test-rawmemchr: make more robust

* modules/rawmemchr-tests (Files): Add zerosize-ptr.h, mmap-anon.m4.
(Depends-on, configure.ac): Add needed prerequisites to use it.
* modules/memchr-tests (Files, Depends-on, configure.ac):
Likewise, to avoid implicit reliance on memchr module prereqs.
* tests/test-memchr.c (main): Ensure proper masking.
* tests/test-rawmemchr.c (main): Likewise.  Detect oversized
reads.

Signed-off-by: Eric Blake <eblake@redhat.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/tests/test-rawmemchr.c b/tests/test-rawmemchr.c
index 94768183e0..804e15780a 100644
--- a/tests/test-rawmemchr.c
+++ b/tests/test-rawmemchr.c
@@ -24,6 +24,7 @@ SIGNATURE_CHECK (rawmemchr, void *, (void const *, int));
 
 #include <stdlib.h>
 
+#include "zerosize-ptr.h"
 #include "macros.h"
 
 /* Calculating void * + int is not portable, so this wrapper converts
@@ -53,6 +54,7 @@ main (void)
 
   ASSERT (RAWMEMCHR (input + 1, 'a') == input + n - 1);
   ASSERT (RAWMEMCHR (input + 1, 'e') == input + n - 2);
+  ASSERT (RAWMEMCHR (input + 1, 0x789abc00 | 'e') == input + n - 2);
 
   ASSERT (RAWMEMCHR (input, '\0') == input + n);
 
@@ -70,6 +72,20 @@ main (void)
       }
   }
 
+  /* Ensure that no unaligned oversized reads occur.  */
+  {
+    char *page_boundary = (char *) zerosize_ptr ();
+    size_t i;
+
+    if (!page_boundary)
+      page_boundary = input + 4096;
+    memset (page_boundary - 512, '1', 511);
+    page_boundary[-1] = '2';
+    for (i = 1; i <= 512; i++)
+      ASSERT (RAWMEMCHR (page_boundary - i, (i * 0x01010100) | '2')
+              == page_boundary - 1);
+  }
+
   free (input);
 
   return 0;