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Commit 9acc1a0f authored by Al Viro's avatar Al Viro
Browse files

process_vm_access: don't bother with returning the amounts of bytes copied 



we can calculate that in the caller just fine, TYVM

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent e21345f9

mm/process_vm_access.c

+16 −31
Original line number Diff line number Diff line
@@ -43,13 +43,10 @@ static int process_vm_rw_pages(struct page **pages, 
			       unsigned offset,

			       size_t len,

			       struct iov_iter *iter,

			       int vm_write,

			       ssize_t *bytes_copied)

			       int vm_write)

{

	*bytes_copied = 0;



	/* Do the copy for each page */

	while (iov_iter_count(iter) && len) {

	while (len && iov_iter_count(iter)) {

		struct page *page = *pages++;

		size_t copy = PAGE_SIZE - offset;

		size_t copied;
@@ -67,7 +64,6 @@ static int process_vm_rw_pages(struct page **pages, 
		} else {

			copied = copy_page_to_iter(page, offset, copy, iter);

		}

		*bytes_copied += copied;

		len -= copied;

		if (copied < copy && iov_iter_count(iter))

			return -EFAULT;
@@ -101,20 +97,16 @@ static int process_vm_rw_single_vec(unsigned long addr, 
				    struct page **process_pages,

				    struct mm_struct *mm,

				    struct task_struct *task,

				    int vm_write,

				    ssize_t *bytes_copied)

				    int vm_write)

{

	unsigned long pa = addr & PAGE_MASK;

	unsigned long start_offset = addr - pa;

	unsigned long nr_pages;

	ssize_t bytes_copied_loop;

	ssize_t rc = 0;

	unsigned long nr_pages_copied = 0;

	unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES

		/ sizeof(struct pages *);



	*bytes_copied = 0;



	/* Work out address and page range required */

	if (len == 0)

		return 0;
@@ -143,11 +135,9 @@ static int process_vm_rw_single_vec(unsigned long addr, 


		rc = process_vm_rw_pages(process_pages,

					 start_offset, n, iter,

					 vm_write,

					 &bytes_copied_loop);

					 vm_write);

		len -= n;

		start_offset = 0;

		*bytes_copied += bytes_copied_loop;

		nr_pages_copied += pages_pinned;

		pa += pages_pinned * PAGE_SIZE;

		while (pages_pinned)
@@ -187,11 +177,10 @@ static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter, 
	struct mm_struct *mm;

	unsigned long i;

	ssize_t rc = 0;

	ssize_t bytes_copied_loop;

	ssize_t bytes_copied = 0;

	unsigned long nr_pages = 0;

	unsigned long nr_pages_iov;

	ssize_t iov_len;

	size_t total_len = iov_iter_count(iter);



	/*

	 * Work out how many pages of struct pages we're going to need
@@ -245,24 +234,20 @@ static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter, 
		goto put_task_struct;

	}



	for (i = 0; i < riovcnt && iov_iter_count(iter); i++) {

	for (i = 0; i < riovcnt && iov_iter_count(iter) && !rc; i++)

		rc = process_vm_rw_single_vec(

			(unsigned long)rvec[i].iov_base, rvec[i].iov_len,

			iter, process_pages, mm, task, vm_write,

			&bytes_copied_loop);

		bytes_copied += bytes_copied_loop;

		if (rc != 0) {

			iter, process_pages, mm, task, vm_write);



	/* copied = space before - space after */

	total_len -= iov_iter_count(iter);



	/* If we have managed to copy any data at all then

	   we return the number of bytes copied. Otherwise

	   we return the error code */

			if (bytes_copied)

				rc = bytes_copied;

			goto put_mm;

		}

	}

	if (total_len)

		rc = total_len;



	rc = bytes_copied;

put_mm:

	mmput(mm);



put_task_struct: