From 227533ac014354eaba944795cf8ff9cb3a31d330 Mon Sep 17 00:00:00 2001 From: Doug Evans Date: Tue, 20 May 2014 13:06:26 -0700 Subject: [PATCH] Fix gdb.multi/base.exp failures. UNRESOLVED: gdb.multi/base.exp: remove-inferiors 2-3 UNRESOLVED: gdb.multi/base.exp: check remove-inferiors gdb is crashing because it's accessing/freeing already freed memory. ==16368== Invalid read of size 4 ==16368== at 0x660A9D: find_pc_section (binutils-gdb/gdb/objfiles.c:1349) ==16368== by 0x663ECB: lookup_minimal_symbol_by_pc_section (binutils-gdb/gdb/minsyms.c:734) ==16368== by 0x5D987A: find_pc_sect_symtab (binutils-gdb/gdb/symtab.c:2153) ==16368== by 0x5D4D77: blockvector_for_pc_sect (binutils-gdb/gdb/block.c:168) ==16368== by 0x5D4F59: block_for_pc_sect (binutils-gdb/gdb/block.c:246) ==16368== by 0x5D4F9B: block_for_pc (binutils-gdb/gdb/block.c:258) ==16368== by 0x734C5D: inline_frame_sniffer (binutils-gdb/gdb/inline-frame.c:218) ==16368== by 0x732104: frame_unwind_try_unwinder (binutils-gdb/gdb/frame-unwind.c:108) ==16368== by 0x73223F: frame_unwind_find_by_frame (binutils-gdb/gdb/frame-unwind.c:159) ==16368== by 0x72D5AA: compute_frame_id (binutils-gdb/gdb/frame.c:453) ==16368== by 0x7300EC: get_prev_frame_if_no_cycle (binutils-gdb/gdb/frame.c:1758) ==16368== by 0x73079A: get_prev_frame_always (binutils-gdb/gdb/frame.c:1931) ==16368== Address 0x5b13500 is 16 bytes inside a block of size 24 free'd ==16368== at 0x403072E: free (valgrind/coregrind/m_replacemalloc/vg_replace_malloc.c:445) ==16368== by 0x762134: xfree (binutils-gdb/gdb/common/common-utils.c:108) ==16368== by 0x65DACF: objfiles_pspace_data_cleanup (binutils-gdb/gdb/objfiles.c:91) ==16368== by 0x75E546: program_spaceregistry_callback_adaptor (binutils-gdb/gdb/progspace.c:45) ==16368== by 0x7644F6: registry_clear_data (binutils-gdb/gdb/registry.c:82) ==16368== by 0x7645AB: registry_container_free_data (binutils-gdb/gdb/registry.c:95) ==16368== by 0x75E5B4: program_space_free_data (binutils-gdb/gdb/progspace.c:45) ==16368== by 0x75E9BA: release_program_space (binutils-gdb/gdb/progspace.c:167) ==16368== by 0x75EB9B: prune_program_spaces (binutils-gdb/gdb/progspace.c:269) ==16368== by 0x75303D: remove_inferior_command (binutils-gdb/gdb/inferior.c:792) ==16368== by 0x50B5FD: do_cfunc (binutils-gdb/gdb/cli/cli-decode.c:107) ==16368== by 0x50E6F2: cmd_func (binutils-gdb/gdb/cli/cli-decode.c:1886) The problem originates from the get_current_arch call in py-progspace.c:py_free_pspace. The inferior associated with the pspace is gone, and the current inferior is a different one and is running. Therefore get_current_arch tries to read the current frame which causes reads of data in the current program space which we've just deleted. * python/py-progspace.c (py_free_pspace): Call target_gdbarch instead of get_current_arch. --- gdb/ChangeLog | 5 +++++ gdb/python/py-progspace.c | 11 ++++++++++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index ece66c261e7..0c87bfff3c5 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2014-05-20 Doug Evans + + * python/py-progspace.c (py_free_pspace): Call target_gdbarch + instead of get_current_arch. + 2014-05-20 Pedro Alves * NEWS: Mention that compare-sections now works with all targets. diff --git a/gdb/python/py-progspace.c b/gdb/python/py-progspace.c index cda5a86ff91..db4c564ac22 100644 --- a/gdb/python/py-progspace.c +++ b/gdb/python/py-progspace.c @@ -241,7 +241,16 @@ py_free_pspace (struct program_space *pspace, void *datum) { struct cleanup *cleanup; pspace_object *object = datum; - struct gdbarch *arch = get_current_arch (); + /* This is a fiction, but we're in a nasty spot: The pspace is in the + process of being deleted, we can't rely on anything in it. Plus + this is one time when the current program space and current inferior + are not in sync: All inferiors that use PSPACE may no longer exist. + We don't need to do much here, and since "there is always an inferior" + using target_gdbarch suffices. + Note: We cannot call get_current_arch because it may try to access + the target, which may involve accessing data in the pspace currently + being deleted. */ + struct gdbarch *arch = target_gdbarch (); cleanup = ensure_python_env (arch, current_language); object->pspace = NULL; -- 2.30.2