http://sourceware.org/ml/gdb-patches/2010-01/msg00661.html Subject: [patch] Fix failed gdb_assert due to the PIE patchset [ Backport for F-12/7.0. ] Hi, the PIE patchset brought in an occasionally failing gdb_assert (according to Fedora ABRT bugreports). solib-svr4.c:600: internal-error: scan_dyntag: Assertion `target_section < current_target_sections->sections_end' failed. Now I understand it as generally current_target_sections are about target-side data while symbols are the GDB side and there is only loose relation of those. ABFD can be from multiple places acting for multiple purposes as parsed by elf_lookup_lib_symbol: exec_bfd: It cannot be from exec_one - this BFD has no associated objfile to pass to symfile_objfile. OK. symfile_objfile: It gets translated by elf_lookup_lib_symbol into exec_bfd which represents the target data. OK. so_list's objfile's separate_debug_objfile file: gdb_assert-forbidden as input to elf_lookup_lib_symbol. OK. so_list's objfile's main file: update_solib_list must have called add_target_sections. OK. objfile's separate_debug_objfile file: gdb_assert-forbidden as input to elf_lookup_lib_symbol. OK. objfile's main file (if it has no associated so_list): Such ABFD from add_symbol_file_command has no add_target_sections called. Still it can have current context BLOCK which crashes scan_dyntag. BUG. No regressions on {x86_64,x86_64-m32,i686}-fedora12-linux-gnu. The patch mostly reverts the PIE part there. OK to check in? Sorry, Jan gdb/ 2010-01-31 Jan Kratochvil * solib-svr4.c (scan_dyntag): New variable dyn_addr. Replace gdb_assert by a conditional setting DYN_ADDR. Use DYN_ADDR. * config/djgpp/fnchange.lst: Add translations for symbol-without-target_section.exp and symbol-without-target_section.c. gdb/testsuite/ 2010-01-31 Jan Kratochvil * gdb.base/symbol-without-target_section.exp, gdb.base/symbol-without-target_section.c: New. --- a/gdb/config/djgpp/fnchange.lst +++ b/gdb/config/djgpp/fnchange.lst @@ -394,6 +394,8 @@ @V@/gdb/testsuite/gdb.base/solib-symbol-main.c @V@/gdb/testsuite/gdb.base/so-symmain.c @V@/gdb/testsuite/gdb.base/solib-overlap-lib.c @V@/gdb/testsuite/gdb.base/so-ovrlib.c @V@/gdb/testsuite/gdb.base/solib-overlap-main.c @V@/gdb/testsuite/gdb.base/so-ovrmain.c +@V@/gdb/testsuite/gdb.base/gdb.base/symbol-without-target_section.exp @V@/gdb/testsuite/gdb.base/symnosec.exp +@V@/gdb/testsuite/gdb.base/gdb.base/symbol-without-target_section.c @V@/gdb/testsuite/gdb.base/symnosec.c @V@/gdb/testsuite/gdb.base/type-opaque-lib.c @V@/gdb/testsuite/gdb.base/ty-opqlib.c @V@/gdb/testsuite/gdb.base/type-opaque-main.c @V@/gdb/testsuite/gdb.base/ty-opqmain.c @V@/gdb/testsuite/gdb.base/watchpoint-hw.c @V@/gdb/testsuite/gdb.base/wp-hw.c --- a/gdb/solib-svr4.c +++ b/gdb/solib-svr4.c @@ -570,7 +570,7 @@ scan_dyntag (int dyntag, bfd *abfd, CORE_ADDR *ptr) { int arch_size, step, sect_size; long dyn_tag; - CORE_ADDR dyn_ptr; + CORE_ADDR dyn_ptr, dyn_addr; gdb_byte *bufend, *bufstart, *buf; Elf32_External_Dyn *x_dynp_32; Elf64_External_Dyn *x_dynp_64; @@ -627,7 +627,17 @@ scan_dyntag (int dyntag, bfd *abfd, CORE target_section++) if (sect == target_section->the_bfd_section) break; - gdb_assert (target_section < target_get_section_table (&exec_ops)->sections_end); + if (target_section < target_get_section_table (&exec_ops)->sections_end) + dyn_addr = target_section->addr; + else + { + /* ABFD may come from OBJFILE acting only as a symbol file without being + loaded into the target (see add_symbol_file_command). This case is + such fallback to the file VMA address without the possibility of + having the section relocated to its actual in-memory address. */ + + dyn_addr = bfd_section_vma (abfd, sect); + } /* Read in .dynamic from the BFD. We will get the actual value from memory later. */ @@ -639,7 +649,7 @@ scan_dyntag (int dyntag, bfd *abfd, CORE_ADDR *ptr) CORE_ADDR ptr_addr; ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr; - ptr_addr = target_section->addr + (buf - bufstart) + arch_size / 8; + ptr_addr = dyn_addr + (buf - bufstart) + arch_size / 8; if (target_read_memory (ptr_addr, ptr_buf, arch_size / 8) == 0) dyn_ptr = extract_typed_address (ptr_buf, ptr_type); *ptr = dyn_ptr; --- /dev/null +++ b/gdb/testsuite/gdb.base/symbol-without-target_section.c @@ -0,0 +1,18 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2010 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +int symbol_without_target_section; --- /dev/null +++ b/gdb/testsuite/gdb.base/symbol-without-target_section.exp @@ -0,0 +1,39 @@ +# Copyright 2010 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +# Exploit formerly failed assertion in scan_dyntag when it got called for +# objfile having ".dynamic" section but without having data loaded in target. +# Such file is ${binmainfile} through add-symbol-file here. Set context first +# by "list main" to have some local BLOCK set in lookup_symbol_global. + +set testfile symbol-without-target_section +set srclibfile ${testfile}.c +set binlibfile ${testfile}.x +set srcmainfile start.c +set binmainfile ${testfile} +if { [gdb_compile "${srcdir}/${subdir}/${srclibfile}" \ + "${objdir}/${subdir}/${binlibfile}" object {debug}] != "" } { + untested ${testfile}.exp + return -1 +} +if {[build_executable ${testfile}.exp ${binmainfile} ${srcmainfile} {debug}] == -1} { + return -1 +} +clean_restart ${binlibfile} + +gdb_test "add-symbol-file ${objdir}/${subdir}/${binmainfile} 0" "" "add-symbol-file" \ + "add symbol table from file \".*\" at.*\\(y or n\\) " "y" +gdb_test "list main" +gdb_test "print symbol_without_target_section"