[rtems commit] Check the alignment in posix_memalign() earlier

[Sebastian Huber]

Module:    rtems
Branch:    master
Commit:    c46d125569a215226602a7d4b9c346ee074fe365
Changeset: http://git.rtems.org/rtems/commit/?id=c46d125569a215226602a7d4b9c346ee074fe365

Author:    Sebastian Huber <sebastian.huber at embedded-brains.de>
Date:      Thu May  6 19:25:09 2021 +0200

Check the alignment in posix_memalign() earlier

Make sure all conditions to do a proper memory allocation are satisfied
before a zero size memory allocation is performed.

Update #4390.

---

 cpukit/libcsupport/src/posix_memalign.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/cpukit/libcsupport/src/posix_memalign.c b/cpukit/libcsupport/src/posix_memalign.c
index 4e89413..418de99 100644
--- a/cpukit/libcsupport/src/posix_memalign.c
+++ b/cpukit/libcsupport/src/posix_memalign.c
@@ -37,10 +37,6 @@ int posix_memalign(
 
   *memptr = NULL;
 
-  if ( size == 0 ) {
-    return 0;
-  }
-
   if ( alignment < sizeof( void * ) ) {
     return EINVAL;
   }
@@ -49,6 +45,10 @@ int posix_memalign(
     return EINVAL;
   }
 
+  if ( size == 0 ) {
+    return 0;
+  }
+
   *memptr = rtems_heap_allocate_aligned_with_boundary( size, alignment, 0 );
 
   if ( *memptr == NULL ) {