Created attachment 111999 [details]
posix_memalign() test

Hi,

The attached file tests posix_memalign() with an invalid alignment of 0.
The expected behavior is for posix_memalign() to return EINVAL and to leave memptr untouched, or to set it to NULL.

I propose the following patch I made on valgrind-3.13.0 sources :
* add a test on alignment == 0
* set mem to NULL explicitely so as to be validly test its value after calling posix_memalign() on failure

--- ./coregrind/m_replacemalloc/vg_replace_malloc.c.orig
+++ ./coregrind/m_replacemalloc/vg_replace_malloc.c
@@ -997,11 +997,11 @@
    int VG_REPLACE_FUNCTION_EZU(10160,soname,fnname) \
           ( void **memptr, SizeT alignment, SizeT size ) \
    { \
-      void *mem; \
+      void *mem = NULL; \
       \
       /* Test whether the alignment argument is valid.  It must be \
          a power of two multiple of sizeof (void *).  */ \
-      if (alignment % sizeof (void *) != 0 \
+      if (alignment == 0 || alignment % sizeof (void *) != 0 \
           || (alignment & (alignment - 1)) != 0) \
          return VKI_EINVAL; \
       \