Davide Libenzi wrote:
>
> Per Linus request I implemented a syscall interface to the old /dev/epoll
> to avoid the creation of magic inodes inside /dev.
>From a (very) quick read:
+static struct vm_operations_struct eventpoll_mmap_ops = {
+ open: eventpoll_mm_open,
+ close: eventpoll_mm_close,
+};
Please use the C99 form.
+ ep = (struct eventpoll *) file->private_data;
The cast there just adds noise. private_data is void *. In
fact you lose a bit of compile-time checking by having the cast
there.
+ addr = do_mmap_pgoff(file, 0, EP_MAP_SIZE(maxfds + 1), PROT_READ | PROT_WRITE,
+ MAP_PRIVATE, 0);
You must hold current->mm->mmap-sem for writing before calling
do_mmap_pgoff(). I shall add the missing comment to do_mmap_pgoff.
+asmlinkage int sys_epoll_wait(int epfd, struct pollfd **events, int timeout)
+{
+ int error = -EBADF;
+ unsigned long eaddr;
+ struct file *file;
+ struct eventpoll *ep;
+ struct evpoll dvp;
+
+ DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_wait(%d, %p, %d)\n",
+ current, epfd, events, timeout));
+
+ file = fget(epfd);
+ if (!file)
+ goto fget_fail;
+ ep = (struct eventpoll *) file->private_data;
+
+ error = -EINVAL;
+ if (!atomic_read(&ep->mmapped))
Will oops if not passed one of your fd's?
(Ditto in sys_epoll_ctl)
+ clear_bit(PG_reserved, &virt_to_page(pages[ii])->flags);
Please use SetPageReserved()/ClearPageReserved().
+static void ep_free(struct eventpoll *ep)
+{
+ int ii;
+ struct list_head *lnk;
+
+ lock_kernel();
+ for (ii = 0; ii <= ep->hmask; ii++) {
+ while ((lnk = list_first(&ep->hash[ii]))) {
+ struct epitem *dpi = list_entry(lnk, struct epitem, llink);
+
What is locking the nodes in this hashtable? Here it seems to
be lock_kernel. Elsewhere it seems to be write_lock_irqsave(&ep->lock);
+static inline struct epitem *ep_find_nl(struct eventpoll *ep, int fd)
Should be uninlined.
+ __copy_from_user(&pfd, buffer, sizeof(pfd));
Check for EFAULT.
+ if (ep->eventcnt || !timeout)
+ break;
+ if (signal_pending(current)) {
+ res = -EINTR;
+ break;
+ }
+
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ write_unlock_irqrestore(&ep->lock, flags);
+ timeout = schedule_timeout(timeout);
You should set current->state before performing the checks.
+ if (res > 0)
+ copy_to_user((void *) arg, &dvp, sizeof(struct evpoll));
EFAULT?
+ write_lock_irqsave(&ep->lock, flags);
+
+ res = -EINVAL;
+ if (numpages != (2 * ep->numpages))
+ goto out;
+
+ start = vma->vm_start;
+ for (ii = 0; ii < ep->numpages; ii++) {
+ if (remap_page_range(vma, start, __pa(ep->pages0[ii]),
+ PAGE_SIZE, vma->vm_page_prot))
remap_page_range() can sleep in pmd_alloc(), etc. May not be called under
spinlock.
-
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This archive was generated by hypermail 2b29 : Wed Oct 23 2002 - 22:00:51 EST