Remove failure for bad mmap address hints.

src/trusted/service_runtime/sys_memory.c

Index: src/trusted/service_runtime/sys_memory.c
diff --git a/src/trusted/service_runtime/sys_memory.c b/src/trusted/service_runtime/sys_memory.c
index 7b0d7033d81a0b7192236b7dc312bb997d656b7a..332f0e08a85828ef0aa121aa4bbc61448e3678ae 100644
--- a/src/trusted/service_runtime/sys_memory.c
+++ b/src/trusted/service_runtime/sys_memory.c
@@ -329,9 +329,14 @@ int32_t NaClSysMmapIntern(struct NaClApp        *nap,
    * granularity.  (Windows.)
    */
   if (!NaClIsAllocPageMultiple(usraddr)) {
-    NaClLog(2, "NaClSysMmap: address not allocation granularity aligned\n");
-    map_result = -NACL_ABI_EINVAL;
-    goto cleanup;
+    if ((NACL_ABI_MAP_FIXED & flags) != 0) {
+      NaClLog(2, "NaClSysMmap: address not allocation granularity aligned\n");
+      map_result = -NACL_ABI_EINVAL;
+      goto cleanup;
+    } else {
+      NaClLog(2, "NaClSysMmap: Force alignment of misaligned hint address\n");
+      usraddr = NaClRoundAllocPage(usraddr);

[Sean Klein, 2015/07/30 21:49:16]

Regarding your comment of 0xffffffff as a usraddr --
I agree with you. Rounding up to 0x100000000, even if appropriate on a typical
64-bit Linux system, is not the desired behavior for NaCl.

I'll change the alignment to "NaClTruncAllocPage".

+    }
   }
   /*
    * Offset should be non-negative (nacl_abi_off_t is signed).  This