Commit 2edb7b55 authored by Oleg Nesterov's avatar Oleg Nesterov
Browse files

uprobes: Change __copy_insn() to use copy_from_page() 



Change __copy_insn() to use copy_from_page() and simplify the code.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarAnton Arapov <anton@redhat.com>
Acked-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
parent ab0d805c

kernel/events/uprobes.c

+2 −11
Original line number Diff line number Diff line
@@ -500,30 +500,21 @@ __copy_insn(struct address_space *mapping, struct file *filp, char *insn, 
			unsigned long nbytes, loff_t offset)

{

	struct page *page;

	void *vaddr;

	unsigned long off;

	pgoff_t idx;



	if (!filp)

		return -EINVAL;



	if (!mapping->a_ops->readpage)

		return -EIO;



	idx = offset >> PAGE_CACHE_SHIFT;

	off = offset & ~PAGE_MASK;



	/*

	 * Ensure that the page that has the original instruction is

	 * populated and in page-cache.

	 */

	page = read_mapping_page(mapping, idx, filp);

	page = read_mapping_page(mapping, offset >> PAGE_CACHE_SHIFT, filp);

	if (IS_ERR(page))

		return PTR_ERR(page);



	vaddr = kmap_atomic(page);

	memcpy(insn, vaddr + off, nbytes);

	kunmap_atomic(vaddr);

	copy_from_page(page, offset, insn, nbytes);

	page_cache_release(page);



	return 0;