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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/base.c
parentca41cc96b2813221b05af57d0355157924de5a07 (diff)
parent2bd2c1941f141ad780135ccc1cd08ca71a24f10a (diff)
downloadlinux-aab174f0df5d72d31caccf281af5f614fa254578.tar.bz2
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/base.c')
-rw-r--r--fs/proc/base.c417
1 files changed, 11 insertions, 406 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index acd1960c28a2..d295af993677 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)
{