With frame-pointers entertrap restores base pointer

ocaml · Feb 22, 2022 · 0ab111a · 0ab111a
1 parent d480c0c
commit 0ab111a
Show file tree

Hide file tree

Showing 2 changed files with 9 additions and 1 deletion.
diff --git a/Changes b/Changes
@@ -48,6 +48,11 @@ OCaml 4.14.0
 
 ### Code generation and optimizations:
 
+- #11031: Exception handlers restore the rbp register when using frame-pointers
+  on amd64.
+  (Fabrice Buoro, with help from Stephen Dolan, Tom Kelly and Mark Shinwell,
+  review by Xavier Leroy)
+
 - #10578: Increase the number of integer registers used for
   parameter passing on PowerPC (16 registers) and on s390x (8 registers).
   (Xavier Leroy, review by Mark Shinwell)

diff --git a/asmcomp/amd64/emit.mlp b/asmcomp/amd64/emit.mlp
@@ -804,7 +804,10 @@ let emit_instr env fallthrough i =
       done;
       emit_named_text_section env.f.fun_name
   | Lentertrap ->
-      ()
+      if fp then begin
+        let delta = frame_size env - 16 (* retaddr + rbp *) in
+        I.lea (mem64 NONE delta RSP) rbp
+      end;
   | Ladjust_trap_depth { delta_traps; } ->
       (* each trap occupies 16 bytes on the stack *)
       let delta = 16 * delta_traps in