calloc: consolidate ENOMEM handling

We can simplify the error paths in calloc and call memset() outside
of the RCU critical section.

1 files changed, 9 insertions, 13 deletions

diff --git a/mwrap_core.h b/mwrap_core.h
index b382018..14e5d79 100644
--- a/mwrap_core.h
+++ b/mwrap_core.h
@@ -662,8 +662,7 @@ void *malloc(size_t size)
                 p = hdr2ptr(h);
         }
         update_stats_rcu_unlock(l);
-        if (caa_unlikely(!p)) errno = ENOMEM;
-        return p;
+        if (p) return p;
 enomem:
         errno = ENOMEM;
         return 0;
@@ -674,14 +673,10 @@ void *calloc(size_t nmemb, size_t size)
         size_t asize;
         size_t generation = 0;
 
-        if (__builtin_mul_overflow(size, nmemb, &size)) {
-                errno = ENOMEM;
-                return 0;
-        }
-        if (__builtin_add_overflow(size, sizeof(struct alloc_hdr), &asize)) {
-                errno = ENOMEM;
-                return 0;
-        }
+        if (__builtin_mul_overflow(size, nmemb, &size))
+                goto enomem;
+        if (__builtin_add_overflow(size, sizeof(struct alloc_hdr), &asize))
+                goto enomem;
         struct alloc_hdr *h;
         SRC_LOC_BT(bt);
         struct src_loc *l = update_stats_rcu_lock(&generation, size, &bt.sl);
@@ -689,11 +684,12 @@ void *calloc(size_t nmemb, size_t size)
         if (p) {
                 alloc_insert_rcu(l, h, size, h, generation);
                 p = hdr2ptr(h);
-                memset(p, 0, size);
         }
         update_stats_rcu_unlock(l);
-        if (caa_unlikely(!p)) errno = ENOMEM;
-        return p;
+        if (p) return memset(p, 0, size);
+enomem:
+        errno = ENOMEM;
+        return 0;
 }
 
 void *realloc(void *ptr, size_t size)