arch/tile: provide a definition of MAP_STACK

It's convenient for userspace (in particular, glibc) to find a
definition of MAP_STACK.  We use MAP_GROWSDOWN as an alias since
that's appropriate for the main stack, and since our current
allocation of mmap flags bits is running a bit short otherwise.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

diff --git a/arch/tile/include/asm/mman.h b/arch/tile/include/asm/mman.h
index 4c6811e..81b8fc3 100644 (file)
--- a/arch/tile/include/asm/mman.h
+++ b/arch/tile/include/asm/mman.h
@@ -23,6 +23,7 @@
 #define MAP_POPULATE   0x0040          /* populate (prefault) pagetables */
 #define MAP_NONBLOCK   0x0080          /* do not block on IO */
 #define MAP_GROWSDOWN  0x0100          /* stack-like segment */
+#define MAP_STACK      MAP_GROWSDOWN   /* provide convenience alias */
 #define MAP_LOCKED     0x0200          /* pages are locked */
 #define MAP_NORESERVE  0x0400          /* don't check for reservations */
 #define MAP_DENYWRITE  0x0800          /* ETXTBSY */