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@@ -1160,36 +1160,6 @@ static long do_splice(struct file *in, loff_t __user *off_in,
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return -EINVAL;
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}
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-/*
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- * Do a copy-from-user while holding the mmap_semaphore for reading, in a
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- * manner safe from deadlocking with simultaneous mmap() (grabbing mmap_sem
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- * for writing) and page faulting on the user memory pointed to by src.
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- * This assumes that we will very rarely hit the partial != 0 path, or this
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- * will not be a win.
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- */
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-static int copy_from_user_mmap_sem(void *dst, const void __user *src, size_t n)
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-{
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- int partial;
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-
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- if (!access_ok(VERIFY_READ, src, n))
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- return -EFAULT;
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-
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- pagefault_disable();
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- partial = __copy_from_user_inatomic(dst, src, n);
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- pagefault_enable();
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-
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- /*
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- * Didn't copy everything, drop the mmap_sem and do a faulting copy
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- */
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- if (unlikely(partial)) {
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- up_read(¤t->mm->mmap_sem);
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- partial = copy_from_user(dst, src, n);
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- down_read(¤t->mm->mmap_sem);
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- }
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-
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- return partial;
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-}
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-
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/*
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* Map an iov into an array of pages and offset/length tupples. With the
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* partial_page structure, we can map several non-contiguous ranges into
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@@ -1203,8 +1173,6 @@ static int get_iovec_page_array(const struct iovec __user *iov,
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{
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int buffers = 0, error = 0;
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- down_read(¤t->mm->mmap_sem);
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-
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while (nr_vecs) {
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unsigned long off, npages;
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struct iovec entry;
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@@ -1213,7 +1181,7 @@ static int get_iovec_page_array(const struct iovec __user *iov,
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int i;
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error = -EFAULT;
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- if (copy_from_user_mmap_sem(&entry, iov, sizeof(entry)))
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+ if (copy_from_user(&entry, iov, sizeof(entry)))
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break;
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base = entry.iov_base;
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@@ -1247,9 +1215,8 @@ static int get_iovec_page_array(const struct iovec __user *iov,
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if (npages > PIPE_BUFFERS - buffers)
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npages = PIPE_BUFFERS - buffers;
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- error = get_user_pages(current, current->mm,
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- (unsigned long) base, npages, 0, 0,
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- &pages[buffers], NULL);
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+ error = get_user_pages_fast((unsigned long)base, npages,
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+ 0, &pages[buffers]);
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if (unlikely(error <= 0))
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break;
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@@ -1288,8 +1255,6 @@ static int get_iovec_page_array(const struct iovec __user *iov,
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iov++;
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}
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- up_read(¤t->mm->mmap_sem);
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-
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if (buffers)
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return buffers;
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