Async error handling and MacOS/X fixes

In the async code for MacOS/X define _XOPEN_SOURCE (if not already
defined) as early as possible.  We must do this before including
any header files, because on MacOS/X <stlib.h> includes <signal.h>
which includes <ucontext.h>.  If we delay defining _XOPEN_SOURCE
and include <ucontext.h> after various system headers are included,
we are very likely to end up with the wrong (truncated) definition
of ucontext_t.

Also, better error handling and some code cleanup in POSIX fibre
construction and destruction.  We make sure that async_fibre_makecontext()
always initializes the fibre to a state that can be freed.

For all implementations, check for error returns from
async_fibre_makecontext().

Reviewed-by: Matt Caswell <matt@openssl.org>

1 files changed, 17 insertions, 15 deletions

diff --git a/crypto/async/async.c b/crypto/async/async.c
index 5664d99..031ca03 100644
--- a/crypto/async/async.c
+++ b/crypto/async/async.c
@@ -59,10 +59,11 @@
  */
 #undef _FORTIFY_SOURCE
 
+/* This must be the first #include file */
+#include "async_locl.h"
+
 #include <openssl/err.h>
-#include <openssl/async.h>
 #include <string.h>
-#include "async_locl.h"
 
 #define ASYNC_JOB_RUNNING   0
 #define ASYNC_JOB_PAUSING   1
@@ -168,8 +169,11 @@ static ASYNC_JOB *async_get_pool_job(void) {
             return NULL;
 
         job = async_job_new();
-        if (job) {
-            async_fibre_makecontext(&job->fibrectx);
+        if (job != NULL) {
+            if (! async_fibre_makecontext(&job->fibrectx)) {
+                async_job_free(job);
+                return NULL;
+            }
             pool->curr_size++;
         }
     }
@@ -369,22 +373,20 @@ int ASYNC_init_thread(size_t max_size, size_t init_size)
     pool->max_size = max_size;
 
     /* Pre-create jobs as required */
-    while (init_size) {
+    while (init_size--) {
         ASYNC_JOB *job;
         job = async_job_new();
-        if (job) {
-            async_fibre_makecontext(&job->fibrectx);
-            job->funcargs = NULL;
-            sk_ASYNC_JOB_push(pool->jobs, job);
-            curr_size++;
-            init_size--;
-        } else {
+        if (job == NULL || !async_fibre_makecontext(&job->fibrectx)) {
             /*
-             * Not actually fatal because we already created the pool, just skip
-             * creation of any more jobs
+             * Not actually fatal because we already created the pool, just
+             * skip creation of any more jobs
              */
-            init_size = 0;
+            async_job_free(job);
+            break;
         }
+        job->funcargs = NULL;
+        sk_ASYNC_JOB_push(pool->jobs, job);
+        curr_size++;
     }
     pool->curr_size = curr_size;
     if (!async_set_pool(pool)) {