; inode->i_op = &proc_tid_attr_inode_operations; inode->i_fop = &proc_tid_attr_operations; break; case PROC_TGID_ATTR: inode->i_nlink = 2; inode->i_op = &proc_tgid_attr_inode_operations; inode->i_fop = &proc_tgid_attr_operations; break; case PROC_TID_ATTR_CURRENT: case PROC_TGID_ATTR_CURRENT: case PROC_TID_ATTR_PREV: case PROC_TGID_ATTR_PREV: case PROC_TID_ATTR_EXEC: case PROC_TGID_ATTR_EXEC: case PROC_TID_ATTR_FSCREATE: case PROC_TGID_ATTR_FSCREATE: inode->i_fop = &proc_pid_attr_operations; break; #endif #ifdef CONFIG_KALLSYMS case PROC_TID_WCHAN: case PROC_TGID_WCHAN: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_pid_wchan; break; #endif #ifdef CONFIG_SCHEDSTATS case PROC_TID_SCHEDSTAT: case PROC_TGID_SCHEDSTAT: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_pid_schedstat; break; #endif case PROC_TID_OOM_SCORE: case PROC_TGID_OOM_SCORE: inode->i_fop = &proc_info_file_operations; ei->op.proc_read = proc_oom_score; break; case PROC_TID_OOM_ADJUST: case PROC_TGID_OOM_ADJUST: inode->i_fop = &proc_oom_adjust_operations; break; #ifdef CONFIG_AUDITSYSCALL case PROC_TID_LOGINUID: case PROC_TGID_LOGINUID: inode->i_fop = &proc_loginuid_operations; break; #endif default: printk("procfs: impossible type (%d)",p->type); iput(inode); return ERR_PTR(-EINVAL); } dentry->d_op = &pid_dentry_operations; d_add(dentry, inode); return NULL; out: return ERR_PTR(error); } static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ return proc_pident_lookup(dir, dentry, tgid_base_stuff); } static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ return proc_pident_lookup(dir, dentry, tid_base_stuff); } static struct file_operations proc_tgid_base_operations = { .read = generic_read_dir, .readdir = proc_tgid_base_readdir, }; static struct file_operations proc_tid_base_operations = { .read = generic_read_dir, .readdir = proc_tid_base_readdir, }; static struct inode_operations proc_tgid_base_inode_operations = { .lookup = proc_tgid_base_lookup, }; static struct inode_operations proc_tid_base_inode_operations = { .lookup = proc_tid_base_lookup, }; #ifdef CONFIG_SECURITY static int proc_tgid_attr_readdir(struct file * filp, void * dirent, filldir_t filldir) { return proc_pident_readdir(filp,dirent,filldir, tgid_attr_stuff,ARRAY_SIZE(tgid_attr_stuff)); } static int proc_tid_attr_readdir(struct file * filp, void * dirent, filldir_t filldir) { return proc_pident_readdir(filp,dirent,filldir, tid_attr_stuff,ARRAY_SIZE(tid_attr_stuff)); } static struct file_operations proc_tgid_attr_operations = { .read = generic_read_dir, .readdir = proc_tgid_attr_readdir, }; static struct file_operations proc_tid_attr_operations = { .read = generic_read_dir, .readdir = proc_tid_attr_readdir, }; static struct dentry *proc_tgid_attr_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { return proc_pident_lookup(dir, dentry, tgid_attr_stuff); } static struct dentry *proc_tid_attr_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { return proc_pident_lookup(dir, dentry, tid_attr_stuff); } static struct inode_operations proc_tgid_attr_inode_operations = { .lookup = proc_tgid_attr_lookup, }; static struct inode_operations proc_tid_attr_inode_operations = { .lookup = proc_tid_attr_lookup, }; #endif /* * /proc/self: */ static int proc_self_readlink(struct dentry *dentry, char __user *buffer, int buflen) { char tmp[30]; sprintf(tmp, "%d", current->tgid); return vfs_readlink(dentry,buffer,buflen,tmp); } static int proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) { char tmp[30]; sprintf(tmp, "%d", current->tgid); return vfs_follow_link(nd,tmp); } static struct inode_operations proc_self_inode_operations = { .readlink = proc_self_readlink, .follow_link = proc_self_follow_link, }; /** * proc_pid_unhash - Unhash /proc/<pid> entry from the dcache. * @p: task that should be flushed. * * Drops the /proc/<pid> dcache entry from the hash chains. * * Dropping /proc/<pid> entries and detach_pid must be synchroneous, * otherwise e.g. /proc/<pid>/exe might point to the wrong executable, * if the pid value is immediately reused. This is enforced by * - caller must acquire spin_lock(p->proc_lock) * - must be called before detach_pid() * - proc_pid_lookup acquires proc_lock, and checks that * the target is not dead by looking at the attach count * of PIDTYPE_PID. */ struct dentry *proc_pid_unhash(struct task_struct *p) { struct dentry *proc_dentry; proc_dentry = p->proc_dentry; if (proc_dentry != NULL) { spin_lock(&dcache_lock); if (!d_unhashed(proc_dentry)) { dget_locked(proc_dentry); __d_drop(proc_dentry); } else proc_dentry = NULL; spin_unlock(&dcache_lock); } return proc_dentry; } /** * proc_pid_flush - recover memory used by stale /proc/<pid>/x entries * @proc_entry: directoy to prune. * * Shrink the /proc directory that was used by the just killed thread. */ void proc_pid_flush(struct dentry *proc_dentry) { might_sleep(); if(proc_dentry != NULL) { shrink_dcache_parent(proc_dentry); dput(proc_dentry); } } /* SMP-safe */ struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) { struct task_struct *task; struct inode *inode; struct proc_inode *ei; unsigned tgid; int died; if (dentry->d_name.len == 4 && !memcmp(dentry->d_name.name,"self",4)) { inode = new_inode(dir->i_sb); if (!inode) return ERR_PTR(-ENOMEM); ei = PROC_I(inode); inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; inode->i_ino = fake_ino(0, PROC_TGID_INO); ei->pde = NULL; inode->i_mode = S_IFLNK|S_IRWXUGO; inode->i_uid = inode->i_gid = 0; inode->i_size = 64; inode->i_op = &proc_self_inode_operations; d_add(dentry, inode); return NULL; } tgid = name_to_int(dentry); if (tgid == ~0U) goto out; read_lock(&tasklist_lock); task = find_task_by_pid(tgid); if (task) get_task_struct(task); read_unlock(&tasklist_lock); if (!task) goto out; inode = proc_pid_make_inode(dir->i_sb, task, PROC_TGID_INO); if (!inode) { put_task_struct(task); goto out; } inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; inode->i_op = &proc_tgid_base_inode_operations; inode->i_fop = &proc_tgid_base_operations; inode->i_flags|=S_IMMUTABLE; #ifdef CONFIG_SECURITY inode->i_nlink = 5; #else inode->i_nlink = 4; #endif dentry->d_op = &pid_base_dentry_operations; died = 0; d_add(dentry, inode); spin_lock(&task->proc_lock); task->proc_dentry = dentry; if (!pid_alive(task)) { dentry = proc_pid_unhash(task); died = 1; } spin_unlock(&task->proc_lock); put_task_struct(task); if (died) { proc_pid_flush(dentry); goto out; } return NULL; out: return ERR_PTR(-ENOENT); } /* SMP-safe */ static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) { struct task_struct *task; struct task_struct *leader = proc_task(dir); struct inode *inode; unsigned tid; tid = name_to_int(dentry); if (tid == ~0U) goto out; read_lock(&tasklist_lock); task = find_task_by_pid(tid); if (task) get_task_struct(task); read_unlock(&tasklist_lock); if (!task) goto out; if (leader->tgid != task->tgid) goto out_drop_task; inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_INO); if (!inode) goto out_drop_task; inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; inode->i_op = &proc_tid_base_inode_operations; inode->i_fop = &proc_tid_base_operations; inode->i_flags|=S_IMMUTABLE; #ifdef CONFIG_SECURITY inode->i_nlink = 4; #else inode->i_nlink = 3; #endif dentry->d_op = &pid_base_dentry_operations; d_add(dentry, inode); put_task_struct(task); return NULL; out_drop_task: put_task_struct(task); out: return ERR_PTR(-ENOENT); } #define PROC_NUMBUF 10 #define PROC_MAXPIDS 20 /* * Get a few tgid's to return for filldir - we need to hold the * tasklist lock while doing this, and we must release it before * we actually do the filldir itself, so we use a temp buffer.. */ static int get_tgid_list(int index, unsigned long version, unsigned int *tgids) { struct task_struct *p; int nr_tgids = 0; index--; read_lock(&tasklist_lock); p = NULL; if (version) { p = find_task_by_pid(version); if (p && !thread_group_leader(p)) p = NULL; } if (p) index = 0; else p = next_task(&init_task); for ( ; p != &init_task; p = next_task(p)) { int tgid = p->pid; if (!pid_alive(p)) continue; if (--index >= 0) continue; tgids[nr_tgids] = tgid; nr_tgids++; if (nr_tgids >= PROC_MAXPIDS) break; } read_unlock(&tasklist_lock); return nr_tgids; } /* * Get a few tid's to return for filldir - we need to hold the * tasklist lock while doing this, and we must release it before * we actually do the filldir itself, so we use a temp buffer.. */ static int get_tid_list(int index, unsigned int *tids, struct inode *dir) { struct task_struct *leader_task = proc_task(dir); struct task_struct *task = leader_task; int nr_tids = 0; index -= 2; read_lock(&tasklist_lock); /* * The starting point task (leader_task) might be an already * unlinked task, which cannot be used to access the task-list * via next_thread(). */ if (pid_alive(task)) do { int tid = task->pid; if (--index >= 0) continue; tids[nr_tids] = tid; nr_tids++; if (nr_tids >= PROC_MAXPIDS) break; } while ((task = next_thread(task)) != leader_task); read_unlock(&tasklist_lock); return nr_tids; } /* for the /proc/ directory itself, after non-process stuff has been done */ int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) { unsigned int tgid_array[PROC_MAXPIDS]; char buf[PROC_NUMBUF]; unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; unsigned int nr_tgids, i; int next_tgid; if (!nr) { ino_t ino = fake_ino(0,PROC_TGID_INO); if (filldir(dirent, "self", 4, filp->f_pos, ino, DT_LNK) < 0) return 0; filp->f_pos++; nr++; } /* f_version caches the tgid value that the last readdir call couldn't * return. lseek aka telldir automagically resets f_version to 0. */ next_tgid = filp->f_version; filp->f_version = 0; for (;;) { nr_tgids = get_tgid_list(nr, next_tgid, tgid_array); if (!nr_tgids) { /* no more entries ! */ break; } next_tgid = 0; /* do not use the last found pid, reserve it for next_tgid */ if (nr_tgids == PROC_MAXPIDS) { nr_tgids--; next_tgid = tgid_array[nr_tgids]; } for (i=0;i<nr_tgids;i++) { int tgid = tgid_array[i]; ino_t ino = fake_ino(tgid,PROC_TGID_INO); unsigned long j = PROC_NUMBUF; do buf[--j] = '0' + (tgid % 10); while ((tgid /= 10) != 0); if (filldir(dirent, buf+j, PROC_NUMBUF-j, filp->f_pos, ino, DT_DIR) < 0) { /* returning this tgid failed, save it as the first * pid for the next readir call */ filp->f_version = tgid_array[i]; goto out; } filp->f_pos++; nr++; } } out: return 0; } /* for the /proc/TGID/task/ directories */ static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) { unsigned int tid_array[PROC_MAXPIDS]; char buf[PROC_NUMBUF]; unsigned int nr_tids, i; struct dentry *dentry = filp->f_dentry; struct inode *inode = dentry->d_inode; int retval = -ENOENT; ino_t ino; unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */ if (!pid_alive(proc_task(inode))) goto out; retval = 0; switch (pos) { case 0: ino = inode->i_ino; if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0) goto out; pos++; /* fall through */ case 1: ino = parent_ino(dentry); if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0) goto out; pos++; /* fall through */ } nr_tids = get_tid_list(pos, tid_array, inode); for (i = 0; i < nr_tids; i++) { unsigned long j = PROC_NUMBUF; int tid = tid_array[i]; ino = fake_ino(tid,PROC_TID_INO); do buf[--j] = '0' + (tid % 10); while ((tid /= 10) != 0); if (filldir(dirent, buf+j, PROC_NUMBUF-j, pos, ino, DT_DIR) < 0) break; pos++; } out: filp->f_pos = pos; return retval; }
Please just apply the patch using patch to make sure you did it correctly.
Found another error case, this one harder to fix! You'll need this patch too: http://www.reactivated.net/patches/linux-kernel/2.6.12/procfs-task-hardlinks.patch I've sent it to Andrew.
Andrew Morton accepted this one too. Any more remaining? :)
~ # reboot .... ~ # find / -name Search find: WARNING: Hard link count is wrong for /: this may be a bug in your filesystem driver. Automatically turning on find's -noleaf option. Earlier results may have failed to include directories that should have been searched. /usr/lib/perl5/5.8.6/Search /usr/share/doc/perl-5.8.6-r4/html/lib/Search ~ # find / -name Search /usr/lib/perl5/5.8.6/Search /usr/share/doc/perl-5.8.6-r4/html/lib/Search The first 'find' after reboot still reports an error, though I did apply both patches. The second, third, fourth etc. do not, so I' m quite desperate now. (please remove the copy of my base.c - it takes ages to load this page now.)
We can't remove comments. You are supposed to use the attachment feature to post big files. My patch only works on /proc, if there are other areas of your disk that have wrong counts then it sounds like filesystem problems. Please try with just "find /proc" to see if you get error messages. Don't add any -iname parameters, let it list everything, otherwise it's not obvious which directory it is stumbling on. Also, make sure you have applied both patches and "uname -v" returns the compilation date for your kernel that you would expect.
# ~ find /proc . // Sorry, I can' t copy the output above . . /proc/22967/oom_adj find: WARNING: Hard link count is wrong for .: this may be a bug in your filesystem driver. Automatically turning on find's -noleaf option. Earlier results may have failed to include directories that should have been searched. /proc/22968 /proc/22968/task /proc/22968/task/22968 /proc/22968/task/22968/fd /proc/22968/task/22968/fd/0 /proc/22968/task/22968/fd/1 /proc/22968/task/22968/fd/2 /proc/22968/task/22968/environ /proc/22968/task/22968/auxv /proc/22968/task/22968/status /proc/22968/task/22968/cmdline /proc/22968/task/22968/stat /proc/22968/task/22968/statm /proc/22968/task/22968/maps /proc/22968/task/22968/mem /proc/22968/task/22968/cwd /proc/22968/task/22968/root /proc/22968/task/22968/exe /proc/22968/task/22968/mounts /proc/22968/task/22968/wchan /proc/22968/task/22968/oom_score /proc/22968/task/22968/oom_adj /proc/22968/fd /proc/22968/fd/0 /proc/22968/fd/1 /proc/22968/fd/2 /proc/22968/environ /proc/22968/auxv /proc/22968/status /proc/22968/cmdline /proc/22968/stat /proc/22968/statm /proc/22968/maps /proc/22968/mem /proc/22968/cwd /proc/22968/root /proc/22968/exe /proc/22968/mounts /proc/22968/wchan /proc/22968/oom_score /proc/22968/oom_adj /proc/22969 /proc/22969/task /proc/22969/task/22969 /proc/22969/task/22969/fd /proc/22969/task/22969/fd/0 /proc/22969/task/22969/fd/1 /proc/22969/task/22969/fd/2 /proc/22969/task/22969/fd/3 /proc/22969/task/22969/fd/4 /proc/22969/task/22969/environ /proc/22969/task/22969/auxv /proc/22969/task/22969/status /proc/22969/task/22969/cmdline /proc/22969/task/22969/stat /proc/22969/task/22969/statm /proc/22969/task/22969/maps /proc/22969/task/22969/mem /proc/22969/task/22969/cwd /proc/22969/task/22969/root /proc/22969/task/22969/exe /proc/22969/task/22969/mounts /proc/22969/task/22969/wchan /proc/22969/task/22969/oom_score /proc/22969/task/22969/oom_adj /proc/22969/fd /proc/22969/fd/0 /proc/22969/fd/1 /proc/22969/fd/2 /proc/22969/fd/3 /proc/22969/fd/4 /proc/22969/environ /proc/22969/auxv /proc/22969/status /proc/22969/cmdline /proc/22969/stat /proc/22969/statm /proc/22969/maps /proc/22969/mem /proc/22969/cwd /proc/22969/root /proc/22969/exe /proc/22969/mounts /proc/22969/wchan /proc/22969/oom_score /proc/22969/oom_adj
Created attachment 55184 [details, diff] be-specific-about-hardlink-counts.patch Ok, lets try another approach. Let's make findutils be specific about whats wrong. Please apply this patch to findutils-4.2.20 and show me the new WARNING message.
/proc/6263/task/6263/fd/6 /proc/6263/task/6263/fd/7 /proc/6263/task/6263/fd/8 /proc/6263/task/6263/fd/9 /proc/6263/task/6263/fd/10 /proc/6263/task/6263/fd/11 /proc/6263/task/6263/fd/12 /proc/6263/task/6263/fd/13 /proc/6263/task/6263/fd/14 /proc/6263/task/6263/fd/15 /proc/6263/task/6263/fd/16 /proc/6263/task/6263/fd/17 /proc/6263/task/6263/fd/18 /proc/6263/task/6263/fd/19 /proc/6263/task/6263/fd/20 /proc/6263/task/6263/fd/21 /proc/6263/task/6263/fd/22 /proc/6263/task/6263/fd/23 /proc/6263/task/6263/fd/24 /proc/6263/task/6263/fd/25 /proc/6263/task/6263/fd/26 /proc/6263/task/6263/environ /proc/6263/task/6263/auxv /proc/6263/task/6263/status /proc/6263/task/6263/cmdline /proc/6263/task/6263/stat /proc/6263/task/6263/statm /proc/6263/task/6263/maps /proc/6263/task/6263/mem /proc/6263/task/6263/cwd /proc/6263/task/6263/root /proc/6263/task/6263/exe /proc/6263/task/6263/mounts /proc/6263/task/6263/wchan /proc/6263/task/6263/oom_score /proc/6263/task/6263/oom_adj /proc/6263/fd /proc/6263/fd/0 /proc/6263/fd/1 /proc/6263/fd/2 /proc/6263/fd/3 /proc/6263/fd/4 /proc/6263/fd/5 /proc/6263/fd/6 /proc/6263/fd/7 /proc/6263/fd/8 /proc/6263/fd/9 /proc/6263/fd/10 /proc/6263/fd/11 /proc/6263/fd/12 /proc/6263/fd/13 /proc/6263/fd/14 /proc/6263/fd/15 /proc/6263/fd/16 /proc/6263/fd/17 /proc/6263/fd/18 /proc/6263/fd/19 /proc/6263/fd/20 /proc/6263/fd/21 /proc/6263/fd/22 /proc/6263/fd/23 /proc/6263/fd/24 /proc/6263/fd/25 /proc/6263/fd/26 /proc/6263/environ /proc/6263/auxv /proc/6263/status /proc/6263/cmdline /proc/6263/stat /proc/6263/statm /proc/6263/maps /proc/6263/mem /proc/6263/cwd /proc/6263/root /proc/6263/exe /proc/6263/mounts /proc/6263/wchan /proc/6263/oom_score /proc/6263/oom_adj /proc/6264 /proc/6264/task /proc/6264/task/6264 /proc/6264/task/6264/fd /proc/6264/task/6264/fd/0 /proc/6264/task/6264/fd/1 /proc/6264/task/6264/fd/2 /proc/6264/task/6264/fd/3 /proc/6264/task/6264/fd/4 /proc/6264/task/6264/fd/5 /proc/6264/task/6264/fd/6 /proc/6264/task/6264/fd/7 /proc/6264/task/6264/fd/8 /proc/6264/task/6264/environ /proc/6264/task/6264/auxv /proc/6264/task/6264/status /proc/6264/task/6264/cmdline /proc/6264/task/6264/stat /proc/6264/task/6264/statm /proc/6264/task/6264/maps /proc/6264/task/6264/mem /proc/6264/task/6264/cwd /proc/6264/task/6264/root /proc/6264/task/6264/exe /proc/6264/task/6264/mounts /proc/6264/task/6264/wchan /proc/6264/task/6264/oom_score /proc/6264/task/6264/oom_adj /proc/6264/fd /proc/6264/fd/0 /proc/6264/fd/1 /proc/6264/fd/2 /proc/6264/fd/3 /proc/6264/fd/4 /proc/6264/fd/5 /proc/6264/fd/6 /proc/6264/fd/7 /proc/6264/fd/8 /proc/6264/environ /proc/6264/auxv /proc/6264/status /proc/6264/cmdline /proc/6264/stat /proc/6264/statm /proc/6264/maps /proc/6264/mem /proc/6264/cwd /proc/6264/root /proc/6264/exe /proc/6264/mounts /proc/6264/wchan /proc/6264/oom_score /proc/6264/oom_adj /proc/6270 /proc/6270/task /proc/6270/task/6270 /proc/6270/task/6270/fd /proc/6270/task/6270/fd/0 /proc/6270/task/6270/fd/1 /proc/6270/task/6270/fd/2 /proc/6270/task/6270/fd/255 /proc/6270/task/6270/environ /proc/6270/task/6270/auxv /proc/6270/task/6270/status /proc/6270/task/6270/cmdline /proc/6270/task/6270/stat /proc/6270/task/6270/statm /proc/6270/task/6270/maps /proc/6270/task/6270/mem /proc/6270/task/6270/cwd /proc/6270/task/6270/root /proc/6270/task/6270/exe /proc/6270/task/6270/mounts /proc/6270/task/6270/wchan /proc/6270/task/6270/oom_score /proc/6270/task/6270/oom_adj /proc/6270/fd /proc/6270/fd/0 /proc/6270/fd/1 /proc/6270/fd/2 /proc/6270/fd/255 /proc/6270/environ /proc/6270/auxv /proc/6270/status /proc/6270/cmdline /proc/6270/stat /proc/6270/statm /proc/6270/maps /proc/6270/mem /proc/6270/cwd /proc/6270/root /proc/6270/exe /proc/6270/mounts /proc/6270/wchan /proc/6270/oom_score /proc/6270/oom_adj find: WARNING: Hard link count (52) is wrong for /proc: this may be a bug in your filesystem driver. Automatically turning on find's -noleaf option. Earlier results may have failed to include directories that should have been searched. /proc/6273 /proc/6273/task /proc/6273/task/6273 /proc/6273/task/6273/fd /proc/6273/task/6273/fd/0 /proc/6273/task/6273/fd/1 /proc/6273/task/6273/fd/2 /proc/6273/task/6273/fd/3 /proc/6273/task/6273/fd/4 /proc/6273/task/6273/environ /proc/6273/task/6273/auxv /proc/6273/task/6273/status /proc/6273/task/6273/cmdline /proc/6273/task/6273/stat /proc/6273/task/6273/statm /proc/6273/task/6273/maps /proc/6273/task/6273/mem /proc/6273/task/6273/cwd /proc/6273/task/6273/root /proc/6273/task/6273/exe /proc/6273/task/6273/mounts /proc/6273/task/6273/wchan /proc/6273/task/6273/oom_score /proc/6273/task/6273/oom_adj /proc/6273/fd /proc/6273/fd/0 /proc/6273/fd/1 /proc/6273/fd/2 /proc/6273/fd/3 /proc/6273/fd/4 /proc/6273/environ /proc/6273/auxv /proc/6273/status /proc/6273/cmdline /proc/6273/stat /proc/6273/statm /proc/6273/maps /proc/6273/mem /proc/6273/cwd /proc/6273/root /proc/6273/exe /proc/6273/mounts /proc/6273/wchan /proc/6273/oom_score /proc/6273/oom_adj Patch applied.
~ # find /proc | grep WARNING find: WARNING: Hard link count (53) is wrong for /proc: this may be a bug in your filesystem driver. Automatically turning on find's -noleaf option. Earlier results may have failed to include directories that should have been searched.
No more ideas?
This one might be unsolvable due to the dynamic nature of /proc. Please *attach* the full output of "find /proc" where the error appears
Created attachment 56268 [details] Find Output Okay, here it is! I used the following commands to create this file: 1: find /proc > find.out 2: find /proc | grep 'Hard link'
That's not useful because the error placement is shown at the end as opposed to where abouts it actually calculated the incorrect count. find / proc > out 2>&1
Created attachment 57518 [details] New output! Results as shown in attachment!
Thats strange. Are you *sure* you have this patch applied: http://www.reactivated.net/patches/linux-kernel/2.6.12/procfs-hardlinks.patch With that applied, it will never read a hardlink count of 3 for any /proc/<pid> directory
Created attachment 57925 [details] NEW Output Sorry, I forgot to patch the new kernel. Now it' s patched and please have a look at the new output :(
dsd: Do you think it might be a problem with processes being created/destroyed changing the hardlink count (correctly), but find reads it once and doesn't expect it to change over the course of its execution? sandman: what's the load like on the box you're testing this on? Are processes getting created/destroyed frequently while you run the find? FWIW, I can't reproduce with g-d-s-2.6.11-r7 or 2.6.12-rc2 + gentoo 2.6-12.pre patches applied.
Yep, thats what I was suspecting. The count is only off by 1 by the time it reaches the end. I can't reproduce it even under lots of load, and even despite the fact that my "find /proc" output is 8000 lines long whereas the one posted here is only 2500. So yes, I think this is due to the highly dynamic nature of the /proc filesystem. Closing as cantfix, even though the fixable bugs have been solved.
The latest error is, for sure, not critical and probably, as you have already said, unresolvable. Thanks for your pains, guys! :) It was a lot of hard work. (When is this patch going to be included into the kernel sources?)
Both patches are included in recent gentoo-sources releases and has been merged by Linus into the official 2.6.12-rc4 http://www.kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.12-rc4
