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Make sure vm_call_cfunc uses inlined cc
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which is checked by the first guard. When JIT-inlined cc and operand
cd->cc are different, the JIT-ed code might wrongly dispatch cd->cc even
while class check is done with another cc inlined by JIT.

This fixes SEGV on railsbench.
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k0kubun committed Jul 10, 2020
1 parent 4989987 commit 7fa3c71
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Showing 2 changed files with 18 additions and 2 deletions.
16 changes: 16 additions & 0 deletions test/ruby/test_jit.rb
Original file line number Diff line number Diff line change
Expand Up @@ -793,6 +793,22 @@ def wrapper(paths, prefixes)
end;
end

def test_inlined_c_method
assert_eval_with_jit("#{<<~"begin;"}\n#{<<~"end;"}", stdout: "aaa", success_count: 2, recompile_count: 1, min_calls: 2)
begin;
def test(obj, recursive: nil)
if recursive
test(recursive)
end
obj.to_s
end
print(test('a')) # set #to_s cc to String#to_s (expecting C method)
print(test('a')) # JIT with #to_s cc: String#to_s
print(test('a', recursive: :foo)) # update #to_s cd->cc to Symbol#to_s, then go through inlined #to_s cc with Symbol#to_s
end;
end

def test_inlined_exivar
assert_eval_with_jit("#{<<~"begin;"}\n#{<<~"end;"}", stdout: "aaa", success_count: 3, recompile_count: 1, min_calls: 2)
begin;
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4 changes: 2 additions & 2 deletions tool/ruby_vm/views/_mjit_compile_send.erb
Original file line number Diff line number Diff line change
Expand Up @@ -75,8 +75,8 @@

if (vm_cc_cme(captured_cc)->def->type == VM_METHOD_TYPE_CFUNC) {
% # TODO: optimize this more
fprintf(f, " CALL_DATA cd = (CALL_DATA)0x%"PRIxVALUE";\n", operands[0]);
fprintf(f, " val = vm_call_cfunc_with_frame(ec, reg_cfp, &calling, cd);\n");
fprintf(f, " struct rb_call_data cc_cd = { .ci = (CALL_INFO)0x%"PRIxVALUE", .cc = cc };\n", (VALUE)ci); // creating local cd here because operand's cd->cc may not be the same as inlined cc.
fprintf(f, " val = vm_call_cfunc_with_frame(ec, reg_cfp, &calling, &cc_cd);\n");
}
else { // VM_METHOD_TYPE_ISEQ
% # fastpath_applied_iseq_p checks rb_simple_iseq_p, which ensures has_opt == FALSE
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