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authorRickard Green <[email protected]>2017-02-17 15:26:01 +0100
committerRickard Green <[email protected]>2017-02-20 14:40:16 +0100
commit0a144d1fc4bebefcc74b0cb63fe76809bc041789 (patch)
tree164ac556f93f6b2531a9fb168509d58db66c938c /erts/preloaded/src/prim_eval.S
parentaa315e1cf1b79ab782e5b4c944595495ebf4e2f4 (diff)
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Ensure prim_eval:'receive' wont clobber def_arg_reg[0]
def_arg_reg[0] is used for storage of timeout instruction when a 'receive after' is executed. When a process was scheduled out inside prim_eval:'receive'/0 due to a function call, def_arg_reg[0] was overwritten due to storage of live registers. prim_eval:'receive'/2 now calls arg_reg_alloc/0 which bumps all reductions and then calls arg_reg_alloc/7 which will cause an allocation of a new arg_reg array since def_arg_reg only can hold 6 values. This ensures that the timeout instruction in def_arg_reg[0] used for the timeout wont be overwritten.
Diffstat (limited to 'erts/preloaded/src/prim_eval.S')
-rw-r--r--erts/preloaded/src/prim_eval.S41
1 files changed, 34 insertions, 7 deletions
diff --git a/erts/preloaded/src/prim_eval.S b/erts/preloaded/src/prim_eval.S
index e7f09a870c..c6623f8e03 100644
--- a/erts/preloaded/src/prim_eval.S
+++ b/erts/preloaded/src/prim_eval.S
@@ -26,7 +26,7 @@
{attributes, []}.
-{labels, 10}.
+{labels, 14}.
{function, 'receive', 2, 2}.
@@ -36,6 +36,9 @@
{allocate,2,2}.
{move,{x,1},{y,0}}.
{move,{x,0},{y,1}}.
+ %% Call arg_reg_alloc() in order to ensure
+ %% that def_arg_reg[0] isn't clobbered
+ {call,0,{f,7}}.
{label,3}.
{loop_rec,{f,5},{x,0}}.
{move,{y,1},{x,1}}.
@@ -53,19 +56,43 @@
{deallocate,2}.
return.
-
-{function, module_info, 0, 8}.
+{function, arg_reg_alloc, 0, 7}.
{label,6}.
- {func_info,{atom,prim_eval},{atom,module_info},0}.
+ {func_info,{atom,prim_eval},{atom,arg_reg_alloc},0}.
{label,7}.
+ {allocate,0,0}.
+ {move,{integer,134217727},{x,0}}.
+ {call_ext,1,{extfunc,erlang,bump_reductions,1}}.
+ {move,{atom,true},{x,3}}.
+ {move,{atom,true},{x,4}}.
+ {move,{atom,true},{x,2}}.
+ {move,{atom,true},{x,5}}.
+ {move,{atom,true},{x,1}}.
+ {move,{atom,true},{x,6}}.
+ {move,{atom,true},{x,0}}.
+ {call_last,7,{f,9},0}.
+
+
+{function, arg_reg_alloc, 7, 9}.
+ {label,8}.
+ {func_info,{atom,prim_eval},{atom,arg_reg_alloc},7}.
+ {label,9}.
+ {move,{atom,ok},{x,0}}.
+ return.
+
+
+{function, module_info, 0, 11}.
+ {label,10}.
+ {func_info,{atom,prim_eval},{atom,module_info},0}.
+ {label,11}.
{move,{atom,prim_eval},{x,0}}.
{call_ext_only,1,{extfunc,erlang,get_module_info,1}}.
-{function, module_info, 1, 10}.
- {label,8}.
+{function, module_info, 1, 13}.
+ {label,12}.
{func_info,{atom,prim_eval},{atom,module_info},1}.
- {label,9}.
+ {label,13}.
{move,{x,0},{x,1}}.
{move,{atom,prim_eval},{x,0}}.
{call_ext_only,2,{extfunc,erlang,get_module_info,2}}.