Setting a breakpoint on an ifunc symbol after the ifunc has already
been resolved by the inferior should result in creating a breakpoint
location at the ifunc target. However, that's not what happens on
current Fedora:
(gdb) n
53 i = gnu_ifunc (1); /* break-at-call */
(gdb)
54 assert (i == 2);
(gdb) b gnu_ifunc
Breakpoint 2 at gnu-indirect-function resolver at 0x7ffff7bd36ee
(gdb) info breakpoints
Num Type Disp Enb Address What
2 STT_GNU_IFUNC resolver keep y 0x00007ffff7bd36ee <gnu_ifunc+4>
The problem is that elf_gnu_ifunc_resolve_by_got never manages to
resolve an ifunc target. The reason is that GDB never actually
creates the internal got.plt symbols:
(gdb) p 'gnu_ifunc@got.plt'
No symbol "gnu_ifunc@got.plt" in current context.
and this is because GDB expects that rela.plt has relocations for
.plt, while it actually has relocations for .got.plt:
Relocation section [10] '.rela.plt' for section [22] '.got.plt' at offset 0x570 contains 2 entries:
Offset Type Value Addend Name
0x0000000000601018 X86_64_JUMP_SLOT 000000000000000000 +0 __assert_fail
0x0000000000601020 X86_64_JUMP_SLOT 000000000000000000 +0 gnu_ifunc
Using an older system on the GCC compile farm (machine gcc15, an
x86-64 running Debian 6.0.8, with GNU ld 2.20.1), we see that it used
to be that we'd get a .rela.plt section for .plt:
Relocation section [ 9] '.rela.plt' for section [11] '.plt' at offset 0x578 contains 3 entries:
Offset Type Value Addend Name
0x0000000000600cc0 X86_64_JUMP_SLOT 000000000000000000 +0 __assert_fail
0x0000000000600cc8 X86_64_JUMP_SLOT 000000000000000000 +0 __libc_start_main
0x0000000000600cd0 X86_64_JUMP_SLOT 000000000000000000 +0 gnu_ifunc
Those offsets did point into .got.plt, as seen with objdump -h:
20 .got.plt 00000030 0000000000600ca8 0000000000600ca8 00000ca8 2**3
CONTENTS, ALLOC, LOAD, DATA
I also tested on gcc110 on the compile farm (PPC64 running CentOS
7.4.1708, with GNU ld 2.25.1), and there we see instead:
Relocation section [ 9] '.rela.plt' for section [23] '.plt' at offset 0x5d0 contains 4 entries:
Offset Type Value Addend Name
0x0000000010020148 PPC64_JMP_SLOT 000000000000000000 +0 __libc_start_main
0x0000000010020160 PPC64_JMP_SLOT 000000000000000000 +0 __gmon_start__
0x0000000010020178 PPC64_JMP_SLOT 000000000000000000 +0 __assert_fail
0x0000000010020190 PPC64_JMP_SLOT 000000000000000000 +0 gnu_ifunc
But note that those offsets point into .plt, not .got.plt, as seen
with objdump -h:
22 .plt 00000078 0000000010020130 0000000010020130 00010130 2**3
ALLOC
This commit makes us support all the different combinations above.
With that addressed, we now get:
(gdb) p 'gnu_ifunc@got.plt'
$1 = (<text from jump slot in .got.plt, no debug info>) 0x400753 <final>
And setting a breakpoint on the ifunc finds the ifunc target:
(gdb) b gnu_ifunc
Breakpoint 2 at 0x400753
(gdb) info breakpoints
Num Type Disp Enb Address What
2 breakpoint keep y 0x0000000000400753 <final>
gdb/ChangeLog:
2018-04-26 Pedro Alves <palves@redhat.com>
* elfread.c (elf_rel_plt_read): Look for relocations for .got.plt too.
There's little point carrying up to three templates per insn flavor
when the sole difference is operand size and the dependency on AVX512VL
being enabled. Instead the need for AVX512VL can be derived from an
operand allowing for ZMMword as well as one or both or XMMword and
YMMword (irrespective of whether this is a register or memory operand).
Without further abstraction to deal with the different Disp8MemShift
values between the templates, only a limited set (mostly ones only
allowing for non-memory operands) can be folded, which is being done
here.
Also drop IgnoreSize wherever possible from anything that's being
touched anyway.
When zeroing an element of a register it doesn't matter whether the zero
results from the actual operation (xor, sub, or nand) or from the
zeroing-masking taking effect due to a clear mask register bit.
Pseudo prefixes are supposed to be a hint only - when the specific
encoding can't be used to encode an insn, silently override it. But
this overriding must only happen after the respective check, to
avoid forcing EVEX encoding because of something that isn't a valid
register name in the given context.
All of AVX, LWP, MPX, and PKU require XSAVE, and hence it as well as
XRSTOR should be enabled when enabling these ISA extensions. Leverage
these implications to shorten some of the cpu_flag_init[] entries.
It's not clear to me why they had been introduced - the respective
comments in opcodes/i386-gen.c are certainly wrong: ymm<N> registers
are very well supported (and necessary) with just AVX512F.
Neither 287 wrt 8087 nor 387 wrt 287 are proper supersets - in each case
some insns get removed from the ISA (they become NOPs, but code intended
for newer co-processors should not use them).
Furthermore with .no87, ST should not be recognized as a register name.
The VEX3SOURCES code was (originally) written with just space
indentation, which is not in line with general coding style as well as
the style later in the function.
There are no templates with VexImmExt and ImmExt set at the same time.
There are also no VEX3SOURCES templates with CpuFMA. I assume both are
left-overs from the implementation of an early specification which was
later revised.
The size of the stack segment defaults to 32KB, and can be overridden
by defining the __stacksize symbol.
2018-04-25 Christophe Lyon <christophe.lyon@st.com>
Mickaël Guêné <mickael.guene@st.com>
bfd/
* elf32-arm.c (DEFAULT_STACK_SIZE): New.
(elf32_arm_always_size_sections): Create stack segment.
Define and handle TLS relocations for FDPIC in BFD and gas.
In gas, the new relocations are rejected if the --fdpic option was not
specified.
We also define the __tdata_start symbol to mark the start of the
.tdata section. This allows FDPIC static binaries to find the start of
.tdata section, since phdr->p_vaddr of TLS segment is not a valid
value for FDPIC.
2018-04-25 Christophe Lyon <christophe.lyon@st.com>
Mickaël Guêné <mickael.guene@st.com>
bfd/:
* bfd-in2.h (BFD_RELOC_ARM_TLS_GD32_FDPIC)
(BFD_RELOC_ARM_TLS_LDM32_FDPIC, BFD_RELOC_ARM_TLS_IE32_FDPIC): New
relocations.
* elf32-arm.c (elf32_arm_howto_table_2): Add R_ARM_TLS_GD32_FDPIC,
R_ARM_TLS_LDM32_FDPIC, R_ARM_TLS_IE32_FDPIC relocations.
(elf32_arm_reloc_map): Add R_ARM_TLS_GD32_FDPIC,
R_ARM_TLS_LDM32_FDPIC, R_ARM_TLS_IE32_FDPIC.
(struct elf32_arm_link_hash_table): Update comment.
(elf32_arm_final_link_relocate): Handle TLS FDPIC relocations.
(IS_ARM_TLS_RELOC): Likewise.
(elf32_arm_check_relocs): Likewise.
(allocate_dynrelocs_for_symbol): Likewise.
(elf32_arm_size_dynamic_sections): Update comment.
* reloc.c: Add BFD_RELOC_ARM_TLS_GD32_FDPIC,
BFD_RELOC_ARM_TLS_LDM32_FDPIC, BFD_RELOC_ARM_TLS_IE32_FDPIC.
gas/
* config/tc-arm.c (reloc_names): Add TLSGD_FDPIC, TLSLDM_FDPIC,
GOTTPOFF_FDIC relocations.
(md_apply_fix): Handle the new TLS FDPIC relocations.
(tc_gen_reloc): Likewise.
(arm_fix_adjustable): Likewise.
include/
* elf/arm.h: Add R_ARM_TLS_GD32_FDPIC, R_ARM_TLS_LDM32_FDPIC,
R_ARM_TLS_IE32_FDPIC.
ld/
* scripttempl/elf.sc: Define __tdata_start for .tdata section.
FDPIC requires special PLT entries, defined in this patch.
Note that lazy binding is not supported because of a race condition
for lack of an atomic 64-bits load instruction.
2018-04-25 Christophe Lyon <christophe.lyon@st.com>
Mickaël Guêné <mickael.guene@st.com>
bfd/
* elf32-arm.c (elf32_arm_fdpic_plt_entry): New.
(elf32_arm_create_dynamic_sections): Handle FDPIC.
(elf32_arm_allocate_plt_entry): Likewise.
(elf32_arm_populate_plt_entry): Likewise.
(elf32_arm_output_plt_map_1): Likewise.
ELF files targetting ARM FDPIC use the ELFOSABI_ARM_FDPIC flag.
Set it appropriately in file generators (eg. gas), and handle it in
readers (eg. readelf).
2018-04-25 Christophe Lyon <christophe.lyon@st.com>
Mickaël Guêné <mickael.guene@st.com>
bfd/
* elf32-arm.c (elf32_arm_print_private_bfd_data): Support
EF_ARM_PIC and ELFOSABI_ARM_FDPIC.
(elf32_arm_post_process_headers): Support ELFOSABI_ARM_FDPIC.
(ELF_OSABI): Define to ELFOSABI_ARM_FDPIC.
binutils/
* readelf.c (decode_ARM_machine_flags): Support EF_ARM_PIC.
(get_osabi_name): Support ELFOSABI_ARM_FDPIC.
gas/
* config/tc-arm.c (arm_fdpic): New.
(elf32_arm_target_format): Support FDPIC.
(OPTION_FDPIC): New.
(md_longopts): Support FDPIC.
(md_parse_option): Likewise.
(md_show_usage): Likewise.
include/
* elf/arm.h (EF_ARM_FDPIC): New.
Since f67c0c9171 ("Enable 'set print inferior-events' and improve
detach/fork/kill/exit messages"), when detaching a remote process, we
get, for detach against a remote target:
(gdb) detach
Detaching from program: ...., process 5388
Ending remote debugging.
[Inferior 1 (Thread 5388.5388) detached]
^^^^^^^^^^^^^^^^
That is incorrect, for it is printing a thread id as string while we
should be printing the process id instead. I.e., either one of:
[Inferior 1 (process 5388) detached]
[Inferior 1 (Remote target) detached]
depending on remote stub support for the multi-process extensions.
Similarly, after killing a process, we're printing thread ids while we
should be printing process ids. E.g., on native GNU/Linux:
(gdb) k
Kill the program being debugged? (y or n) y
[Inferior 1 (Thread 0x7ffff7faa8c0 (LWP 30721)) has been killed]
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
while it should have been:
Kill the program being debugged? (y or n) y
[Inferior 1 (process 30721) has been killed]
^^^^^^^^^^^^^
There's a wording inconsistency between detach and kill:
[Inferior 1 (process 30721) has been killed]
[Inferior 1 (process 30721) detached]
Given we were already saying "detached" instead of "has been
detached", and we used to say just "exited", and given that the "has
been" doesn't really add any information, this commit changes the
message to just "killed":
[Inferior 1 (process 30721) killed]
gdb/ChangeLog:
2018-04-25 Pedro Alves <palves@redhat.com>
* infcmd.c (kill_command): Print the pid as string, not the whole
thread's ptid. Add comment. s/has been killed/killed/ in output
message.
* remote.c (remote_detach_1): Print the pid as string, not the
whole thread's ptid.
gdb/testsuite/ChangeLog:
2018-04-25 Pedro Alves <palves@redhat.com>
* gdb.base/hook-stop.exp: Expect "killed" instead of "has been
killed".
* gdb.base/kill-after-signal.exp: Likewise.
* gdb.threads/kill.exp: Likewise.
Rn is supposed to have a 5 bit range but instead was given 4 bits
causing these instructions to disassemble as unknown instructions.
opcodes/
* aarch64-tbl.h (sqrdmlah, sqrdmlsh): Fix masks.
gas/
* testsuite/gas/aarch64/rdma.s: Test for larger register numbers.
* testsuite/gas/aarch64/rdma.d: Update results.
* testsuite/gas/aarch64/rdma-directive.d: Likewise.
This seems to work with gcc-8 and a bunch of prior gcc versions I tested.
* elf-linux-core.h: Disable gcc-8 string truncation warning.
* elf.c (elfcore_write_prpsinfo): Likewise.
During --icf processing, gold was incorrectly processing the relocation
addend for references to items in a merge section. PC-relative references
and other forms of reference with a biased base address require a
non-section local symbol, where the addend is purely the bias.
gold/
PR gold/20642
PR gold/22820
* gc.h (gc_process_relocs): Flag STT_SECTION symbols in symvec.
* icf.cc (get_section_contents): For merge sections, ignore the
addend for relocations against non-section symbols.
gold/
PR gold/16504
* dynobj.cc (Versions::symbol_section_contents): Don't set
VERSYM_HIDDEN flag for undefined symbols.
* symtab.cc (Symbol_table::add_from_object): Don't override default
version definition with a different default version.
* symtab.h (Symbol::from_dyn): New method.
* testsuite/plugin_test.c (struct sym_info): Add ver field.
(claim_file_hook): Pass symbol version to plugin API.
(parse_readelf_line): Parse symbol version.
* testsuite/Makefile.am (ver_test_pr16504): New test case.
* testsuite/Makefile.in: Regenerate.
* testsuite/ver_test_pr16504.sh: New test script.
* testsuite/ver_test_pr16504_a.c: New source file.
* testsuite/ver_test_pr16504_a.script: New version script.
* testsuite/ver_test_pr16504_b.c: New source file.
* testsuite/ver_test_pr16504_b.script: New version script.
This patch aims to turn 'set print inferior-events' always on, and do
some cleanup on the messages printed by GDB when various inferior
events happen (attach, detach, fork, kill, exit).
To make sure that the patch is correct, I've tested it with a handful
of combinations of 'set follow-fork-mode', 'set detach-on-fork' and
'set print inferior-events'. In the end, I decided to make my
hand-made test into an official testcase. More on that below.
Using the following program as an example:
#include <unistd.h>
int main ()
{
fork ();
return 0;
}
We see the following outputs from the patched GDB:
- With 'set print inferior-events on':
(gdb) r
Starting program: a.out
[Detaching after fork from child process 27749]
[Inferior 1 (process 27745) exited normally]
(gdb)
- With 'set print inferior-events off':
(gdb) r
Starting program: a.out
[Inferior 1 (process 27823) exited normally]
(gdb)
Comparing this against an unpatched GDB:
- With 'set print inferior-events off' and 'set follow-fork-mode
child':
(gdb) r
Starting program: a.out
[Inferior 2 (process 5993) exited normally]
(gdb)
Compare this against an unpatched GDB:
(unpatched-gdb) r
Starting program: a.out
[New process 5702]
[Inferior 2 (process 5702) exited normally]
(unpatched-gdb)
It is possible to notice that, in this scenario, the patched GDB
will lose the '[New process %d]' message.
- With 'set print inferior-events on', 'set follow-fork-mode child'
and 'set detach-on-fork on':
(gdb) r
Starting program: a.out
[Attaching after process 27905 fork to child process 27909]
[New inferior 2 (process 27909)]
[Detaching after fork from parent process 27905]
[Inferior 1 (process 27905) detached]
[Inferior 2 (process 27909) exited normally]
(gdb)
Compare this output with an unpatched GDB, using the same settings:
(unpatched-gdb) r
Starting program: a.out
[New inferior 28033]
[Inferior 28029 detached]
[New process 28033]
[Inferior 2 (process 28033) exited normally]
[Inferior 28033 exited]
(unpatched-gdb)
As can be seen above, I've also made a few modifications to messages
that are printed when 'set print inferior-events' is on. For example,
a few of the messages did not contain the '[' and ']' as
prefix/suffix, which led to a few inconsistencies like:
Attaching after process 22995 fork to child process 22999.
[New inferior 22999]
Detaching after fork from child process 22999.
[Inferior 22995 detached]
[Inferior 2 (process 22999) exited normally]
So I took the opportunity and included the square brackets where
applicable. I have also made the existing messages more uniform, by
always printing "Inferior %d (process %d)..." where applicable. This
makes it easier to identify the inferior number and the PID number
from the messages.
As suggested by Pedro, the "[Inferior %d exited]" message from
'exit_inferior' has been removed, because it got duplicated when
'inferior-events' is on. I'm also using the
'add_{thread,inferior}_silent' versions (instead of their verbose
counterparts) on some locations, also to avoid duplicated messages.
For example, a patched GDB with 'set print inferior-events on', 'set
detach-on-fork on' and 'set follow-fork-mode child', but using
'add_thread', would print:
(gdb) run
Starting program: a.out
[Attaching after process 25088 fork to child process 25092.]
[New inferior 25092] <--- duplicated
[Detaching after fork from child process 25092.]
[Inferior 25088 detached]
[New process 25092] <--- duplicated
[Inferior 2 (process 25092) exited normally]
But if we use 'add_thread_silent' (with the same configuration as
before):
(gdb) run
Starting program: a.out
[Attaching after process 31606 fork to child process 31610]
[New inferior 2 (process 31610)]
[Detaching after fork from parent process 31606]
[Inferior 1 (process 31606) detached]
[Inferior 2 (process 31610) exited normally]
As for the tests, the configuration options being exercised are:
- follow-fork-mode: child/parent
- detach-on-fork: on/off
- print inferior-events: on/off
It was also necessary to perform adjustments on several testcases,
because the expected messages changed considerably.
Built and regtested on BuildBot, without regressions.
gdb/ChangeLog:
2018-04-24 Jan Kratochvil <jan.kratochvil@redhat.com>
Sergio Durigan Junior <sergiodj@redhat.com>
Pedro Alves <palves@redhat.com>
* infcmd.c (kill_command): Print message when inferior has
been killed.
* inferior.c (print_inferior_events): Remove 'static'. Set as
'1'.
(add_inferior): Improve message printed when
'print_inferior_events' is on.
(exit_inferior): Remove message printed when
'print_inferior_events' is on.
(detach_inferior): Improve message printed when
'print_inferior_events' is on.
(initialize_inferiors): Use 'add_inferior_silent' to set
'current_inferior_'.
* inferior.h (print_inferior_events): Declare here as
'extern'.
* infrun.c (follow_fork_inferior): Print '[Attaching...]' or
'[Detaching...]' messages when 'print_inferior_events' is on.
Use 'add_thread_silent' instead of 'add_thread'. Add '[' and ']'
as prefix/suffix for messages. Remove periods. Fix erroneous
'Detaching after fork from child...', replace it by '... from
parent...'.
(handle_vfork_child_exec_or_exit): Add '[' and ']' as
prefix/suffix when printing 'Detaching...' messages. Print
them when 'print_inferior_events' is on.
* remote.c (remote_detach_1): Print message when detaching
from inferior and '!is_fork_parent'.
gdb/testsuite/ChangeLog:
2018-04-24 Jan Kratochvil <jan.kratochvil@redhat.com>
Sergio Durigan Junior <sergiodj@redhat.com>
Pedro Alves <palves@redhat.com>
* gdb.base/attach-non-pgrp-leader.exp: Adjust 'Detaching...'
regexps to expect for '[Inferior ... detached]' as well.
* gdb.base/attach.exp: Likewise.
* gdb.base/catch-syscall.exp (check_for_program_end): Adjust
"gdb_continue_to_end".
(test_catch_syscall_with_wrong_args): Likewise.
* gdb.base/foll-fork.exp: Adjust regexps to match '[' and
']'. Don't set 'verbose' on.
* gdb.base/foll-vfork.exp: Likewise.
* gdb.base/fork-print-inferior-events.c: New file.
* gdb.base/fork-print-inferior-events.exp: New file.
* gdb.base/hook-stop.exp: Adjust regexps to expect for new
'[Inferior ... has been killed]' message.
* gdb.base/kill-after-signal.exp: Likewise.
* gdb.base/solib-overlap.exp: Adjust regexps to expect for new
detach message.
* gdb.threads/kill.exp: Adjust regexps to expect for new kill
message.
* gdb.threads/clone-attach-detach.exp: Adjust 'Detaching...'
regexps to expect for '[Inferior ... detached]' as well.
* gdb.threads/process-dies-while-detaching.exp: Likewise.
As reported in PR 23104, -ldl doesn't work on FreeBSD. Replace it with
shlib_load, which adds the right flags for dynamic library loading based
on the current target platform.
The test still passes on Linux, and should now pass on FreeBSD, though I
did not test personally.
gdb/testsuite/ChangeLog:
PR gdb/23104
* gdb.base/info-shared.exp: Replace libs=-ldl with shlib_load.
I noticed that cli-out.h had incorrect indentation in some spots.
This fixes it.
ChangeLog
2018-04-24 Tom Tromey <tom@tromey.com>
* cli-out.h: Reindent.
I noticed that cli_ui_out::out_field_fmt is only used by a single
caller, and it can easily be replaced by fputs_filtered. So, this
patch removes it.
ChangeLog
2018-04-24 Tom Tromey <tom@tromey.com>
* cli-out.c (cli_ui_out::out_field_fmt): Remove.
(cli_ui_out::do_field_string): Use fputs_filtered.
* cli-out.h (class cli_ui_out) <out_field_fmt>: Remove.
This removes a cleanup from scm-frame.c, replacing it with
unique_xmalloc_ptr and a new scope. I believe this also fixes a
latent bug involving calling do_cleanups twice for a single cleanup.
Regression tested using the gdb.guile test suite on x86-64 Fedora 26.
ChangeLog
2018-04-23 Tom Tromey <tom@tromey.com>
* guile/scm-frame.c (gdbscm_frame_read_var): Use
gdb::unique_xmalloc_ptr.
Pedro pointed out that gdb/configure and gdbserver/configure weren't
updated after some recent *.m4 changes.
This patch rebuilds those files. Tested by rebuilding. Pedro
approved this in the thread where he raised this issue, so I'm pushing
it in.
ChangeLog
2018-04-23 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
gdbserver/ChangeLog
2018-04-23 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
The gcc warning has been fixed, and the patch regressed builds with
some older versions of gcc.
* elf-linux-core.h: Revert last change.
* elf.c: Likewise.
All of these warnings were false positives. -Wstringop-truncation is
particularly annoying when it warns about strncpy used quite correctly.
bfd/
* elf-linux-core.h (swap_linux_prpsinfo32_ugid32_out): Disable
gcc-8 string truncation warning.
(swap_linux_prpsinfo32_ugid16_out): Likewise.
(swap_linux_prpsinfo64_ugid32_out): Likewise.
(swap_linux_prpsinfo64_ugid16_out): Likewise.
* elf.c (elfcore_write_prpsinfo): Likewise.
gas/
* stabs.c (generate_asm_file): Use memcpy rather than strncpy.
Remove call to strlen inside loop.
* config/tc-cr16.c (getreg_image): Warning fix.
* config/tc-crx.c (getreg_image): Warning fix.
Problems:
1. linking -dl lib on FreeBSD platform
2. backtrace from ld-elf shows r_debug_state() instead of _dl_debug_state()
Cause:
1. There is no dl library on FreeBSD platform test has to ignore linking "-ldl"
2. The stop due to a shared library event shows backtrace frame #0
function as r_debug_state()
gdb/ChangeLog:
PR gdb/23095
* gdb/testsuite/gdb.base/break-probes.exp: Pass shlib_load to
prepare_for_testing. Set normal_bp to r_debug_state if target
is bsd.
