The problem is that with hardware step targets and displaced stepping,
"signal FOO" when stopped at a breakpoint steps the breakpoint
instruction at the same time it delivers a signal. This results in
tp->stepped_breakpoint set, but no step-resume breakpoint set. When
the next stop event arrives, GDB crashes. Irrespective of whether we
should do something more/different to step past the breakpoint in this
scenario (e.g., PR 18225), it's just wrong to assume there'll be a
step-resume breakpoint set (and was not the original intention).
gdb/ChangeLog:
2015-04-10 Pedro Alves <palves@redhat.com>
PR gdb/18216
* infrun.c (process_event_stop_test): Don't assume a step-resume
is set if tp->stepped_breakpoint is true.
gdb/testsuite/ChangeLog:
2015-04-10 Pedro Alves <palves@redhat.com>
PR gdb/18216
* gdb.threads/multiple-step-overs.exp: Remove expected eof.
Recent patch series "V2 All-stop on top of non-stop" causes a SIGSEGV
in the test case,
> -PASS: gdb.base/info-shared.exp: continue to breakpoint: library function #4
> +FAIL: gdb.base/info-shared.exp: continue to breakpoint: library function #4
>
> continue^M
> Continuing.^M
> ^M
> Program received signal SIGSEGV, Segmentation fault.^M
> 0x40021564 in ?? () gdb/testsuite/gdb.base/info-shared-solib1.so^M
> (gdb) FAIL: gdb.base/info-shared.exp: continue to breakpoint: library function #4
and an ARM displaced stepping bug is exposed. It can be reproduced by
the modified gdb.arch/arm-disp-step.exp as below,
continue^M
Continuing.^M
^M
Program received signal SIGSEGV, Segmentation fault.^M
0xa713cfcc in ?? ()^M
(gdb) FAIL: gdb.arch/arm-disp-step.exp: continue to breakpoint: continue to test_add_rn_pc_end
This patch is to fix it.
gdb:
2015-04-10 Yao Qi <yao.qi@linaro.org>
* arm-tdep.c (install_alu_reg): Update comment.
(thumb_copy_alu_reg): Remove local variable rn. Update
debugging message. Use r2 instead of r1 in the modified
instruction.
gdb/testsuite:
2015-04-10 Yao Qi <yao.qi@linaro.org>
* gdb.arch/arm-disp-step.S (main): Call test_add_rn_pc.
(test_add_rn_pc): New function.
* gdb.arch/arm-disp-step.exp (test_add_rn_pc): New proc.
(top level): Invoke test_add_rn_pc.
Running break-interp.exp with the target always in non-stop mode trips
on PR13858, as enabling non-stop also enables displaced stepping.
The problem is that when GDB doesn't know where the entry point is, it
doesn't know where to put the displaced stepping scratch pad. The
test added by this commit exercises this. Without the fix, we get:
(gdb) PASS: gdb.base/step-over-no-symbols.exp: displaced=on: break *$pc
set displaced-stepping on
(gdb) PASS: gdb.base/step-over-no-symbols.exp: displaced=on: set displaced-stepping on
stepi
0x00000000004005be in ?? ()
Entry point address is not known.
(gdb) PASS: gdb.base/step-over-no-symbols.exp: displaced=on: stepi
p /x $pc
$2 = 0x4005be
(gdb) PASS: gdb.base/step-over-no-symbols.exp: displaced=on: get after PC
FAIL: gdb.base/step-over-no-symbols.exp: displaced=on: advanced
The fix switches all GNU/Linux ports to get the entry point from
AT_ENTRY in the target auxiliary vector instead of from symbols. This
is currently only done by PPC when Cell debugging is enabled, but I
think all archs should be able to do the same. Note that
ppc_linux_displaced_step_location cached the result, I'm guessing to
avoid constantly re-fetching the auxv out of remote targets, but
that's no longer necessary nowadays, as the auxv blob is itself cached
in the inferior object. The ppc_linux_entry_point_addr global is
obviously bad for multi-process too nowadays.
Tested on x86-64 (-m64/-m32), PPC64 (-m64/-m32) and S/390 GNU/Linux.
Yao tested the new test on ARM as well.
gdb/ChangeLog:
2015-04-10 Pedro Alves <palves@redhat.com>
PR gdb/13858
* amd64-linux-tdep.c (amd64_linux_init_abi_common): Install
linux_displaced_step_location as gdbarch_displaced_step_location
hook.
* arm-linux-tdep.c (arm_linux_init_abi): Likewise.
* i386-linux-tdep.c (i386_linux_init_abi): Likewise.
* linux-tdep.c (linux_displaced_step_location): New function,
based on ppc_linux_displaced_step_location.
* linux-tdep.h (linux_displaced_step_location): New declaration.
* ppc-linux-tdep.c (ppc_linux_entry_point_addr): Delete.
(ppc_linux_inferior_created, ppc_linux_displaced_step_location):
Delete.
(ppc_linux_init_abi): Install linux_displaced_step_location as
gdbarch_displaced_step_location hook, even without Cell/B.E..
(_initialize_ppc_linux_tdep): Don't install
ppc_linux_inferior_created as inferior_created observer.
* s390-linux-tdep.c (s390_gdbarch_init): Install
linux_displaced_step_location as gdbarch_displaced_step_location
hook.
gdb/testsuite/
2015-04-10 Pedro Alves <palves@redhat.com>
PR gdb/13858
* gdb.base/step-over-no-symbols.exp: New file.
gdb/doc/ChangeLog
2015-04-10 Jan Kratochvil <jan.kratochvil@redhat.com>
Eli Zaretskii <eliz@gnu.org>
* gdb.texinfo (Compiling and Injecting Code): Describe set debug
compile, show debug compile. New subsection Compilation options for
the compile command. New subsection Compiler search for the compile
command.
PR binutils/18198
* ld.texinfo (--be8): Add a note about the interaction of this
option with the assembler's -EB option.
* doc/c-arm.texi (ARM Options): Add a note about the interaction of
the -EB option with the linker's --be8 option.
gold marks _init and _fini via symbol, ld marks them via section
(default scripts set .init and .fini section KEEP). This makes it
possible for people to write their own _init and not bother to put the
function into the right section.
PR ld/18223
* ldlang.c (lang_process): Add _init and _fini to gc_sym_list.
This patch fixes Symbol::final_value_is_known so that a defined TLS symbol
in a PIE link is treated as having a known final value, thus allowing
GD->LE TLS optimization, eliminating an unnecessary GOT entry and dynamic
relocation.
gold/
* symtab.cc (Symbol::final_value_is_known): Check for TLS symbol
in a PIE link.
* testsuite/Makefile.am (tls_pie_test.sh): New test.
* testsuite/Makefile.in: Regenerate.
* testsuite/tls_pie_test.sh: New.
gold/
* debug.h (DEBUG_LOCATION): New.
(DEBUG_ALL): Include DEBUG_LOCATION.
(debug_string_to_enum): Add DEBUG_LOCATION.
* dwarf_reader.cc (Sized_dwarf_line_info::read_lines): Fix debug
output to print correct context.
(Sized_dwarf_line_info::do_addr2line): Add debug output. Return
up to 4 more locations at the beginning of the function.
* symtab.cc (Symbol_table::detect_odr_violations): Get canonical
result before sorting list of line numbers.
* testsuite/debug_msg.sh: Allow range of line numbers for
canonical results on optimized code.
We can't check if input is ELF in copy_file since some targets may only
set xvec after bfd_check_format_matches is called. This patch moves
this check to copy_object.
bfd/
* elfxx-target.h (TARGET_BIG_SYM): Add BFD_COMPRESS_GABI to
object_flags.
(TARGET_LITTLE_SYM): Likewise.
binutils/
* objcopy.c (do_debug_sections): Use bit patterns.
(copy_object): Return FALSE for compress_zlib, compress_gnu_zlib
and compress_gabi_zlib on non-ELF input.
(copy_file): Don't check non-ELF input here.
text_action_add uses linear list search to order text actions list by
action VMA. The list is used at the first relaxation pass, when it's not
fixed yet.
Replace the list with splay tree from libiberty.
Original profile:
% time self children called name
-----------------------------------------
0.00 0.00 14/158225 compute_text_actions
3.62 0.00 25211/158225 remove_dead_literal
8.42 0.00 58645/158225 coalesce_shared_literal
10.68 0.00 74355/158225 text_action_add_proposed
38.8 22.73 0.00 158225 text_action_add
0.00 0.00 144527/293246 bfd_zmalloc
-----------------------------------------
Same data, after optimization:
% time self children called name
-----------------------------------------
0.00 0.00 14/158225 compute_text_actions
0.00 0.00 25211/158225 remove_dead_literal
0.00 0.01 58645/158225 coalesce_shared_literal
0.00 0.01 74355/158225 text_action_add_proposed
0.1 0.00 0.02 158225 text_action_add
0.01 0.00 144527/144527 splay_tree_insert
0.00 0.00 144527/195130 splay_tree_lookup
0.00 0.00 144527/293246 bfd_zmalloc
-----------------------------------------
2015-04-03 Max Filippov <jcmvbkbc@gmail.com>
bfd/
* elf32-xtensa.c (splay-tree.h): include header.
(text_action_struct): drop next pointer.
(text_action_list_struct): drop head pointer, add count and
tree fields.
(find_fill_action): instead of linear search in text_action_list
search in the tree.
(text_action_compare, action_first, action_next): new functions.
(text_action_add, text_action_add_literal): instead of linear
search and insertion insert new node into the tree.
(removed_by_actions): pass additional parameter: action_list,
use it to traverse the tree.
(offset_with_removed_text): pass additional action_list parameter
to removed_by_actions.
(map_action_fn_context): new typedef.
(map_action_fn_context_struct): new structure.
(map_action_fn): new function.
(map_removal_by_action): use splay_tree_foreach to build map.
(find_insn_action): replace linear search in text_action_list
with series of splay_tree_lookups.
(print_action, print_action_list_fn): new functions.
(print_action_list): use splay_tree_foreach.
(init_xtensa_relax_info): drop action_list.head initialization.
Initialize the tree.
(compute_text_actions): use non-zero action_list_count instead of
non-NULL action list.
(xlate_map_context): new typedef.
(xlate_map_context_struct): new structure.
(xlate_map_fn): new function.
(build_xlate_map): use splay_tree_foreach to build map.
(action_remove_bytes_fn): new function.
(relax_section): use zero action_list_count instead of NULL
action list. Use splay_tree_foreach to count final section size.
Drop unused variable 'removed'.
find_removed_literal uses linear search to find removed literal by its
VMA. The list of literals is fixed at that point, build an ordered index
array and use binary search instead.
Original profile:
% time self children called name
-----------------------------------------
56.72 0.00 297578/669392 translate_reloc
70.86 0.00 371814/669392 relax_section
67.9 127.58 0.00 669392 find_removed_literal
-----------------------------------------
Same data, after optimization:
% time self children called name
-----------------------------------------
0.00 0.00 297578/669392 translate_reloc
0.00 0.00 371814/669392 relax_section
0.0 0.00 0.00 669392 find_removed_literal
0.00 0.00 23838/23838 map_removed_literal
-----------------------------------------
2015-04-03 Max Filippov <jcmvbkbc@gmail.com>
bfd/
* elf32-xtensa.c (removed_literal_map_entry): new typedef.
(removed_literal_map_entry_struct): new structure.
(removed_literal_list_struct): add new fields: n_map and map.
(map_removed_literal, removed_literal_compare): new functions.
(find_removed_literal): build index array for literals ordered
by VMA, use binary search to find removed literal.
The function removed_by_actions iterates through text actions to
calculate an offset applied by text actions to a given VMA. Although it
has a parameter p_start_action that allows for incremental offset
calculation, in many places it's used with p_start_action explicitly set
to the first action. After the first relaxation pass when the list of
text actions is finalized, an array of offsets sorted by VMA may be used
to speed up this function.
Original profile:
% time self children called name
-----------------------------------------
0.35 0.00 33872/4808961 relax_section_symbols
3.32 0.00 326022/4808961 relax_property_section
12.83 0.00 1259379/4808961 offset_with_removed_text
32.50 0.00 3189688/4808961 translate_reloc
71.5 49.00 0.00 4808961 removed_by_actions
-----------------------------------------
Same data, after optimization:
% time self children called name
-----------------------------------------
0.00 0.00 33872/4808537 relax_section_symbols
0.01 0.00 326022/4808537 relax_property_section
0.05 0.00 1258955/4808537 offset_with_removed_text_map
0.13 0.00 3189688/4808537 translate_reloc
1.0 0.20 0.00 4808537 removed_by_actions_map
0.00 0.00 120/120 map_removal_by_action
-----------------------------------------
2015-04-01 Max Filippov <jcmvbkbc@gmail.com>
bfd/
* elf32-xtensa.c (removal_by_action_entry_struct,
removal_by_action_map_struct): new structures.
(removal_by_action_entry, removal_by_action_map): new typedefs.
(text_action_list_struct): add new field: map.
(map_removal_by_action, removed_by_actions_map,
offset_with_removed_text_map): new functions.
(relax_section): replace offset_with_removed_text with
offset_with_removed_text_map.
(translate_reloc, relax_property_section, relax_section_symbols):
replace removed_by_actions with removed_by_actions_map.
The original check_section_ebb_pcrels_fit algorithm checks that text
actions proposed for current EBB are OK for every relocation in a
section. There's no need to check every relocation, because text actions
for EBB can only change size of that EBB, thus only affecting
relocations that in any way cross that EBB. In addition EBBs are
iterated in ascending order of their VMA, making it easier to track
relevant relocations.
Introduce a structure that can track relocations that cross the range of
VMAs of EBB and use it to only check relocations relevant to current EBB
in check_section_ebb_pcrels_fit.
It takes O(N log N) operations to build it and O(N) operations to move
current EBB VMA window through its entire range, where N is the number
of relocations in a section. The resulting complexity of
compute_text_actions is thus reduced from O(N^2) to O(N log N + N * M),
where M is the average number of relocations crossing each EBB.
Original profile:
% time self children called name
-----------------------------------------
44.26 71.53 6429/6429 compute_text_actions
50.2 44.26 71.53 6429 check_section_ebb_pcrels_fit
1.16 20.12 347506666/347576152 pcrel_reloc_fits
2.95 16.52 347506666/348104944 get_relocation_opnd
2.01 9.74 347575100/361252208 r_reloc_init
0.55 7.53 347575100/363381467 r_reloc_get_section
5.76 0.02 695013332/695013332 xlate_offset_with_removed_text
0.68 3.89 347575100/363483827 bfd_octets_per_byte
0.32 0.00 347506666/349910253 is_alt_relocation
0.18 0.11 6391/6391 build_xlate_map
0.00 0.00 6429/19417168 get_xtensa_relax_info
0.00 0.00 6391/6391 free_xlate_map
-----------------------------------------
Same data, after optimization:
% time self children called name
-----------------------------------------
2.56 3.08 6429/6429 compute_text_actions
8.2 2.56 3.08 6429 check_section_ebb_pcrels_fit
0.08 0.91 17721075/17790561 pcrel_reloc_fits
0.17 0.47 17721075/31685977 r_reloc_init
0.43 0.00 35442150/35442150 xlate_offset_with_removed_text
0.02 0.37 17721075/33815236 r_reloc_get_section
0.22 0.11 6391/6391 build_xlate_map
0.05 0.22 17721075/33917596 bfd_octets_per_byte
0.03 0.00 17721075/20405299 is_alt_relocation
0.01 0.00 6429/6429 reloc_range_list_update_range
0.00 0.00 6429/19417168 get_xtensa_relax_info
0.00 0.00 6391/6391 free_xlate_map
-----------------------------------------
2015-04-01 Max Filippov <jcmvbkbc@gmail.com>
bfd/
* elf32-xtensa.c (reloc_range_list, reloc_range_list_entry,
reloc_range): new typedef.
(reloc_range_list_struct, reloc_range_list_entry_struct,
reloc_range_struct): new structures.
(reloc_range_compare, build_reloc_ranges,
reloc_range_list_append, reloc_range_list_remove,
reloc_range_list_update_range, free_reloc_range_list): new
functions.
(compute_text_actions): precompute relocation opcodes before the
loop. Add relevant_relocs variable, initialize it before the
loop, pass it to the check_section_ebb_pcrels_fit.
(check_section_ebb_pcrels_fit): add new parameter:
relevant_relocs. Update address range in the relevant_relocs if
it's non-NULL and iterate only over relevant relocations.
This commit introduces a new shared function to replace three
identical functions in various places in the codebase.
gdb/ChangeLog:
* common/common-remote-fileio.h (remote_fileio_to_fio_error):
New declaration.
* common/common-remote-fileio.c (remote_fileio_to_fio_error):
New function, factored out the named functions below.
* inf-child.c (gdb/fileio.h): Remove include.
(common-remote-fileio.h): New include.
(inf_child_errno_to_fileio_error): Remove function. Update
all callers to use remote_fileio_to_fio_error.
* remote-fileio.c (remote_fileio_errno_to_target): Likewise.
gdb/gdbserver/ChangeLog:
* hostio-errno.c (errno_to_fileio_error): Remove function.
Update caller to use remote_fileio_to_fio_error.
bfd * elf32-rx.c (describe_flags): Report the settings of the string
insn using bits.
(rx_elf_merge_private_bfd_data): Handle merging of the string insn
using bits.
bin * readelf.c (get_machine_flags): Report the setting of the string
insn using bits.
gas * config/tc-rx.c (enum options): Add OPTION_DISALLOW_STRING_INSNS.
(md_longopts): Add -mno-allow-string-insns.
(md_parse_option): Handle -mno-allow-string-insns.
(md_show_usage): Mention -mno-allow-string-insns.
(rx_note_string_insn_use): New function. Produces an error
message if a string insn is used when it is not allowed.
* config/rx-parse.y (SCMPU): Call rx_note_string_insn_use.
(SMOVU, SMOVB, SMOVF, SUNTIL, SWHILE, RMPA): Likewise.
* config/rx-defs.h (rx_note_string_insn_use): Prototype.
* doc/c-rx.texi: Document -mno-allow-string-insns.
elf * rx.h (E_FLAG_RX_SINSNS_SET): New bit in e_flags field.
(E_FLAG_RX_SINSNS_YES): Likewise.
(E_FLAG_RX_SINSNS_MASK): New define.
gdb/ChangeLog:
2015-04-09 Pedro Alves <palves@redhat.com>
* gnulib/update-gnulib.sh (aclocal version check): Filter out
"called too early to check prototype".
Hi,
I see the following error on arm linux gdbserver,
continue^M
Continuing.^M
../../../binutils-gdb/gdb/gdbserver/linux-arm-low.c:458: A problem internal to GDBserver has been detected.^M
raw_bkpt_type_to_arm_hwbp_type: unhandled raw type^M
Remote connection closed^M
(gdb) FAIL: gdb.base/cond-eval-mode.exp: hbreak: continue
After we make GDBserver handling Zx/zx packet idempotent,
[PATCH 3/3] [GDBserver] Make Zx/zx packet handling idempotent.
https://sourceware.org/ml/gdb-patches/2014-04/msg00480.html
> Now removal/insertion of all kinds of breakpoints/watchpoints, either
> internal, or from GDB, always go through the target methods.
GDBserver handles all kinds of breakpoints/watchpoints through target
methods. However, some target backends, such as arm, don't support Z0
packet but need software breakpoint to do breakpoint stepping over in
linux-low.c:start_step_over,
if (can_hardware_single_step ())
{
step = 1;
}
else
{
CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
set_reinsert_breakpoint (raddr);
step = 0;
}
a software breakpoint is requested to the backend, and the error is
triggered. This problem should affect targets having
breakpoint_reinsert_addr hooked.
Instead of handling memory breakpoint in these affected linux backend,
this patch handles memory breakpoint in linux_{insert,remove}_point,
that, if memory breakpoint is requested, call
{insert,remove}_memory_breakpoint respectively. Then, it becomes
unnecessary to handle memory breakpoint for linux x86 backend, so
this patch removes the code there.
This patch is tested with GDBserver on x86_64-linux and arm-linux
(-marm, -mthumb). Note that there are still some fails in
gdb.base/cond-eval-mode.exp with -mthumb, because GDBserver doesn't
know how to select the correct breakpoint instruction according to
the arm-or-thumb-mode of requested address. This is a separate
issue, anyway.
gdb/gdbserver:
2015-04-09 Yao Qi <yao.qi@linaro.org>
* linux-low.c (linux_insert_point): Call
insert_memory_breakpoint if TYPE is raw_bkpt_type_sw.
(linux_remove_point): Call remove_memory_breakpoint if type is
raw_bkpt_type_sw.
* linux-x86-low.c (x86_insert_point): Don't call
insert_memory_breakpoint.
(x86_remove_point): Don't call remove_memory_breakpoint.
When --enable-targets=all is used with non-ELF target, we should enable
ELF ld_list_options.
* configure.ac (elf_list_options): Set to TRUE for
--enable-targets=all.
(elf_shlib_list_options): Likewise.
(elf_plt_unwind_list_options): Likewise.
* configure: Regenerated.
This patch is related to PR python/16699, and is an improvement over the
patch posted here:
<https://sourceware.org/ml/gdb-patches/2014-03/msg00301.html>
Keith noticed that, when using the "complete" command on GDB to complete
a Python command, some strange things could happen. In order to
understand what can go wrong, I need to explain how the Python
completion mechanism works.
When the user requests a completion of a Python command by using TAB,
GDB will first try to determine the right set of "brkchars" that will be
used when doing the completion. This is done by actually calling the
"complete" method of the Python class. Then, when we already know the
"brkchars" that will be used, we call the "complete" method again, for
the same values.
If you read the thread mentioned above, you will see that one of the
design decisions was to make the "cmdpy_completer_helper" (which is the
function the does the actual calling of the "complete" method) cache the
first result of the completion, since this result will be used in the
second call, to do the actual completion.
The problem is that the "complete" command does not process the
brkchars, and the current Python completion mechanism (improved by the
patch mentioned above) relies on GDB trying to determine the brkchars,
and then doing the completion itself. Therefore, when we use the
"complete" command instead of doing a TAB-completion on GDB, there is a
scenario where we can use the invalid cache of a previous Python command
that was completed before. For example:
(gdb) A <TAB>
(gdb) complete B
B value1
B value10
B value2
B value3
B value4
B value5
B value6
B value7
B value8
B value9
(gdb) B <TAB>
comp1 comp2 comp4 comp6 comp8
comp10 comp3 comp5 comp7 comp9
Here, we see that "complete B " gave a different result than "B <TAB>".
The reason for that is because "A <TAB>" was called before, and its
completion results were "value*", so when GDB tried to "complete B " it
wrongly answered with the results for A. The problem here is using a
wrong cache (A's cache) for completing B.
We tried to come up with a solution that would preserve the caching
mechanism, but it wasn't really possible. So I decided to completely
remove the cache, and doing the method calling twice for every
completion. This is not optimal, but I do not think it will impact
users noticeably.
It is worth mentioning another small issue that I found. The code was
doing:
wordobj = PyUnicode_Decode (word, sizeof (word), host_charset (), NULL);
which is totally wrong, because using "sizeof" here will lead to always
the same result. So I changed this to use "strlen". The testcase also
catches this problem.
Keith kindly expanded the existing testcase to cover the problem
described above, and everything is passing.
gdb/ChangeLog:
2015-04-08 Sergio Durigan Junior <sergiodj@redhat.com>
PR python/16699
* python/py-cmd.c (cmdpy_completer_helper): Adjust function to not
use a caching mechanism. Adjust comments and code to reflect
that. Replace 'sizeof' by 'strlen' when fetching 'wordobj'.
(cmdpy_completer_handle_brkchars): Adjust call to
cmdpy_completer_helper. Call Py_XDECREF for 'resultobj'.
(cmdpy_completer): Likewise.
gdb/testsuite/ChangeLog:
2015-04-08 Keith Seitz <keiths@redhat.com>
PR python/16699
* gdb.python/py-completion.exp: New tests for completion.
* gdb.python/py-completion.py (CompleteLimit1): New class.
(CompleteLimit2): Likewise.
(CompleteLimit3): Likewise.
(CompleteLimit4): Likewise.
(CompleteLimit5): Likewise.
(CompleteLimit6): Likewise.
(CompleteLimit7): Likewise.
Both PRs are triggered by the same use case.
PR18214 is about software single-step targets. On those, the 'resume'
code that detects that we're stepping over a breakpoint and delivering
a signal at the same time:
/* Currently, our software single-step implementation leads to different
results than hardware single-stepping in one situation: when stepping
into delivering a signal which has an associated signal handler,
hardware single-step will stop at the first instruction of the handler,
while software single-step will simply skip execution of the handler.
...
Fortunately, we can at least fix this particular issue. We detect
here the case where we are about to deliver a signal while software
single-stepping with breakpoints removed. In this situation, we
revert the decisions to remove all breakpoints and insert single-
step breakpoints, and instead we install a step-resume breakpoint
at the current address, deliver the signal without stepping, and
once we arrive back at the step-resume breakpoint, actually step
over the breakpoint we originally wanted to step over. */
doesn't handle the case of _another_ thread also needing to step over
a breakpoint. Because the other thread is just resumed at the PC
where it had stopped and a breakpoint is still inserted there, the
thread immediately re-traps the same breakpoint. This test exercises
that. On software single-step targets, it fails like this:
KFAIL: gdb.threads/multiple-step-overs.exp: displaced=off: signal thr3: continue to sigusr1_handler
KFAIL: gdb.threads/multiple-step-overs.exp: displaced=off: signal thr2: continue to sigusr1_handler
gdb.log (simplified):
(gdb) continue
Continuing.
Breakpoint 4, child_function_2 (arg=0x0) at src/gdb/testsuite/gdb.threads/multiple-step-overs.c:66
66 callme (); /* set breakpoint thread 2 here */
(gdb) thread 3
(gdb) queue-signal SIGUSR1
(gdb) thread 1
[Switching to thread 1 (Thread 0x7ffff7fc1740 (LWP 24824))]
#0 main () at src/gdb/testsuite/gdb.threads/multiple-step-overs.c:106
106 wait_threads (); /* set wait-threads breakpoint here */
(gdb) break sigusr1_handler
Breakpoint 5 at 0x400837: file src/gdb/testsuite/gdb.threads/multiple-step-overs.c, line 31.
(gdb) continue
Continuing.
[Switching to Thread 0x7ffff7fc0700 (LWP 24828)]
Breakpoint 4, child_function_2 (arg=0x0) at src/gdb/testsuite/gdb.threads/multiple-step-overs.c:66
66 callme (); /* set breakpoint thread 2 here */
(gdb) KFAIL: gdb.threads/multiple-step-overs.exp: displaced=off: signal thr3: continue to sigusr1_handler
For good measure, I made the test try displaced stepping too. And
then I found it crashes GDB on x86-64 (a hardware step target), but
only when displaced stepping... :
KFAIL: gdb.threads/multiple-step-overs.exp: displaced=on: signal thr1: continue to sigusr1_handler (PRMS: gdb/18216)
KFAIL: gdb.threads/multiple-step-overs.exp: displaced=on: signal thr2: continue to sigusr1_handler (PRMS: gdb/18216)
KFAIL: gdb.threads/multiple-step-overs.exp: displaced=on: signal thr3: continue to sigusr1_handler (PRMS: gdb/18216)
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x000000000062a83a in process_event_stop_test (ecs=0x7fff847eeee0) at src/gdb/infrun.c:4964
4964 if (sr_bp->loc->permanent
Setting up the environment for debugging gdb.
Breakpoint 1 at 0x79fcfc: file src/gdb/common/errors.c, line 54.
Breakpoint 2 at 0x50a26c: file src/gdb/cli/cli-cmds.c, line 217.
(top-gdb) p sr_bp
$1 = (struct breakpoint *) 0x0
(top-gdb) bt
#0 0x000000000062a83a in process_event_stop_test (ecs=0x7fff847eeee0) at src/gdb/infrun.c:4964
#1 0x000000000062a1af in handle_signal_stop (ecs=0x7fff847eeee0) at src/gdb/infrun.c:4715
#2 0x0000000000629097 in handle_inferior_event (ecs=0x7fff847eeee0) at src/gdb/infrun.c:4165
#3 0x0000000000627482 in fetch_inferior_event (client_data=0x0) at src/gdb/infrun.c:3298
#4 0x000000000064ad7b in inferior_event_handler (event_type=INF_REG_EVENT, client_data=0x0) at src/gdb/inf-loop.c:56
#5 0x00000000004c375f in handle_target_event (error=0, client_data=0x0) at src/gdb/linux-nat.c:4658
#6 0x0000000000648c47 in handle_file_event (file_ptr=0x2e0eaa0, ready_mask=1) at src/gdb/event-loop.c:658
The all-stop-non-stop series fixes this, but meanwhile, this augments
the multiple-step-overs.exp test to cover this, KFAILed.
gdb/testsuite/ChangeLog:
2015-04-08 Pedro Alves <palves@redhat.com>
PR gdb/18214
PR gdb/18216
* gdb.threads/multiple-step-overs.c (sigusr1_handler): New
function.
(main): Install it as SIGUSR1 handler.
* gdb.threads/multiple-step-overs.exp (setup): Remove 'prefix'
parameter. Always use "setup" as prefix. Toggle "set
displaced-stepping" off/on depending on global. Don't switch to
thread 1 here.
(top level): Add displaced stepping "off/on" test axis. Update
"setup" calls. Wrap each subtest with with_test_prefix. Test
continuing with a queued signal in each thread.
Nowadays, in infrun.c:resume, the setting to 'step' variable is like:
if (use_displaced_stepping (gdbarch)
&& tp->control.trap_expected
&& sig == GDB_SIGNAL_0
&& !current_inferior ()->waiting_for_vfork_done)
{
}
/* Do we need to do it the hard way, w/temp breakpoints? */
else if (step)
step = maybe_software_singlestep (gdbarch, pc); <-- [1]
...
if (execution_direction != EXEC_REVERSE
&& step && breakpoint_inserted_here_p (aspace, pc))
{
...
if (gdbarch_cannot_step_breakpoint (gdbarch)) <-- [2]
step = 0;
}
spu doesn't have displaced stepping and uses software single step,
so 'step' is set to zero in [1], and [2] becomes unreachable as a
result. So don't have to call set_gdbarch_cannot_step_breakpoint
in spu_gdbarch_init.
gdb:
2015-04-08 Yao Qi <yao.qi@linaro.org>
* spu-tdep.c (spu_gdbarch_init): Don't call
set_gdbarch_cannot_step_breakpoint.
This patch adds --compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}
options to gas and objcopy for ELF files. They control how DWARF debug
sections are compressed. --compress-debug-sections=none is equivalent to
--nocompress-debug-sections. --compress-debug-sections=zlib and
--compress-debug-sections=zlib-gnu are equivalent to
--compress-debug-sections. --compress-debug-sections=zlib-gabi compresses
DWARF debug sections with SHF_COMPRESSED from the ELF ABI. No linker
changes are required to support SHF_COMPRESSED.
bfd/
* archive.c (_bfd_get_elt_at_filepos): Also copy BFD_COMPRESS_GABI
bit.
* bfd.c (bfd::flags): Increase size to 18 bits.
(BFD_COMPRESS_GABI): New.
(BFD_FLAGS_SAVED): Add BFD_COMPRESS_GABI.
(BFD_FLAGS_FOR_BFD_USE_MASK): Likewise.
(bfd_update_compression_header): New fuction.
(bfd_check_compression_header): Likewise.
(bfd_get_compression_header_size): Likewise.
(bfd_is_section_compressed_with_header): Likewise.
* compress.c (MAX_COMPRESSION_HEADER_SIZE): New.
(bfd_compress_section_contents): Return the uncompressed size if
the full section contents is compressed successfully. Support
converting from/to .zdebug* sections.
(bfd_get_full_section_contents): Call
bfd_get_compression_header_size to get compression header size.
(bfd_is_section_compressed): Renamed to ...
(bfd_is_section_compressed_with_header): This. Add a pointer
argument to return compression header size.
(bfd_is_section_compressed): Use it.
(bfd_init_section_decompress_status): Call
bfd_get_compression_header_size to get compression header size.
Return FALSE if uncompressed section size is 0.
* elf.c (_bfd_elf_make_section_from_shdr): Support converting
from/to .zdebug* sections.
* bfd-in2.h: Regenerated.
binutils/
* objcopy.c (do_debug_sections): Add compress_zlib,
compress_gnu_zlib and compress_gabi_zlib.
(copy_options): Use optional_argument on compress-debug-sections.
(copy_usage): Update --compress-debug-sections.
(copy_file): Handle compress_zlib, compress_gnu_zlib and
compress_gabi_zlib.
(copy_main): Handle
--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
* doc/binutils.texi: Document
--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
binutils/testsuite/
* compress.exp: Add tests for
--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
* binutils-all/dw2-3.rS: New file.
* binutils-all/dw2-3.rt: Likewise.
* binutils-all/libdw2-compressedgabi.out: Likewise.
gas/
* as.c (show_usage): Update --compress-debug-sections.
(std_longopts): Use optional_argument on compress-debug-sections.
(parse_args): Handle
--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
* as.h (compressed_debug_section_type): New.
(flag_compress_debug): Change type to compressed_debug_section_type.
--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
* write.c (compress_debug): Set BFD_COMPRESS_GABI for
--compress-debug-sections=zlib-gabi. Call
bfd_get_compression_header_size to get compression header size.
Don't rename section name for --compress-debug-sections=zlib-gabi.
* config/tc-i386.c (compressed_debug_section_type): Set to
COMPRESS_DEBUG_ZLIB.
* doc/as.texinfo: Document
--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
gas/testsuite/
* gas/i386/dw2-compressed-1.d: New file.
* gas/i386/dw2-compressed-2.d: Likewise.
* gas/i386/dw2-compressed-3.d: Likewise.
* gas/i386/x86-64-dw2-compressed-2.d: Likewise.
* gas/i386/i386.exp: Run dw2-compressed-2, dw2-compressed-1,
dw2-compressed-3 and x86-64-dw2-compressed-2.
ld/testsuite/
* ld-elf/compress.exp: Add a test for
--compress-debug-sections=zlib-gabi.
(build_tests): Add 2 tests for --compress-debug-sections=zlib-gabi.
(run_tests): Likewise.
Verify linker output with zlib-gabi compressed debug input.
* ld-elf/compressed1a.d: New file.
* ld-elf/compressed1b.d: Likewise.
* ld-elf/compressed1c.d: Likewise.
Optional argument of a command line option must start with "=".
* objcopy.c (copy_usage): Replace "--interleave [<number>]" with
--interleave[=<number>].
The recent actions.exp change to check gdb_run_cmd succeeded caught
further problems. The test now fails like this
with --target_board=native-extended-gdbserver:
FAIL: gdb.trace/actions.exp: Can't run to main
gdb.log shows:
(gdb) run
Starting program: /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.trace/actions
Running the default executable on the remote target failed; try "set remote exec-file"?
(gdb) FAIL: gdb.trace/actions.exp: Can't run to main
The problem is that a gdb_load call is missing.
Grepping around for similar problems in other tests, I found that
infotrace.exp and while-stepping.exp should be likewise affected. And
indeed this is what we get today:
FAIL: gdb.trace/infotrace.exp: tstart
FAIL: gdb.trace/infotrace.exp: continue to end (the program is no longer running)
FAIL: gdb.trace/infotrace.exp: tstop
FAIL: gdb.trace/infotrace.exp: 2.6: info tracepoints (trace buffer usage)
FAIL: gdb.trace/while-stepping.exp: tstart
FAIL: gdb.trace/while-stepping.exp: tstop
FAIL: gdb.trace/while-stepping.exp: tfile: info tracepoints
FAIL: gdb.trace/while-stepping.exp: ctf: info tracepoints
while-stepping.exp even has the same race bug actions.exp had.
After this, {actions,infotrace,while-stepping}.exp all pass cleanly
with the native-extended-gdbserver board.
gdb/testsuite/ChangeLog:
2015-04-08 Pedro Alves <palves@redhat.com>
* gdb.trace/actions.exp: Use gdb_load before gdb_run_cmd.
* gdb.trace/infotrace.exp: Use gdb_load before gdb_run_cmd. Use
gdb_breakpoint instead of gdb_test that doesn't expect anything.
Return early if running to main fails.
* gdb.trace/while-stepping.exp: Likewise.
The gdb.base/interrupt.exp test is important for testing system call
restarting, but because it depends on inferior I/O, it ends up skipped
against gdbserver. This patch adjusts the test to use send_inferior
and $inferior_spawn_id so it works against GDBserver.
gdb/testsuite/ChangeLog:
2015-04-07 Pedro Alves <palves@redhat.com>
* gdb.base/interrupt.exp: Don't skip if $inferior_spawn_id !=
$gdb_spawn_id. Use send_inferior and $inferior_spawn_id to
interact with inferior program.
Some important tests, like gdb.base/interrupt.exp end up skipped
against gdbserver, because they depend on inferior I/O, which
gdbserver doesn't do.
This patch adds a mechanism that makes it possible to make them work.
It adds a new "inferior_spawn_id" global that is the spawn ID used for
I/O interaction with the inferior. By default, for native targets, or
remote targets that can do I/O through GDB (semi-hosting) this will be
the same as the gdb/host spawn ID. Otherwise, the board may set this
to some other spawn ID. When debugging with GDBserver, this will be
set to GDBserver's spawn ID.
Then tests can use send_inferior instead of send_gdb to send input to
the inferior, and use expect's "-i" switch to select which spawn ID to
use for matching input/output. That is, something like this will now
work:
send_inferior "echo me\n"
gdb_test_multiple "continue" "test msg" {
-i "$inferior_spawn_id" -re "echo me\r\necho\r\n" {
...
}
}
Or even:
gdb_test_multiple "continue" "test msg" {
-i "$inferior_spawn_id" -re "hello world" {
...
}
-i "$gdb_spawn_id" -re "error.*$gdb_prompt $" {
...
}
}
Of course, by default, gdb_test_multiple still matches with
$gdb_spawn_id.
gdb/testsuite/ChangeLog:
2015-04-07 Pedro Alves <palves@redhat.com>
* lib/gdb.exp (inferior_spawn_id): New global.
(gdb_test_multiple): Handle "-i". Reset the spawn id to GDB's
spawn id after processing the user code.
(default_gdb_start): Set inferior_spawn_id.
(send_inferior): New procedure.
* lib/gdbserver-support.exp (gdbserver_start): Set
inferior_spawn_id.
(close_gdbserver, gdb_exit): Unset inferior_spawn_id.
I adjusted a test to do 'expect -i $server_spawn_id -re ...', and saw
really strange behavior. Whether that expect would work, depended on
whether GDB would also send output and the same expect matched it too
(on $gdb_spawn_id). I was perplexed until I noticed that
gdbserver_spawn spawns gdbserver and then uses expect_background to
reap gdbserver. That expect_background conflicts/races with any
"expect -i $server_spawn_id" done anywhere else in parallel...
In order to make it possible for tests to read inferior I/O out of
$server_spawn_id, we to get rid of that expect_background. This patch
makes us instead reap gdbserver's spawn id when GDB exits. If GDB is
still around, this gives a chance for gdbserver to exit cleanly. The
current code in gdb_finish uses "kill", but that doesn't work with
extended-remote (gdbserver doesn't exit). We now use "monitor exit"
instead which works in both remote and extended-remote modes.
gdb/testsuite/ChangeLog:
2015-04-07 Pedro Alves <palves@redhat.com>
* lib/gdb.exp (gdb_finish): Delete persistent gdbserver handling.
* lib/gdbserver-support.exp (gdbserver_start): Make
$server_spawn_id global.
(gdbserver_start): Don't wait for gdbserver's spawn id with
expect_background.
(close_gdbserver): New procedure.
(gdb_exit): Rename the default version and reimplement.
While teaching gdb_test_multiple to forward "-i" to gdb_expect, I
found that with:
gdb_test_multiple (...) {
-i $some_variable -re "..." {}
}
$some_variable was not getting expanded in the gdb_test_multiple
caller's scope. This is a bug inside gdb_test_multiple. When
processing an argument in passed in user code, it was appending the
original argument literally, instead of appending the uplist'ed
argument.
gdb/testsuite/ChangeLog:
2015-04-07 Pedro Alves <palves@redhat.com>
* lib/gdb.exp (gdb_test_multiple): When processing an argument,
append the substituted item, not the original item.
Pedro Alves
Yao Qi
Alan Modra
Jan Kratochvil
Nick Clifton
GDB Administrator
Cary Coutant
H.J. Lu
Hans-Peter Nilsson
Max Filippov
Gary Benson
Andy Wingo
Sergio Durigan Junior
Han Shen