From 2671709e62e51d103dc067e86c4b0bbbffa98d41 Mon Sep 17 00:00:00 2001
From: Xiang Xiao <xiaoxiang@xiaomi.com>
Date: Sat, 26 Jan 2019 10:42:36 -0600
Subject: [PATCH] mm/umm_heap: Ensure all user allocation try sbrk before fail

---
 mm/umm_heap/umm_calloc.c   | 27 +++++++++++++++++++++++++++
 mm/umm_heap/umm_memalign.c | 33 +++++++++++++++++++++++++++++++++
 mm/umm_heap/umm_realloc.c  | 33 +++++++++++++++++++++++++++++++++
 3 files changed, 93 insertions(+)

diff --git a/mm/umm_heap/umm_calloc.c b/mm/umm_heap/umm_calloc.c
index 627843caad..e506385396 100644
--- a/mm/umm_heap/umm_calloc.c
+++ b/mm/umm_heap/umm_calloc.c
@@ -59,5 +59,32 @@
 
 FAR void *calloc(size_t n, size_t elem_size)
 {
+#ifdef CONFIG_ARCH_ADDRENV
+  /* Use zalloc() because it implements the sbrk() logic */
+
+  FAR void *ret = NULL;
+
+  /* Verify input parameters */
+
+  if (n > 0 && elem_size > 0)
+    {
+      /* Assure that the following multiplication cannot overflow the size_t
+       * type, i.e., that:  SIZE_MAX >= n * elem_size
+       *
+       * Refer to SEI CERT C Coding Standard.
+       */
+
+      if (n <= (SIZE_MAX / elem_size))
+        {
+          ret = zalloc(n * elem_size);
+        }
+    }
+
+  return ret;
+
+#else
+  /* Use mm_calloc() becuase it implements the clear */
+
   return mm_calloc(USR_HEAP, n, elem_size);
+#endif
 }
diff --git a/mm/umm_heap/umm_memalign.c b/mm/umm_heap/umm_memalign.c
index 4e198cc8a9..1769d7e798 100644
--- a/mm/umm_heap/umm_memalign.c
+++ b/mm/umm_heap/umm_memalign.c
@@ -40,6 +40,7 @@
 #include <nuttx/config.h>
 
 #include <stdlib.h>
+#include <unistd.h>
 
 #include <nuttx/mm/mm.h>
 
@@ -64,5 +65,37 @@
 
 FAR void *memalign(size_t alignment, size_t size)
 {
+#ifdef CONFIG_ARCH_ADDRENV
+  FAR void *brkaddr;
+  FAR void *mem;
+
+  /* Loop until we successfully allocate the memory or until an error
+   * occurs. If we fail to allocate memory on the first pass, then call
+   * sbrk to extend the heap by one page.  This may require several
+   * passes if more the size of the allocation is more than one page.
+   *
+   * An alternative would be to increase the size of the heap by the
+   * full requested allocation in sbrk().  Then the loop should never
+   * execute more than twice (but more memory than we need may be
+   * allocated).
+   */
+
+  do
+    {
+      mem = mm_memalign(USR_HEAP, alignment, size);
+      if (!mem)
+        {
+          brkaddr = sbrk(size);
+          if (brkaddr == (FAR void *)-1)
+            {
+              return NULL;
+            }
+        }
+    }
+  while (mem == NULL);
+
+  return mem;
+#else
   return mm_memalign(USR_HEAP, alignment, size);
+#endif
 }
diff --git a/mm/umm_heap/umm_realloc.c b/mm/umm_heap/umm_realloc.c
index e740271ca0..1de5583a4b 100644
--- a/mm/umm_heap/umm_realloc.c
+++ b/mm/umm_heap/umm_realloc.c
@@ -40,6 +40,7 @@
 #include <nuttx/config.h>
 
 #include <stdlib.h>
+#include <unistd.h>
 
 #include <nuttx/mm/mm.h>
 
@@ -66,5 +67,37 @@
 
 FAR void *realloc(FAR void *oldmem, size_t size)
 {
+#ifdef CONFIG_ARCH_ADDRENV
+  FAR void *brkaddr;
+  FAR void *mem;
+
+  /* Loop until we successfully allocate the memory or until an error
+   * occurs. If we fail to allocate memory on the first pass, then call
+   * sbrk to extend the heap by one page.  This may require several
+   * passes if more the size of the allocation is more than one page.
+   *
+   * An alternative would be to increase the size of the heap by the
+   * full requested allocation in sbrk().  Then the loop should never
+   * execute more than twice (but more memory than we need may be
+   * allocated).
+   */
+
+  do
+    {
+      mem = mm_realloc(USR_HEAP, oldmem, size);
+      if (!mem)
+        {
+          brkaddr = sbrk(size);
+          if (brkaddr == (FAR void *)-1)
+            {
+              return NULL;
+            }
+        }
+    }
+  while (mem == NULL);
+
+  return mem;
+#else
   return mm_realloc(USR_HEAP, oldmem, size);
+#endif
 }