net: allow skb_datagram_iter to be called from any context

[ Upstream commit d2d30a376d ]

We only use the mapping in a single context, so kmap_local is sufficient
and cheaper. Make sure to use skb_frag_foreach_page as skb frags may
contain compound pages and we need to map page by page.

Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202406161539.b5ff7b20-oliver.sang@intel.com
Fixes: 950fcaecd5 ("datagram: consolidate datagram copy to iter helpers")
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Link: https://patch.msgid.link/20240626100008.831849-1-sagi@grimberg.me
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Sagi Grimberg 2024-06-26 13:00:08 +03:00 committed by Greg Kroah-Hartman
parent 895f5633a0
commit 702b17f72d

View File

@ -434,15 +434,22 @@ static int __skb_datagram_iter(const struct sk_buff *skb, int offset,
end = start + skb_frag_size(frag); end = start + skb_frag_size(frag);
if ((copy = end - offset) > 0) { if ((copy = end - offset) > 0) {
struct page *page = skb_frag_page(frag); u32 p_off, p_len, copied;
u8 *vaddr = kmap(page); struct page *p;
u8 *vaddr;
if (copy > len) if (copy > len)
copy = len; copy = len;
skb_frag_foreach_page(frag,
skb_frag_off(frag) + offset - start,
copy, p, p_off, p_len, copied) {
vaddr = kmap_local_page(p);
n = INDIRECT_CALL_1(cb, simple_copy_to_iter, n = INDIRECT_CALL_1(cb, simple_copy_to_iter,
vaddr + skb_frag_off(frag) + offset - start, vaddr + p_off, p_len, data, to);
copy, data, to); kunmap_local(vaddr);
kunmap(page); }
offset += n; offset += n;
if (n != copy) if (n != copy)
goto short_copy; goto short_copy;