This patch splits the TRY_CATCH macro into three, so that we go from
this:
~~~
volatile gdb_exception ex;
TRY_CATCH (ex, RETURN_MASK_ERROR)
{
}
if (ex.reason < 0)
{
}
~~~
to this:
~~~
TRY
{
}
CATCH (ex, RETURN_MASK_ERROR)
{
}
END_CATCH
~~~
Thus, we'll be getting rid of the local volatile exception object, and
declaring the caught exception in the catch block.
This allows reimplementing TRY/CATCH in terms of C++ exceptions when
building in C++ mode, while still allowing to build GDB in C mode
(using setjmp/longjmp), as a transition step.
TBC, after this patch, is it _not_ valid to have code between the TRY
and the CATCH blocks, like:
TRY
{
}
// some code here.
CATCH (ex, RETURN_MASK_ERROR)
{
}
END_CATCH
Just like it isn't valid to do that with C++'s native try/catch.
By switching to creating the exception object inside the CATCH block
scope, we can get rid of all the explicitly allocated volatile
exception objects all over the tree, and map the CATCH block more
directly to C++'s catch blocks.
The majority of the TRY_CATCH -> TRY+CATCH+END_CATCH conversion was
done with a script, rerun from scratch at every rebase, no manual
editing involved. After the mechanical conversion, a few places
needed manual intervention, to fix preexisting cases where we were
using the exception object outside of the TRY_CATCH block, and cases
where we were using "else" after a 'if (ex.reason) < 0)' [a CATCH
after this patch]. The result was folded into this patch so that GDB
still builds at each incremental step.
END_CATCH is necessary for two reasons:
First, because we name the exception object in the CATCH block, which
requires creating a scope, which in turn must be closed somewhere.
Declaring the exception variable in the initializer field of a for
block, like:
#define CATCH(EXCEPTION, mask) \
for (struct gdb_exception EXCEPTION; \
exceptions_state_mc_catch (&EXCEPTION, MASK); \
EXCEPTION = exception_none)
would avoid needing END_CATCH, but alas, in C mode, we build with C90,
which doesn't allow mixed declarations and code.
Second, because when TRY/CATCH are wired to real C++ try/catch, as
long as we need to handle cleanup chains, even if there's no CATCH
block that wants to catch the exception, we need for stop at every
frame in the unwind chain and run cleanups, then rethrow. That will
be done in END_CATCH.
After we require C++, we'll still need TRY/CATCH/END_CATCH until
cleanups are completely phased out -- TRY/CATCH in C++ mode will
save/restore the current cleanup chain, like in C mode, and END_CATCH
catches otherwise uncaugh exceptions, runs cleanups and rethrows, so
that C++ cleanups and exceptions can coexist.
IMO, this still makes the TRY/CATCH code look a bit more like a
newcomer would expect, so IMO worth it even if we weren't considering
C++.
gdb/ChangeLog.
2015-03-07 Pedro Alves <palves@redhat.com>
* common/common-exceptions.c (struct catcher) <exception>: No
longer a pointer to volatile exception. Now an exception value.
<mask>: Delete field.
(exceptions_state_mc_init): Remove all parameters. Adjust.
(exceptions_state_mc): No longer pop the catcher here.
(exceptions_state_mc_catch): New function.
(throw_exception): Adjust.
* common/common-exceptions.h (exceptions_state_mc_init): Remove
all parameters.
(exceptions_state_mc_catch): Declare.
(TRY_CATCH): Rename to ...
(TRY): ... this. Remove EXCEPTION and MASK parameters.
(CATCH, END_CATCH): New.
All callers adjusted.
gdb/gdbserver/ChangeLog:
2015-03-07 Pedro Alves <palves@redhat.com>
Adjust all callers of TRY_CATCH to use TRY/CATCH/END_CATCH
instead.
More preparation for running the TRY_CATCH->TRY/CATCH conversion
script.
gdb/ChangeLog:
2015-03-07 Tom Tromey <tromey@redhat.com>
* top.c (quit_force): Inline and delete DO_TRY, DO_PRINT_EX.
This normalizes some exception catch blocks that check for ex.reason
to look like this:
~~~
volatile gdb_exception ex;
TRY_CATCH (ex, RETURN_MASK_ALL)
{
...
}
if (ex.reason < 0)
{
...
}
~~~
This is a preparation step for running a script that converts all
TRY_CATCH uses to look like this instead:
~~~
TRY
{
...
}
CATCH (ex, RETURN_MASK_ALL)
{
...
}
END_CATCH
~~~
The motivation for that change is being able to reimplent TRY/CATCH in
terms of C++ try/catch.
This commit makes it so that:
- no condition other than ex.reason < 0 is checked in the if
predicate
- there's no "else" block to check whether no exception was caught
- there's no code between the TRY_CATCH (TRY) block and the
'if (ex.reason < 0)' block (CATCH).
- the exception object is no longer referred to outside the if/catch
block. Note the local volatile exception objects that are
currently defined inside functions that use TRY_CATCH will
disappear. In cases it's more convenient to still refer to the
exception outside the catch block, a new non-volatile local is
added and copy to that object is made within the catch block.
The following patches should make this all clearer.
gdb/ChangeLog:
2015-03-07 Pedro Alves <palves@redhat.com>
* amd64-tdep.c (amd64_frame_cache, amd64_sigtramp_frame_cache)
(amd64_epilogue_frame_cache): Normal exception handling code.
* break-catch-throw.c (check_status_exception_catchpoint)
(re_set_exception_catchpoint): Ditto.
* cli/cli-interp.c (safe_execute_command):
* cli/cli-script.c (script_from_file): Ditto.
* compile/compile-c-symbols.c (generate_c_for_for_one_variable):
Ditto.
* compile/compile-object-run.c (compile_object_run): Ditto.
* cp-abi.c (baseclass_offset): Ditto.
* cp-valprint.c (cp_print_value): Ditto.
* exceptions.c (catch_exceptions_with_msg):
* frame-unwind.c (frame_unwind_try_unwinder): Ditto.
* frame.c (get_frame_address_in_block_if_available): Ditto.
* i386-tdep.c (i386_frame_cache, i386_epilogue_frame_cache)
(i386_sigtramp_frame_cache): Ditto.
* infcmd.c (post_create_inferior): Ditto.
* linespec.c (parse_linespec, find_linespec_symbols):
* p-valprint.c (pascal_object_print_value): Ditto.
* parse.c (parse_expression_for_completion): Ditto.
* python/py-finishbreakpoint.c (bpfinishpy_init): Ditto.
* remote.c (remote_get_noisy_reply): Ditto.
* s390-linux-tdep.c (s390_frame_unwind_cache): Ditto.
* solib-svr4.c (solib_svr4_r_map): Ditto.
I happen to see that show_debug_regs is used as an arithmetic type,
but it should be a boolean,
if (show_debug_regs > 1)
On the other hand, GDB RSP only allows setting it to either 0 or 1,
so it makes no sense to check whether it is greater than 1. This
patch fixes it.
gdb/gdbserver:
2015-03-06 Yao Qi <yao.qi@linaro.org>
* linux-aarch64-low.c (aarch64_insert_point): Use
show_debug_regs as a boolean.
(aarch64_remove_point): Likewise.
This commit introduces a new inline common function "startswith"
which takes two string arguments and returns nonzero if the first
string starts with the second. It also updates the 295 places
where this logic was written out longhand to use the new function.
gdb/ChangeLog:
* common/common-utils.h (startswith): New inline function.
All places where this logic was used updated to use the above.
Trying to fix a permanent breakpoints bug, I broke "next" over a
regular breakpoint. "next" would immediately hit the breakpoint the
program was already stopped at. But, the "next over setup" test
failed to notice this and still issued a pass. That's because the
regex matches "testsuite" in:
Breakpoint 2 at 0x400687: file src/gdb/testsuite/gdb.base/bp-permanent.c, line 46.
gdb/testsuite/ChangeLog:
2015-03-05 Pedro Alves <palves@redhat.com>
* gdb.base/bp-permanent.exp: Tighten "next over setup" regex.
When we find out that a breakpoint is set on top of a program
breakpoint, we mark it as "permanent". E.g.,:
...
if (bp_loc_is_permanent (loc))
{
loc->inserted = 1;
loc->permanent = 1;
}
...
Note we didn't fill in the breakpoint's shadow (shadow_len remains 0).
In case the target claims support for evaluating breakpoint
conditions, GDB sometimes reinserts breakpoints that are already
inserted (to update the conditions on the target side). Since GDB
doesn't know whether the target supports evaluating conditions _of_
software breakpoints (vs hardware breakpoints, etc.) until it actually
tries it, if the target doesn't actually support z0 breakpoints, GDB
ends up reinserting a GDB-managed software/memory breakpoint
(mem-break.c).
And that is the case that is buggy: breakpoints that are marked
inserted contribute their shadows (if any) to the memory returned by
target_read_memory, to mask out breakpoints. Permanent breakpoints
are always marked as inserted. So if the permanent breakpoint doesn't
have a shadow yet in its shadow buffer, but we set shadow_len before
calling target_read_memory, then the still clear shadow_contents
buffer will be used by the breakpoint masking code... And then from
there on, the permanent breakpoint has a broken shadow buffer, and
thus any memory read out of that address will read bogus code, and
many random bad things fall out from that.
The fix is just to set shadow_len at the same time shadow_contents is
set, not one before and another after...
Fixes all gdb.base/bp-permanent.exp FAILs on PPC64 GNU/Linux gdbserver
and probably any other gdbserver port that doesn't do z0 breakpoints.
gdb/ChangeLog:
2015-03-05 Pedro Alves <palves@redhat.com>
PR gdb/18002
* mem-break.c (default_memory_insert_breakpoint): Set shadow_len
after reading the breakpoint's shadow memory.
PR binutils/18064
* doc/binutils.texi (objcopy): Extend description of
--add-gnu-debuglink option to explain that the separate debug info
file must exist. Add a description of what to do if the debug
info file is built in one place but then installed into a separate
location.
GCC 4.2 complains:
binutils/gold/object.cc:3261: error: using ‘typename’ outside of template
This patch removes typename. It works with both GCC 4.2 and 4.8.
* output.cc (Relobj::initialize_input_to_output_map<size>):
Remove typename on elfcpp::Elf_types<size>::Elf_Addr.
PR binutils/17994
* dlltool.c (temp_file_to_remove): New local array.
(unlink_temp_files): New functions - unlinks any file in the
temp_file_to_remove array, unless dotdeltemps is set.
(gen_exp_file): Add temp files to array.
(make_head): Likewise.
(make_delay_head): Likewise.
(make_tail): Likewise.
(gen_lib_file): Call unlink_temp_files.
With copy relocation, address of protected data defined in the shared
library may be external. This patch adds extern_protected_data and
changes _bfd_elf_symbol_refs_local_p to return false for protected data
if extern_protected_data is true.
bfd/
PR ld/pr15228
PR ld/pr17709
* elf-bfd.h (elf_backend_data): Add extern_protected_data.
* elf32-i386.c (elf_backend_extern_protected_data): New.
Defined to 1.
* elf64-x86-64.c (elf_backend_extern_protected_data): Likewise.
* elflink.c (_bfd_elf_adjust_dynamic_copy): Don't error on
copy relocs against protected symbols if extern_protected_data
is true.
(_bfd_elf_symbol_refs_local_p): Don't return true on protected
non-function symbols if extern_protected_data is true.
* elfxx-target.h (elf_backend_extern_protected_data): New.
Default to 0.
(elfNN_bed): Initialize extern_protected_data with
elf_backend_extern_protected_data.
ld/testsuite/
PR ld/pr15228
PR ld/pr17709
* ld-i386/i386.exp (i386tests): Add a test for PR ld/17709.
* ld-i386/pr17709-nacl.rd: New file.
* ld-i386/pr17709.rd: Likewise.
* ld-i386/pr17709a.s: Likewise.
* ld-i386/pr17709b.s: Likewise.
* ld-i386/protected3.d: Updated.
* ld-i386/protected3.s: Likewise.
* ld-x86-64/pr17709-nacl.rd: New file.
* ld-x86-64/pr17709.rd: Likewise.
* ld-x86-64/pr17709a.s: Likewise.
* ld-x86-64/pr17709b.s: Likewise.
* ld-x86-64/protected3.d: Updated.
* ld-x86-64/protected3.s: Likewise.
* ld-x86-64/x86-64.exp (x86_64tests): Add a test for PR ld/17709.
* config/tc-v850.c (md_parse_option): Fix code to set or clear
EF_RH850_DATA_ALIGN8 bit in ELF header, based upon the use of the
-m8byte-align and -m4byte-align command line options.
PR binutils/18025
* coffgen.c (coff_find_nearest_line_with_names): If the dwarf2
lookup fails, check for an address bias in the dwarf info, and if
one exists, retry the lookup with the biased value.
* dwarf2.c (_bfd_dwarf2_find_symbol_bias): New function.
Determines if a bias exists bewteen the addresses of functions
based on DWARF information vs symbol table information.
* libbfd-in.h (_bfd_dwarf2_find_symbol_bias): Prototype.
* libbfd.h: Regenerate.
I forgot to update these target_ops instances when I added these new
hooks.
I confirmed mingw32-w64 builds again at least.
gdb/gdbserver/ChangeLog:
2015-03-05 Pedro Alves <palves@redhat.com>
* lynx-low.c (lynx_target_ops): Install NULL hooks for
stopped_by_sw_breakpoint, supports_stopped_by_sw_breakpoint,
stopped_by_hw_breakpoint, supports_stopped_by_hw_breakpoint.
* nto-low.c (nto_target_ops): Likewise.
* spu-low.c (spu_target_ops): Likewise.
* win32-low.c (win32_target_ops): Likewise.
gold/
* parameters.cc (Parameters::set_target_once): Call
Target::select_as_default_target just once from here...
(set_parameters_target): ...instead of from here.
2015-03-02 Rafael Ávila de Espíndola <rafael.espindola@gmail.com>
* ehframe.cc (Cie::set_output_offset): Pass in and use a
Output_section_data instead of a Merge_map.
(Eh_frame::Eh_frame): Don't initialize merge_map_.
(Eh_frame::read_cie): Use add_merge_mapping instead of
Merge_map::add_mapping.
(Eh_frame::read_fde): Ditto.
(Eh_frame::set_final_data_size): Use this instead of this->merge_map_.
(Eh_frame::do_output_offset): Use merge_output_offset istead of
merge_map_->get_output_offset.
(Eh_frame::do_is_merge_section_for): Delete.
* ehframe.h (Fde::add_mapping): Pass in and use a Output_section_data
instead of a Merge_map.
(Cie::set_output_offset): Pass in a Output_section_data instead of a
Merge_map.
(Eh_frame::do_is_merge_section_for): Delete.
(Eh_frame::merge_map_): Delete.
* merge.cc (Object_merge_map::get_or_make_input_merge_map): Pass in
and use a Output_section_data instead of a Merge_map.
(Object_merge_map::add_mapping): Ditto.
(Object_merge_map::get_output_offset): Remove the merge_map argument.
(Object_merge_map::is_merge_section_for): Pass in and use a
Output_section_data instead of a Merge_map.
(Merge_map): Delete.
(Output_merge_base::do_output_offset): Use merge_output_offset instead
of merge_map_.get_output_offset.
(Output_merge_base::do_is_merge_section_for): Delete.
(Output_merge_data::do_add_input_section): Use
object->add_merge_mapping instead of add_mapping.
(Output_merge_string<Char_type>::finalize_merged_data): Ditto.
* merge.h (Merge_map): Delete forward declaration.
(Object_merge_map::add_mapping): Pass in and use a Output_section_data
instead of a Merge_map.
(Object_merge_map::get_output_offset): Remove the merge_map argument.
(Object_merge_map::is_merge_section_for): Pass in and use a
Output_section_data instead of a Merge_map.
(Input_merge_map::Object_merge_map::merge_map): Replace with
output_data.
(Object_merge_map::get_or_make_input_merge_map): Pass in and use a
Output_section_data instead of a Merge_map.
(Merge_map): Delete.
(Output_merge_base::Output_merge_base): Don't initialize merge_map_.
(Output_merge_base::do_is_merge_section_for): Delete.
(Output_merge_base::add_mapping): Delete.
(Output_merge_base::merge_map_): Delete.
* object.cc (Relobj::initialize_input_to_output_map): New.
(Relobj::initialize_input_to_output_map): New.
(Relobj::merge_output_offset): New.
(Relobj::is_merge_section_for): New.
(Relobj::initialize_input_to_output_map): Instantiate for 32 and 64
bits.
* object.h (Relobj::merge_map): Delete.
(initialize_input_to_output_map): New.
(set_merge_map): Delete.
(add_merge_mapping): New.
(merge_output_offset): New.
(is_merge_section_for): New.
* output.cc (Output_section::Input_section::is_merge_section_for):
Use object->is_merge_section_for.
* output.h (Output_section_data::is_merge_section_for): Delete.
(Output_section_data::do_is_merge_section_for): Delete.
* reloc.cc (Merged_symbol_value<size>::initialize_input_to_output_map):
Use object->initialize_input_to_output_map.
(Merged_symbol_value<size>::value_from_output_section): Use
object->merge_output_offset.
When interrupting a thread in non-stop vs all-stop, the signal given in
the MI *stopped event is not the same. Currently, mi_expect_interrupt only
accepts the case for non-stop, so this adds the alternative for all-stop.
gdb/testsuite/ChangeLog:
* lib/mi-support.exp (mi_expect_interrupt): Accept
alternative event for when in all-stop mode.
record-btrace was the only target making use of this, and it no longer
uses it.
gdb/ChangeLog:
2015-03-04 Pedro Alves <palves@redhat.com>
* target.h (struct target_ops) <to_decr_pc_after_break>: Delete.
(target_decr_pc_after_break): Delete declaration.
* target.c (default_target_decr_pc_after_break)
(target_decr_pc_after_break): Delete.
* linux-nat.c (check_stopped_by_breakpoint, linux_nat_wait_1): Use
gdbarch_decr_pc_after_break instead of target_decr_pc_after_break.
* linux-thread-db.c (check_event): Likewise.
* infrun.c (adjust_pc_after_break): Likewise.
* darwin-nat.c (cancel_breakpoint): Likewise.
* aix-thread.c (aix_thread_wait): Likewise.
* target-delegates.c: Regenerate.
This patch adjusts gdbserver's Linux backend to tell gdbserver core
(and ultimately GDB) whether a trap was caused by a breakpoint.
It teaches the backend to get that information out of the si_code of
the SIGTRAP siginfo.
gdb/gdbserver/ChangeLog:
2015-03-04 Pedro Alves <palves@redhat.com>
* linux-low.c (check_stopped_by_breakpoint) [USE_SIGTRAP_SIGINFO]:
Decide whether a breakpoint triggered based on the SIGTRAP's
siginfo.si_code.
(thread_still_has_status_pending_p) [USE_SIGTRAP_SIGINFO]: Don't check whether a
breakpoint is inserted if relying on SIGTRAP's siginfo.si_code.
(linux_low_filter_event): Check for breakpoints before checking
watchpoints.
(linux_wait_1): Don't re-increment the PC if relying on SIGTRAP's
siginfo.si_code.
(linux_stopped_by_sw_breakpoint)
(linux_supports_stopped_by_sw_breakpoint)
(linux_stopped_by_hw_breakpoint)
(linux_supports_stopped_by_hw_breakpoint): New functions.
(linux_target_ops): Install new target methods.
This patch teaches the core of gdbserver about the new "swbreak" and
"hwbreak" stop reasons, and adds the necessary hooks a backend needs
to implement to support the feature.
gdb/gdbserver/ChangeLog:
2015-03-04 Pedro Alves <palves@redhat.com>
* remote-utils.c (prepare_resume_reply): Report swbreak/hbreak.
* server.c (swbreak_feature, hwbreak_feature): New globals.
(handle_query) <qSupported>: Handle "swbreak+" and "hwbreak+".
(captured_main): Clear swbreak_feature and hwbreak_feature.
* server.h (swbreak_feature, hwbreak_feature): Declare.
* target.h (struct target_ops) <stopped_by_sw_breakpoint,
supports_stopped_by_sw_breakpoint, stopped_by_hw_breakpoint,
supports_stopped_by_hw_breakpoint>: New fields.
(target_supports_stopped_by_sw_breakpoint)
(target_stopped_by_sw_breakpoint)
(target_supports_stopped_by_hw_breakpoint)
(target_stopped_by_hw_breakpoint): Declare.
This patch adjusts the native Linux target backend to tell the core
whether a trap was caused by a breakpoint.
It teaches the target to get that information out of the si_code of
the SIGTRAP siginfo.
Tested on x86-64 Fedora 20, s390 RHEL 7, and PPC64 Fedora 18. An
earlier version was tested on ARM Fedora 21.
gdb/ChangeLog:
2015-03-04 Pedro Alves <palves@redhat.com>
* linux-nat.c (save_sigtrap): Check for breakpoints before
checking watchpoints.
(status_callback) [USE_SIGTRAP_SIGINFO]: Don't check whether a
breakpoint is inserted if relying on SIGTRAP's siginfo.si_code.
(check_stopped_by_breakpoint) [USE_SIGTRAP_SIGINFO]: Decide whether
a breakpoint triggered based on the SIGTRAP's siginfo.si_code.
(linux_nat_stopped_by_sw_breakpoint)
(linux_nat_supports_stopped_by_sw_breakpoint)
(linux_nat_stopped_by_hw_breakpoint)
(linux_nat_supports_stopped_by_hw_breakpoint): New functions.
(linux_nat_wait_1): Don't re-increment the PC if relying on
SIGTRAP's siginfo->si_code.
(linux_nat_add_target): Install new target methods.
* linux-thread-db.c (check_event): Don't account for breakpoint PC
offset if the target already adjusted the PC.
* nat/linux-ptrace.h (USE_SIGTRAP_SIGINFO): New.
(GDB_ARCH_TRAP_BRKPT): New.
(TRAP_HWBKPT): Define if not already defined.
This adjusts target remote to tell the core whether a trap was caused
by a breakpoint.
To that end, the patch teaches GDB about new RSP stop reasons "T05
swbreak" and "T05 hwbreak", that remote targets report back to GDB,
similarly to how "T05 watch" indicates a stop caused by a watchpoint.
Because targets that can report these events are expected to
themselves adjust the PC after a software breakpoint, these new stop
reasons must only be reported if the stub is talking to a GDB that
understands them. Because of that, the use of the new stop reasons
needs to be handshaked on initial connection, using the qSupported
mechanism. GDB simply sends "swbreak+" in its qSupports query, and
the stub reports back "swbreak+" too.
Because these new stop reasons are required to fix a fundamental
non-stop mode problem, this commit extends the remote non-stop intro
section in the manual, documenting the events as required.
To be clear, GDB will still cope with remote targets that don't
support these new stop reasons; it will behave just like today.
Tested on x86-64 Fedora 20, native and gdbserver.
gdb/ChangeLog:
2015-03-04 Pedro Alves <palves@redhat.com>
* NEWS: Mention the new "swbreak" and "hwbreak" stop reasons.
* remote.c (struct remote_state) <remote_stopped_by_watchpoint_p>:
Delete field.
<stop_reason>: New field.
(PACKET_swbreak_feature, PACKET_hwbreak_feature): New enum values.
(packet_set_cmd_state): New function.
(remote_protocol_features): Register the "swbreak" and "hwbreak"
features.
(remote_query_supported): If not disabled with the corresponding
"set remote foo-packet" command, report support for the swbreak
and hwbreak features.
(struct stop_reply) <remote_stopped_by_watchpoint_p>: Delete
field.
<stop_reason>: New field.
(remote_parse_stop_reply): Handle "swbreak" and "hwbreak".
(remote_wait_as): Adjust.
(remote_stopped_by_sw_breakpoint)
(remote_supports_stopped_by_sw_breakpoint)
(remote_stopped_by_hw_breakpoint)
(remote_supports_stopped_by_hw_breakpoint): New functions.
(remote_stopped_by_watchpoint): New function.
(init_remote_ops): Install them.
(_initialize_remote): Register new "set/show remote
swbreak-feature-packet" and "set/show remote
swbreak-feature-packet" commands.
gdb/doc/ChangeLog:
2015-03-04 Pedro Alves <palves@redhat.com>
* gdb.texinfo (Remote Configuration): Document the "set/show
remote swbreak-feature-packet" and "set/show remote
hwbreak-feature-packet" commands.
(Packets) <Z0>: Add cross link to the "swbreak" stop reason's
decription.
(Stop Reply Packets): Document the swbreak and hwbreak stop
reasons.
(General Query Packets): Document the swbreak and hwbreak
qSupported features.
(Remote Non-Stop): Explain that swbreak and hwbreak are required.
This adjusts the record targets to tell the core whether a trap was
caused by a breakpoint. Targets that can do this should report
breakpoint traps with the PC already adjusted, so this removes the
re-incrementing record-full was doing.
These targets need to be adjusted before process_stratum targets
beneath are, otherwise target_supports_stopped_by_sw_breakpoint,
etc. would fall through to the target beneath while
recording/replaying, and the core would get confused.
Tested on x86-64 Fedora 20, native and gdbserver.
gdb/ChangeLog:
2015-03-04 Pedro Alves <palves@redhat.com>
* btrace.h: Include target/waitstatus.h.
(struct btrace_thread_info) <stop_reason>: New field.
* record-btrace.c (record_btrace_step_thread): Use
record_check_stopped_by_breakpoint instead of breakpoint_here_p.
(record_btrace_decr_pc_after_break): Delete.
(record_btrace_stopped_by_sw_breakpoint)
(record_btrace_supports_stopped_by_sw_breakpoint)
(record_btrace_stopped_by_hw_breakpoint)
(record_btrace_supports_stopped_by_hw_breakpoint): New functions.
(init_record_btrace_ops): Install them.
* record-full.c (record_full_hw_watchpoint): Delete and replace
with ...
(record_full_stop_reason): ... this throughout.
(record_full_exec_insn): Adjust.
(record_full_wait_1): Adjust. No longer re-increment the PC.
(record_full_wait_1): Adjust. Use
record_check_stopped_by_breakpoint instead of breakpoint_here_p.
(record_full_stopped_by_watchpoint): Adjust.
(record_full_stopped_by_sw_breakpoint)
(record_full_supports_stopped_by_sw_breakpoint)
(record_full_supports_stopped_by_sw_breakpoint)
(record_full_stopped_by_hw_breakpoint)
(record_full_supports_stopped_by_hw_breakpoint): New functions.
(init_record_full_ops, init_record_full_core_ops): Install them.
* record.c (record_check_stopped_by_breakpoint): New function.
* record.h: Include target/waitstatus.h.
(record_check_stopped_by_breakpoint): New declaration.
The moribund locations heuristics are problematic. This patch teaches
GDB about targets that can reliably tell whether a trap was caused by
a software or hardware breakpoint, and thus don't need moribund
locations, thus bypassing all the problems that mechanism has.
The non-stop-fair-events.exp test is frequently failing currently.
E.g., see https://sourceware.org/ml/gdb-testers/2015-q1/msg03148.html.
The root cause is a fundamental problem with moribund locations. For
example, the stepped_breakpoint logic added by af48d08f breaks in this
case (which is what happens with that test):
- Step thread A, no breakpoint is set at PC.
- The kernel doesn't schedule thread A yet.
- Insert breakpoint at A's PC, for some reason (e.g., a step-resume
breakpoint for thread B).
- Kernel finally schedules thread A.
- thread A's stepped_breakpoint flag is not set, even though it now
stepped a breakpoint instruction.
- adjust_pc_after_break gets the PC wrong, because PC == PREV_PC, but
stepped_breakpoint is not set.
We needed the stepped_breakpoint logic to workaround moribund
locations, because otherwise adjust_pc_after_break could apply an
adjustment when it shouldn't just because there _used_ to be a
breakpoint at PC (a moribund breakpoint location). For example, on
x86, that's wrong if the thread really hasn't executed an int3, but
instead executed some other 1-byte long instruction. Getting the PC
adjustment wrong of course leads to the inferior executing the wrong
instruction.
Other problems with moribund locations are:
- if a true SIGTRAP happens to be raised when the program is
executing the PC that used to have a breakpoint, GDB will assume
that is a trap for a breakpoint that has recently been removed, and
thus we miss reporting the random signal to the user.
- to minimize that, we get rid of moribund location after a while.
That while is defined as just a certain number of events being
processed. That number of events sometimes passes by before a
delayed breakpoint is processed, and GDB confuses the trap for a
random signal, thus reporting the random trap. Once the user
resumes the thread, the program crashes because the PC was not
adjusted...
The fix for all this is to bite the bullet and get rid of heuristics
and instead rely on the target knowing accurately what caused the
SIGTRAP. The target/kernel/stub is in the best position to know what
that, because it can e.g. consult priviledged CPU flags GDB has no
access to, or by knowing which exception vector entry was called when
the instruction trapped, etc. Most debug APIs I've seen to date
report breakpoint hits as a distinct event in some fashion. For
example, on the Linux kernel, whether a breakpoint was executed is
exposed to userspace in the si_code field of the SIGTRAP's siginfo.
On Windows, the debug API reports a EXCEPTION_BREAKPOINT exception
code.
We needed to keep around deleted breakpoints in an on-the-side list
(the moribund locations) for two main reasons:
- Know that a SIGTRAP actually is a delayed event for a hit of a
breakpoint that was removed before the event was processed, and
thus should not be reported as a random signal.
- So we still do the decr_pc_after_break adjustment in that case, so
that the thread is resumed at the correct address.
In the new model, if GDB processes an event the target tells is a
breakpoint trap, and GDB doesn't find the corresponding breakpoint in
its breakpoint tables, it means that event is a delayed event for a
breakpoint that has since been removed, and thus the event should be
ignored.
For the decr_pc_after_after issue, it ends up being much simpler that
on targets that can reliably tell whether a breakpoint trapped, for
the breakpoint trap to present the PC already adjusted. Proper
multi-threading support already implies that targets needs to be doing
decr_pc_after_break adjustment themselves, otherwise for example, in
all-stop if two threads hit a breakpoint simultaneously, and the user
does "info threads", he'll see the non-event thread that hit the
breakpoint stopped at the wrong PC.
This way (target adjusts) also ends up eliminating the need for some
awkward re-incrementing of the PC in the record-full and Linux targets
that we do today, and the need for the target_decr_pc_after_break
hook.
If the target always adjusts, then there's a case where GDB needs to
re-increment the PC. Say, on x86, an "int3" instruction that was
explicitly written in the program traps. In this case, GDB should
report a random SIGTRAP signal to the user, with the PC pointing at
the instruction past the int3, just like if GDB was not debugging the
program. The user may well decide to pass the SIGTRAP to the program
because the program being debugged has a SIGTRAP handler that handles
its own breakpoints, and expects the PC to be unadjusted.
Tested on x86-64 Fedora 20.
gdb/ChangeLog:
2015-03-04 Pedro Alves <palves@redhat.com>
* breakpoint.c (need_moribund_for_location_type): New function.
(bpstat_stop_status): Don't skipping checking moribund locations
of breakpoint types which the target tell caused a stop.
(program_breakpoint_here_p): New function, factored out from ...
(bp_loc_is_permanent): ... this.
(update_global_location_list): Don't create a moribund location if
the target supports reporting stops of the type of the removed
breakpoint.
* breakpoint.h (program_breakpoint_here_p): New declaration.
* infrun.c (adjust_pc_after_break): Return early if the target has
already adjusted the PC. Add comments.
(handle_signal_stop): If nothing explains a signal, and the target
tells us the stop was caused by a software breakpoint, check if
there's a breakpoint instruction in the memory. If so, adjust the
PC before presenting the stop to the user. Otherwise, ignore the
trap. If nothing explains a signal, and the target tells us the
stop was caused by a hardware breakpoint, ignore the trap.
* target.h (struct target_ops) <to_stopped_by_sw_breakpoint,
to_supports_stopped_by_sw_breakpoint, to_stopped_by_hw_breakpoint,
to_supports_stopped_by_hw_breakpoint>: New fields.
(target_stopped_by_sw_breakpoint)
(target_supports_stopped_by_sw_breakpoint)
(target_stopped_by_hw_breakpoint)
(target_supports_stopped_by_hw_breakpoint): Define.
* target-delegates.c: Regenerate.
Gary stumbled on this:
(gdb) PASS: gdb.threads/thread-specific-bp.exp: all-stop: continue to end
info threads
Id Target Id Frame
* 1 Thread 0x7ffff7fdb700 (LWP 13717) "thread-specific" end () at /home/gary/work/archer/startswith/src/gdb/testsuite/gdb.threads/thread-specific-bp.c:29
(gdb) FAIL: gdb.threads/thread-specific-bp.exp: all-stop: thread start is gone
info breakpoint
The problem is that "...archer/startswith/src..." has a "start" in it,
which matches the too-lax regex in the test.
Rather than tweaking the regex, we can just remove the whole "info
threads", like we removed similar ones in other files -- GDB nowadays
does this implicitly already, so things should work without it. Thus
removing this even improves testing here a bit.
gdb/testsuite/ChangeLog:
2015-03-04 Pedro Alves <palves@redhat.com>
* gdb.threads/thread-specific-bp.exp: Delete "info threads" test.
This Linuxism has made its way into infrun.c, in the follow-fork code:
inferior_ptid = ptid_build (child_pid, child_pid, 0);
The OS-specific code should fill in the LWPID, TID parts with the
appropriate values, if any, and the core code should not be peeking at
the components of the ptids.
gdb/
2015-03-04 Pedro Alves <palves@redhat.com>
* infrun.c (follow_fork_inferior): Use the whole of the
inferior_ptid and pending_follow.related_pid ptids instead of
building ptids from the process components. Adjust verbose output
to use target_pid_to_str.
* linux-nat.c (linux_child_follow_fork): Use the whole of the
inferior_ptid and pending_follow.related_pid ptids instead of
building ptids from the process components.
These systems (OpenBSD and HP-UX 10.x) already support follow-fork
including the events needed to for "catch fork". This just makes
the upper layers realize this.
gdb/
2015-03-04 Mark Kettenis <kettenis@gnu.org>
* inf-ptrace.c [PT_GET_PROCESS_STATE]
(inf_ptrace_insert_fork_catchpoint): New function.
(inf_ptrace_remove_fork_catchpoint): New function.
(inf_ptrace_target) [PT_GET_PROCESS_STATE]: Install them.
Ensure we hard stop via abort() for unhandled stub types rather than
continuing either silently (or noisly with a BFD_FAIL()).
Call abort() giving a hard stop rather than BFD_FAIL () for unhandled
stub types.
When adding vector register support to GDB, s390_register_name() was
added to suppress the right halves of the first 16 vector registers.
However, that function returned NULL instead of an empty string in such
a case. This leads to an incomplete list of registers returned by
"complete info registers ", because completion stops at the first NULL
return value from user_reg_map_regnum_to_name().
gdb/ChangeLog:
* s390-linux-tdep.c (s390_register_name): Return empty string
instead of NULL for registers that shouldn't be visible.
On some targets each of the assignments "i = 0" in the C source for
"breakpoint-in-ro-region.exp" are compiled to a single instruction.
Then each "si" stops at the beginning of the next source line. But on
some other targets (like s390) such an assignment compiles to multiple
instructions. Then "si" may stop in mid-line, and GDB displays the PC
address in addition to the source line number. This was not considered
by the regexp for this case.
gdb/testsuite/ChangeLog:
* gdb.base/breakpoint-in-ro-region.exp (test_single_step): In the
regexps for GDB's current line display, accept a hex address
preceding the line number.
For the "multiple targets" test in catch-syscall.exp, set the 'arch1'
variable to a valid string.
gdb/testsuite/ChangeLog:
* gdb.base/catch-syscall.exp (test_catch_syscall_multi_arch): Set
the 'arch1' variable for "s390*-linux*" targets.
This patch fixes a typo that caused the wrong syscall XML file to be
used for s390x targets.
gdb/ChangeLog:
* s390-linux-tdep.c (s390_gdbarch_init): Use the correct syscall
XML file for 64-bit targets.
On 64-bit platforms GDB did not include "s390:31-bit" in its list of
architecture names. This patch fixes that.
To determine the list of architecture names for S390,
gdbarch_printable_names() walks through the linked list of BFD arches
starting with the default S390 arch, which is "s390:64-bit" on 64-bit
platforms. But since "s390:64-bit" was at the end of that list, the
31-bit architecture was not reached. The patch swaps the elements of
that list on 64-bit platforms.
bfd/ChangeLog:
* cpu-s390.c (N): New macro.
(bfd_s390_31_arch): New. Define only if default target word size
is 64 bits. Otherwise define...
(bfd_390_64_arch): ...this. Make static.
(bfd_s390_arch): Define according to the default target word size.
Let the 'next' field point to the alternate arch.
This fixes:
> gdb compile failed, /gdb/testsuite/gdb.threads/clone-thread_db.c: In function 'main':
> /gdb/testsuite/gdb.threads/clone-thread_db.c:67:3: warning: implicit declaration of function 'alarm' [-Wimplicit-function-declaration]
> alarm (300);
> ^
> /gdb/testsuite/gdb.threads/clone-thread_db.c:69:3: warning: implicit declaration of function 'pthread_create' [-Wimplicit-function-declaration]
> pthread_create (&child, NULL, thread_fn, NULL);
> ^
> /gdb/testsuite/gdb.threads/clone-thread_db.c:70:3: warning: implicit declaration of function 'pthread_join' [-Wimplicit-function-declaration]
> pthread_join (child);
> ^
And then adding the missing headers revealed the pthread_join call was
incorrect. This probably fixes the crash we see on ppc64be, e.g., at
https://sourceware.org/ml/gdb-testers/2015-q1/msg04415.html
the logs there show:
...
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x3fffb7ff54a0 (LWP 9275)]
0x00003fffb7f3ce74 in .pthread_join () from /lib64/libpthread.so.0
(gdb) FAIL: gdb.threads/clone-thread_db.exp: continue to end
...
Tested on x86_64 Fedora 20.
gdb/testsuite/
2015-03-04 Pedro Alves <palves@redhat.com>
* gdb.threads/clone-thread_db.c: Include unistd.h and pthread.h.
(main): Pass missing retval argument to pthread_join call.
bfd/
PR gas/17843
* elfxx-aarch64.c (_bfd_aarch64_elf_put_addend): Expect
R_AARCH64_TLSLE_MOVW_TPREL_G0_NC and R_AARCH64_TLSLE_MOVW_TPREL_G1_NC
to be used with MOVK rather than MOVZ.
gas/
PR gas/17843
* config/tc-aarch64.c (process_movw_reloc_info): Allow
R_AARCH64_TLSLE_MOVW_TPREL_G0_NC and R_AARCH64_TLSLE_MOVW_TPREL_G1_NC
for MOVK.
gas/testsuite/
PR gas/17843
* gas/aarch64/tls.s, gas/aarch64/tls.d: Add test for
R_AARCH64_TLSLE_MOVW_TPREL_G0/R_AARCH64_TLSLE_MOVW_TPREL_G1_NC
sequence.
ld/testsuite/
PR gas/17843
* ld-aarch64/tlsle.s, ld-aarch64/tlsle.d: New test.
* ld-aarch64/aarch64-elf.exp: Run it.
find_default_create_inferior and find_default_attach were removed in b3ccfe11.
gdb/ChangeLog:
* target.h (find_default_create_inferior): Remove declaration.
(find_default_attach): Likewise.
