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Diffstat (limited to 'fs/eventpoll.c')
-rw-r--r--fs/eventpoll.c48
1 files changed, 26 insertions, 22 deletions
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 6ab1dd0ca90..4284cd31eba 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -101,6 +101,10 @@
/* Maximum number of poll wake up nests we are allowing */
#define EP_MAX_POLLWAKE_NESTS 4
+/* Maximum msec timeout value storeable in a long int */
+#define EP_MAX_MSTIMEO min(1000ULL * MAX_SCHEDULE_TIMEOUT / HZ, (LONG_MAX - 999ULL) / HZ)
+
+
struct epoll_filefd {
struct file *file;
int fd;
@@ -231,8 +235,9 @@ struct ep_pqueue {
static void ep_poll_safewake_init(struct poll_safewake *psw);
static void ep_poll_safewake(struct poll_safewake *psw, wait_queue_head_t *wq);
-static int ep_getfd(int *efd, struct inode **einode, struct file **efile);
-static int ep_file_init(struct file *file);
+static int ep_getfd(int *efd, struct inode **einode, struct file **efile,
+ struct eventpoll *ep);
+static int ep_alloc(struct eventpoll **pep);
static void ep_free(struct eventpoll *ep);
static struct epitem *ep_find(struct eventpoll *ep, struct file *file, int fd);
static void ep_use_epitem(struct epitem *epi);
@@ -501,38 +506,37 @@ void eventpoll_release_file(struct file *file)
asmlinkage long sys_epoll_create(int size)
{
int error, fd;
+ struct eventpoll *ep;
struct inode *inode;
struct file *file;
DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_create(%d)\n",
current, size));
- /* Sanity check on the size parameter */
+ /*
+ * Sanity check on the size parameter, and create the internal data
+ * structure ( "struct eventpoll" ).
+ */
error = -EINVAL;
- if (size <= 0)
+ if (size <= 0 || (error = ep_alloc(&ep)) != 0)
goto eexit_1;
/*
* Creates all the items needed to setup an eventpoll file. That is,
* a file structure, and inode and a free file descriptor.
*/
- error = ep_getfd(&fd, &inode, &file);
- if (error)
- goto eexit_1;
-
- /* Setup the file internal data structure ( "struct eventpoll" ) */
- error = ep_file_init(file);
+ error = ep_getfd(&fd, &inode, &file, ep);
if (error)
goto eexit_2;
-
DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_create(%d) = %d\n",
current, size, fd));
return fd;
eexit_2:
- sys_close(fd);
+ ep_free(ep);
+ kfree(ep);
eexit_1:
DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_create(%d) = %d\n",
current, size, error));
@@ -706,7 +710,8 @@ eexit_1:
/*
* Creates the file descriptor to be used by the epoll interface.
*/
-static int ep_getfd(int *efd, struct inode **einode, struct file **efile)
+static int ep_getfd(int *efd, struct inode **einode, struct file **efile,
+ struct eventpoll *ep)
{
struct qstr this;
char name[32];
@@ -756,7 +761,7 @@ static int ep_getfd(int *efd, struct inode **einode, struct file **efile)
file->f_op = &eventpoll_fops;
file->f_mode = FMODE_READ;
file->f_version = 0;
- file->private_data = NULL;
+ file->private_data = ep;
/* Install the new setup file into the allocated fd. */
fd_install(fd, file);
@@ -777,14 +782,13 @@ eexit_1:
}
-static int ep_file_init(struct file *file)
+static int ep_alloc(struct eventpoll **pep)
{
- struct eventpoll *ep;
+ struct eventpoll *ep = kzalloc(sizeof(*ep), GFP_KERNEL);
- if (!(ep = kmalloc(sizeof(struct eventpoll), GFP_KERNEL)))
+ if (!ep)
return -ENOMEM;
- memset(ep, 0, sizeof(*ep));
rwlock_init(&ep->lock);
init_rwsem(&ep->sem);
init_waitqueue_head(&ep->wq);
@@ -792,9 +796,9 @@ static int ep_file_init(struct file *file)
INIT_LIST_HEAD(&ep->rdllist);
ep->rbr = RB_ROOT;
- file->private_data = ep;
+ *pep = ep;
- DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ep_file_init() ep=%p\n",
+ DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ep_alloc() ep=%p\n",
current, ep));
return 0;
}
@@ -1506,8 +1510,8 @@ static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events,
* and the overflow condition. The passed timeout is in milliseconds,
* that why (t * HZ) / 1000.
*/
- jtimeout = timeout == -1 || timeout > (MAX_SCHEDULE_TIMEOUT - 1000) / HZ ?
- MAX_SCHEDULE_TIMEOUT: (timeout * HZ + 999) / 1000;
+ jtimeout = (timeout < 0 || timeout >= EP_MAX_MSTIMEO) ?
+ MAX_SCHEDULE_TIMEOUT : (timeout * HZ + 999) / 1000;
retry:
write_lock_irqsave(&ep->lock, flags);