Add control page offset checksstaging

Make sure the kernel and userspace compilers have the same idea of the
layout of the control page.

2 files changed, 12 insertions, 1 deletions

diff --git a/include/internal.h b/include/internal.h
index 747f095..035440b 100644
--- a/include/internal.h
+++ b/include/internal.h
@@ -23,6 +23,8 @@ int __launch_rt_task(rt_fn_t rt_prog, void *rt_arg,
 #define likely(x)   __builtin_expect((x), 1)
 #define unlikely(x) __builtin_expect((x), 0)
 
+#define offsetof(s, x) __builtin_offsetof(s, x)
+
 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
 #define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition))
 
diff --git a/src/kernel_iface.c b/src/kernel_iface.c
index b9c8f59..4cc1af5 100644
--- a/src/kernel_iface.c
+++ b/src/kernel_iface.c
@@ -82,7 +82,16 @@ int init_kernel_iface(void)
         int err = 0;
         long page_size = sysconf(_SC_PAGESIZE);
 
-        BUILD_BUG_ON(sizeof(union np_flag) != sizeof(uint32_t));
+        BUILD_BUG_ON(sizeof(union np_flag) != sizeof(uint64_t));
+
+        BUILD_BUG_ON(offsetof(struct control_page, sched.raw)
+                     != LITMUS_CP_OFFSET_SCHED);
+        BUILD_BUG_ON(offsetof(struct control_page, irq_count)
+                     != LITMUS_CP_OFFSET_IRQ_COUNT);
+        BUILD_BUG_ON(offsetof(struct control_page, ts_syscall_start)
+                     != LITMUS_CP_OFFSET_TS_SC_START);
+        BUILD_BUG_ON(offsetof(struct control_page, irq_syscall_start)
+                     != LITMUS_CP_OFFSET_IRQ_SC_START);
 
         err = map_file(LITMUS_CTRL_DEVICE, (void**) &ctrl_page, CTRL_PAGES * page_size);
         if (err) {