[PATCH 5.3 127/135] net/tls: use sg_next() to walk sg entries

Greg Kroah-Hartman
2019-12-03T23:08:55Z

From: Jakub Kicinski <jakub.kicinski@netronome.com>

[ Upstream commit c5daa6cccdc2f94aca2c9b3fa5f94e4469997293 ]

Partially sent record cleanup path increments an SG entry
directly instead of using sg_next(). This should not be a
problem today, as encrypted messages should be always
allocated as arrays. But given this is a cleanup path it's
easy to miss was this ever to change. Use sg_next(), and
simplify the code.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/net/tls.h | 2 +-
net/tls/tls_main.c | 13 ++-----------
net/tls/tls_sw.c | 3 ++-
3 files changed, 5 insertions(+), 13 deletions(-)

--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -407,7 +407,7 @@ int tls_push_sg(struct sock *sk, struct
int flags);
int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
int flags);
-bool tls_free_partial_record(struct sock *sk, struct tls_context *ctx);
+void tls_free_partial_record(struct sock *sk, struct tls_context *ctx);

static inline struct tls_msg *tls_msg(struct sk_buff *skb)
{
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -208,24 +208,15 @@ int tls_push_partial_record(struct sock
return tls_push_sg(sk, ctx, sg, offset, flags);
}

-bool tls_free_partial_record(struct sock *sk, struct tls_context *ctx)
+void tls_free_partial_record(struct sock *sk, struct tls_context *ctx)
{
struct scatterlist *sg;

- sg = ctx->partially_sent_record;
- if (!sg)
- return false;
-
- while (1) {
+ for (sg = ctx->partially_sent_record; sg; sg = sg_next(sg)) {
put_page(sg_page(sg));
sk_mem_uncharge(sk, sg->length);
-
- if (sg_is_last(sg))
- break;
- sg++;
}
ctx->partially_sent_record = NULL;
- return true;
}

static void tls_write_space(struct sock *sk)
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -2086,7 +2086,8 @@ void tls_sw_release_resources_tx(struct
/* Free up un-sent records in tx_list. First, free
* the partially sent record if any at head of tx_list.
*/
- if (tls_free_partial_record(sk, tls_ctx)) {
+ if (tls_ctx->partially_sent_record) {
+ tls_free_partial_record(sk, tls_ctx);
rec = list_first_entry(&ctx->tx_list,
struct tls_rec, list);
list_del(&rec->list);