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Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Browse source 
Pull misc vfs updates from Al Viro:
 "All kinds of misc stuff, without any unifying topic, from various
  people.

  Neil's d_anon patch, several bugfixes, introduction of kvmalloc
  analogue of kmemdup_user(), extending bitfield.h to deal with
  fixed-endians, assorted cleanups all over the place..."

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
  alpha: osf_sys.c: use timespec64 where appropriate
  alpha: osf_sys.c: fix put_tv32 regression
  jffs2: Fix use-after-free bug in jffs2_iget()'s error handling path
  dcache: delete unused d_hash_mask
  dcache: subtract d_hash_shift from 32 in advance
  fs/buffer.c: fold init_buffer() into init_page_buffers()
  fs: fold __inode_permission() into inode_permission()
  fs: add RWF_APPEND
  sctp: use vmemdup_user() rather than badly open-coding memdup_user()
  snd_ctl_elem_init_enum_names(): switch to vmemdup_user()
  replace_user_tlv(): switch to vmemdup_user()
  new primitive: vmemdup_user()
  memdup_user(): switch to GFP_USER
  eventfd: fold eventfd_ctx_get() into eventfd_ctx_fileget()
  eventfd: fold eventfd_ctx_read() into eventfd_read()
  eventfd: convert to use anon_inode_getfd()
  nfs4file: get rid of pointless include of btrfs.h
  uvc_v4l2: clean copyin/copyout up
  vme_user: don't use __copy_..._user()
  usx2y: don't bother with memdup_user() for 16-byte structure
  ...
This commit is contained in:
Linus Torvalds 2018-01-31 09:25:20 -08:00
commit 19e7b5f994
28 changed files with 297 additions and 404 deletions
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127
fs/eventfd.c
View file

@ -79,25 +79,12 @@ static void eventfd_free(struct kref *kref)
eventfd_free_ctx(ctx);
}
/**
* eventfd_ctx_get - Acquires a reference to the internal eventfd context.
* @ctx: [in] Pointer to the eventfd context.
*
* Returns: In case of success, returns a pointer to the eventfd context.
*/
struct eventfd_ctx *eventfd_ctx_get(struct eventfd_ctx *ctx)
{
kref_get(&ctx->kref);
return ctx;
}
EXPORT_SYMBOL_GPL(eventfd_ctx_get);
/**
* eventfd_ctx_put - Releases a reference to the internal eventfd context.
* @ctx: [in] Pointer to eventfd context.
*
* The eventfd context reference must have been previously acquired either
* with eventfd_ctx_get() or eventfd_ctx_fdget().
* with eventfd_ctx_fdget() or eventfd_ctx_fileget().
*/
void eventfd_ctx_put(struct eventfd_ctx *ctx)
{
@ -207,36 +194,27 @@ int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *w
}
EXPORT_SYMBOL_GPL(eventfd_ctx_remove_wait_queue);
/**
* eventfd_ctx_read - Reads the eventfd counter or wait if it is zero.
* @ctx: [in] Pointer to eventfd context.
* @no_wait: [in] Different from zero if the operation should not block.
* @cnt: [out] Pointer to the 64-bit counter value.
*
* Returns %0 if successful, or the following error codes:
*
* - -EAGAIN : The operation would have blocked but @no_wait was non-zero.
* - -ERESTARTSYS : A signal interrupted the wait operation.
*
* If @no_wait is zero, the function might sleep until the eventfd internal
* counter becomes greater than zero.
*/
ssize_t eventfd_ctx_read(struct eventfd_ctx *ctx, int no_wait, __u64 *cnt)
static ssize_t eventfd_read(struct file *file, char __user *buf, size_t count,
loff_t *ppos)
{
struct eventfd_ctx *ctx = file->private_data;
ssize_t res;
__u64 ucnt = 0;
DECLARE_WAITQUEUE(wait, current);
if (count < sizeof(ucnt))
return -EINVAL;
spin_lock_irq(&ctx->wqh.lock);
*cnt = 0;
res = -EAGAIN;
if (ctx->count > 0)
res = 0;
else if (!no_wait) {
res = sizeof(ucnt);
else if (!(file->f_flags & O_NONBLOCK)) {
__add_wait_queue(&ctx->wqh, &wait);
for (;;) {
set_current_state(TASK_INTERRUPTIBLE);
if (ctx->count > 0) {
res = 0;
res = sizeof(ucnt);
break;
}
if (signal_pending(current)) {
@ -250,32 +228,18 @@ ssize_t eventfd_ctx_read(struct eventfd_ctx *ctx, int no_wait, __u64 *cnt)
__remove_wait_queue(&ctx->wqh, &wait);
__set_current_state(TASK_RUNNING);
}
if (likely(res == 0)) {
eventfd_ctx_do_read(ctx, cnt);
if (likely(res > 0)) {
eventfd_ctx_do_read(ctx, &ucnt);
if (waitqueue_active(&ctx->wqh))
wake_up_locked_poll(&ctx->wqh, POLLOUT);
}
spin_unlock_irq(&ctx->wqh.lock);
if (res > 0 && put_user(ucnt, (__u64 __user *)buf))
return -EFAULT;
return res;
}
EXPORT_SYMBOL_GPL(eventfd_ctx_read);
static ssize_t eventfd_read(struct file *file, char __user *buf, size_t count,
loff_t *ppos)
{
struct eventfd_ctx *ctx = file->private_data;
ssize_t res;
__u64 cnt;
if (count < sizeof(cnt))
return -EINVAL;
res = eventfd_ctx_read(ctx, file->f_flags & O_NONBLOCK, &cnt);
if (res < 0)
return res;
return put_user(cnt, (__u64 __user *) buf) ? -EFAULT : sizeof(cnt);
}
static ssize_t eventfd_write(struct file *file, const char __user *buf, size_t count,
loff_t *ppos)
@ -405,79 +369,44 @@ EXPORT_SYMBOL_GPL(eventfd_ctx_fdget);
*/
struct eventfd_ctx *eventfd_ctx_fileget(struct file *file)
{
struct eventfd_ctx *ctx;
if (file->f_op != &eventfd_fops)
return ERR_PTR(-EINVAL);
return eventfd_ctx_get(file->private_data);
ctx = file->private_data;
kref_get(&ctx->kref);
return ctx;
}
EXPORT_SYMBOL_GPL(eventfd_ctx_fileget);
/**
* eventfd_file_create - Creates an eventfd file pointer.
* @count: Initial eventfd counter value.
* @flags: Flags for the eventfd file.
*
* This function creates an eventfd file pointer, w/out installing it into
* the fd table. This is useful when the eventfd file is used during the
* initialization of data structures that require extra setup after the eventfd
* creation. So the eventfd creation is split into the file pointer creation
* phase, and the file descriptor installation phase.
* In this way races with userspace closing the newly installed file descriptor
* can be avoided.
* Returns an eventfd file pointer, or a proper error pointer.
*/
struct file *eventfd_file_create(unsigned int count, int flags)
SYSCALL_DEFINE2(eventfd2, unsigned int, count, int, flags)
{
struct file *file;
struct eventfd_ctx *ctx;
int fd;
/* Check the EFD_* constants for consistency. */
BUILD_BUG_ON(EFD_CLOEXEC != O_CLOEXEC);
BUILD_BUG_ON(EFD_NONBLOCK != O_NONBLOCK);
if (flags & ~EFD_FLAGS_SET)
return ERR_PTR(-EINVAL);
return -EINVAL;
ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return ERR_PTR(-ENOMEM);
return -ENOMEM;
kref_init(&ctx->kref);
init_waitqueue_head(&ctx->wqh);
ctx->count = count;
ctx->flags = flags;
file = anon_inode_getfile("[eventfd]", &eventfd_fops, ctx,
O_RDWR | (flags & EFD_SHARED_FCNTL_FLAGS));
if (IS_ERR(file))
fd = anon_inode_getfd("[eventfd]", &eventfd_fops, ctx,
O_RDWR | (flags & EFD_SHARED_FCNTL_FLAGS));
if (fd < 0)
eventfd_free_ctx(ctx);
return file;
}
SYSCALL_DEFINE2(eventfd2, unsigned int, count, int, flags)
{
int fd, error;
struct file *file;
error = get_unused_fd_flags(flags & EFD_SHARED_FCNTL_FLAGS);
if (error < 0)
return error;
fd = error;
file = eventfd_file_create(count, flags);
if (IS_ERR(file)) {
error = PTR_ERR(file);
goto err_put_unused_fd;
}
fd_install(fd, file);
return fd;
err_put_unused_fd:
put_unused_fd(fd);
return error;
}
SYSCALL_DEFINE1(eventfd, unsigned int, count)