[PATCH/cr_tests] pass a valid stack address to clone(2)

[Nathan Lynch]

Off-by-one error: the stack address passed to clone() must be within
the region allocated.

Signed-off-by: Nathan Lynch <ntl at pobox.com>
---
 ns_exec.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/ns_exec.c b/ns_exec.c
index 09574e2..1f61771 100644
--- a/ns_exec.c
+++ b/ns_exec.c
@@ -272,7 +272,7 @@ int main(int argc, char *argv[])
 			perror("malloc");
 			return -1;
 		}
-		childstack = stack + stacksize;
+		childstack = stack + stacksize - 1;
 
 		printf("about to clone with %lx\n", flags);
 		flags |= SIGCHLD;
-- 
1.6.0.6