diff options
author | Davide Libenzi <davidel@xmailserver.org> | 2008-04-29 07:58:34 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-29 15:05:59 (GMT) |
commit | cdac75e6f2fec9abc21d0abb4e5d80720eeebb10 (patch) | |
tree | 0962ee591a96d5ebbd8e572b4aa05fe725754eb2 /fs | |
parent | b781ecb6a379f155568ef7093e38c6c1d857fe53 (diff) | |
download | linux-cdac75e6f2fec9abc21d0abb4e5d80720eeebb10.tar.xz |
epoll: avoid kmemcheck warning
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 <davidel@xmailserver.org>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/eventpoll.c | 27 |
1 files changed, 3 insertions, 24 deletions
diff --git a/fs/eventpoll.c b/fs/eventpoll.c index a415f42..0d23718 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -257,25 +257,6 @@ static inline int ep_cmp_ffd(struct epoll_filefd *p1, (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 list_head *p) } /* 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 *ep, struct epitem *epi) 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 *ep, struct epoll_event *event, 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); |