rt: Insert stack alignment checks into upcalls

1 files changed, 10 insertions, 0 deletions

diff --git a/src/rt/rust_upcall.cpp b/src/rt/rust_upcall.cpp
index 97e1321c02d..dd7e275cd04 100644
--- a/src/rt/rust_upcall.cpp
+++ b/src/rt/rust_upcall.cpp
@@ -14,6 +14,14 @@
 #include "rust_upcall.h"
 #include <stdint.h>
 
+
+// This is called to ensure we've set up our rust stacks
+// correctly. Strategically placed at entry to upcalls because they begin on
+// the rust stack and happen frequently enough to catch most stack changes,
+// including at the beginning of all landing pads.
+extern "C" void
+check_stack_alignment() __attribute__ ((aligned (16)));
+
 #define SWITCH_STACK(A, F) upcall_call_shim_on_c_stack((void*)A, (void*)F)
 
 extern "C" void record_sp(void *limit);
@@ -26,6 +34,7 @@ extern "C" void record_sp(void *limit);
  */
 extern "C" CDECL void
 upcall_call_shim_on_c_stack(void *args, void *fn_ptr) {
+    check_stack_alignment();
     rust_task *task = rust_scheduler::get_task();
 
     // FIXME (1226) - The shim functions generated by rustc contain the
@@ -594,6 +603,7 @@ upcall_del_stack() {
 // needs to acquire the value of the stack pointer
 extern "C" CDECL void
 upcall_reset_stack_limit() {
+    check_stack_alignment();
     rust_task *task = rust_scheduler::get_task();
     task->reset_stack_limit();
 }