[PATCH v11 08/14] net, arm64: untag user pointers in tcp_zerocopy_receive
andreyknvl at google.com
Fri Mar 15 12:51:32 PDT 2019
This patch is a part of a series that extends arm64 kernel ABI to allow to
pass tagged user pointers (with the top byte set to something else other
than 0x00) as syscall arguments.
tcp_zerocopy_receive() uses provided user pointers for vma lookups, which
can only by done with untagged pointers.
Untag user pointers in this function.
Signed-off-by: Andrey Konovalov <andreyknvl at google.com>
net/ipv4/tcp.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 6baa6dc1b13b..89db3b4fc753 100644
@@ -1758,6 +1758,8 @@ static int tcp_zerocopy_receive(struct sock *sk,
+ address = untagged_addr(address);
if (address & (PAGE_SIZE - 1) || address != zc->address)
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