Commit 3089f54a authored by Linus Torvalds's avatar Linus Torvalds

Merge tag 'driver-core-3.16-rc4' of...

Merge tag 'driver-core-3.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Well, one drivercore fix for kernfs to resolve a reported issue with
  sysfs files being updated from atomic contexts, and another lz4 bugfix
  for testing potential buffer overflows"

* tag 'driver-core-3.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  lz4: add overrun checks to lz4_uncompress_unknownoutputsize()
  kernfs: kernfs_notify() must be useable from non-sleepable contexts
parents ef34c6ce 4a3a9904
......@@ -39,6 +39,19 @@ struct kernfs_open_node {
struct list_head files; /* goes through kernfs_open_file.list */
};
/*
* kernfs_notify() may be called from any context and bounces notifications
* through a work item. To minimize space overhead in kernfs_node, the
* pending queue is implemented as a singly linked list of kernfs_nodes.
* The list is terminated with the self pointer so that whether a
* kernfs_node is on the list or not can be determined by testing the next
* pointer for NULL.
*/
#define KERNFS_NOTIFY_EOL ((void *)&kernfs_notify_list)
static DEFINE_SPINLOCK(kernfs_notify_lock);
static struct kernfs_node *kernfs_notify_list = KERNFS_NOTIFY_EOL;
static struct kernfs_open_file *kernfs_of(struct file *file)
{
return ((struct seq_file *)file->private_data)->private;
......@@ -783,24 +796,25 @@ static unsigned int kernfs_fop_poll(struct file *filp, poll_table *wait)
return DEFAULT_POLLMASK|POLLERR|POLLPRI;
}
/**
* kernfs_notify - notify a kernfs file
* @kn: file to notify
*
* Notify @kn such that poll(2) on @kn wakes up.
*/
void kernfs_notify(struct kernfs_node *kn)
static void kernfs_notify_workfn(struct work_struct *work)
{
struct kernfs_root *root = kernfs_root(kn);
struct kernfs_node *kn;
struct kernfs_open_node *on;
struct kernfs_super_info *info;
unsigned long flags;
if (WARN_ON(kernfs_type(kn) != KERNFS_FILE))
repeat:
/* pop one off the notify_list */
spin_lock_irq(&kernfs_notify_lock);
kn = kernfs_notify_list;
if (kn == KERNFS_NOTIFY_EOL) {
spin_unlock_irq(&kernfs_notify_lock);
return;
}
kernfs_notify_list = kn->attr.notify_next;
kn->attr.notify_next = NULL;
spin_unlock_irq(&kernfs_notify_lock);
/* kick poll */
spin_lock_irqsave(&kernfs_open_node_lock, flags);
spin_lock_irq(&kernfs_open_node_lock);
on = kn->attr.open;
if (on) {
......@@ -808,12 +822,12 @@ void kernfs_notify(struct kernfs_node *kn)
wake_up_interruptible(&on->poll);
}
spin_unlock_irqrestore(&kernfs_open_node_lock, flags);
spin_unlock_irq(&kernfs_open_node_lock);
/* kick fsnotify */
mutex_lock(&kernfs_mutex);
list_for_each_entry(info, &root->supers, node) {
list_for_each_entry(info, &kernfs_root(kn)->supers, node) {
struct inode *inode;
struct dentry *dentry;
......@@ -833,6 +847,33 @@ void kernfs_notify(struct kernfs_node *kn)
}
mutex_unlock(&kernfs_mutex);
kernfs_put(kn);
goto repeat;
}
/**
* kernfs_notify - notify a kernfs file
* @kn: file to notify
*
* Notify @kn such that poll(2) on @kn wakes up. Maybe be called from any
* context.
*/
void kernfs_notify(struct kernfs_node *kn)
{
static DECLARE_WORK(kernfs_notify_work, kernfs_notify_workfn);
unsigned long flags;
if (WARN_ON(kernfs_type(kn) != KERNFS_FILE))
return;
spin_lock_irqsave(&kernfs_notify_lock, flags);
if (!kn->attr.notify_next) {
kernfs_get(kn);
kn->attr.notify_next = kernfs_notify_list;
kernfs_notify_list = kn;
schedule_work(&kernfs_notify_work);
}
spin_unlock_irqrestore(&kernfs_notify_lock, flags);
}
EXPORT_SYMBOL_GPL(kernfs_notify);
......
......@@ -91,6 +91,7 @@ struct kernfs_elem_attr {
const struct kernfs_ops *ops;
struct kernfs_open_node *open;
loff_t size;
struct kernfs_node *notify_next; /* for kernfs_notify() */
};
/*
......
......@@ -192,6 +192,8 @@ static int lz4_uncompress_unknownoutputsize(const char *source, char *dest,
int s = 255;
while ((ip < iend) && (s == 255)) {
s = *ip++;
if (unlikely(length > (size_t)(length + s)))
goto _output_error;
length += s;
}
}
......@@ -232,6 +234,8 @@ static int lz4_uncompress_unknownoutputsize(const char *source, char *dest,
if (length == ML_MASK) {
while (ip < iend) {
int s = *ip++;
if (unlikely(length > (size_t)(length + s)))
goto _output_error;
length += s;
if (s == 255)
continue;
......@@ -284,7 +288,7 @@ static int lz4_uncompress_unknownoutputsize(const char *source, char *dest,
/* write overflow error detected */
_output_error:
return (int) (-(((char *) ip) - source));
return -1;
}
int lz4_decompress(const unsigned char *src, size_t *src_len,
......
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