From: Sagi Grimberg <sagi@grimberg.me>
Date: Wed, 26 Jun 2024 07:01:53 +0000 (+0300)
Subject: Revert "net: micro-optimize skb_datagram_iter"
X-Git-Tag: v6.11-rc1~163^2~126
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2d5f6801db8ec0ce97bc520ecd51a7be06a35042;p=thirdparty%2Flinux.git

Revert "net: micro-optimize skb_datagram_iter"

This reverts commit 934c29999b57b835d65442da6f741d5e27f3b584.
This triggered a usercopy BUG() in systems with HIGHMEM, reported
by the test robot in:
 https://lore.kernel.org/oe-lkp/202406161539.b5ff7b20-oliver.sang@intel.com

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Link: https://patch.msgid.link/20240626070153.759257-1-sagi@grimberg.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/net/core/datagram.c b/net/core/datagram.c
index 95f242591fd23..e614cfd8e14a5 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -417,14 +417,14 @@ static int __skb_datagram_iter(const struct sk_buff *skb, int offset,
 		end = start + skb_frag_size(frag);
 		if ((copy = end - offset) > 0) {
 			struct page *page = skb_frag_page(frag);
-			u8 *vaddr = kmap_local_page(page);
+			u8 *vaddr = kmap(page);
 
 			if (copy > len)
 				copy = len;
 			n = INDIRECT_CALL_1(cb, simple_copy_to_iter,
 					vaddr + skb_frag_off(frag) + offset - start,
 					copy, data, to);
-			kunmap_local(vaddr);
+			kunmap(page);
 			offset += n;
 			if (n != copy)
 				goto short_copy;