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Commit b030a4dd authored by Pekka Enberg's avatar Pekka Enberg Committed by Linus Torvalds
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[PATCH] Remove eventpoll macro obfuscation 

This patch gets rid of some macro obfuscation from fs/eventpoll.c by
removing slab allocator wrappers and converting macros to static inline
functions.
Signed-off-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
Acked-by: default avatarDavide Libenzi <davidel@xmailserver.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 46c271be
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Inline Side-by-side
Showing with 110 additions and 85 deletions
fs/eventpoll.c
View file @ b030a4dd
...@@ -101,57 +101,6 @@ ...@@ -101,57 +101,6 @@
/* Maximum number of poll wake up nests we are allowing */ /* Maximum number of poll wake up nests we are allowing */
#define EP_MAX_POLLWAKE_NESTS 4 #define EP_MAX_POLLWAKE_NESTS 4
/* Macro to allocate a "struct epitem" from the slab cache */
#define EPI_MEM_ALLOC() (struct epitem *) kmem_cache_alloc(epi_cache, SLAB_KERNEL)
/* Macro to free a "struct epitem" to the slab cache */
#define EPI_MEM_FREE(p) kmem_cache_free(epi_cache, p)
/* Macro to allocate a "struct eppoll_entry" from the slab cache */
#define PWQ_MEM_ALLOC() (struct eppoll_entry *) kmem_cache_alloc(pwq_cache, SLAB_KERNEL)
/* Macro to free a "struct eppoll_entry" to the slab cache */
#define PWQ_MEM_FREE(p) kmem_cache_free(pwq_cache, p)
/* Fast test to see if the file is an evenpoll file */
#define IS_FILE_EPOLL(f) ((f)->f_op == &eventpoll_fops)
/* Setup the structure that is used as key for the rb-tree */
#define EP_SET_FFD(p, f, d) do { (p)->file = (f); (p)->fd = (d); } while (0)
/* Compare rb-tree keys */
#define EP_CMP_FFD(p1, p2) ((p1)->file > (p2)->file ? +1: \
((p1)->file < (p2)->file ? -1: (p1)->fd - (p2)->fd))
/* Special initialization for the rb-tree node to detect linkage */
#define EP_RB_INITNODE(n) (n)->rb_parent = (n)
/* Removes a node from the rb-tree and marks it for a fast is-linked check */
#define EP_RB_ERASE(n, r) do { rb_erase(n, r); (n)->rb_parent = (n); } while (0)
/* Fast check to verify that the item is linked to the main rb-tree */
#define EP_RB_LINKED(n) ((n)->rb_parent != (n))
/*
* Remove the item from the list and perform its initialization.
* This is useful for us because we can test if the item is linked
* using "EP_IS_LINKED(p)".
*/
#define EP_LIST_DEL(p) do { list_del(p); INIT_LIST_HEAD(p); } while (0)
/* Tells us if the item is currently linked */
#define EP_IS_LINKED(p) (!list_empty(p))
/* Get the "struct epitem" from a wait queue pointer */
#define EP_ITEM_FROM_WAIT(p) ((struct epitem *) container_of(p, struct eppoll_entry, wait)->base)
/* Get the "struct epitem" from an epoll queue wrapper */
#define EP_ITEM_FROM_EPQUEUE(p) (container_of(p, struct ep_pqueue, pt)->epi)
/* Tells if the epoll_ctl(2) operation needs an event copy from userspace */
#define EP_OP_HASH_EVENT(op) ((op) != EPOLL_CTL_DEL)
struct epoll_filefd { struct epoll_filefd {
struct file *file; struct file *file;
int fd; int fd;
...@@ -357,6 +306,82 @@ static struct dentry_operations eventpollfs_dentry_operations = { ...@@ -357,6 +306,82 @@ static struct dentry_operations eventpollfs_dentry_operations = {
/* Fast test to see if the file is an evenpoll file */
static inline int is_file_epoll(struct file *f)
{
return f->f_op == &eventpoll_fops;
}
/* Setup the structure that is used as key for the rb-tree */
static inline void ep_set_ffd(struct epoll_filefd *ffd,
struct file *file, int fd)
{
ffd->file = file;
ffd->fd = fd;
}
/* Compare rb-tree keys */
static inline int ep_cmp_ffd(struct epoll_filefd *p1,
struct epoll_filefd *p2)
{
return (p1->file > p2->file ? +1:
(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)
{
n->rb_parent = 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);
n->rb_parent = 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 n->rb_parent != n;
}
/*
* Remove the item from the list and perform its initialization.
* This is useful for us because we can test if the item is linked
* using "ep_is_linked(p)".
*/
static inline void ep_list_del(struct list_head *p)
{
list_del(p);
INIT_LIST_HEAD(p);
}
/* Tells us if the item is currently linked */
static inline int ep_is_linked(struct list_head *p)
{
return !list_empty(p);
}
/* Get the "struct epitem" from a wait queue pointer */
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)
{
return container_of(p, struct ep_pqueue, pt)->epi;
}
/* Tells if the epoll_ctl(2) operation needs an event copy from userspace */
static inline int ep_op_hash_event(int op)
{
return op != EPOLL_CTL_DEL;
}
/* Initialize the poll safe wake up structure */ /* Initialize the poll safe wake up structure */
static void ep_poll_safewake_init(struct poll_safewake *psw) static void ep_poll_safewake_init(struct poll_safewake *psw)
{ {
...@@ -456,7 +481,7 @@ void eventpoll_release_file(struct file *file) ...@@ -456,7 +481,7 @@ void eventpoll_release_file(struct file *file)
epi = list_entry(lsthead->next, struct epitem, fllink); epi = list_entry(lsthead->next, struct epitem, fllink);
ep = epi->ep; ep = epi->ep;
EP_LIST_DEL(&epi->fllink); ep_list_del(&epi->fllink);
down_write(&ep->sem); down_write(&ep->sem);
ep_remove(ep, epi); ep_remove(ep, epi);
up_write(&ep->sem); up_write(&ep->sem);
...@@ -534,7 +559,7 @@ sys_epoll_ctl(int epfd, int op, int fd, struct epoll_event __user *event) ...@@ -534,7 +559,7 @@ sys_epoll_ctl(int epfd, int op, int fd, struct epoll_event __user *event)
current, epfd, op, fd, event)); current, epfd, op, fd, event));
error = -EFAULT; error = -EFAULT;
if (EP_OP_HASH_EVENT(op) && if (ep_op_hash_event(op) &&
copy_from_user(&epds, event, sizeof(struct epoll_event))) copy_from_user(&epds, event, sizeof(struct epoll_event)))
goto eexit_1; goto eexit_1;
...@@ -560,7 +585,7 @@ sys_epoll_ctl(int epfd, int op, int fd, struct epoll_event __user *event) ...@@ -560,7 +585,7 @@ sys_epoll_ctl(int epfd, int op, int fd, struct epoll_event __user *event)
* adding an epoll file descriptor inside itself. * adding an epoll file descriptor inside itself.
*/ */
error = -EINVAL; error = -EINVAL;
if (file == tfile || !IS_FILE_EPOLL(file)) if (file == tfile || !is_file_epoll(file))
goto eexit_3; goto eexit_3;
/* /*
...@@ -656,7 +681,7 @@ asmlinkage long sys_epoll_wait(int epfd, struct epoll_event __user *events, ...@@ -656,7 +681,7 @@ asmlinkage long sys_epoll_wait(int epfd, struct epoll_event __user *events,
* the user passed to us _is_ an eventpoll file. * the user passed to us _is_ an eventpoll file.
*/ */
error = -EINVAL; error = -EINVAL;
if (!IS_FILE_EPOLL(file)) if (!is_file_epoll(file))
goto eexit_2; goto eexit_2;
/* /*
...@@ -831,11 +856,11 @@ static struct epitem *ep_find(struct eventpoll *ep, struct file *file, int fd) ...@@ -831,11 +856,11 @@ static struct epitem *ep_find(struct eventpoll *ep, struct file *file, int fd)
struct epitem *epi, *epir = NULL; struct epitem *epi, *epir = NULL;
struct epoll_filefd ffd; struct epoll_filefd ffd;
EP_SET_FFD(&ffd, file, fd); ep_set_ffd(&ffd, file, fd);
read_lock_irqsave(&ep->lock, flags); read_lock_irqsave(&ep->lock, flags);
for (rbp = ep->rbr.rb_node; rbp; ) { for (rbp = ep->rbr.rb_node; rbp; ) {
epi = rb_entry(rbp, struct epitem, rbn); epi = rb_entry(rbp, struct epitem, rbn);
kcmp = EP_CMP_FFD(&ffd, &epi->ffd); kcmp = ep_cmp_ffd(&ffd, &epi->ffd);
if (kcmp > 0) if (kcmp > 0)
rbp = rbp->rb_right; rbp = rbp->rb_right;
else if (kcmp < 0) else if (kcmp < 0)
...@@ -875,7 +900,7 @@ static void ep_release_epitem(struct epitem *epi) ...@@ -875,7 +900,7 @@ static void ep_release_epitem(struct epitem *epi)
{ {
if (atomic_dec_and_test(&epi->usecnt)) if (atomic_dec_and_test(&epi->usecnt))
EPI_MEM_FREE(epi); kmem_cache_free(epi_cache, epi);
} }
...@@ -886,10 +911,10 @@ static void ep_release_epitem(struct epitem *epi) ...@@ -886,10 +911,10 @@ static void ep_release_epitem(struct epitem *epi)
static void ep_ptable_queue_proc(struct file *file, wait_queue_head_t *whead, static void ep_ptable_queue_proc(struct file *file, wait_queue_head_t *whead,
poll_table *pt) poll_table *pt)
{ {
struct epitem *epi = EP_ITEM_FROM_EPQUEUE(pt); struct epitem *epi = ep_item_from_epqueue(pt);
struct eppoll_entry *pwq; struct eppoll_entry *pwq;
if (epi->nwait >= 0 && (pwq = PWQ_MEM_ALLOC())) { if (epi->nwait >= 0 && (pwq = kmem_cache_alloc(pwq_cache, SLAB_KERNEL))) {
init_waitqueue_func_entry(&pwq->wait, ep_poll_callback); init_waitqueue_func_entry(&pwq->wait, ep_poll_callback);
pwq->whead = whead; pwq->whead = whead;
pwq->base = epi; pwq->base = epi;
...@@ -912,7 +937,7 @@ static void ep_rbtree_insert(struct eventpoll *ep, struct epitem *epi) ...@@ -912,7 +937,7 @@ static void ep_rbtree_insert(struct eventpoll *ep, struct epitem *epi)
while (*p) { while (*p) {
parent = *p; parent = *p;
epic = rb_entry(parent, struct epitem, rbn); epic = rb_entry(parent, struct epitem, rbn);
kcmp = EP_CMP_FFD(&epi->ffd, &epic->ffd); kcmp = ep_cmp_ffd(&epi->ffd, &epic->ffd);
if (kcmp > 0) if (kcmp > 0)
p = &parent->rb_right; p = &parent->rb_right;
else else
...@@ -932,17 +957,17 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event, ...@@ -932,17 +957,17 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event,
struct ep_pqueue epq; struct ep_pqueue epq;
error = -ENOMEM; error = -ENOMEM;
if (!(epi = EPI_MEM_ALLOC())) if (!(epi = kmem_cache_alloc(epi_cache, SLAB_KERNEL)))
goto eexit_1; goto eexit_1;
/* Item initialization follow here ... */ /* Item initialization follow here ... */
EP_RB_INITNODE(&epi->rbn); ep_rb_initnode(&epi->rbn);
INIT_LIST_HEAD(&epi->rdllink); INIT_LIST_HEAD(&epi->rdllink);
INIT_LIST_HEAD(&epi->fllink); INIT_LIST_HEAD(&epi->fllink);
INIT_LIST_HEAD(&epi->txlink); INIT_LIST_HEAD(&epi->txlink);
INIT_LIST_HEAD(&epi->pwqlist); INIT_LIST_HEAD(&epi->pwqlist);
epi->ep = ep; epi->ep = ep;
EP_SET_FFD(&epi->ffd, tfile, fd); ep_set_ffd(&epi->ffd, tfile, fd);
epi->event = *event; epi->event = *event;
atomic_set(&epi->usecnt, 1); atomic_set(&epi->usecnt, 1);
epi->nwait = 0; epi->nwait = 0;
...@@ -978,7 +1003,7 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event, ...@@ -978,7 +1003,7 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event,
ep_rbtree_insert(ep, epi); ep_rbtree_insert(ep, epi);
/* If the file is already "ready" we drop it inside the ready list */ /* If the file is already "ready" we drop it inside the ready list */
if ((revents & event->events) && !EP_IS_LINKED(&epi->rdllink)) { if ((revents & event->events) && !ep_is_linked(&epi->rdllink)) {
list_add_tail(&epi->rdllink, &ep->rdllist); list_add_tail(&epi->rdllink, &ep->rdllist);
/* Notify waiting tasks that events are available */ /* Notify waiting tasks that events are available */
...@@ -1007,11 +1032,11 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event, ...@@ -1007,11 +1032,11 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event,
* allocated wait queue. * allocated wait queue.
*/ */
write_lock_irqsave(&ep->lock, flags); write_lock_irqsave(&ep->lock, flags);
if (EP_IS_LINKED(&epi->rdllink)) if (ep_is_linked(&epi->rdllink))
EP_LIST_DEL(&epi->rdllink); ep_list_del(&epi->rdllink);
write_unlock_irqrestore(&ep->lock, flags); write_unlock_irqrestore(&ep->lock, flags);
EPI_MEM_FREE(epi); kmem_cache_free(epi_cache, epi);
eexit_1: eexit_1:
return error; return error;
} }
...@@ -1050,14 +1075,14 @@ static int ep_modify(struct eventpoll *ep, struct epitem *epi, struct epoll_even ...@@ -1050,14 +1075,14 @@ static int ep_modify(struct eventpoll *ep, struct epitem *epi, struct epoll_even
* If the item is not linked to the hash it means that it's on its * If the item is not linked to the hash it means that it's on its
* way toward the removal. Do nothing in this case. * way toward the removal. Do nothing in this case.
*/ */
if (EP_RB_LINKED(&epi->rbn)) { if (ep_rb_linked(&epi->rbn)) {
/* /*
* If the item is "hot" and it is not registered inside the ready * If the item is "hot" and it is not registered inside the ready
* list, push it inside. If the item is not "hot" and it is currently * list, push it inside. If the item is not "hot" and it is currently
* registered inside the ready list, unlink it. * registered inside the ready list, unlink it.
*/ */
if (revents & event->events) { if (revents & event->events) {
if (!EP_IS_LINKED(&epi->rdllink)) { if (!ep_is_linked(&epi->rdllink)) {
list_add_tail(&epi->rdllink, &ep->rdllist); list_add_tail(&epi->rdllink, &ep->rdllist);
/* Notify waiting tasks that events are available */ /* Notify waiting tasks that events are available */
...@@ -1097,9 +1122,9 @@ static void ep_unregister_pollwait(struct eventpoll *ep, struct epitem *epi) ...@@ -1097,9 +1122,9 @@ static void ep_unregister_pollwait(struct eventpoll *ep, struct epitem *epi)
while (!list_empty(lsthead)) { while (!list_empty(lsthead)) {
pwq = list_entry(lsthead->next, struct eppoll_entry, llink); pwq = list_entry(lsthead->next, struct eppoll_entry, llink);
EP_LIST_DEL(&pwq->llink); ep_list_del(&pwq->llink);
remove_wait_queue(pwq->whead, &pwq->wait); remove_wait_queue(pwq->whead, &pwq->wait);
PWQ_MEM_FREE(pwq); kmem_cache_free(pwq_cache, pwq);
} }
} }
} }
...@@ -1118,7 +1143,7 @@ static int ep_unlink(struct eventpoll *ep, struct epitem *epi) ...@@ -1118,7 +1143,7 @@ static int ep_unlink(struct eventpoll *ep, struct epitem *epi)
* The check protect us from doing a double unlink ( crash ). * The check protect us from doing a double unlink ( crash ).
*/ */
error = -ENOENT; error = -ENOENT;
if (!EP_RB_LINKED(&epi->rbn)) if (!ep_rb_linked(&epi->rbn))
goto eexit_1; goto eexit_1;
/* /*
...@@ -1133,14 +1158,14 @@ static int ep_unlink(struct eventpoll *ep, struct epitem *epi) ...@@ -1133,14 +1158,14 @@ static int ep_unlink(struct eventpoll *ep, struct epitem *epi)
* This operation togheter with the above check closes the door to * This operation togheter with the above check closes the door to
* double unlinks. * double unlinks.
*/ */
EP_RB_ERASE(&epi->rbn, &ep->rbr); ep_rb_erase(&epi->rbn, &ep->rbr);
/* /*
* If the item we are going to remove is inside the ready file descriptors * If the item we are going to remove is inside the ready file descriptors
* we want to remove it from this list to avoid stale events. * we want to remove it from this list to avoid stale events.
*/ */
if (EP_IS_LINKED(&epi->rdllink)) if (ep_is_linked(&epi->rdllink))
EP_LIST_DEL(&epi->rdllink); ep_list_del(&epi->rdllink);
error = 0; error = 0;
eexit_1: eexit_1:
...@@ -1174,8 +1199,8 @@ static int ep_remove(struct eventpoll *ep, struct epitem *epi) ...@@ -1174,8 +1199,8 @@ static int ep_remove(struct eventpoll *ep, struct epitem *epi)
/* Remove the current item from the list of epoll hooks */ /* Remove the current item from the list of epoll hooks */
spin_lock(&file->f_ep_lock); spin_lock(&file->f_ep_lock);
if (EP_IS_LINKED(&epi->fllink)) if (ep_is_linked(&epi->fllink))
EP_LIST_DEL(&epi->fllink); ep_list_del(&epi->fllink);
spin_unlock(&file->f_ep_lock); spin_unlock(&file->f_ep_lock);
/* We need to acquire the write IRQ lock before calling ep_unlink() */ /* We need to acquire the write IRQ lock before calling ep_unlink() */
...@@ -1210,7 +1235,7 @@ static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync, void *k ...@@ -1210,7 +1235,7 @@ static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync, void *k
{ {
int pwake = 0; int pwake = 0;
unsigned long flags; unsigned long flags;
struct epitem *epi = EP_ITEM_FROM_WAIT(wait); struct epitem *epi = ep_item_from_wait(wait);
struct eventpoll *ep = epi->ep; struct eventpoll *ep = epi->ep;
DNPRINTK(3, (KERN_INFO "[%p] eventpoll: poll_callback(%p) epi=%p ep=%p\n", DNPRINTK(3, (KERN_INFO "[%p] eventpoll: poll_callback(%p) epi=%p ep=%p\n",
...@@ -1228,7 +1253,7 @@ static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync, void *k ...@@ -1228,7 +1253,7 @@ static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync, void *k
goto is_disabled; goto is_disabled;
/* If this file is already in the ready list we exit soon */ /* If this file is already in the ready list we exit soon */
if (EP_IS_LINKED(&epi->rdllink)) if (ep_is_linked(&epi->rdllink))
goto is_linked; goto is_linked;
list_add_tail(&epi->rdllink, &ep->rdllist); list_add_tail(&epi->rdllink, &ep->rdllist);
...@@ -1307,7 +1332,7 @@ static int ep_collect_ready_items(struct eventpoll *ep, struct list_head *txlist ...@@ -1307,7 +1332,7 @@ static int ep_collect_ready_items(struct eventpoll *ep, struct list_head *txlist
lnk = lnk->next; lnk = lnk->next;
/* If this file is already in the ready list we exit soon */ /* If this file is already in the ready list we exit soon */
if (!EP_IS_LINKED(&epi->txlink)) { if (!ep_is_linked(&epi->txlink)) {
/* /*
* This is initialized in this way so that the default * This is initialized in this way so that the default
* behaviour of the reinjecting code will be to push back * behaviour of the reinjecting code will be to push back
...@@ -1322,7 +1347,7 @@ static int ep_collect_ready_items(struct eventpoll *ep, struct list_head *txlist ...@@ -1322,7 +1347,7 @@ static int ep_collect_ready_items(struct eventpoll *ep, struct list_head *txlist
/* /*
* Unlink the item from the ready list. * Unlink the item from the ready list.
*/ */
EP_LIST_DEL(&epi->rdllink); ep_list_del(&epi->rdllink);
} }
} }
...@@ -1401,7 +1426,7 @@ static void ep_reinject_items(struct eventpoll *ep, struct list_head *txlist) ...@@ -1401,7 +1426,7 @@ static void ep_reinject_items(struct eventpoll *ep, struct list_head *txlist)
epi = list_entry(txlist->next, struct epitem, txlink); epi = list_entry(txlist->next, struct epitem, txlink);
/* Unlink the current item from the transfer list */ /* Unlink the current item from the transfer list */
EP_LIST_DEL(&epi->txlink); ep_list_del(&epi->txlink);
/* /*
* If the item is no more linked to the interest set, we don't * If the item is no more linked to the interest set, we don't
...@@ -1410,8 +1435,8 @@ static void ep_reinject_items(struct eventpoll *ep, struct list_head *txlist) ...@@ -1410,8 +1435,8 @@ static void ep_reinject_items(struct eventpoll *ep, struct list_head *txlist)
* item is set to have an Edge Triggered behaviour, we don't have * item is set to have an Edge Triggered behaviour, we don't have
* to push it back either. * to push it back either.
*/ */
if (EP_RB_LINKED(&epi->rbn) && !(epi->event.events & EPOLLET) && if (ep_rb_linked(&epi->rbn) && !(epi->event.events & EPOLLET) &&
(epi->revents & epi->event.events) && !EP_IS_LINKED(&epi->rdllink)) { (epi->revents & epi->event.events) && !ep_is_linked(&epi->rdllink)) {
list_add_tail(&epi->rdllink, &ep->rdllist); list_add_tail(&epi->rdllink, &ep->rdllist);
ricnt++; ricnt++;
} }
......
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