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authorLinus Torvalds <torvalds@linux-foundation.org>2012-10-02 20:25:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-02 20:25:04 -0700
commitaab174f0df5d72d31caccf281af5f614fa254578 (patch)
tree2a172c5009c4ac8755e858593154c258ce7709a0 /fs/proc
parentca41cc96b2813221b05af57d0355157924de5a07 (diff)
parent2bd2c1941f141ad780135ccc1cd08ca71a24f10a (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs update from Al Viro: - big one - consolidation of descriptor-related logics; almost all of that is moved to fs/file.c (BTW, I'm seriously tempted to rename the result to fd.c. As it is, we have a situation when file_table.c is about handling of struct file and file.c is about handling of descriptor tables; the reasons are historical - file_table.c used to be about a static array of struct file we used to have way back). A lot of stray ends got cleaned up and converted to saner primitives, disgusting mess in android/binder.c is still disgusting, but at least doesn't poke so much in descriptor table guts anymore. A bunch of relatively minor races got fixed in process, plus an ext4 struct file leak. - related thing - fget_light() partially unuglified; see fdget() in there (and yes, it generates the code as good as we used to have). - also related - bits of Cyrill's procfs stuff that got entangled into that work; _not_ all of it, just the initial move to fs/proc/fd.c and switch of fdinfo to seq_file. - Alex's fs/coredump.c spiltoff - the same story, had been easier to take that commit than mess with conflicts. The rest is a separate pile, this was just a mechanical code movement. - a few misc patches all over the place. Not all for this cycle, there'll be more (and quite a few currently sit in akpm's tree)." Fix up trivial conflicts in the android binder driver, and some fairly simple conflicts due to two different changes to the sock_alloc_file() interface ("take descriptor handling from sock_alloc_file() to callers" vs "net: Providing protocol type via system.sockprotoname xattr of /proc/PID/fd entries" adding a dentry name to the socket) * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits) MAX_LFS_FILESIZE should be a loff_t compat: fs: Generic compat_sys_sendfile implementation fs: push rcu_barrier() from deactivate_locked_super() to filesystems btrfs: reada_extent doesn't need kref for refcount coredump: move core dump functionality into its own file coredump: prevent double-free on an error path in core dumper usb/gadget: fix misannotations fcntl: fix misannotations ceph: don't abuse d_delete() on failure exits hypfs: ->d_parent is never NULL or negative vfs: delete surplus inode NULL check switch simple cases of fget_light to fdget new helpers: fdget()/fdput() switch o2hb_region_dev_write() to fget_light() proc_map_files_readdir(): don't bother with grabbing files make get_file() return its argument vhost_set_vring(): turn pollstart/pollstop into bool switch prctl_set_mm_exe_file() to fget_light() switch xfs_find_handle() to fget_light() switch xfs_swapext() to fget_light() ...
Diffstat (limited to 'fs/proc')
-rw-r--r--fs/proc/Makefile2
-rw-r--r--fs/proc/base.c417
-rw-r--r--fs/proc/fd.c367
-rw-r--r--fs/proc/fd.h14
-rw-r--r--fs/proc/internal.h48
5 files changed, 441 insertions, 407 deletions
diff --git a/fs/proc/Makefile b/fs/proc/Makefile
index c1c72933592..99349efbbc2 100644
--- a/fs/proc/Makefile
+++ b/fs/proc/Makefile
@@ -8,7 +8,7 @@ proc-y := nommu.o task_nommu.o
proc-$(CONFIG_MMU) := mmu.o task_mmu.o
proc-y += inode.o root.o base.o generic.o array.o \
- proc_tty.o
+ proc_tty.o fd.o
proc-y += cmdline.o
proc-y += consoles.o
proc-y += cpuinfo.o
diff --git a/fs/proc/base.c b/fs/proc/base.c
index acd1960c28a..d295af99367 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -90,6 +90,7 @@
#endif
#include <trace/events/oom.h>
#include "internal.h"
+#include "fd.h"
/* NOTE:
* Implementing inode permission operations in /proc is almost
@@ -136,8 +137,6 @@ struct pid_entry {
NULL, &proc_single_file_operations, \
{ .proc_show = show } )
-static int proc_fd_permission(struct inode *inode, int mask);
-
/*
* Count the number of hardlinks for the pid_entry table, excluding the .
* and .. links.
@@ -1500,7 +1499,7 @@ out:
return error;
}
-static const struct inode_operations proc_pid_link_inode_operations = {
+const struct inode_operations proc_pid_link_inode_operations = {
.readlink = proc_pid_readlink,
.follow_link = proc_pid_follow_link,
.setattr = proc_setattr,
@@ -1509,21 +1508,6 @@ static const struct inode_operations proc_pid_link_inode_operations = {
/* 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;
-}
-
struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
{
struct inode * inode;
@@ -1649,15 +1633,6 @@ int pid_revalidate(struct dentry *dentry, unsigned int flags)
return 0;
}
-static int pid_delete_dentry(const struct dentry * dentry)
-{
- /* Is the task we represent dead?
- * If so, then don't put the dentry on the lru list,
- * kill it immediately.
- */
- return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
-}
-
const struct dentry_operations pid_dentry_operations =
{
.d_revalidate = pid_revalidate,
@@ -1720,289 +1695,6 @@ end_instantiate:
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) {
- unsigned int f_flags;
- struct fdtable *fdt;
-
- fdt = files_fdtable(files);
- f_flags = file->f_flags & ~O_CLOEXEC;
- if (close_on_exec(fd, fdt))
- f_flags |= O_CLOEXEC;
-
- 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,
- 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 dentry *dentry, struct path *path)
-{
- return proc_fd_info(dentry->d_inode, path, NULL);
-}
-
-static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
-{
- struct inode *inode;
- struct task_struct *task;
- int fd;
- struct files_struct *files;
- const struct cred *cred;
-
- if (flags & LOOKUP_RCU)
- return -ECHILD;
-
- inode = dentry->d_inode;
- task = get_proc_task(inode);
- fd = proc_fd(inode);
-
- if (task) {
- files = get_files_struct(task);
- if (files) {
- struct file *file;
- rcu_read_lock();
- file = fcheck_files(files, fd);
- if (file) {
- unsigned f_mode = file->f_mode;
-
- rcu_read_unlock();
- put_files_struct(files);
-
- if (task_dumpable(task)) {
- rcu_read_lock();
- cred = __task_cred(task);
- inode->i_uid = cred->euid;
- inode->i_gid = cred->egid;
- rcu_read_unlock();
- } else {
- inode->i_uid = GLOBAL_ROOT_UID;
- inode->i_gid = GLOBAL_ROOT_GID;
- }
-
- if (S_ISLNK(inode->i_mode)) {
- unsigned i_mode = S_IFLNK;
- if (f_mode & FMODE_READ)
- i_mode |= S_IRUSR | S_IXUSR;
- if (f_mode & FMODE_WRITE)
- i_mode |= S_IWUSR | S_IXUSR;
- inode->i_mode = i_mode;
- }
-
- 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 const 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 = (unsigned long)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_IFLNK;
- inode->i_op = &proc_pid_link_inode_operations;
- inode->i_size = 64;
- ei->op.proc_get_link = proc_fd_link;
- d_set_d_op(dentry, &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, 0))
- error = NULL;
-
- out:
- return error;
-}
-
-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, (void *)(unsigned long)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;
- int rv;
-
- if (!fcheck_files(files, fd))
- continue;
- rcu_read_unlock();
-
- len = snprintf(name, sizeof(name), "%d", fd);
- rv = proc_fill_cache(filp, dirent, filldir,
- name, len, instantiate, p,
- (void *)(unsigned long)fd);
- if (rv < 0)
- goto out_fd_loop;
- rcu_read_lock();
- }
- rcu_read_unlock();
-out_fd_loop:
- 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,
- unsigned int flags)
-{
- 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,
- .llseek = no_llseek,
-};
-
-static const struct file_operations proc_fd_operations = {
- .read = generic_read_dir,
- .readdir = proc_readfd,
- .llseek = default_llseek,
-};
-
#ifdef CONFIG_CHECKPOINT_RESTORE
/*
@@ -2121,7 +1813,7 @@ out:
}
struct map_files_info {
- struct file *file;
+ fmode_t mode;
unsigned long len;
unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
};
@@ -2130,13 +1822,10 @@ static struct dentry *
proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
struct task_struct *task, const void *ptr)
{
- const struct file *file = ptr;
+ fmode_t mode = (fmode_t)(unsigned long)ptr;
struct proc_inode *ei;
struct inode *inode;
- if (!file)
- return ERR_PTR(-ENOENT);
-
inode = proc_pid_make_inode(dir->i_sb, task);
if (!inode)
return ERR_PTR(-ENOENT);
@@ -2148,9 +1837,9 @@ proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
inode->i_size = 64;
inode->i_mode = S_IFLNK;
- if (file->f_mode & FMODE_READ)
+ if (mode & FMODE_READ)
inode->i_mode |= S_IRUSR;
- if (file->f_mode & FMODE_WRITE)
+ if (mode & FMODE_WRITE)
inode->i_mode |= S_IWUSR;
d_set_d_op(dentry, &tid_map_files_dentry_operations);
@@ -2194,7 +1883,8 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
if (!vma)
goto out_no_vma;
- result = proc_map_files_instantiate(dir, dentry, task, vma->vm_file);
+ result = proc_map_files_instantiate(dir, dentry, task,
+ (void *)(unsigned long)vma->vm_file->f_mode);
out_no_vma:
up_read(&mm->mmap_sem);
@@ -2295,8 +1985,7 @@ proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
if (++pos <= filp->f_pos)
continue;
- get_file(vma->vm_file);
- info.file = vma->vm_file;
+ info.mode = vma->vm_file->f_mode;
info.len = snprintf(info.name,
sizeof(info.name), "%lx-%lx",
vma->vm_start, vma->vm_end);
@@ -2311,19 +2000,11 @@ proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
ret = proc_fill_cache(filp, dirent, filldir,
p->name, p->len,
proc_map_files_instantiate,
- task, p->file);
+ task,
+ (void *)(unsigned long)p->mode);
if (ret)
break;
filp->f_pos++;
- fput(p->file);
- }
- for (; i < nr_files; i++) {
- /*
- * In case of error don't forget
- * to put rest of file refs.
- */
- p = flex_array_get(fa, i);
- fput(p->file);
}
if (fa)
flex_array_free(fa);
@@ -2345,82 +2026,6 @@ static const struct file_operations proc_map_files_operations = {
#endif /* CONFIG_CHECKPOINT_RESTORE */
-/*
- * /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 = generic_permission(inode, mask);
- 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 long)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;
- d_set_d_op(dentry, &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, 0))
- error = NULL;
-
- out:
- return error;
-}
-
-static struct dentry *proc_lookupfdinfo(struct inode *dir,
- struct dentry *dentry,
- unsigned int flags)
-{
- 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,
- .llseek = default_llseek,
-};
-
-/*
- * 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)
{
diff --git a/fs/proc/fd.c b/fs/proc/fd.c
new file mode 100644
index 00000000000..f28a875f877
--- /dev/null
+++ b/fs/proc/fd.c
@@ -0,0 +1,367 @@
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/dcache.h>
+#include <linux/path.h>
+#include <linux/fdtable.h>
+#include <linux/namei.h>
+#include <linux/pid.h>
+#include <linux/security.h>
+#include <linux/file.h>
+#include <linux/seq_file.h>
+
+#include <linux/proc_fs.h>
+
+#include "internal.h"
+#include "fd.h"
+
+static int seq_show(struct seq_file *m, void *v)
+{
+ struct files_struct *files = NULL;
+ int f_flags = 0, ret = -ENOENT;
+ struct file *file = NULL;
+ struct task_struct *task;
+
+ task = get_proc_task(m->private);
+ if (!task)
+ return -ENOENT;
+
+ files = get_files_struct(task);
+ put_task_struct(task);
+
+ if (files) {
+ int fd = proc_fd(m->private);
+
+ spin_lock(&files->file_lock);
+ file = fcheck_files(files, fd);
+ if (file) {
+ struct fdtable *fdt = files_fdtable(files);
+
+ f_flags = file->f_flags;
+ if (close_on_exec(fd, fdt))
+ f_flags |= O_CLOEXEC;
+
+ get_file(file);
+ ret = 0;
+ }
+ spin_unlock(&files->file_lock);
+ put_files_struct(files);
+ }
+
+ if (!ret) {
+ seq_printf(m, "pos:\t%lli\nflags:\t0%o\n",
+ (long long)file->f_pos, f_flags);
+ fput(file);
+ }
+
+ return ret;
+}
+
+static int seq_fdinfo_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, seq_show, inode);
+}
+
+static const struct file_operations proc_fdinfo_file_operations = {
+ .open = seq_fdinfo_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
+{
+ struct files_struct *files;
+ struct task_struct *task;
+ const struct cred *cred;
+ struct inode *inode;
+ int fd;
+
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = dentry->d_inode;
+ task = get_proc_task(inode);
+ fd = proc_fd(inode);
+
+ if (task) {
+ files = get_files_struct(task);
+ if (files) {
+ struct file *file;
+
+ rcu_read_lock();
+ file = fcheck_files(files, fd);
+ if (file) {
+ unsigned f_mode = file->f_mode;
+
+ rcu_read_unlock();
+ put_files_struct(files);
+
+ if (task_dumpable(task)) {
+ rcu_read_lock();
+ cred = __task_cred(task);
+ inode->i_uid = cred->euid;
+ inode->i_gid = cred->egid;
+ rcu_read_unlock();
+ } else {
+ inode->i_uid = GLOBAL_ROOT_UID;
+ inode->i_gid = GLOBAL_ROOT_GID;
+ }
+
+ if (S_ISLNK(inode->i_mode)) {
+ unsigned i_mode = S_IFLNK;
+ if (f_mode & FMODE_READ)
+ i_mode |= S_IRUSR | S_IXUSR;
+ if (f_mode & FMODE_WRITE)
+ i_mode |= S_IWUSR | S_IXUSR;
+ inode->i_mode = i_mode;
+ }
+
+ 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 const struct dentry_operations tid_fd_dentry_operations = {
+ .d_revalidate = tid_fd_revalidate,
+ .d_delete = pid_delete_dentry,
+};
+
+static int proc_fd_link(struct dentry *dentry, struct path *path)
+{
+ struct files_struct *files = NULL;
+ struct task_struct *task;
+ int ret = -ENOENT;
+
+ task = get_proc_task(dentry->d_inode);
+ if (task) {
+ files = get_files_struct(task);
+ put_task_struct(task);
+ }
+
+ if (files) {
+ int fd = proc_fd(dentry->d_inode);
+ struct file *fd_file;
+
+ spin_lock(&files->file_lock);
+ fd_file = fcheck_files(files, fd);
+ if (fd_file) {
+ *path = fd_file->f_path;
+ path_get(&fd_file->f_path);
+ ret = 0;
+ }
+ spin_unlock(&files->file_lock);
+ put_files_struct(files);
+ }
+
+ return ret;
+}
+
+static struct dentry *
+proc_fd_instantiate(struct inode *dir, struct dentry *dentry,
+ struct task_struct *task, const void *ptr)
+{
+ struct dentry *error = ERR_PTR(-ENOENT);
+ unsigned fd = (unsigned long)ptr;
+ struct proc_inode *ei;
+ struct inode *inode;
+
+ inode = proc_pid_make_inode(dir->i_sb, task);
+ if (!inode)
+ goto out;
+
+ ei = PROC_I(inode);
+ ei->fd = fd;
+
+ inode->i_mode = S_IFLNK;
+ inode->i_op = &proc_pid_link_inode_operations;
+ inode->i_size = 64;
+
+ ei->op.proc_get_link = proc_fd_link;
+
+ d_set_d_op(dentry, &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, 0))
+ error = NULL;
+ out:
+ return error;
+}
+
+static struct dentry *proc_lookupfd_common(struct inode *dir,
+ struct dentry *dentry,
+ instantiate_t instantiate)
+{
+ struct task_struct *task = get_proc_task(dir);
+ struct dentry *result = ERR_PTR(-ENOENT);
+ unsigned fd = name_to_int(dentry);
+
+ if (!task)
+ goto out_no_task;
+ if (fd == ~0U)
+ goto out;
+
+ result = instantiate(dir, dentry, task, (void *)(unsigned long)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);
+ struct files_struct *files;
+ unsigned int fd, ino;
+ int retval;
+
+ 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;
+ int rv;
+
+ if (!fcheck_files(files, fd))
+ continue;
+ rcu_read_unlock();
+
+ len = snprintf(name, sizeof(name), "%d", fd);
+ rv = proc_fill_cache(filp, dirent, filldir,
+ name, len, instantiate, p,
+ (void *)(unsigned long)fd);
+ if (rv < 0)
+ goto out_fd_loop;
+ rcu_read_lock();
+ }
+ rcu_read_unlock();
+out_fd_loop:
+ put_files_struct(files);
+ }
+out:
+ put_task_struct(p);
+out_no_task:
+ return retval;
+}
+
+static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
+{
+ return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
+}
+
+const struct file_operations proc_fd_operations = {
+ .read = generic_read_dir,
+ .readdir = proc_readfd,
+ .llseek = default_llseek,
+};
+
+static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
+ unsigned int flags)
+{
+ return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
+}
+
+/*
+ * /proc/pid/fd needs a special permission handler so that a process can still
+ * access /proc/self/fd after it has executed a setuid().
+ */
+int proc_fd_permission(struct inode *inode, int mask)
+{
+ int rv = generic_permission(inode, mask);
+ if (rv == 0)
+ return 0;
+ if (task_pid(current) == proc_pid(inode))
+ rv = 0;
+ return rv;
+}
+
+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)
+{
+ struct dentry *error = ERR_PTR(-ENOENT);
+ unsigned fd = (unsigned long)ptr;
+ struct proc_inode *ei;
+ struct inode *inode;
+
+ 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;
+
+ d_set_d_op(dentry, &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, 0))
+ error = NULL;
+ out:
+ return error;
+}
+
+static struct dentry *
+proc_lookupfdinfo(struct inode *dir, struct dentry *dentry, unsigned int flags)
+{
+ 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);
+}
+
+const struct inode_operations proc_fdinfo_inode_operations = {
+ .lookup = proc_lookupfdinfo,
+ .setattr = proc_setattr,
+};
+
+const struct file_operations proc_fdinfo_operations = {
+ .read = generic_read_dir,
+ .readdir = proc_readfdinfo,
+ .llseek = default_llseek,
+};
diff --git a/fs/proc/fd.h b/fs/proc/fd.h
new file mode 100644
index 00000000000..cbb1d47deda
--- /dev/null
+++ b/fs/proc/fd.h
@@ -0,0 +1,14 @@
+#ifndef __PROCFS_FD_H__
+#define __PROCFS_FD_H__
+
+#include <linux/fs.h>
+
+extern const struct file_operations proc_fd_operations;
+extern const struct inode_operations proc_fd_inode_operations;
+
+extern const struct file_operations proc_fdinfo_operations;
+extern const struct inode_operations proc_fdinfo_inode_operations;
+
+extern int proc_fd_permission(struct inode *inode, int mask);
+
+#endif /* __PROCFS_FD_H__ */
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index e1167a1c912..67925a7bd8c 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -9,6 +9,7 @@
* 2 of the License, or (at your option) any later version.
*/
+#include <linux/sched.h>
#include <linux/proc_fs.h>
struct ctl_table_header;
@@ -65,6 +66,7 @@ extern const struct file_operations proc_clear_refs_operations;
extern const struct file_operations proc_pagemap_operations;
extern const struct file_operations proc_net_operations;
extern const struct inode_operations proc_net_inode_operations;
+extern const struct inode_operations proc_pid_link_inode_operations;
struct proc_maps_private {
struct pid *pid;
@@ -91,6 +93,52 @@ static inline int proc_fd(struct inode *inode)
return PROC_I(inode)->fd;
}
+static inline 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 inline int pid_delete_dentry(const struct dentry * dentry)
+{
+ /* Is the task we represent dead?
+ * If so, then don't put the dentry on the lru list,
+ * kill it immediately.
+ */
+ return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
+}
+
+static inline 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;
+}
+
struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *ino,
struct dentry *dentry);
int proc_readdir_de(struct proc_dir_entry *de, struct file *filp, void *dirent,