Today, GDB only allows a single displaced stepping operation to happen
per inferior at a time. There is a single displaced stepping buffer per
inferior, whose address is fixed (obtained with
gdbarch_displaced_step_location), managed by infrun.c.
In the case of the AMD ROCm target [1] (in the context of which this
work has been done), it is typical to have thousands of threads (or
waves, in SMT terminology) executing the same code, hitting the same
breakpoint (possibly conditional) and needing to to displaced step it at
the same time. The limitation of only one displaced step executing at a
any given time becomes a real bottleneck.
To fix this bottleneck, we want to make it possible for threads of a
same inferior to execute multiple displaced steps in parallel. This
patch builds the foundation for that.
In essence, this patch moves the task of preparing a displaced step and
cleaning up after to gdbarch functions. This allows using different
schemes for allocating and managing displaced stepping buffers for
different platforms. The gdbarch decides how to assign a buffer to a
thread that needs to execute a displaced step.
On the ROCm target, we are able to allocate one displaced stepping
buffer per thread, so a thread will never have to wait to execute a
displaced step.
On Linux, the entry point of the executable if used as the displaced
stepping buffer, since we assume that this code won't get used after
startup. From what I saw (I checked with a binary generated against
glibc and musl), on AMD64 we have enough space there to fit two
displaced stepping buffers. A subsequent patch makes AMD64/Linux use
two buffers.
In addition to having multiple displaced stepping buffers, there is also
the idea of sharing displaced stepping buffers between threads. Two
threads doing displaced steps for the same PC could use the same buffer
at the same time. Two threads stepping over the same instruction (same
opcode) at two different PCs may also be able to share a displaced
stepping buffer. This is an idea for future patches, but the
architecture built by this patch is made to allow this.
Now, the implementation details. The main part of this patch is moving
the responsibility of preparing and finishing a displaced step to the
gdbarch. Before this patch, preparing a displaced step is driven by the
displaced_step_prepare_throw function. It does some calls to the
gdbarch to do some low-level operations, but the high-level logic is
there. The steps are roughly:
- Ask the gdbarch for the displaced step buffer location
- Save the existing bytes in the displaced step buffer
- Ask the gdbarch to copy the instruction into the displaced step buffer
- Set the pc of the thread to the beginning of the displaced step buffer
Similarly, the "fixup" phase, executed after the instruction was
successfully single-stepped, is driven by the infrun code (function
displaced_step_finish). The steps are roughly:
- Restore the original bytes in the displaced stepping buffer
- Ask the gdbarch to fixup the instruction result (adjust the target's
registers or memory to do as if the instruction had been executed in
its original location)
The displaced_step_inferior_state::step_thread field indicates which
thread (if any) is currently using the displaced stepping buffer, so it
is used by displaced_step_prepare_throw to check if the displaced
stepping buffer is free to use or not.
This patch defers the whole task of preparing and cleaning up after a
displaced step to the gdbarch. Two new main gdbarch methods are added,
with the following semantics:
- gdbarch_displaced_step_prepare: Prepare for the given thread to
execute a displaced step of the instruction located at its current PC.
Upon return, everything should be ready for GDB to resume the thread
(with either a single step or continue, as indicated by
gdbarch_displaced_step_hw_singlestep) to make it displaced step the
instruction.
- gdbarch_displaced_step_finish: Called when the thread stopped after
having started a displaced step. Verify if the instruction was
executed, if so apply any fixup required to compensate for the fact
that the instruction was executed at a different place than its
original pc. Release any resources that were allocated for this
displaced step. Upon return, everything should be ready for GDB to
resume the thread in its "normal" code path.
The displaced_step_prepare_throw function now pretty much just offloads
to gdbarch_displaced_step_prepare and the displaced_step_finish function
offloads to gdbarch_displaced_step_finish.
The gdbarch_displaced_step_location method is now unnecessary, so is
removed. Indeed, the core of GDB doesn't know how many displaced step
buffers there are nor where they are.
To keep the existing behavior for existing architectures, the logic that
was previously implemented in infrun.c for preparing and finishing a
displaced step is moved to displaced-stepping.c, to the
displaced_step_buffer class. Architectures are modified to implement
the new gdbarch methods using this class. The behavior is not expected
to change.
The other important change (which arises from the above) is that the
core of GDB no longer prevents concurrent displaced steps. Before this
patch, start_step_over walks the global step over chain and tries to
initiate a step over (whether it is in-line or displaced). It follows
these rules:
- if an in-line step is in progress (in any inferior), don't start any
other step over
- if a displaced step is in progress for an inferior, don't start
another displaced step for that inferior
After starting a displaced step for a given inferior, it won't start
another displaced step for that inferior.
In the new code, start_step_over simply tries to initiate step overs for
all the threads in the list. But because threads may be added back to
the global list as it iterates the global list, trying to initiate step
overs, start_step_over now starts by stealing the global queue into a
local queue and iterates on the local queue. In the typical case, each
thread will either:
- have initiated a displaced step and be resumed
- have been added back by the global step over queue by
displaced_step_prepare_throw, because the gdbarch will have returned
that there aren't enough resources (i.e. buffers) to initiate a
displaced step for that thread
Lastly, if start_step_over initiates an in-line step, it stops
iterating, and moves back whatever remaining threads it had in its local
step over queue to the global step over queue.
Two other gdbarch methods are added, to handle some slightly annoying
corner cases. They feel awkwardly specific to these cases, but I don't
see any way around them:
- gdbarch_displaced_step_copy_insn_closure_by_addr: in
arm_pc_is_thumb, arm-tdep.c wants to get the closure for a given
buffer address.
- gdbarch_displaced_step_restore_all_in_ptid: when a process forks
(at least on Linux), the address space is copied. If some displaced
step buffers were in use at the time of the fork, we need to restore
the original bytes in the child's address space.
These two adjustments are also made in infrun.c:
- prepare_for_detach: there may be multiple threads doing displaced
steps when we detach, so wait until all of them are done
- handle_inferior_event: when we handle a fork event for a given
thread, it's possible that other threads are doing a displaced step at
the same time. Make sure to restore the displaced step buffer
contents in the child for them.
[1] https://github.com/ROCm-Developer-Tools/ROCgdb
gdb/ChangeLog:
* displaced-stepping.h (struct
displaced_step_copy_insn_closure): Adjust comments.
(struct displaced_step_inferior_state) <step_thread,
step_gdbarch, step_closure, step_original, step_copy,
step_saved_copy>: Remove fields.
(struct displaced_step_thread_state): New.
(struct displaced_step_buffer): New.
* displaced-stepping.c (displaced_step_buffer::prepare): New.
(write_memory_ptid): Move from infrun.c.
(displaced_step_instruction_executed_successfully): New,
factored out of displaced_step_finish.
(displaced_step_buffer::finish): New.
(displaced_step_buffer::copy_insn_closure_by_addr): New.
(displaced_step_buffer::restore_in_ptid): New.
* gdbarch.sh (displaced_step_location): Remove.
(displaced_step_prepare, displaced_step_finish,
displaced_step_copy_insn_closure_by_addr,
displaced_step_restore_all_in_ptid): New.
* gdbarch.c: Re-generate.
* gdbarch.h: Re-generate.
* gdbthread.h (class thread_info) <displaced_step_state>: New
field.
(thread_step_over_chain_remove): New declaration.
(thread_step_over_chain_next): New declaration.
(thread_step_over_chain_length): New declaration.
* thread.c (thread_step_over_chain_remove): Make non-static.
(thread_step_over_chain_next): New.
(global_thread_step_over_chain_next): Use
thread_step_over_chain_next.
(thread_step_over_chain_length): New.
(global_thread_step_over_chain_enqueue): Add debug print.
(global_thread_step_over_chain_remove): Add debug print.
* infrun.h (get_displaced_step_copy_insn_closure_by_addr):
Remove.
* infrun.c (get_displaced_stepping_state): New.
(displaced_step_in_progress_any_inferior): Remove.
(displaced_step_in_progress_thread): Adjust.
(displaced_step_in_progress): Adjust.
(displaced_step_in_progress_any_thread): New.
(get_displaced_step_copy_insn_closure_by_addr): Remove.
(gdbarch_supports_displaced_stepping): Use
gdbarch_displaced_step_prepare_p.
(displaced_step_reset): Change parameter from inferior to
thread.
(displaced_step_prepare_throw): Implement using
gdbarch_displaced_step_prepare.
(write_memory_ptid): Move to displaced-step.c.
(displaced_step_restore): Remove.
(displaced_step_finish): Implement using
gdbarch_displaced_step_finish.
(start_step_over): Allow starting more than one displaced step.
(prepare_for_detach): Handle possibly multiple threads doing
displaced steps.
(handle_inferior_event): Handle possibility that fork event
happens while another thread displaced steps.
* linux-tdep.h (linux_displaced_step_prepare): New.
(linux_displaced_step_finish): New.
(linux_displaced_step_copy_insn_closure_by_addr): New.
(linux_displaced_step_restore_all_in_ptid): New.
(linux_init_abi): Add supports_displaced_step parameter.
* linux-tdep.c (struct linux_info) <disp_step_buf>: New field.
(linux_displaced_step_prepare): New.
(linux_displaced_step_finish): New.
(linux_displaced_step_copy_insn_closure_by_addr): New.
(linux_displaced_step_restore_all_in_ptid): New.
(linux_init_abi): Add supports_displaced_step parameter,
register displaced step methods if true.
(_initialize_linux_tdep): Register inferior_execd observer.
* amd64-linux-tdep.c (amd64_linux_init_abi_common): Add
supports_displaced_step parameter, adjust call to
linux_init_abi. Remove call to
set_gdbarch_displaced_step_location.
(amd64_linux_init_abi): Adjust call to
amd64_linux_init_abi_common.
(amd64_x32_linux_init_abi): Likewise.
* aarch64-linux-tdep.c (aarch64_linux_init_abi): Adjust call to
linux_init_abi. Remove call to
set_gdbarch_displaced_step_location.
* arm-linux-tdep.c (arm_linux_init_abi): Likewise.
* i386-linux-tdep.c (i386_linux_init_abi): Likewise.
* alpha-linux-tdep.c (alpha_linux_init_abi): Adjust call to
linux_init_abi.
* arc-linux-tdep.c (arc_linux_init_osabi): Likewise.
* bfin-linux-tdep.c (bfin_linux_init_abi): Likewise.
* cris-linux-tdep.c (cris_linux_init_abi): Likewise.
* csky-linux-tdep.c (csky_linux_init_abi): Likewise.
* frv-linux-tdep.c (frv_linux_init_abi): Likewise.
* hppa-linux-tdep.c (hppa_linux_init_abi): Likewise.
* ia64-linux-tdep.c (ia64_linux_init_abi): Likewise.
* m32r-linux-tdep.c (m32r_linux_init_abi): Likewise.
* m68k-linux-tdep.c (m68k_linux_init_abi): Likewise.
* microblaze-linux-tdep.c (microblaze_linux_init_abi): Likewise.
* mips-linux-tdep.c (mips_linux_init_abi): Likewise.
* mn10300-linux-tdep.c (am33_linux_init_osabi): Likewise.
* nios2-linux-tdep.c (nios2_linux_init_abi): Likewise.
* or1k-linux-tdep.c (or1k_linux_init_abi): Likewise.
* riscv-linux-tdep.c (riscv_linux_init_abi): Likewise.
* s390-linux-tdep.c (s390_linux_init_abi_any): Likewise.
* sh-linux-tdep.c (sh_linux_init_abi): Likewise.
* sparc-linux-tdep.c (sparc32_linux_init_abi): Likewise.
* sparc64-linux-tdep.c (sparc64_linux_init_abi): Likewise.
* tic6x-linux-tdep.c (tic6x_uclinux_init_abi): Likewise.
* tilegx-linux-tdep.c (tilegx_linux_init_abi): Likewise.
* xtensa-linux-tdep.c (xtensa_linux_init_abi): Likewise.
* ppc-linux-tdep.c (ppc_linux_init_abi): Adjust call to
linux_init_abi. Remove call to
set_gdbarch_displaced_step_location.
* arm-tdep.c (arm_pc_is_thumb): Call
gdbarch_displaced_step_copy_insn_closure_by_addr instead of
get_displaced_step_copy_insn_closure_by_addr.
* rs6000-aix-tdep.c (rs6000_aix_init_osabi): Adjust calls to
clear gdbarch methods.
* rs6000-tdep.c (struct ppc_inferior_data): New structure.
(get_ppc_per_inferior): New function.
(ppc_displaced_step_prepare): New function.
(ppc_displaced_step_finish): New function.
(ppc_displaced_step_restore_all_in_ptid): New function.
(rs6000_gdbarch_init): Register new gdbarch methods.
* s390-tdep.c (s390_gdbarch_init): Don't call
set_gdbarch_displaced_step_location, set new gdbarch methods.
gdb/testsuite/ChangeLog:
* gdb.arch/amd64-disp-step-avx.exp: Adjust pattern.
* gdb.threads/forking-threads-plus-breakpoint.exp: Likewise.
* gdb.threads/non-stop-fair-events.exp: Likewise.
Change-Id: I387cd235a442d0620ec43608fd3dc0097fcbf8c8
When loading the code file provided in PR 26828 and GDB is build with
UBSan, we get:
Core was generated by `./Foo'.
Program terminated with signal SIGABRT, Aborted.
#0 0xb6c3809c in pthread_cond_wait () from /home/simark/build/binutils-gdb/gdb/repo/lib/libpthread.so.0
[Current thread is 1 (LWP 29367)]
(gdb) bt
/home/simark/src/binutils-gdb/gdb/arm-tdep.c:1551:30: runtime error: shift exponent 32 is too large for 32-bit type 'unsigned int'
The sequence of instructions at pthread_cond_wait, in the
libpthread.so.0 library, contains this instruction with an immediate
constant with a "rotate amount" of 0:
e24dd044 sub sp, sp, #68 ; 0x44
Since arm_analyze_prologue shifts by "32 - rotate amount", it does a 32
bit shift of a 32 bit type, which is caught by UBSan.
Fix it by factoring out the decoding of immediates in a new function,
arm_expand_immediate.
I added a selftest for arm_analyze_prologue that replicates the
instruction sequence. Without the fix, it crashes GDB if it is build
with --enable-ubsan.
I initially wanted to re-use the abstract_memory_reader class already in
arm-tdep.c, used to make arm_process_record testable. However,
arm_process_record and arm_analyze_prologue don't use the same kind of
memory reading functions. arm_process_record uses a function that
returns an error status on failure while arm_analyze_prologue uses one
that throws an exception. Since i didn't want to introduce any other
behavior change, I decided to just introduce a separate interface
(arm_instruction_reader). It is derived from
abstract_instruction_reader in aarch64-tdep.c.
gdb/ChangeLog:
PR gdb/26835
* arm-tdep.c (class arm_instruction_reader): New.
(target_arm_instruction_reader): New.
(arm_analyze_prologue): Add instruction reader parameter and use
it. Use arm_expand_immediate.
(class target_arm_instruction_reader): Adjust.
(arm_skip_prologue): Adjust.
(arm_expand_immediate): New.
(arm_scan_prologue): Adjust.
(arm_analyze_prologue_test): New.
(class test_arm_instruction_reader): New.
Change-Id: Ieb1c1799bd66f8c7421384f44f5c2777b578ff8d
Move all debug prints of the "displaced" category to use a new
displaced_debug_printf macro, like what was done for infrun and others
earlier.
The debug output for one displaced step one amd64 looks like:
[displaced] displaced_step_prepare_throw: stepping process 3367044 now
[displaced] displaced_step_prepare_throw: saved 0x555555555042: 1e fa 31 ed 49 89 d1 5e 48 89 e2 48 83 e4 f0 50
[displaced] amd64_displaced_step_copy_insn: copy 0x555555555131->0x555555555042: b8 00 00 00 00 5d c3 0f 1f 84 00 00 00 00 00 f3
[displaced] displaced_step_prepare_throw: displaced pc to 0x555555555042
[displaced] resume_1: run 0x555555555042: b8 00 00 00
[displaced] displaced_step_restore: restored process 3367044 0x555555555042
[displaced] amd64_displaced_step_fixup: fixup (0x555555555131, 0x555555555042), insn = 0xb8 0x00 ...
[displaced] amd64_displaced_step_fixup: relocated %rip from 0x555555555047 to 0x555555555136
On test case needed to be updated because it relied on the specific
formatting of the message.
gdb/ChangeLog:
* infrun.h (displaced_debug_printf): New macro. Replace
displaced debug prints throughout to use it.
(displaced_debug_printf_1): New declaration.
(displaced_step_dump_bytes): Return string, remove ui_file
parameter, update all callers.
* infrun.c (displaced_debug_printf_1): New function.
(displaced_step_dump_bytes): Return string, remove ui_file
parameter
gdb/testsuite/ChangeLog:
* gdb.arch/amd64-disp-step-avx.exp: Update displaced step debug
expected output.
Change-Id: Ie78837f56431f6f98378790ba1e6051337bf6533
This changes some ELF osabi tag-sniffing functions to avoid
bfd_map_over_sections, in favor of iteration. I could only readily
test the generic one.
gdb/ChangeLog
2020-09-19 Tom Tromey <tom@tromey.com>
* osabi.h (generic_elf_osabi_sniff_abi_tag_sections): Update.
* osabi.c (generic_elf_osabi_sniff_abi_tag_sections): Change
parameters.
(generic_elf_osabi_sniffer): Use foreach.
* mips-sde-tdep.c (mips_sde_elf_osabi_sniffer): Use foreach.
* arm-tdep.c (arm_elf_osabi_sniffer): Use foreach.
While working on something else, I noticed that tdesc_data_cleanup
took a void* parameter. Looking more into this, I found that
tdesc_use_registers expected a transfer of ownership.
I think it's better to express this sort of thing via the type system,
when possible. This patch changes tdesc_data_alloc to return a unique
pointer, changes tdesc_use_registers to accept an rvalue reference,
and then adapts all the users.
Note that a deleter structure is introduced to avoid having to move
tdesc_arch_data to the header file.
2020-09-17 Tom Tromey <tromey@adacore.com>
* tic6x-tdep.c (tic6x_gdbarch_init): Update.
* target-descriptions.h (struct tdesc_arch_data_deleter): New.
(tdesc_arch_data_up): New typedef.
(tdesc_use_registers, tdesc_data_alloc): Update.
(tdesc_data_cleanup): Don't declare.
* target-descriptions.c (tdesc_data_alloc): Return a
tdesc_arch_data_up.
(tdesc_arch_data_deleter::operator()): Rename from
tdesc_data_cleanup. Change argument type.
(tdesc_use_registers): Change early_data to an rvalue reference.
(tdesc_use_registers): Don't use delete.
* sparc-tdep.c (sparc32_gdbarch_init): Update.
* s390-tdep.c (s390_gdbarch_init): Update.
* rx-tdep.c (rx_gdbarch_init): Update.
* rs6000-tdep.c (rs6000_gdbarch_init): Update.
* riscv-tdep.c (riscv_gdbarch_init): Update.
* or1k-tdep.c (or1k_gdbarch_init): Update.
* nios2-tdep.c (nios2_gdbarch_init): Update.
* nds32-tdep.c (nds32_gdbarch_init): Update.
* mips-tdep.c (mips_gdbarch_init): Update.
* microblaze-tdep.c (microblaze_gdbarch_init): Update.
* m68k-tdep.c (m68k_gdbarch_init): Update.
* i386-tdep.c (i386_gdbarch_init): Update.
* arm-tdep.c (arm_gdbarch_init): Update.
* arc-tdep.c (arc_tdesc_init): Update.
(arc_gdbarch_init): Update.
* aarch64-tdep.c (aarch64_gdbarch_init): Update.
Add the `is_vector` and `set_is_vector` methods on `struct type`, in
order to remove the `TYPE_VECTOR` macro. In this patch, the macro is
changed to use the getter, so all the call sites of the macro that are
used as a setter are changed to use the setter method directly. The
next patch will remove the macro completely.
gdb/ChangeLog:
* gdbtypes.h (struct type) <is_vector, set_is_vector>: New methods.
(TYPE_VECTOR): Use type::is_vector, change all write call sites to
use type::set_is_vector.
Change-Id: I415e8d169f058662e0750329bfa4017bea3ca0cb
For Cortex-M targets using floating-point, eg the Cortex-M4F, its not possible
to get any call-stack backtrace if setting a breakpoint in ISR.
The exception stack unwinder for Cortex-M does not consider if floating-point
registers was stacked or not, further the Cortex-M has two stack pointers: MSP
(Main Stack Pointer) and PSP (Process Stack Pointer).
This is not handled when GDB tries to backtrace in the exception stack
unwinder.
This patch fixes this, and gives a correct call-stack backtrace from
breakpoints set in a handler or ISR.
gdb/ChangeLog:
* arm-tdep.c (arm_m_exception_cache): Try use correct stack
pointer and stack frame offset when unwinding.
Currently, GDB is not able to set a breakpoint at subprogram post
prologue for flang generated binaries. This is due to clang having
two line notes one before and another after the prologue.
Now the end of prologue is determined using symbol table, which was
the way for clang generated binaries already. Since clang and flang
both share same back-end it is true for flang as well.
gdb/ChangeLog
* amd64-tdep.c (amd64_skip_prologue): Using symbol table
to find the end of prologue for flang compiled binaries.
* arm-tdep.c (arm_skip_prologue): Likewise.
* i386-tdep.c (i386_skip_prologue): Likewise.
* producer.c (producer_is_llvm): New function.
(producer_parsing_tests): Added new tests for clang/flang.
* producer.h (producer_is_llvm): New declaration.
gdb/testsuite/ChangeLog
* gdb.fortran/vla-type.exp: Skip commands not required for
the Flang compiled binaries after prologue fix.
Remove the `TYPE_FIELD_TYPE` macro, changing all the call sites to use
`type::field` and `field::type` directly.
gdb/ChangeLog:
* gdbtypes.h (TYPE_FIELD_TYPE): Remove. Change all call sites
to use type::field and field::type instead.
Change-Id: Ifda6226a25c811cfd334a756a9fbc5c0afdddff3
This fixes an instruction mask typo. We should be matching only
ldrd (immediate) and not any other of its variants. As is, it never matches
anything.
With the patch, the instruction mask also allows matching of ldrd (literal),
but the check for SP discards this particular instruction pattern, as it has
a hardcoded PC register.
gdb/ChangeLog:
2020-05-27 Luis Machado <luis.machado@linaro.org>
PR tdep/26000
* arm-tdep.c (thumb_analyze_prologue): Fix instruction matching
for ldrd (immediate).
Replace all uses of it by type::field.
Note that since type::field returns a reference to the field, some spots
are used to assign the whole field structure. See ctfread.c, function
attach_fields_to_type, for example. This is the same as was happening
with the macro, so I don't think it's a problem, but if anybody sees a
really nicer way to do this, now could be a good time to implement it.
gdb/ChangeLog:
* gdbtypes.h (TYPE_FIELD): Remove. Replace all uses with
type::field.
Remove `TYPE_NFIELDS`, changing all the call sites to use
`type::num_fields` directly. This is quite a big diff, but this was
mostly done using sed and coccinelle. A few call sites were done by
hand.
gdb/ChangeLog:
* gdbtypes.h (TYPE_NFIELDS): Remove. Change all cal sites to use
type::num_fields instead.
Change-Id: Ib73be4c36f9e770e0f729bac3b5257d7cb2f9591
Add the `name` and `set_name` methods on `struct type`, in order to
remove the `TYPE_NAME` macro. In this patch, the `TYPE_NAME` macro is
changed to use `type::name`, so all the call sites that are used to set
the type name are changed to use `type::set_name`. The next patch will
remove `TYPE_NAME` completely.
gdb/ChangeLog:
* gdbtypes.h (struct type) <name, set_name>: New methods.
(TYPE_CODE): Use type::name. Change all call sites used to set
the name to use type::set_name instead.
Remove TYPE_CODE, changing all the call sites to use type::code
directly. This is quite a big diff, but this was mostly done using sed
and coccinelle. A few call sites were done by hand.
gdb/ChangeLog:
* gdbtypes.h (TYPE_CODE): Remove. Change all call sites to use
type::code instead.
Currently there are many prefix commands that do nothing but call
either help_list or cmd_show_list. I happened to notice that one such
call, for "set print type", used the wrong command list parameter,
causing incorrect output.
Rather than fix this bug in isolation, I decided to eliminate this
possibility by adding two new ways to add prefix commands, which
simply route the call to help_list or cmd_show_list, as appropriate.
This makes it impossible for a mismatch to occur.
In some cases, a bit of output was removed; however, I don't think
this output in general was very useful. It seemed redundant with
what's already printed by help_list. A representative example is this
hunk, removed from ada-lang.c:
- printf_unfiltered (_(\
-"\"set ada\" must be followed by the name of a setting.\n"));
This simplified the CLI style set/show commands quite a bit, and
allowed the deletion of a macro.
This also cleans up some unusual code in windows-tdep.c.
Tested on x86-64 Fedora 30. Note that I have no way to build the
go32-nat.c change.
gdb/ChangeLog
2020-04-17 Tom Tromey <tromey@adacore.com>
* auto-load.c (show_auto_load_cmd): Remove.
(auto_load_show_cmdlist_get): Use add_show_prefix_cmd.
* arc-tdep.c (_initialize_arc_tdep): Use add_show_prefix_cmd.
(maintenance_print_arc_command): Remove.
* tui/tui-win.c (tui_command): Remove.
(tui_get_cmd_list): Use add_basic_prefix_cmd.
* tui/tui-layout.c (tui_layout_command): Remove.
(_initialize_tui_layout): Use add_basic_prefix_cmd.
* python/python.c (user_set_python, user_show_python): Remove.
(_initialize_python): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* guile/guile.c (set_guile_command, show_guile_command): Remove.
(install_gdb_commands): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
(info_guile_command): Remove.
* dwarf2/read.c (set_dwarf_cmd, show_dwarf_cmd): Remove.
(_initialize_dwarf2_read): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* cli/cli-style.h (class cli_style_option) <add_setshow_commands>:
Remove do_set and do_show parameters.
* cli/cli-style.c (set_style, show_style): Remove.
(_initialize_cli_style): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
(cli_style_option::add_setshow_commands): Remove do_set and
do_show parameters.
(cli_style_option::add_setshow_commands): Use
add_basic_prefix_cmd, add_show_prefix_cmd.
(STYLE_ADD_SETSHOW_COMMANDS): Remove macro.
(set_style_name): Remove.
* cli/cli-dump.c (dump_command, append_command): Remove.
(srec_dump_command, ihex_dump_command, verilog_dump_command)
(tekhex_dump_command, binary_dump_command)
(binary_append_command): Remove.
(_initialize_cli_dump): Use add_basic_prefix_cmd.
* windows-tdep.c (w32_prefix_command_valid): Remove global.
(init_w32_command_list): Remove; move into ...
(_initialize_windows_tdep): ... here. Use add_basic_prefix_cmd.
* valprint.c (set_print, show_print, set_print_raw)
(show_print_raw): Remove.
(_initialize_valprint): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* typeprint.c (set_print_type, show_print_type): Remove.
(_initialize_typeprint): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* record.c (set_record_command, show_record_command): Remove.
(_initialize_record): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* cli/cli-cmds.c (_initialize_cli_cmds): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
(info_command, show_command, set_debug, show_debug): Remove.
* top.h (set_history, show_history): Don't declare.
* top.c (set_history, show_history): Remove.
* target-descriptions.c (set_tdesc_cmd, show_tdesc_cmd)
(unset_tdesc_cmd): Remove.
(_initialize_target_descriptions): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* symtab.c (info_module_command): Remove.
(_initialize_symtab): Use add_basic_prefix_cmd.
* symfile.c (overlay_command): Remove.
(_initialize_symfile): Use add_basic_prefix_cmd.
* sparc64-tdep.c (info_adi_command): Remove.
(_initialize_sparc64_adi_tdep): Use add_basic_prefix_cmd.
* sh-tdep.c (show_sh_command, set_sh_command): Remove.
(_initialize_sh_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* serial.c (serial_set_cmd, serial_show_cmd): Remove.
(_initialize_serial): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* ser-tcp.c (set_tcp_cmd, show_tcp_cmd): Remove.
(_initialize_ser_tcp): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* rs6000-tdep.c (set_powerpc_command, show_powerpc_command)
(_initialize_rs6000_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* riscv-tdep.c (show_riscv_command, set_riscv_command)
(show_debug_riscv_command, set_debug_riscv_command): Remove.
(_initialize_riscv_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* remote.c (remote_command, set_remote_cmd): Remove.
(_initialize_remote): Use add_basic_prefix_cmd.
* record-full.c (set_record_full_command)
(show_record_full_command): Remove.
(_initialize_record_full): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* record-btrace.c (cmd_set_record_btrace)
(cmd_show_record_btrace, cmd_set_record_btrace_bts)
(cmd_show_record_btrace_bts, cmd_set_record_btrace_pt)
(cmd_show_record_btrace_pt): Remove.
(_initialize_record_btrace): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* ravenscar-thread.c (set_ravenscar_command)
(show_ravenscar_command): Remove.
(_initialize_ravenscar): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* mips-tdep.c (show_mips_command, set_mips_command)
(_initialize_mips_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* maint.c (maintenance_command, maintenance_info_command)
(maintenance_check_command, maintenance_print_command)
(maintenance_set_cmd, maintenance_show_cmd): Remove.
(_initialize_maint_cmds): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
(show_per_command_cmd): Remove.
* maint-test-settings.c (maintenance_set_test_settings_cmd):
Remove.
(maintenance_show_test_settings_cmd): Remove.
(_initialize_maint_test_settings): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* maint-test-options.c (maintenance_test_options_command):
Remove.
(_initialize_maint_test_options): Use add_basic_prefix_cmd.
* macrocmd.c (macro_command): Remove
(_initialize_macrocmd): Use add_basic_prefix_cmd.
* language.c (set_check, show_check): Remove.
(_initialize_language): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* infcmd.c (unset_command): Remove.
(_initialize_infcmd): Use add_basic_prefix_cmd.
* i386-tdep.c (set_mpx_cmd, show_mpx_cmd): Remove.
(_initialize_i386_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* go32-nat.c (go32_info_dos_command): Remove.
(_initialize_go32_nat): Use add_basic_prefix_cmd.
* cli/cli-decode.c (do_prefix_cmd, add_basic_prefix_cmd)
(do_show_prefix_cmd, add_show_prefix_cmd): New functions.
* frame.c (set_backtrace_cmd, show_backtrace_cmd): Remove.
(_initialize_frame): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* dcache.c (set_dcache_command, show_dcache_command): Remove.
(_initialize_dcache): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* cp-support.c (maint_cplus_command): Remove.
(_initialize_cp_support): Use add_basic_prefix_cmd.
* btrace.c (maint_btrace_cmd, maint_btrace_set_cmd)
(maint_btrace_show_cmd, maint_btrace_pt_set_cmd)
(maint_btrace_pt_show_cmd, _initialize_btrace): Use
add_basic_prefix_cmd, add_show_prefix_cmd.
* breakpoint.c (save_command): Remove.
(_initialize_breakpoint): Use add_basic_prefix_cmd.
* arm-tdep.c (set_arm_command, show_arm_command): Remove.
(_initialize_arm_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* ada-lang.c (maint_set_ada_cmd, maint_show_ada_cmd)
(set_ada_command, show_ada_command): Remove.
(_initialize_ada_language): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* command.h (add_basic_prefix_cmd, add_show_prefix_cmd): Declare.
gdb/testsuite/ChangeLog
2020-04-17 Tom Tromey <tromey@adacore.com>
* gdb.cp/maint.exp (test_help): Simplify multiple_help_body.
Update tests.
* gdb.btrace/cpu.exp: Update tests.
* gdb.base/maint.exp: Update tests.
* gdb.base/default.exp: Update tests.
* gdb.base/completion.exp: Update tests.
Some arm-tdep.c data structures use a bfd_vma. A couple of spots will
warn about an implicit narrowing cast when building a gdb where
CORE_ADDR is 64-bit but bfd_vma is 32-bit.
This patch silences these warnings by changing the types in question
to CORE_ADDR.
gdb/ChangeLog
2020-03-12 Tom Tromey <tom@tromey.com>
* arm-tdep.c (struct arm_mapping_symbol) <value>: Now a
CORE_ADDR.
(struct arm_exidx_entry) <addr>: Now a CORE_ADDR.
For a fix I intend to submit, I would need a function that counts the
number of set bits in a word. There is __builtin_popcount that is
supported by gcc and clang, but there is also a gnulib module that wraps
that and provides a fallback for other compilers, so I think it would be
good to use it.
I also noticed that there is a bitcount function in arch/arm.c, so I
thought that as a first step I would replace that one with the gnulib
count-one-bits module. This is what this patch does.
The gnulib module provides multiple functions, with various parameter
length (unsigned int, unsigned long int, unsigned long long int), I
chose the one that made sense for each call site based on the argument
type.
gnulib/ChangeLog:
* update-gnulib.sh (IMPORTED_GNULIB_MODULES): Import
count-one-bits module.
* configure: Re-generate.
* aclocal.m4: Re-generate.
* Makefile.in: Re-generate.
* import/count-one-bits.c: New file.
* import/count-one-bits.h: New file.
* import/Makefile.am: Re-generate.
* import/Makefile.in: Re-generate.
* import/m4/gnulib-cache.m4: Re-generate.
* import/m4/gnulib-comp.m4: Re-generate.
* import/m4/count-one-bits.m4: New file.
gdb/ChangeLog:
* arm-tdep.c: Include count-one-bits.h.
(cleanup_block_store_pc): Use count_one_bits.
(cleanup_block_load_pc): Use count_one_bits.
(arm_copy_block_xfer): Use count_one_bits.
(thumb2_copy_block_xfer): Use count_one_bits.
(thumb_copy_pop_pc_16bit): Use count_one_bits.
* arch/arm-get-next-pcs.c: Include count-one-bits.h.
(thumb_get_next_pcs_raw): Use count_one_bits.
(arm_get_next_pcs_raw): Use count_one_bits_l.
* arch/arm.c (bitcount): Remove.
* arch/arm.h (bitcount): Remove.
I am keeping the (int) casts because a future patch will change the type
to bool.
gdb/ChangeLog:
2020-02-12 Christian Biesinger <cbiesinger@google.com>
* arm-tdep.c (arm_dump_tdep): Print more fields of tdep.
The speed optimization from commit 5f6cac4085
made GDB skip reloading all symbols when the same symbol file is reloaded.
As a result, ARM targets only read the mapping symbols the first time we
load a symbol file. When reloaded, the speed optimization above will
cause an early return and gdbarch_record_special_symbol won't be called to
save mapping symbol data, which in turn affects disassembling of thumb
instructions.
First load and correct disassemble output:
Dump of assembler code for function main:
0x0000821c <+0>: bx pc
0x0000821e <+2>: nop
0x00008220 <+4>: mov r0, #0
0x00008224 <+8>: bx lr
Second load and incorrect disassemble output:
Dump of assembler code for function main:
0x0000821c <+0>: bx pc
0x0000821e <+2>: nop
0x00008220 <+4>: movs r0, r0
0x00008222 <+6>: b.n 0x8966
0x00008224 <+8>: vrhadd.u16 d14, d14, d31
This happens because the mapping symbol data is stored in an objfile_key-based
container, and that data isn't preserved across the two symbol loading
operations.
The following patch fixes this by storing the mapping symbol data in a
bfd_key-based container, which doesn't change as long as the bfd is the same.
I've also added a new test to verify the correct disassemble output.
gdb/ChangeLog:
2019-11-01 Luis Machado <luis.machado@linaro.org>
PR gdb/25124
* arm-tdep.c (arm_per_objfile): Rename to ...
(arm_per_bfd): ... this.
(arm_objfile_data_key): Rename to ...
(arm_bfd_data_key): ... this.
(arm_find_mapping_symbol): Adjust access to new bfd_key-based
data.
(arm_record_special_symbol): Likewise.
gdb/testsuite/ChangeLog:
2019-11-01 Luis Machado <luis.machado@linaro.org>
PR gdb/25124
* gdb.arch/pr25124.S: New file.
* gdb.arch/pr25124.exp: New file.
Change-Id: I22c3e6ebe9bfedad66d56fe9656994fa1761c485
Based on feedback from Tromey, update the use of objfile_key in gdb/arm-tdep.c
to use bfd_key instead. That way we don't have to re-create the exception
handling data all over again if it was done before for the same BFD.
gdb/ChangeLog:
2019-10-31 Luis Machado <luis.machado@linaro.org>
* arm-tdep.c (arm_exidx_data_key): Use bfd_key instead of
objfile_key.
(arm_exidx_new_objfile): Adjust to use objfile->obfd instead of
objfile to fetch per-bfd data.
(arm_find_exidx_entry): Likewise.
Change-Id: Ia7b3208ea8d788414600fa6d770ac76db0562859
Instead of having several extern declarations for arm_apcs_32
in a few .c files, declare it in arm-tdep.h. This file is already
included from these .c files.
gdb/ChangeLog:
2019-09-19 Christian Biesinger <cbiesinger@google.com>
* arm-linux-nat.c: Remove extern declaration for arm_apcs_32.
* arm-linux-tdep.c: Likewise.
* arm-nbsd-nat.c: Likewise.
* arm-tdep.h: Declare arm_apcs_32.
GDB is not able to execute "step" command on function calls of Armv8-M cmse secure entry functions.
Everytime GNU linker come across definition of any cmse secure entry function in object file(s),
it creates two new instructions secure gateway (sg) and original branch destination (b.w),
place those two instructions in ".gnu.sgstubs" section of executable.
Any function calls to these cmse secure entry functions is re-directed through secure gateway (sg)
present in ".gnu.sgstubs" section.
Example:
Following is a function call to cmse secure entry function "foo":
...
bl xxxx <foo> --->(a)
...
<foo>
xxxx: push {r7, lr}
GNU linker on finding out "foo" is a cmse secure entry function, created sg and b.w instructions and
place them in ".gnu.sgstubs" section (marked by c).
The "bl" instruction (marked by a) which is a call to cmse secure entry function is modified by GNU linker
(as marked by b) and call flow is re-directly through secure gateway (sg) in ".gnu.sgstubs" section.
...
bl yyyy <foo> ---> (b)
...
section .gnu.sgstubs: ---> (c)
yyyy <foo>
yyyy: sg // secure gateway
b.w xxxx <__acle_se_foo> // original_branch_dest
...
0000xxxx <__acle_se_foo>
xxxx: push {r7, lr} ---> (d)
On invoking GDB, when the control is at "b" and we pass "step" command, the pc returns "yyyy"
(sg address) which is a trampoline and which does not exist in source code. So GDB jumps
to next line without jumping to "__acle_se_foo" (marked by d).
The above details are published on the Arm website [1], please refer to section 5.4 (Entry functions)
and section 3.4.4 (C level development flow of secure code).
[1] https://developer.arm.com/architectures/cpu-architecture/m-profile/docs/ecm0359818/latest/armv8-m-security-extensions-requirements-on-development-tools-engineering-specification
This patch fixes above problem by returning target pc "xxxx" to GDB on executing "step"
command at "b", so that the control jumps to "__acle_se_foo" (marked by d).
gdb/ChangeLog:
* arm-tdep.c (arm_skip_cmse_entry): New function.
(arm_is_sgstubs_section): New function.
(arm_skip_stub): Add call to arm_skip_cmse_entry function.
gdb/testsuite/ChangeLog:
* gdb.arch/arm-cmse-sgstubs.c: New test.
* gdb.arch/arm-cmse-sgstubs.exp: New file.
Remove the xml tests. Now that it has been proven the new descriptions
are identical, there is no need to keep testing that. Also, it would
prevent the old xml files from being removed.
Remove the old xml files from gdbserver and delete them.
gdb/ChangeLog:
* arm-tdep.c (_initialize_arm_tdep): Remove xml tests.
* features/arm/arm-with-iwmmxt.c: Remove.
* features/arm/arm-with-iwmmxt.xml: Remove.
* features/arm/arm-with-m-fpa-layout.c: Remove.
* features/arm/arm-with-m-fpa-layout.xml: Remove.
* features/arm/arm-with-m-vfp-d16.c: Remove.
* features/arm/arm-with-m-vfp-d16.xml: Remove.
* features/arm/arm-with-m.c: Remove.
* features/arm/arm-with-m.xml: Remove.
* features/arm/arm-with-neon.c: Remove.
* features/arm/arm-with-neon.xml: Remove.
* features/arm/arm-with-vfpv2.c: Remove.
* features/arm/arm-with-vfpv2.xml: Remove.
* features/arm/arm-with-vfpv3.c: Remove.
* features/arm/arm-with-vfpv3.xml: Remove.
gdb/gdbserver/ChangeLog:
2019-07-05 Alan Hayward <alan.hayward@arm.com>
* configure.srv: Remove Arm xml files.
Use the record_xml_tdesc tests to prove the new target descriptions
are identical to the previous xml file ones.
This is tested as part of gdb.gdb/unittest.exp.
gdb/ChangeLog:
* arm-tdep.c (_initialize_arm_tdep): Add xml regression tests.
In arm arm_create_target_description and
aarch32_create_target_description create feature based target descriptions
instead of returning the old style descriptions.
Ensure the descriptions are created in exactly the same way as the old xml
files.
Remove the old initialize calls.
gdb/ChangeLog:
* arch/aarch32.c (aarch32_create_target_description): Create
target descriptions using features.
* arch/arm.c (arm_create_target_description)
(arm_create_mprofile_target_description): Likewise.
* arm-tdep.c (_initialize_arm_tdep): Remove tdesc init calls.
Switch the Arm target to get target descriptions via arm_read_description
and aarch32_read_description, in the same style as other feature targets.
Add an enum to specify the different types - this will also be of use to
gdbserver in a later patch.
Under the hood return the same existing pre-feature target descriptions.
gdb/ChangeLog:
* Makefile.in: Add new files.
* aarch32-tdep.c: New file.
* aarch32-tdep.h: New file.
* aarch64-linux-nat.c (aarch64_linux_nat_target::read_description):
Call aarch32_read_description.
* arch/aarch32.c: New file.
* arch/aarch32.h: New file.
* arch/arm.c (arm_create_target_description)
(arm_create_mprofile_target_description): New function.
* arch/arm.h (arm_fp_type, arm_m_profile_type): New enum.
(arm_create_target_description)
(arm_create_mprofile_target_description): New declaration.
* arm-fbsd-tdep.c (arm_fbsd_read_description_auxv): Call
read_description functions.
* arm-linux-nat.c (arm_linux_nat_target::read_description):
Likewise.
* arm-linux-tdep.c (arm_linux_core_read_description): Likewise.
* arm-tdep.c (tdesc_arm_list): New variable.
(arm_register_g_packet_guesses): Call create description functions.
(arm_read_description) (arm_read_mprofile_description): New
function.
* arm-tdep.h (arm_read_description)
(arm_read_mprofile_description): Add declaration.
* configure.tgt: Add new files.
This changes arm-tdep.c to use the type-safe registry, removing a use
of VEC in the process.
2019-07-10 Tom Tromey <tromey@adacore.com>
* arm-tdep.c (arm_exidx_entry_s): Remove typedef. Don't define
VEC.
(struct arm_exidx_entry): New method operator<.
(struct arm_exidx_data) <section_maps>: Change type.
(arm_exidx_data_free): Remove.
(arm_exidx_data_key): Change type. Move lower.
(arm_exidx_new_objfile): Update.
(arm_compare_exidx_entries): Remove.
(arm_find_exidx_entry, _initialize_arm_tdep)
Both targets were using a mixture of defines and hardcoded values.
Add a standard set in arch/arm.h and use throughout, ensuring that
none of the existing sizes change.
No functionality changes.
gdb/ChangeLog:
* aarch32-linux-nat.h (VFP_REGS_SIZE): Remove define.
* aarch64-linux-nat.c (fetch_fpregs_from_thread)
(store_fpregs_to_thread)
(aarch64_linux_nat_target::read_description): Use ARM_VFP3_REGS_SIZE.
* arch/arm.h (IWMMXT_VEC_REGISTER_SIZE, ARM_CORE_REGS_SIZE)
(ARM_FP_REGS_SIZE, ARM_VFP2_REGS_SIZE, ARM_VFP3_REGS_SIZE)
(IWMMXT_REGS_SIZE): Add define.
* arm-linux-nat.c (IWMMXT_REGS_SIZE): Remove define.
(fetch_vfp_regs, store_vfp_regs)
(arm_linux_nat_target::read_description): Use ARM_VFP3_REGS_SIZE.
* arm-tdep.c (arm_register_g_packet_guesses): Use new defines.
gdb/gdbserver/ChangeLog:
* linux-aarch32-low.c (arm_read_description, arm_regsets): Use new
defines.
* linux-arm-low.c (arm_read_description, arm_regsets): Likewise.
Add ARM_ to the front of INT_REGISTER_SIZE, FP_REGISTER_SIZE and
ARM_VFP_REGISTER_SIZE to make it obvious they are for the Arm target.
Move the defines to arch/arm.h
No functionality changes.
gdb/ChangeLog:
* arch/arm-get-next-pcs.c (thumb_get_next_pcs_raw): Use ARM_
defines.
* arch/arm-linux.c (arm_linux_sigreturn_next_pc_offset): Likewise.
* arch/arm.h (INT_REGISTER_SIZE) Rename from...
(ARM_INT_REGISTER_SIZE): ...to this.
(ARM_FP_REGISTER_SIZE) (ARM_VFP_REGISTER_SIZE): Add define.
* arm-linux-tdep.c (ARM_LINUX_JB_ELEMENT_SIZE)
(ARM_LINUX_SIZEOF_GREGSET, arm_linux_supply_gregset)
(arm_linux_collect_gregset, supply_nwfpe_register)
(collect_nwfpe_register, arm_linux_collect_nwfpe): Use ARM_
defines.
* arm-linux-tdep.h (ARM_LINUX_SIZEOF_NWFPE, NWFPE_FPSR_OFFSET)
(NWFPE_FPCR_OFFSET, NWFPE_TAGS_OFFSET): Likewise
* arm-nbsd-tdep.c (ARM_NBSD_JB_ELEMENT_SIZE): Likewise.
* arm-tdep.c (arm_push_dummy_call, arm_extract_return_value)
(arm_return_in_memory, arm_store_return_value)
(arm_get_longjmp_target, arm_register_g_packet_guesses)
(arm_record_ld_st_multiple): Likewise.
* arm-tdep.h (FP_REGISTER_SIZE, VFP_REGISTER_SIZE): Remove.
* arm-wince-tdep.c (ARM_WINCE_JB_ELEMENT_SIZE): Use ARM_ defines.
Both targets define DISPLACED_MODIFIED_INSNS, each with different values.
Add ARM_ and AARCH64_ to the start of the name to prevent confusion.
No functionality changes.
gdb/ChangeLog:
* aarch64-linux-tdep.c (aarch64_linux_init_abi): Use
AARCH64_DISPLACED_MODIFIED_INSNS.
* aarch64-tdep.c (struct aarch64_displaced_step_data)
(aarch64_displaced_step_copy_insn): Likewise.
* aarch64-tdep.h (DISPLACED_MODIFIED_INSNS): Rename from..
(AARCH64_DISPLACED_MODIFIED_INSNS): ...to this.
* arm-linux-tdep.c (arm_linux_cleanup_svc): Use
ARM_DISPLACED_MODIFIED_INSNS.
* arm-tdep.c (arm_gdbarch_init): Likewise.
* arm-tdep.h (DISPLACED_MODIFIED_INSNS): Rename from..
(ARM_DISPLACED_MODIFIED_INSNS): ...to this.
(struct arm_displaced_step_closure): Use
ARM_DISPLACED_MODIFIED_INSNS.
Simon Marchi