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YJIT: Fix tailcall and JIT entry eating up FINISH frames (#9729)

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Suppose YJIT runs a rb_vm_opt_send_without_block()
fallback and the control frame stack looks like:

```
will_tailcall_bar [FINISH]
caller_that_used_fallback
```

will_tailcall_bar() runs in the interpreter and sets up a tailcall.
Right before JIT_EXEC() in the `send` instruction, the stack will look like:

```
bar [FINISH]
caller_that_used_fallback
```

Previously, JIT_EXEC() ran bar() in JIT code, which caused the `FINISH`
flag to return to the interpreter instead of to the JIT code running
caller_that_used_fallback(), causing code to run twice and probably
crash. Recent flaky failures on CI about "each stub expects a particular
iseq" are probably due to leaving methods twice in
`test_optimizations.rb`.

Only run JIT code from the interpreter if a new frame is pushed.
This commit is contained in:
Alan Wu 2024-01-29 12:21:17 -05:00 committed by GitHub
parent 9a5a11f3d0
commit b0711b1cf1
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2 changed files with 13 additions and 1 deletions
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11
test/ruby/test_optimization.rb
View File

@ -451,6 +451,17 @@ class TestRubyOptimization < Test::Unit::TestCase
assert_equal(3, one_plus_two) assert_equal(3, one_plus_two)
end end
def test_tailcall_and_post_arg
tailcall(<<~RUBY)
def ret_const = :ok
def post_arg(_a = 1, _b) = ret_const
RUBY
# YJIT probably uses a fallback on the call to post_arg
assert_equal(:ok, post_arg(0))
end
def test_tailcall_interrupted_by_sigint def test_tailcall_interrupted_by_sigint
bug12576 = 'ruby-core:76327' bug12576 = 'ruby-core:76327'
script = "#{<<-"begin;"}\n#{<<~'end;'}" script = "#{<<-"begin;"}\n#{<<~'end;'}"

3
vm_exec.h
View File

@ -176,7 +176,8 @@ default: \
// Run the JIT from the interpreter // Run the JIT from the interpreter
#define JIT_EXEC(ec, val) do { \ #define JIT_EXEC(ec, val) do { \
rb_jit_func_t func; \ rb_jit_func_t func; \
if (val == Qundef && (func = jit_compile(ec))) { \ /* don't run tailcalls since that breaks FINISH */ \
if (val == Qundef && GET_CFP() != ec->cfp && (func = jit_compile(ec))) { \
val = func(ec, ec->cfp); \ val = func(ec, ec->cfp); \
RESTORE_REGS(); /* fix cfp for tailcall */ \ RESTORE_REGS(); /* fix cfp for tailcall */ \
if (ec->tag->state) THROW_EXCEPTION(val); \ if (ec->tag->state) THROW_EXCEPTION(val); \