Issue #10206 has been updated by Eric Wong. Eric Wong <normalperson / yhbt.net> wrote: > I think this may be a fix (still testing): Nope. However, I think it takes longer in the test-all loop to reproduce the problem. > --- a/symbol.c > +++ b/symbol.c > @@ -458,7 +458,10 @@ dsymbol_pindown(VALUE sym) > > if (UNLIKELY(SYMBOL_PINNED_P(sym) == 0)) { > VALUE fstr = RSYMBOL(sym)->fstr; > - sym = dsymbol_check(sym); > + > + if (UNLIKELY(rb_objspace_garbage_object_p(sym))) { > + rb_bug("attempted to pindown garbage sym"); > + } I still hit this rb_bug (similar backtraces as before). > FL_SET(sym, SYMBOL_PINNED); > > /* make it permanent object */ > @@ -525,6 +528,9 @@ rb_intern_cstr_without_pindown(const char *name, long len, rb_encoding *enc) > OBJ_FREEZE(str); > > if (st_lookup(global_symbols.str_id, str, &id)) { > + if (ID_DYNAMIC_SYM_P((ID)id)) { > + return (ID)dsymbol_check((VALUE)id); > + } However, I think this dsymbol_check still is worthwhile. > return (ID)id; > } > ---------------------------------------- Bug #10206: garbage symbols crash symbol GC https://bugs.ruby-lang.org/issues/10206#change-48723 * Author: Eric Wong * Status: Open * Priority: Normal * Assignee: Koichi Sasada * Category: core * Target version: current: 2.2.0 * ruby -v: trunk * Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN ---------------------------------------- This is reproducible with just a test loop running for serveral minutes/hours: while make test-all TESTS=-j8; do :; done It looks like SYM2ID/rb_sym2id interacts badly with dsymbol_check when it encounters garbage objects. dsymbol_check replaces an invalid object and returns a new object for the caller, but the original arg for SYM2ID remains usable to the caller: id = SYM2ID(garbage_sym); do_something(garbage_sym); /* bad invalid object used */ Changing: rb_sym2id(VALUE) to rb_sym2id(VALUE *) might solve the issue, but introduces many incompatibilities in existing code: id = rb_sym2id(&garbage_sym); do_something(garbage_sym); /* id == garbage_sym, safe to use */ ref: ruby-core thread starting at [ruby-core:64671] backtraces: http://80x24.org/r35240/rb-dump.txt http://80x24.org/r35240/gdb-bt.txt -- https://bugs.ruby-lang.org/