I noticed GDB was failing to enable threading support for 32-bit AIX
cores. I traced it to failure to read variables from libpthreads.a.
The issue is that data for that library is loaded at a high address,
and bfd is sign extending the section addresses:
(gdb) info files
Symbols from "/home/palves/crash".
Local core dump file:
`/home/palves/core', file type aixcoff-rs6000.
0x2ff22000 - 0x2ff23000 is .stack
0x20000000 - 0x200316e0 is .data
0x20000e90 - 0x200016c0 is .data
0xfffffffff0254000 - 0xfffffffff0297920 is .data
0xfffffffff07b46a8 - 0xfffffffff07b47c8 is .data
0xfffffffff0298000 - 0xfffffffff029bfcc is .data
0xfffffffff06dafe0 - 0xfffffffff07b3838 is .data
Local exec file:
`/home/palves/crash', file type aixcoff-rs6000.
Entry point: 0x20001394
0x10000150 - 0x10000e90 is .text
0x20000e90 - 0x2000149c is .data
0x2000149c - 0x200016c0 is .bss
0xd053b124 - 0xd053e15f is .text in /usr/lib/libpthreads.a(shr_comm.o)
0xf0254000 - 0xf0297920 is .data in /usr/lib/libpthreads.a(shr_comm.o)
0xf0254450 - 0xf0297920 is .bss in /usr/lib/libpthreads.a(shr_comm.o)
0xd053a280 - 0xd053aabe is .text in /usr/lib/libcrypt.a(shr.o)
0xf07b46a8 - 0xf07b47c8 is .data in /usr/lib/libcrypt.a(shr.o)
0xf07b47c8 - 0xf07b47c8 is .bss in /usr/lib/libcrypt.a(shr.o)
0xd04fb180 - 0xd053917e is .text in /usr/lib/libpthreads.a(shr_xpg5.o)
0xf0298000 - 0xf029bfcc is .data in /usr/lib/libpthreads.a(shr_xpg5.o)
0xf029bf64 - 0xf029bfcc is .bss in /usr/lib/libpthreads.a(shr_xpg5.o)
0xd0100900 - 0xd04fa39c is .text in /usr/lib/libc.a(shr.o)
0xf06dafe0 - 0xf07b3838 is .data in /usr/lib/libc.a(shr.o)
0xf0751e94 - 0xf07b3838 is .bss in /usr/lib/libc.a(shr.o)
Notice:
...
0xfffffffff0298000 - 0xfffffffff029bfcc is .data
...
Those are the bfd section start/end addresses. It't not visible here:
...
0xf0298000 - 0xf029bfcc is .data in /usr/lib/libpthreads.a(shr_xpg5.o)
...
... just because GDB trims that number to 32-bit when printing.
GDB then fails to find the memory for libpthreads.a variables in the
core, and falls back to reading it directly from the executable (which
yields the values as originally initialized in the code).
E.g.:
(gdb) p &__n_pthreads
$2 = (<data variable, no debug info> *) 0xf074fda8 <__n_pthreads>
(gdb) p __n_pthreads
$1 = -1
That should have returned 2 instead of -1.
bfd/
2014-03-07 Pedro Alves <palves@redhat.com>
* rs6000-core.c (rs6000coff_core_p): Cast pointers to bfd_vma
through ptr_to_uint instead of through long.
keyword in c++.
* bfd/aoutx.h (NAME (aout, make_empty_symbol)): Rename variable
new to new_symbol.
* bfd/coffgen.c (coff_make_empty_symbol)
(coff_bfd_make_debug_symbol): Rename variable new to new_symbol.
* bfd/cpu-ia64-opc.c (ext_reg, ins_imms_scaled): Rename variable
new to new_insn.
* bfd/doc/chew.c (newentry, add_intrinsic): Rename variable new to
new_d.
* bfd/ecoff.c (_bfd_ecoff_make_empty_symbol): Rename variable new
to new_symbol.
* bfd/elf32-m68k.c (elf_m68k_get_got_entry_type): Rename argument
new to new_reloc.
* bfd/hash.c (bfd_hash_lookup): Rename variable new to new_string.
* bfd/ieee.c (ieee_make_empty_symbol): Rename variable new to
new_symbol.
* bfd/linker.c (bfd_new_link_order): Rename variable new to
new_lo.
* bfd/mach-o.c (bfd_mach_o_sizeof_headers): Rename variable new to
symbol.
* bfd/oasys.c (oasys_make_empty_symbol): Rename variable new to
new_symbol_type.
* bfd/pdp11.c (NAME (aout, make_empty_symbol)): Rename variable
new to new_symbol_type.
* bfd/plugin.c (bfd_plugin_make_empty_symbol): Rename variable new
to new_symbol.
* bfd/rs6000-core.c (CoreHdr, VmInfo): Rename union member new to
new_dump.
(read_hdr, rs6000coff_core_p)
(rs6000coff_core_file_matches_executable_p)
(rs6000coff_core_file_failing_command)
(rs6000coff_core_file_failing_signal): Updated function to use new
union member name.
* bfd/som.c (som_make_empty_symbol): Rename variable new to
new_symbol_type.
* bfd/syms.c (_bfd_generic_make_empty_symbol): Rename variable new
to new_symbol.
* bfd/tekhex.c (first_phase, tekhex_make_empty_symbol): Rename
variable new to new_symbol.
* binutils/nlmconv.c (main): Rename variable new to new_name.
* gas/config/tc-arm.c (insert_reg_alias): Rename variable new to
new_reg.
* gas/config/tc-dlx.c (parse_operand): Rename variable new to
new_pos.
* gas/config/tc-ia64.c (ia64_gen_real_reloc_type): Rename variable
new to newr.
* gas/config/tc-mcore.c (parse_exp, parse_imm): Rename variable
new to new_pointer.
* gas/config/tc-microblaze.c (parse_exp, parse_imm, check_got):
Change name from new to new_pointer.
* gas/config/tc-or32.c (parse_operand): Rename variable new to
new_pointer.
* gas/config/tc-pdp11.c (md_assemble): Rename variable new to
new_pointer.
* gas/config/tc-pj.c (alias): Change argument new to new_name.
* gas/config/tc-score.c (s3_build_score_ops_hsh): Rename variable
new to new_opcode. (s3_build_dependency_insn_hsh) Rename variable
new to new_i2n. (s3_convert): Rename variables old and new to
r_old and r_new.
* gas/config/tc-score7.c (s7_build_score_ops_hsh): Rename variable
new to new_opcode. (s7_build_dependency_insn_hsh): Rename variable
new to new_i2d. (s7_b32_relax_to_b16, s7_convert_frag): Rename
variables old and new to r_old and r_new.
* gas/config/tc-sh.c (parse_exp): Rename variable new to
new_pointer.
* gas/config/tc-sh64.c (shmedia_parse_exp): Rename variable new to
new_pointer.
* gas/config/tc-tic4x.c (tic4x_operand_parse): Rename variable new
to new_pointer.
* gas/config/tc-z8k.c (parse_exp): Rename variable new to
new_pointer.
* gas/listing.c (listing_newline): Rename variable new to new_i.
* ld/ldexp.c (exp_intop, exp_bigintop, exp_relop, exp_binop)
(exp_trinop, exp_unop, exp_nameop, exp_assop): Rename variable new
to new_e.
* ld/ldfile.c (ldfile_add_library_path): Rename variable new to
new_dirs. (ldfile_add_arch): Rename variable new to new_arch.
* ld/ldlang.c (new_statement, lang_final, lang_add_wild)
(lang_target, lang_add_fill, lang_add_data, lang_add_assignment)
(lang_add_insert): Rename variable new to new_stmt. (new_afile):
Added missing cast. (lang_memory_region_lookup): Rename variable
new to new_region. (init_os): Rename variable new to
new_userdata. (lang_add_section): Rename variable new to
new_section. (ldlang_add_undef): Rename variable new to
new_undef. (realsymbol): Rename variable new to new_name.
* opcodes/z8kgen.c (internal, gas): Rename variable new to new_op.
Updated sources to avoid using the identifier name "template",
which is a keyword in c++.
* bfd/elf32-arm.c (struct stub_def): Rename member template to
template_sequence. (arm_build_one_stub,
find_stub_size_and_template, arm_size_one_stub, arm_map_one_stub):
Rename variable template to template_sequence.
* bfd/elfxx-ia64.c (elfNN_ia64_relax_br, elfNN_ia64_relax_brl):
Rename variable template to template_val.
* gas/config/tc-arm.c (struct asm_cond, struct asm_psr, struct
asm_barrier_opt): Change member template to
template_name. (md_begin): Update code to reflect new member
names.
* gas/config/tc-i386.c (struct templates, struct _i386_insn)
(match_template, cpu_flags_match, match_reg_size, match_mem_size)
(operand_size_match, md_begin, i386_print_statistics, pi)
(build_vex_prefix, md_assemble, parse_insn, optimize_imm)
(optimize_disp): Updated code to use new names. (parse_insn):
Added casts.
* gas/config/tc-ia64.c (dot_template, emit_one_bundle): Updated
code to use new names.
* gas/config/tc-score.c (struct s3_asm_opcode): Renamed member
template to template_name. (s3_parse_16_32_inst, s3_parse_48_inst,
s3_do_macro_ldst_label, s3_build_score_ops_hsh): Update code to
use new names.
* gas/config/tc-score7.c (struct s7_asm_opcode): Renamed member
template to template_name. (s7_parse_16_32_inst,
s7_do_macro_ldst_label, s7_build_score_ops_hsh): Update code to
use new names.
* gas/config/tc-tic30.c (md_begin, struct tic30_insn)
(md_assemble): Update code to use new names.
* gas/config/tc-tic54x.c (struct _tic54x_insn, md_begin)
(optimize_insn, tic54x_parse_insn, next_line_shows_parallel):
Update code to use new names.
* include/opcode/tic30.h (template): Rename type template to
insn_template. Updated code to use new name.
* include/opcode/tic54x.h (template): Rename type template to
insn_template.
* opcodes/cris-dis.c (bytes_to_skip): Update code to use new name.
* opcodes/i386-dis.c (putop): Update code to use new name.
* opcodes/i386-gen.c (process_i386_opcodes): Update code to use
new name.
* opcodes/i386-opc.h (struct template): Rename struct template to
insn_template. Update code accordingly.
* opcodes/i386-tbl.h (i386_optab): Update type to use new name.
* opcodes/ia64-dis.c (print_insn_ia64): Rename variable template
to template_val.
* opcodes/tic30-dis.c (struct instruction, get_tic30_instruction):
Update code to use new name.
* opcodes/tic54x-dis.c (has_lkaddr, get_insn_size)
(print_parallel_instruction, print_insn_tic54x, tic54x_get_insn):
Update code to use new name.
* opcodes/tic54x-opc.c (tic54x_unknown_opcode, tic54x_optab):
Update type to new name.
machine for matching core files.
(xcoff64_core_p): Set the architecture and machine to the default
values defined in the macros mentioned above.
* rs6000-core.c: Define macros to determine whether or not the
core file header uses the core_dumpxx header format.
(rs6000coff_core_p): Don't match core files that use the
core_dumpxx header format.
* rs6000-core.c: ANSIfy all function definitions.
Add missing function prototypes.
(ptr_to_uint): New type.
(rs6000coff_core_p): Use it as intermediate step in casts.
(rs6000coff_core_file_matches_executable_p): Likewise.
* xcoff-target.h (rs6000coff_core_p): Fix prototype.
(rs6000coff_core_file_matches_executable_p): Likewise.
o bfd_read and bfd_write lose an unnecessary param and become
bfd_bread and bfd_bwrite.
o bfd_*alloc now all take a bfd_size_type arg, and will error if
size_t is too small. eg. 32 bit host, 64 bit bfd, verrry big files
or bugs in linker scripts etc.
o file_ptr becomes a bfd_signed_vma. Besides matching sizes with
various other types involved in handling sections, this should make
it easier for bfd to support a 64 bit off_t on 32 bit hosts that
provide it.
o I've made the H_GET_* and H_PUT_* macros (which invoke bfd_h_{get,put}_*)
generally available. They now cast their args to bfd_vma and
bfd_byte * as appropriate, which removes a swag of casts from the
source.
o Bug fixes to bfd_get8, aix386_core_vec, elf32_h8_relax_section, and
aout-encap.c.
o Zillions of formatting and -Wconversion fixes.
files on AIX 4.3.
(read_hdr): New function.
(rs6000coff_core_p): Store mstsave or __context64 struct instead
of trying to extract individual registers. Set abfd->arch_info
to match the architecture that created the core file.
(rs6000coff_get_section_contents): Delete.
* xcoff-target.h (rs6000coff_get_section_contents): Delete.
