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authorDavid S. Miller <davem@davemloft.net>2019-11-06 17:33:32 -0800
committerDavid S. Miller <davem@davemloft.net>2019-11-06 17:33:32 -0800
commit9990a79d8fe21ba9598e8d98383552a9fea632da (patch)
treec15a43aa3ea0d35d17e7e2bcbadd19a07439bfd2
parent17fdd7638cb687cd7f15a48545f25d738f0101e0 (diff)
parent41098af59d8d753aa8d3bb4310cc4ecb61fc82c7 (diff)
downloadlinux-9990a79d8fe21ba9598e8d98383552a9fea632da.tar.bz2
Merge branch 'net-tls-add-a-TX-lock'
Jakub Kicinski says: ==================== net/tls: add a TX lock Some time ago Pooja and Mallesham started reporting crashes with an async accelerator. After trying to poke the existing logic into shape I came to the conclusion that it can't be trusted, and to preserve our sanity we should just add a lock around the TX side. First patch removes the sk_write_pending checks from the write space callbacks. Those don't seem to have a logical justification. Patch 2 adds the TX lock and patch 3 associated test (which should hang with current net). Mallesham reports that even with these fixes applied the async accelerator workload still occasionally hangs waiting for socket memory. I suspect that's strictly related to the way async crypto is integrated in TLS, so I think we should get these into net or net-next and move from there. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/tls.h5
-rw-r--r--net/tls/tls_device.c10
-rw-r--r--net/tls/tls_main.c2
-rw-r--r--net/tls/tls_sw.c30
-rw-r--r--tools/testing/selftests/net/tls.c108
5 files changed, 134 insertions, 21 deletions
diff --git a/include/net/tls.h b/include/net/tls.h
index c664e6dba0d1..794e297483ea 100644
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -40,6 +40,7 @@
#include <linux/socket.h>
#include <linux/tcp.h>
#include <linux/skmsg.h>
+#include <linux/mutex.h>
#include <linux/netdevice.h>
#include <linux/rcupdate.h>
@@ -269,6 +270,10 @@ struct tls_context {
bool in_tcp_sendpages;
bool pending_open_record_frags;
+
+ struct mutex tx_lock; /* protects partially_sent_* fields and
+ * per-type TX fields
+ */
unsigned long flags;
/* cache cold stuff */
diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index f959487c5cd1..683d00837693 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -523,8 +523,10 @@ last_record:
int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
{
unsigned char record_type = TLS_RECORD_TYPE_DATA;
+ struct tls_context *tls_ctx = tls_get_ctx(sk);
int rc;
+ mutex_lock(&tls_ctx->tx_lock);
lock_sock(sk);
if (unlikely(msg->msg_controllen)) {
@@ -538,12 +540,14 @@ int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
out:
release_sock(sk);
+ mutex_unlock(&tls_ctx->tx_lock);
return rc;
}
int tls_device_sendpage(struct sock *sk, struct page *page,
int offset, size_t size, int flags)
{
+ struct tls_context *tls_ctx = tls_get_ctx(sk);
struct iov_iter msg_iter;
char *kaddr = kmap(page);
struct kvec iov;
@@ -552,6 +556,7 @@ int tls_device_sendpage(struct sock *sk, struct page *page,
if (flags & MSG_SENDPAGE_NOTLAST)
flags |= MSG_MORE;
+ mutex_lock(&tls_ctx->tx_lock);
lock_sock(sk);
if (flags & MSG_OOB) {
@@ -568,6 +573,7 @@ int tls_device_sendpage(struct sock *sk, struct page *page,
out:
release_sock(sk);
+ mutex_unlock(&tls_ctx->tx_lock);
return rc;
}
@@ -623,9 +629,11 @@ static int tls_device_push_pending_record(struct sock *sk, int flags)
void tls_device_write_space(struct sock *sk, struct tls_context *ctx)
{
- if (!sk->sk_write_pending && tls_is_partially_sent_record(ctx)) {
+ if (tls_is_partially_sent_record(ctx)) {
gfp_t sk_allocation = sk->sk_allocation;
+ WARN_ON_ONCE(sk->sk_write_pending);
+
sk->sk_allocation = GFP_ATOMIC;
tls_push_partial_record(sk, ctx,
MSG_DONTWAIT | MSG_NOSIGNAL |
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index ac88877dcade..0775ae40fcfb 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -267,6 +267,7 @@ void tls_ctx_free(struct sock *sk, struct tls_context *ctx)
memzero_explicit(&ctx->crypto_send, sizeof(ctx->crypto_send));
memzero_explicit(&ctx->crypto_recv, sizeof(ctx->crypto_recv));
+ mutex_destroy(&ctx->tx_lock);
if (sk)
kfree_rcu(ctx, rcu);
@@ -612,6 +613,7 @@ static struct tls_context *create_ctx(struct sock *sk)
if (!ctx)
return NULL;
+ mutex_init(&ctx->tx_lock);
rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
ctx->sk_proto = sk->sk_prot;
return ctx;
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index c2b5e0d2ba1a..446f23c1f3ce 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -897,15 +897,9 @@ int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL))
return -ENOTSUPP;
+ mutex_lock(&tls_ctx->tx_lock);
lock_sock(sk);
- /* Wait till there is any pending write on socket */
- if (unlikely(sk->sk_write_pending)) {
- ret = wait_on_pending_writer(sk, &timeo);
- if (unlikely(ret))
- goto send_end;
- }
-
if (unlikely(msg->msg_controllen)) {
ret = tls_proccess_cmsg(sk, msg, &record_type);
if (ret) {
@@ -1091,6 +1085,7 @@ send_end:
ret = sk_stream_error(sk, msg->msg_flags, ret);
release_sock(sk);
+ mutex_unlock(&tls_ctx->tx_lock);
return copied ? copied : ret;
}
@@ -1114,13 +1109,6 @@ static int tls_sw_do_sendpage(struct sock *sk, struct page *page,
eor = !(flags & (MSG_MORE | MSG_SENDPAGE_NOTLAST));
sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
- /* Wait till there is any pending write on socket */
- if (unlikely(sk->sk_write_pending)) {
- ret = wait_on_pending_writer(sk, &timeo);
- if (unlikely(ret))
- goto sendpage_end;
- }
-
/* Call the sk_stream functions to manage the sndbuf mem. */
while (size > 0) {
size_t copy, required_size;
@@ -1219,15 +1207,18 @@ sendpage_end:
int tls_sw_sendpage(struct sock *sk, struct page *page,
int offset, size_t size, int flags)
{
+ struct tls_context *tls_ctx = tls_get_ctx(sk);
int ret;
if (flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |
MSG_SENDPAGE_NOTLAST | MSG_SENDPAGE_NOPOLICY))
return -ENOTSUPP;
+ mutex_lock(&tls_ctx->tx_lock);
lock_sock(sk);
ret = tls_sw_do_sendpage(sk, page, offset, size, flags);
release_sock(sk);
+ mutex_unlock(&tls_ctx->tx_lock);
return ret;
}
@@ -2170,9 +2161,11 @@ static void tx_work_handler(struct work_struct *work)
if (!test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask))
return;
+ mutex_lock(&tls_ctx->tx_lock);
lock_sock(sk);
tls_tx_records(sk, -1);
release_sock(sk);
+ mutex_unlock(&tls_ctx->tx_lock);
}
void tls_sw_write_space(struct sock *sk, struct tls_context *ctx)
@@ -2180,12 +2173,9 @@ void tls_sw_write_space(struct sock *sk, struct tls_context *ctx)
struct tls_sw_context_tx *tx_ctx = tls_sw_ctx_tx(ctx);
/* Schedule the transmission if tx list is ready */
- if (is_tx_ready(tx_ctx) && !sk->sk_write_pending) {
- /* Schedule the transmission */
- if (!test_and_set_bit(BIT_TX_SCHEDULED,
- &tx_ctx->tx_bitmask))
- schedule_delayed_work(&tx_ctx->tx_work.work, 0);
- }
+ if (is_tx_ready(tx_ctx) &&
+ !test_and_set_bit(BIT_TX_SCHEDULED, &tx_ctx->tx_bitmask))
+ schedule_delayed_work(&tx_ctx->tx_work.work, 0);
}
void tls_sw_strparser_arm(struct sock *sk, struct tls_context *tls_ctx)
diff --git a/tools/testing/selftests/net/tls.c b/tools/testing/selftests/net/tls.c
index 4c285b6e1db8..1c8f194d6556 100644
--- a/tools/testing/selftests/net/tls.c
+++ b/tools/testing/selftests/net/tls.c
@@ -898,6 +898,114 @@ TEST_F(tls, nonblocking)
}
}
+static void
+test_mutliproc(struct __test_metadata *_metadata, struct _test_data_tls *self,
+ bool sendpg, unsigned int n_readers, unsigned int n_writers)
+{
+ const unsigned int n_children = n_readers + n_writers;
+ const size_t data = 6 * 1000 * 1000;
+ const size_t file_sz = data / 100;
+ size_t read_bias, write_bias;
+ int i, fd, child_id;
+ char buf[file_sz];
+ pid_t pid;
+
+ /* Only allow multiples for simplicity */
+ ASSERT_EQ(!(n_readers % n_writers) || !(n_writers % n_readers), true);
+ read_bias = n_writers / n_readers ?: 1;
+ write_bias = n_readers / n_writers ?: 1;
+
+ /* prep a file to send */
+ fd = open("/tmp/", O_TMPFILE | O_RDWR, 0600);
+ ASSERT_GE(fd, 0);
+
+ memset(buf, 0xac, file_sz);
+ ASSERT_EQ(write(fd, buf, file_sz), file_sz);
+
+ /* spawn children */
+ for (child_id = 0; child_id < n_children; child_id++) {
+ pid = fork();
+ ASSERT_NE(pid, -1);
+ if (!pid)
+ break;
+ }
+
+ /* parent waits for all children */
+ if (pid) {
+ for (i = 0; i < n_children; i++) {
+ int status;
+
+ wait(&status);
+ EXPECT_EQ(status, 0);
+ }
+
+ return;
+ }
+
+ /* Split threads for reading and writing */
+ if (child_id < n_readers) {
+ size_t left = data * read_bias;
+ char rb[8001];
+
+ while (left) {
+ int res;
+
+ res = recv(self->cfd, rb,
+ left > sizeof(rb) ? sizeof(rb) : left, 0);
+
+ EXPECT_GE(res, 0);
+ left -= res;
+ }
+ } else {
+ size_t left = data * write_bias;
+
+ while (left) {
+ int res;
+
+ ASSERT_EQ(lseek(fd, 0, SEEK_SET), 0);
+ if (sendpg)
+ res = sendfile(self->fd, fd, NULL,
+ left > file_sz ? file_sz : left);
+ else
+ res = send(self->fd, buf,
+ left > file_sz ? file_sz : left, 0);
+
+ EXPECT_GE(res, 0);
+ left -= res;
+ }
+ }
+}
+
+TEST_F(tls, mutliproc_even)
+{
+ test_mutliproc(_metadata, self, false, 6, 6);
+}
+
+TEST_F(tls, mutliproc_readers)
+{
+ test_mutliproc(_metadata, self, false, 4, 12);
+}
+
+TEST_F(tls, mutliproc_writers)
+{
+ test_mutliproc(_metadata, self, false, 10, 2);
+}
+
+TEST_F(tls, mutliproc_sendpage_even)
+{
+ test_mutliproc(_metadata, self, true, 6, 6);
+}
+
+TEST_F(tls, mutliproc_sendpage_readers)
+{
+ test_mutliproc(_metadata, self, true, 4, 12);
+}
+
+TEST_F(tls, mutliproc_sendpage_writers)
+{
+ test_mutliproc(_metadata, self, true, 10, 2);
+}
+
TEST_F(tls, control_msg)
{
if (self->notls)