(allocate_stack): If MULTI_PAGE_ALIASING is defined and the size of the stack which...

diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c
index a43d94a..14a2ab0 100644 (file)
--- a/nptl/allocatestack.c
+++ b/nptl/allocatestack.c
@@ -379,6 +379,15 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
       pd = get_cached_stack (&size, &mem);
       if (pd == NULL)
        {
+         /* To avoid aliasing effects on a larger scale then pages we
+            adjust the allocated stack size if necessary.  This way
+            allocations directly following each other will not have
+            aliasing problems.  */
+#if MULTI_PAGE_ALIASING != 0
+         if ((size % MULTI_PAGE_ALIASING) == 0)
+           size += pagesize_m1 + 1;
+#endif
+
          mem = mmap (NULL, size, PROT_READ | PROT_WRITE | PROT_EXEC,
                      MAP_PRIVATE | MAP_ANONYMOUS | ARCH_MAP_FLAGS, -1, 0);