xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

llist/xen-blkfront: implement safe version of llist_for_each_entry

Browse Source 
Implement a safe version of llist_for_each_entry, and use it in
blkif_free. Previously grants where freed while iterating the list,
which lead to dereferences when trying to fetch the next item.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by:  Andrew Morton <akpm@linux-foundation.org>
[v2: Move the llist_for_each_entry_safe in llist.h]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Roger Pau Monne
2012-12-04 15:21:53 +01:00
committed by Konrad Rzeszutek Wilk
parent 7dc341175a
commit ebb351cf78
2 changed files with 27 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
include/linux/llist.h
View File

@@ -124,6 +124,31 @@ static inline void init_llist_head(struct llist_head *list)
&(pos)->member != NULL; \
(pos) = llist_entry((pos)->member.next, typeof(*(pos)), member))
/**
* llist_for_each_entry_safe - iterate safely against remove over some entries
* of lock-less list of given type.
* @pos: the type * to use as a loop cursor.
* @n: another type * to use as a temporary storage.
* @node: the fist entry of deleted list entries.
* @member: the name of the llist_node with the struct.
*
* In general, some entries of the lock-less list can be traversed
* safely only after being removed from list, so start with an entry
* instead of list head. This variant allows removal of entries
* as we iterate.
*
* If being used on entries deleted from lock-less list directly, the
* traverse order is from the newest to the oldest added entry. If
* you want to traverse from the oldest to the newest, you must
* reverse the order by yourself before traversing.
*/
#define llist_for_each_entry_safe(pos, n, node, member) \
for ((pos) = llist_entry((node), typeof(*(pos)), member), \
(n) = (pos)->member.next; \
&(pos)->member != NULL; \
(pos) = llist_entry(n, typeof(*(pos)), member), \
(n) = (&(pos)->member != NULL) ? (pos)->member.next : NULL)
/**
* llist_empty - tests whether a lock-less list is empty
* @head: the list to test