The patch titled
epoll: avoid kmemcheck warning
has been added to the -mm tree. Its filename is
epoll-avoid-kmemcheck-warning.patch
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------------------------------------------------------
Subject: epoll: avoid kmemcheck warning
From: Davide Libenzi <[EMAIL PROTECTED]>
Epoll calls rb_set_parent(n, n) to initialize the rb-tree node, but
rb_set_parent() accesses node's pointer in its code. This creates a
warning in kmemcheck (reported by Vegard Nossum) about an uninitialized
memory access. The warning is harmless since the following rb-tree node
insert is going to overwrite the node data. In any case I think it's
better to not have that happening at all, and fix it by simplifying the
code to get rid of a few lines that became superfluous after the previous
epoll changes.
Signed-off-by: Davide Libenzi <[EMAIL PROTECTED]>
Cc: Vegard Nossum <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
---
fs/eventpoll.c | 27 +++------------------------
1 file changed, 3 insertions(+), 24 deletions(-)
diff -puN fs/eventpoll.c~epoll-avoid-kmemcheck-warning fs/eventpoll.c
--- a/fs/eventpoll.c~epoll-avoid-kmemcheck-warning
+++ a/fs/eventpoll.c
@@ -257,25 +257,6 @@ static inline int ep_cmp_ffd(struct epol
(p1->file < p2->file ? -1 : p1->fd - p2->fd));
}
-/* Special initialization for the RB tree node to detect linkage */
-static inline void ep_rb_initnode(struct rb_node *n)
-{
- rb_set_parent(n, n);
-}
-
-/* Removes a node from the RB tree and marks it for a fast is-linked check */
-static inline void ep_rb_erase(struct rb_node *n, struct rb_root *r)
-{
- rb_erase(n, r);
- rb_set_parent(n, n);
-}
-
-/* Fast check to verify that the item is linked to the main RB tree */
-static inline int ep_rb_linked(struct rb_node *n)
-{
- return rb_parent(n) != n;
-}
-
/* Tells us if the item is currently linked */
static inline int ep_is_linked(struct list_head *p)
{
@@ -283,13 +264,13 @@ static inline int ep_is_linked(struct li
}
/* Get the "struct epitem" from a wait queue pointer */
-static inline struct epitem * ep_item_from_wait(wait_queue_t *p)
+static inline struct epitem *ep_item_from_wait(wait_queue_t *p)
{
return container_of(p, struct eppoll_entry, wait)->base;
}
/* Get the "struct epitem" from an epoll queue wrapper */
-static inline struct epitem * ep_item_from_epqueue(poll_table *p)
+static inline struct epitem *ep_item_from_epqueue(poll_table *p)
{
return container_of(p, struct ep_pqueue, pt)->epi;
}
@@ -411,8 +392,7 @@ static int ep_remove(struct eventpoll *e
list_del_init(&epi->fllink);
spin_unlock(&file->f_ep_lock);
- if (ep_rb_linked(&epi->rbn))
- ep_rb_erase(&epi->rbn, &ep->rbr);
+ rb_erase(&epi->rbn, &ep->rbr);
spin_lock_irqsave(&ep->lock, flags);
if (ep_is_linked(&epi->rdllink))
@@ -728,7 +708,6 @@ static int ep_insert(struct eventpoll *e
goto error_return;
/* Item initialization follow here ... */
- ep_rb_initnode(&epi->rbn);
INIT_LIST_HEAD(&epi->rdllink);
INIT_LIST_HEAD(&epi->fllink);
INIT_LIST_HEAD(&epi->pwqlist);
_
Patches currently in -mm which might be from [EMAIL PROTECTED] are
origin.patch
git-kvm.patch
epoll-avoid-kmemcheck-warning.patch
-
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