[PATCH v4 net-next 10/19] tls: Fix zerocopy_from_iter iov handling

[Boris Pismenny]

zerocopy_from_iter iterates over the message, but it doesn't revert the
updates made by the iov iteration. This patch fixes it. Now, the iov can
be used after calling zerocopy_from_iter.

Fixes: 3c4d75591 ("tls: kernel TLS support")
Signed-off-by: Boris Pismenny <bor...@mellanox.com>
---
 net/tls/tls_sw.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 2a6ba0f..ea78678 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -267,7 +267,7 @@ static int zerocopy_from_iter(struct sock *sk, struct 
iov_iter *from,
                              int length, int *pages_used,
                              unsigned int *size_used,
                              struct scatterlist *to, int to_max_pages,
-                             bool charge)
+                             bool charge, bool revert)
 {
        struct page *pages[MAX_SKB_FRAGS];
 
@@ -318,6 +318,8 @@ static int zerocopy_from_iter(struct sock *sk, struct 
iov_iter *from,
 out:
        *size_used = size;
        *pages_used = num_elem;
+       if (revert)
+               iov_iter_revert(from, size);
 
        return rc;
 }
@@ -419,7 +421,7 @@ int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, 
size_t size)
                                &ctx->sg_plaintext_size,
                                ctx->sg_plaintext_data,
                                ARRAY_SIZE(ctx->sg_plaintext_data),
-                               true);
+                               true, false);
                        if (ret)
                                goto fallback_to_reg_send;
 
@@ -834,7 +836,7 @@ int tls_sw_recvmsg(struct sock *sk,
                                err = zerocopy_from_iter(sk, &msg->msg_iter,
                                                         to_copy, &pages,
                                                         &chunk, &sgin[1],
-                                                        MAX_SKB_FRAGS, false);
+                                                        MAX_SKB_FRAGS, false, 
true);
                                if (err < 0)
                                        goto fallback_to_reg_recv;
 
-- 
1.8.3.1