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diff --git a/cipher-ctr-mt.c b/cipher-ctr-mt.c
index fdc9b2f..300cd90 100644
--- a/cipher-ctr-mt.c
+++ b/cipher-ctr-mt.c
@@ -127,7 +127,7 @@ struct kq {
u_char keys[KQLEN][AES_BLOCK_SIZE];
u_char ctr[AES_BLOCK_SIZE];
u_char pad0[CACHELINE_LEN];
- volatile int qstate;
+ int qstate;
pthread_mutex_t lock;
pthread_cond_t cond;
u_char pad1[CACHELINE_LEN];
@@ -141,6 +141,11 @@ struct ssh_aes_ctr_ctx
STATS_STRUCT(stats);
u_char aes_counter[AES_BLOCK_SIZE];
pthread_t tid[CIPHER_THREADS];
+ pthread_rwlock_t tid_lock;
+#ifdef __APPLE__
+ pthread_rwlock_t stop_lock;
+ int exit_flag;
+#endif /* __APPLE__ */
int state;
int qidx;
int ridx;
@@ -187,6 +192,57 @@ thread_loop_cleanup(void *x)
pthread_mutex_unlock((pthread_mutex_t *)x);
}
+#ifdef __APPLE__
+/* Check if we should exit, we are doing both cancel and exit condition
+ * since on OSX threads seem to occasionally fail to notice when they have
+ * been cancelled. We want to have a backup to make sure that we won't hang
+ * when the main process join()-s the cancelled thread.
+ */
+static void
+thread_loop_check_exit(struct ssh_aes_ctr_ctx *c)
+{
+ int exit_flag;
+
+ pthread_rwlock_rdlock(&c->stop_lock);
+ exit_flag = c->exit_flag;
+ pthread_rwlock_unlock(&c->stop_lock);
+
+ if (exit_flag)
+ pthread_exit(NULL);
+}
+#else
+# define thread_loop_check_exit(s)
+#endif /* __APPLE__ */
+
+/*
+ * Helper function to terminate the helper threads
+ */
+static void
+stop_and_join_pregen_threads(struct ssh_aes_ctr_ctx *c)
+{
+ int i;
+
+#ifdef __APPLE__
+ /* notify threads that they should exit */
+ pthread_rwlock_wrlock(&c->stop_lock);
+ c->exit_flag = TRUE;
+ pthread_rwlock_unlock(&c->stop_lock);
+#endif /* __APPLE__ */
+
+ /* Cancel pregen threads */
+ for (i = 0; i < CIPHER_THREADS; i++) {
+ pthread_cancel(c->tid[i]);
+ }
+ for (i = 0; i < NUMKQ; i++) {
+ pthread_mutex_lock(&c->q[i].lock);
+ pthread_cond_broadcast(&c->q[i].cond);
+ pthread_mutex_unlock(&c->q[i].lock);
+ }
+ for (i = 0; i < CIPHER_THREADS; i++) {
+ pthread_join(c->tid[i], NULL);
+ }
+}
+
/*
* The life of a pregen thread:
* Find empty keystream queues and fill them using their counter.
@@ -201,6 +257,7 @@ thread_loop(void *x)
struct kq *q;
int i;
int qidx;
+ pthread_t first_tid;
/* Threads stats on cancellation */
STATS_INIT(stats);
@@ -211,11 +268,15 @@ thread_loop(void *x)
/* Thread local copy of AES key */
memcpy(&key, &c->aes_ctx, sizeof(key));
+ pthread_rwlock_rdlock(&c->tid_lock);
+ first_tid = c->tid[0];
+ pthread_rwlock_unlock(&c->tid_lock);
+
/*
* Handle the special case of startup, one thread must fill
* the first KQ then mark it as draining. Lock held throughout.
*/
- if (pthread_equal(pthread_self(), c->tid[0])) {
+ if (pthread_equal(pthread_self(), first_tid)) {
q = &c->q[0];
pthread_mutex_lock(&q->lock);
if (q->qstate == KQINIT) {
@@ -245,12 +306,16 @@ thread_loop(void *x)
/* Check if I was cancelled, also checked in cond_wait */
pthread_testcancel();
+ /* Check if we should exit as well */
+ thread_loop_check_exit(c);
+
/* Lock queue and block if its draining */
q = &c->q[qidx];
pthread_mutex_lock(&q->lock);
pthread_cleanup_push(thread_loop_cleanup, &q->lock);
while (q->qstate == KQDRAINING || q->qstate == KQINIT) {
STATS_WAIT(stats);
+ thread_loop_check_exit(c);
pthread_cond_wait(&q->cond, &q->lock);
}
pthread_cleanup_pop(0);
@@ -268,6 +333,7 @@ thread_loop(void *x)
* can see that it's being filled.
*/
q->qstate = KQFILLING;
+ pthread_cond_broadcast(&q->cond);
pthread_mutex_unlock(&q->lock);
for (i = 0; i < KQLEN; i++) {
AES_encrypt(q->ctr, q->keys[i], &key);
@@ -279,7 +345,7 @@ thread_loop(void *x)
ssh_ctr_add(q->ctr, KQLEN * (NUMKQ - 1), AES_BLOCK_SIZE);
q->qstate = KQFULL;
STATS_FILL(stats);
- pthread_cond_signal(&q->cond);
+ pthread_cond_broadcast(&q->cond);
pthread_mutex_unlock(&q->lock);
}
@@ -371,6 +437,7 @@ ssh_aes_ctr(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src,
pthread_cond_wait(&q->cond, &q->lock);
}
q->qstate = KQDRAINING;
+ pthread_cond_broadcast(&q->cond);
pthread_mutex_unlock(&q->lock);
/* Mark consumed queue empty and signal producers */
@@ -397,6 +464,11 @@ ssh_aes_ctr_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv,
if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
c = xmalloc(sizeof(*c));
+ pthread_rwlock_init(&c->tid_lock, NULL);
+#ifdef __APPLE__
+ pthread_rwlock_init(&c->stop_lock, NULL);
+ c->exit_flag = FALSE;
+#endif /* __APPLE__ */
c->state = HAVE_NONE;
for (i = 0; i < NUMKQ; i++) {
@@ -409,11 +481,14 @@ ssh_aes_ctr_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv,
}
if (c->state == (HAVE_KEY | HAVE_IV)) {
- /* Cancel pregen threads */
- for (i = 0; i < CIPHER_THREADS; i++)
- pthread_cancel(c->tid[i]);
- for (i = 0; i < CIPHER_THREADS; i++)
- pthread_join(c->tid[i], NULL);
+ /* tell the pregen threads to exit */
+ stop_and_join_pregen_threads(c);
+
+#ifdef __APPLE__
+ /* reset the exit flag */
+ c->exit_flag = FALSE;
+#endif /* __APPLE__ */
+
/* Start over getting key & iv */
c->state = HAVE_NONE;
}
@@ -444,10 +519,12 @@ ssh_aes_ctr_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv,
/* Start threads */
for (i = 0; i < CIPHER_THREADS; i++) {
debug("spawned a thread");
+ pthread_rwlock_wrlock(&c->tid_lock);
pthread_create(&c->tid[i], NULL, thread_loop, c);
+ pthread_rwlock_unlock(&c->tid_lock);
}
pthread_mutex_lock(&c->q[0].lock);
- while (c->q[0].qstate != KQDRAINING)
+ while (c->q[0].qstate == KQINIT)
pthread_cond_wait(&c->q[0].cond, &c->q[0].lock);
pthread_mutex_unlock(&c->q[0].lock);
}
@@ -461,15 +538,10 @@ void
ssh_aes_ctr_thread_destroy(EVP_CIPHER_CTX *ctx)
{
struct ssh_aes_ctr_ctx *c;
- int i;
+
c = EVP_CIPHER_CTX_get_app_data(ctx);
- /* destroy threads */
- for (i = 0; i < CIPHER_THREADS; i++) {
- pthread_cancel(c->tid[i]);
- }
- for (i = 0; i < CIPHER_THREADS; i++) {
- pthread_join(c->tid[i], NULL);
- }
+
+ stop_and_join_pregen_threads(c);
}
void
@@ -481,7 +553,9 @@ ssh_aes_ctr_thread_reconstruction(EVP_CIPHER_CTX *ctx)
/* reconstruct threads */
for (i = 0; i < CIPHER_THREADS; i++) {
debug("spawned a thread");
+ pthread_rwlock_wrlock(&c->tid_lock);
pthread_create(&c->tid[i], NULL, thread_loop, c);
+ pthread_rwlock_unlock(&c->tid_lock);
}
}
@@ -489,18 +563,13 @@ static int
ssh_aes_ctr_cleanup(EVP_CIPHER_CTX *ctx)
{
struct ssh_aes_ctr_ctx *c;
- int i;
if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) {
#ifdef CIPHER_THREAD_STATS
debug("main thread: %u drains, %u waits", c->stats.drains,
c->stats.waits);
#endif
- /* Cancel pregen threads */
- for (i = 0; i < CIPHER_THREADS; i++)
- pthread_cancel(c->tid[i]);
- for (i = 0; i < CIPHER_THREADS; i++)
- pthread_join(c->tid[i], NULL);
+ stop_and_join_pregen_threads(c);
memset(c, 0, sizeof(*c));
free(c);
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