define macro for stack alignment

Replace stack alignment magic constant with
__stack_aligned__ macro.
Also align stack for sigaltstack test case.
Signed-off-by: Vijaya Kumar K <vijayak@caviumnetworks.com>
Reviewed-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

cr-check.c

@@ -808,7 +808,7 @@ struct clone_arg {
 	 * Reserve some space for clone() to locate arguments
 	 * and retcode in this place
 	 */
-	char stack[128] __attribute__((aligned (16)));
+	char stack[128] __stack_aligned__;
 	char stack_ptr[0];
 };
 

cr-restore.c

@@ -1075,7 +1075,7 @@ struct cr_clone_arg {
 	 * Reserve some space for clone() to locate arguments
 	 * and retcode in this place
 	 */
-	char stack[128] __attribute__((aligned (16)));
+	char stack[128] __stack_aligned__;
 	char stack_ptr[0];
 	struct pstree_item *item;
 	unsigned long clone_flags;

include/compiler.h

@@ -38,6 +38,12 @@
 
 #define __aligned(x)		__attribute__((aligned(x)))
 
+/*
+ * Macro to define stack alignment. 
+ * aarch64 requires stack to be aligned to 16 bytes.
+ */
+#define __stack_aligned__	__attribute__((aligned(16)))
+
 #ifndef offsetof
 # define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
 #endif

include/restorer.h

@@ -50,7 +50,7 @@ struct restore_mem_zone {
 	u8				redzone[RESTORE_STACK_REDZONE];
 	u8				stack[RESTORE_STACK_SIZE];
 	u8				rt_sigframe[RESTORE_STACK_SIGFRAME];
-} __aligned(16);
+} __stack_aligned__;
 
 struct rst_sched_param {
 	int policy;

test/zdtm/lib/ns.c

@@ -16,6 +16,7 @@
 #include <sched.h>
 #include <sys/socket.h>
 
+#include "zdtmtst.h"
 #include "ns.h"
 
 extern int pivot_root(const char *new_root, const char *put_old);
@@ -143,7 +144,7 @@ static int prepare_namespaces(void)
 
 /* All arguments should be above stack, because it grows down */
 struct ns_exec_args {
-	char stack[NS_STACK_SIZE] __attribute__((aligned (16)));
+	char stack[NS_STACK_SIZE] __stack_aligned__;
 	char stack_ptr[0];
 	int argc;
 	char **argv;

test/zdtm/lib/zdtmtst.h

@@ -99,6 +99,12 @@ extern int parse_opt_string(char *param, void *arg);
 #define __stringify_1(x)        #x
 #define __stringify(x)          __stringify_1(x)
 
+/*
+ * Macro to define stack alignment. 
+ * aarch64 requires stack to be aligned to 16 bytes.
+ */
+#define __stack_aligned__	__attribute__((aligned(16)))
+
 /* message helpers */
 extern int test_log_init(const char *outfile, const char *suffix);
 extern int zdtm_seccomp;

test/zdtm/live/static/fdt_shared.c

@@ -48,7 +48,7 @@ static void wait_children()
 
 static pid_t clone_child(int (*fn)(void *), int flags)
 {
-	char stack[STACK_SIZE] __attribute__((aligned (16)));
+	char stack[STACK_SIZE] __stack_aligned__;
 	pid_t pid;
 
 	pid = clone(fn, stack + STACK_SIZE,

test/zdtm/live/static/mntns_link_remap.c

@@ -29,7 +29,7 @@ TEST_OPTION(dirname, string, "directory name", 1);
 #define NS_STACK_SIZE	4096
 /* All arguments should be above stack, because it grows down */
 struct ns_exec_args {
-	char stack[NS_STACK_SIZE] __attribute__((aligned (16)));
+	char stack[NS_STACK_SIZE] __stack_aligned__;
 	char stack_ptr[0];
 	int fd;
 	int sync;

test/zdtm/live/static/mntns_open.c

@@ -29,7 +29,7 @@ char fpath[PATH_MAX];
 #define NS_STACK_SIZE	4096
 /* All arguments should be above stack, because it grows down */
 struct ns_exec_args {
-	char stack[NS_STACK_SIZE] __attribute__((aligned (16)));
+	char stack[NS_STACK_SIZE] __stack_aligned__;
 	char stack_ptr[0];
 	int fd;
 };

test/zdtm/live/static/mountpoints.c

@@ -22,7 +22,7 @@ static char buf[1024];
 #define NS_STACK_SIZE	4096
 /* All arguments should be above stack, because it grows down */
 struct ns_exec_args {
-	char stack[NS_STACK_SIZE] __attribute__((aligned (16)));
+	char stack[NS_STACK_SIZE] __stack_aligned__;
 	char stack_ptr[0];
 	int status_pipe[2];
 };

test/zdtm/live/static/session02.c

@@ -67,7 +67,7 @@ static void mainloop()
 #define CLONE_STACK_SIZE	4096
 /* All arguments should be above stack, because it grows down */
 struct clone_args {
-	char stack[CLONE_STACK_SIZE] __attribute__((aligned (16)));
+	char stack[CLONE_STACK_SIZE] __stack_aligned__;
 	char stack_ptr[0];
 	int id;
 };

test/zdtm/live/static/session03.c

@@ -109,7 +109,7 @@ static void mainloop()
 #define CLONE_STACK_SIZE	4096
 /* All arguments should be above stack, because it grows down */
 struct clone_args {
-	char stack[CLONE_STACK_SIZE] __attribute__((aligned (16)));
+	char stack[CLONE_STACK_SIZE] __stack_aligned__;
 	char stack_ptr[0];
 	int id;
 };

test/zdtm/live/static/sigaltstack.c

@@ -16,8 +16,8 @@
 const char *test_doc	= "Check for alternate signal stack";
 const char *test_author	= "Cyrill Gorcunov <gorcunov@openvz.org>";
 
-static char stack_thread[SIGSTKSZ + TEST_MSG_BUFFER_SIZE];
-static char stack_main[SIGSTKSZ + TEST_MSG_BUFFER_SIZE];
+static char stack_thread[SIGSTKSZ + TEST_MSG_BUFFER_SIZE] __stack_aligned__;
+static char stack_main[SIGSTKSZ + TEST_MSG_BUFFER_SIZE] __stack_aligned__;
 
 enum {
 	SAS_MAIN_OLD,