From 918dd9105923fdbf070e5782aed7cd6275caa321 Mon Sep 17 00:00:00 2001 From: Jan Kratochvil Date: Tue, 19 Jul 2011 20:28:52 +0000 Subject: [PATCH] gdb/ Fix crash if referenced CU is aged out. * dwarf2loc.c (per_cu_dwarf_call): New variable back_to, use to for xfree of block.data. (indirect_pieced_value): New variable back_to, use to for xfree of baton.data. (dwarf2_compile_expr_to_ax): New variable back_to, use to for xfree of block.data. * dwarf2read.c (dwarf2_find_base_address): New prototype. (load_cu): New function from ... (dw2_do_instantiate_symtab): ... the code here ... (process_full_comp_unit): ... and here. (dwarf2_fetch_die_location_block): Call load_cu first. Call xmemdup on retval.data. gdb/testsuite/ Fix crash if referenced CU is aged out. * gdb.dwarf2/dw2-op-call.exp (maintenance set dwarf2 max-cache-age 0): New. * gdb.dwarf2/implptr.exp: Likewise. --- gdb/ChangeLog | 16 ++++++++++++ gdb/dwarf2loc.c | 14 +++++++++++ gdb/dwarf2read.c | 42 ++++++++++++++++++++++++++------ gdb/testsuite/ChangeLog | 7 ++++++ gdb/testsuite/gdb.dwarf2/dw2-op-call.exp | 3 +++ gdb/testsuite/gdb.dwarf2/implptr.exp | 3 +++ 6 files changed, 77 insertions(+), 8 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index debc803..4d9eb04 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,21 @@ 2011-07-19 Jan Kratochvil + Fix crash if referenced CU is aged out. + * dwarf2loc.c (per_cu_dwarf_call): New variable back_to, use to for + xfree of block.data. + (indirect_pieced_value): New variable back_to, use to for xfree of + baton.data. + (dwarf2_compile_expr_to_ax): New variable back_to, use to for xfree of + block.data. + * dwarf2read.c (dwarf2_find_base_address): New prototype. + (load_cu): New function from ... + (dw2_do_instantiate_symtab): ... the code here ... + (process_full_comp_unit): ... and here. + (dwarf2_fetch_die_location_block): Call load_cu first. Call xmemdup on + retval.data. + +2011-07-19 Jan Kratochvil + * dwarf2loc.c (indirect_pieced_value): Use check_typedef for VALUE's type. diff --git a/gdb/dwarf2loc.c b/gdb/dwarf2loc.c index 9d4aa8d..c29a07c 100644 --- a/gdb/dwarf2loc.c +++ b/gdb/dwarf2loc.c @@ -265,14 +265,19 @@ per_cu_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset, void *baton) { struct dwarf2_locexpr_baton block; + struct cleanup *back_to; block = dwarf2_fetch_die_location_block (die_offset, per_cu, get_frame_pc, baton); + back_to = make_cleanup (xfree, (void *) block.data); + /* DW_OP_call_ref is currently not supported. */ gdb_assert (block.per_cu == per_cu); dwarf_expr_eval (ctx, block.data, block.size); + + do_cleanups (back_to); } /* Helper interface of per_cu_dwarf_call for dwarf2_evaluate_loc_desc. */ @@ -966,6 +971,7 @@ indirect_pieced_value (struct value *value) struct dwarf_expr_piece *piece = NULL; struct value *result; LONGEST byte_offset; + struct cleanup *back_to; type = check_typedef (value_type (value)); if (TYPE_CODE (type) != TYPE_CODE_PTR) @@ -1013,10 +1019,14 @@ indirect_pieced_value (struct value *value) get_frame_address_in_block_wrapper, frame); + back_to = make_cleanup (xfree, (void *) baton.data); + result = dwarf2_evaluate_loc_desc_full (TYPE_TARGET_TYPE (type), frame, baton.data, baton.size, baton.per_cu, byte_offset); + do_cleanups (back_to); + return result; } @@ -2123,12 +2133,14 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, { struct dwarf2_locexpr_baton block; int size = (op == DW_OP_call2 ? 2 : 4); + struct cleanup *back_to; uoffset = extract_unsigned_integer (op_ptr, size, byte_order); op_ptr += size; block = dwarf2_fetch_die_location_block (uoffset, per_cu, get_ax_pc, expr); + back_to = make_cleanup (xfree, (void *) block.data); /* DW_OP_call_ref is currently not supported. */ gdb_assert (block.per_cu == per_cu); @@ -2136,6 +2148,8 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, dwarf2_compile_expr_to_ax (expr, loc, arch, addr_size, block.data, block.data + block.size, per_cu); + + do_cleanups (back_to); } break; diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c index da82a2e..a84d356 100644 --- a/gdb/dwarf2read.c +++ b/gdb/dwarf2read.c @@ -884,6 +884,9 @@ static void dwarf2_locate_sections (bfd *, asection *, void *); static void dwarf2_create_include_psymtab (char *, struct partial_symtab *, struct objfile *); +static void dwarf2_find_base_address (struct die_info *die, + struct dwarf2_cu *cu); + static void dwarf2_build_psymtabs_hard (struct objfile *); static void scan_partial_symbols (struct partial_die_info *, @@ -1788,6 +1791,23 @@ create_quick_file_names_table (unsigned int nr_initial_entries) delete_file_name_entry, xcalloc, xfree); } +/* Read in PER_CU->CU. This function is unrelated to symtabs, symtab would + have to be created afterwards. You should call age_cached_comp_units after + processing PER_CU->CU. dw2_setup must have been already called. */ + +static void +load_cu (struct dwarf2_per_cu_data *per_cu) +{ + if (per_cu->from_debug_types) + read_signatured_type_at_offset (per_cu->objfile, per_cu->offset); + else + load_full_comp_unit (per_cu, per_cu->objfile); + + dwarf2_find_base_address (per_cu->cu->dies, per_cu->cu); + + gdb_assert (per_cu->cu != NULL); +} + /* Read in the symbols for PER_CU. OBJFILE is the objfile from which this CU came. */ @@ -1801,10 +1821,7 @@ dw2_do_instantiate_symtab (struct objfile *objfile, queue_comp_unit (per_cu, objfile); - if (per_cu->from_debug_types) - read_signatured_type_at_offset (objfile, per_cu->offset); - else - load_full_comp_unit (per_cu, objfile); + load_cu (per_cu); process_queue (objfile); @@ -4714,8 +4731,6 @@ process_full_comp_unit (struct dwarf2_per_cu_data *per_cu) cu->list_in_scope = &file_symbols; - dwarf2_find_base_address (cu->dies, cu); - /* Do line number decoding in read_file_scope () */ process_die (cu->dies, cu); @@ -13813,7 +13828,8 @@ follow_die_ref (struct die_info *src_die, struct attribute *attr, } /* Return DWARF block and its CU referenced by OFFSET at PER_CU. Returned - value is intended for DW_OP_call*. */ + value is intended for DW_OP_call*. You must call xfree on returned + dwarf2_locexpr_baton->data. */ struct dwarf2_locexpr_baton dwarf2_fetch_die_location_block (unsigned int offset, @@ -13821,13 +13837,17 @@ dwarf2_fetch_die_location_block (unsigned int offset, CORE_ADDR (*get_frame_pc) (void *baton), void *baton) { - struct dwarf2_cu *cu = per_cu->cu; + struct dwarf2_cu *cu; struct die_info *die; struct attribute *attr; struct dwarf2_locexpr_baton retval; dw2_setup (per_cu->objfile); + if (per_cu->cu == NULL) + load_cu (per_cu); + cu = per_cu->cu; + die = follow_die_offset (offset, &cu); if (!die) error (_("Dwarf Error: Cannot find DIE at 0x%x referenced in module %s"), @@ -13864,6 +13884,12 @@ dwarf2_fetch_die_location_block (unsigned int offset, retval.size = DW_BLOCK (attr)->size; } retval.per_cu = cu->per_cu; + + if (retval.data) + retval.data = xmemdup (retval.data, retval.size, retval.size); + + age_cached_comp_units (); + return retval; } diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 2d60ff1..e3b3adb 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,5 +1,12 @@ 2011-07-19 Jan Kratochvil + Fix crash if referenced CU is aged out. + * gdb.dwarf2/dw2-op-call.exp (maintenance set dwarf2 max-cache-age 0): + New. + * gdb.dwarf2/implptr.exp: Likewise. + +2011-07-19 Jan Kratochvil + * gdb.dwarf2/implptr.S: Rebuilt. * gdb.dwarf2/implptr.c (intp, intpp, intppp): New typedefs. (bar): Use them for j, k, l. diff --git a/gdb/testsuite/gdb.dwarf2/dw2-op-call.exp b/gdb/testsuite/gdb.dwarf2/dw2-op-call.exp index 3fcef09..3319133 100644 --- a/gdb/testsuite/gdb.dwarf2/dw2-op-call.exp +++ b/gdb/testsuite/gdb.dwarf2/dw2-op-call.exp @@ -31,6 +31,9 @@ if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${objdir}/${subdir}/${execu clean_restart $executable +# Additional test to verify the referenced CU is not aged out. +gdb_test_no_output "maintenance set dwarf2 max-cache-age 0" + gdb_test "p array1" " = 1" gdb_test "p array2" " = 2" "array2 using DW_OP_call2" gdb_test "p array3" " = 3" "array3 using DW_OP_call4" diff --git a/gdb/testsuite/gdb.dwarf2/implptr.exp b/gdb/testsuite/gdb.dwarf2/implptr.exp index 8f9b5fb..562e983 100644 --- a/gdb/testsuite/gdb.dwarf2/implptr.exp +++ b/gdb/testsuite/gdb.dwarf2/implptr.exp @@ -40,6 +40,9 @@ if {[prepare_for_testing ${testfile}.exp ${testfile}.x $srcfile $opts]} { return -1 } +# Additional test to verify the referenced CU is not aged out. +gdb_test_no_output "maintenance set dwarf2 max-cache-age 0" + if ![runto_main] { return -1 } -- 2.7.4