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drm: move drm authentication to new generic hash table.

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Fix drm_remove_magic potential memory leak / corruption. Move drm
authentication token hashing to new generic hash table implementation.

Signed-off-by: Dave Airlie <airlied@linux.ie>
This commit is contained in:
Thomas Hellstrom
2006-08-07 22:22:10 +10:00
committed by Dave Airlie
parent 3d45dbd611
commit 8669cbc5e6
5 changed files with 26 additions and 62 deletions
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62
drivers/char/drm/drm_auth.c
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@@ -35,20 +35,6 @@
#include "drmP.h"
/**
* Generate a hash key from a magic.
*
* \param magic magic.
* \return hash key.
*
* The key is the modulus of the hash table size, #DRM_HASH_SIZE, which must be
* a power of 2.
*/
static int drm_hash_magic(drm_magic_t magic)
{
return magic & (DRM_HASH_SIZE - 1);
}
/**
* Find the file with the given magic number.
*
@@ -63,14 +49,12 @@ static drm_file_t *drm_find_file(drm_device_t * dev, drm_magic_t magic)
{
drm_file_t *retval = NULL;
drm_magic_entry_t *pt;
int hash = drm_hash_magic(magic);
drm_hash_item_t *hash;
mutex_lock(&dev->struct_mutex);
for (pt = dev->magiclist[hash].head; pt; pt = pt->next) {
if (pt->magic == magic) {
retval = pt->priv;
break;
}
if (!drm_ht_find_item(&dev->magiclist, (unsigned long)magic, &hash)) {
pt = drm_hash_entry(hash, drm_magic_entry_t, hash_item);
retval = pt->priv;
}
mutex_unlock(&dev->struct_mutex);
return retval;
@@ -90,28 +74,20 @@ static drm_file_t *drm_find_file(drm_device_t * dev, drm_magic_t magic)
static int drm_add_magic(drm_device_t * dev, drm_file_t * priv,
drm_magic_t magic)
{
int hash;
drm_magic_entry_t *entry;
DRM_DEBUG("%d\n", magic);
hash = drm_hash_magic(magic);
entry = drm_alloc(sizeof(*entry), DRM_MEM_MAGIC);
if (!entry)
return -ENOMEM;
memset(entry, 0, sizeof(*entry));
entry->magic = magic;
entry->priv = priv;
entry->next = NULL;
entry->hash_item.key = (unsigned long)magic;
mutex_lock(&dev->struct_mutex);
if (dev->magiclist[hash].tail) {
dev->magiclist[hash].tail->next = entry;
dev->magiclist[hash].tail = entry;
} else {
dev->magiclist[hash].head = entry;
dev->magiclist[hash].tail = entry;
}
drm_ht_insert_item(&dev->magiclist, &entry->hash_item);
list_add_tail(&entry->head, &dev->magicfree);
mutex_unlock(&dev->struct_mutex);
return 0;
@@ -128,29 +104,19 @@ static int drm_add_magic(drm_device_t * dev, drm_file_t * priv,
*/
static int drm_remove_magic(drm_device_t * dev, drm_magic_t magic)
{
drm_magic_entry_t *prev = NULL;
drm_magic_entry_t *pt;
int hash;
drm_hash_item_t *hash;
DRM_DEBUG("%d\n", magic);
hash = drm_hash_magic(magic);
mutex_lock(&dev->struct_mutex);
for (pt = dev->magiclist[hash].head; pt; prev = pt, pt = pt->next) {
if (pt->magic == magic) {
if (dev->magiclist[hash].head == pt) {
dev->magiclist[hash].head = pt->next;
}
if (dev->magiclist[hash].tail == pt) {
dev->magiclist[hash].tail = prev;
}
if (prev) {
prev->next = pt->next;
}
mutex_unlock(&dev->struct_mutex);
return 0;
}
if (drm_ht_find_item(&dev->magiclist, (unsigned long)magic, &hash)) {
mutex_unlock(&dev->struct_mutex);
return -EINVAL;
}
pt = drm_hash_entry(hash, drm_magic_entry_t, hash_item);
drm_ht_remove_item(&dev->magiclist, hash);
list_del(&pt->head);
mutex_unlock(&dev->struct_mutex);
drm_free(pt, sizeof(*pt), DRM_MEM_MAGIC);