This patch makes thumb2_breakpoint static. When writing this patch,
I find the only reason we keep thumb2_breakpoint extern is that it
is used as an argument passed to arm_gdbserver_get_next_pcs. However,
field arm_thumb2_breakpoint is only used in a null check in
thumb_get_next_pcs_raw, so I wonder why do need to pass thumb2_breakpoint
to arm_gdbserver_get_next_pcs.
thumb2_breakpoint was added by Daniel Jacobowitz in order to support
single-step IT block
https://sourceware.org/ml/gdb-patches/2010-01/msg00624.html the logic
there was if we have 32-bit thumb-2 breakpoint defined, we can safely
single-step IT block, otherwise, we can't. Daniel didn't want to use
16-bit thumb BKPT instruction, because it triggers even on instruction
which should be executed. Secondly, using 16-bit thumb illegal
instruction on top of 32-bit thumb instruction may break the meaning of
original IT blocks, because the other 16-bit can be regarded as an
instruction. See more explanations from Daniel's kernel patch
http://www.spinics.net/lists/arm-kernel/msg80476.html
Let us back to this patch, GDB/GDBserver can safely single step
IT block if thumb2_breakpoint is defined, but the single step logic
doesn't have to know the thumb-2 breakpoint instruction. Only
breakpoint insertion mechanism decides to use which breakpoint
instruction. In the software single step code, instead of pass
thumb2_breakpoint, we can pass a boolean variable
has_thumb2_breakpoint indicate whether the target has thumb-2
breakpoint defined, which is equivalent to the original code.
Regression tested on arm-linux. No regression.
gdb:
2016-01-14 Yao Qi <yao.qi@linaro.org>
* arch/arm-get-next-pcs.c (arm_get_next_pcs_ctor): Change
argument arm_thumb2_breakpoint to has_thumb2_breakpoint.
(thumb_get_next_pcs_raw): Check has_thumb2_breakpoint
instead.
* arch/arm-get-next-pcs.h (struct arm_get_next_pcs)
<arm_thumb2_breakpoint>: Remove.
<has_thumb2_breakpoint>: New field.
(arm_get_next_pcs_ctor): Update declaration.
* arm-linux-tdep.c (arm_linux_software_single_step): Pass
1 to arm_get_next_pcs_ctor.
* arm-tdep.c (arm_software_single_step): Pass 0 to
arm_get_next_pcs_ctor.
gdb/gdbserver:
2016-01-14 Yao Qi <yao.qi@linaro.org>
* linux-aarch32-low.c (thumb2_breakpoint): Make it static.
* linux-aarch32-low.h (thumb2_breakpoint): Remove declaration.
* linux-arm-low.c (arm_gdbserver_get_next_pcs): Pass 1 to
arm_get_next_pcs_ctor.
This patch fixes gcc warning when build ARM GDBserver and AArch64
GDBserver,
AArch64 GDBserver:
gdb/gdbserver/linux-aarch32-low.h:36:29: error: 'thumb2_breakpoint' defined but not used [-Werror=unused-const-variable]
static const unsigned short thumb2_breakpoint[] = { 0xf7f0, 0xa000 };
^
gdb/gdbserver/linux-aarch32-low.h:34:29: error: 'thumb_breakpoint' defined but not used [-Werror=unused-const-variable]
static const unsigned short thumb_breakpoint = 0xde01;
^
gdb/gdbserver/linux-aarch32-low.h:28:28: error: 'arm_breakpoint' defined but not used [-Werror=unused-const-variable]
static const unsigned long arm_breakpoint = arm_eabi_breakpoint;
^
cc1: all warnings being treated as errors
ARM GDBserver:
gdb/gdbserver/linux-aarch32-low.h:34:29: error: 'thumb_breakpoint' defined but not used [-Werror=unused-const-variable]
static const unsigned short thumb_breakpoint = 0xde01;
^~~~~~~~~~~~~~~~
gdb/gdbserver/linux-aarch32-low.h:28:28: error: 'arm_breakpoint' defined but not used [-Werror=unused-const-variable]
static const unsigned long arm_breakpoint = arm_eabi_breakpoint;
^~~~~~~~~~~~~~
by simply moving these macros and variables to
linux-aarch32-low.c and only declare thumb2_breakpoint in
linux-aarch32-low.h, which is not perfect, and reveals some issues
in recent arm GDBserver software single step changes. I'll post
follow-up patches.
gdb/gdbserver:
2016-01-06 Yao Qi <yao.qi@linaro.org>
* linux-aarch32-low.h (arm_abi_breakpoint): Move to
linux-aarch32-low.c.
(arm_eabi_breakpoint, arm_breakpoint): Likewise.
(arm_breakpoint_len, thumb_breakpoint_len): Likewise.
(thumb2_breakpoint, thumb2_breakpoint_len): Likewise.
(thumb2_breakpoint): Declare.
* linux-aarch32-low.c (arm_abi_breakpoint): Moved from
linux-aarch32-low.h.
(arm_eabi_breakpoint, arm_breakpoint): Likewise.
(arm_breakpoint_len, thumb_breakpoint_len): Likewise.
(thumb2_breakpoint, thumb2_breakpoint_len): Likewise.
This patch is to get b37a6290 back again, which was removed by
d9311bfa by mistake.
gdb/gdbserver:
2015-12-21 Yao Qi <yao.qi@linaro.org>
* linux-aarch32-low.h [__aarch64__]: Use arm_abi_breakpoint
arm breakpoint.
This patch teaches GDBServer how to software single step on ARM
linux by sharing code with GDB.
The arm_get_next_pcs function in GDB is now shared with GDBServer. So
that GDBServer can use the function to return the possible addresses of
the next PC.
A proper shared context was also needed so that we could share the code,
this context is described in the arm_get_next_pcs structure.
Testing :
No regressions, tested on ubuntu 14.04 ARMv7 and x86.
With gdbserver-{native,extended} / { -marm -mthumb }
gdb/ChangeLog:
* Makefile.in (ALL_TARGET_OBS): Append arm-get-next-pcs.o,
arm-linux.o.
(ALLDEPFILES): Append arm-get-next-pcs.c, arm-linux.c
(arm-linux.o): New rule.
(arm-get-next-pcs.o): New rule.
* arch/arm-get-next-pcs.c: New file.
* arch/arm-get-next-pcs.h: New file.
* arch/arm-linux.h: New file.
* arch/arm-linux.c: New file.
* arm.c: Include common-regcache.c.
(thumb_advance_itstate): Moved from arm-tdep.c.
(arm_instruction_changes_pc): Likewise.
(thumb_instruction_changes_pc): Likewise.
(thumb2_instruction_changes_pc): Likewise.
(shifted_reg_val): Likewise.
* arm.h (submask): Move macro from arm-tdep.h
(bit): Likewise.
(bits): Likewise.
(sbits): Likewise.
(BranchDest): Likewise.
(thumb_advance_itstate): Moved declaration from arm-tdep.h
(arm_instruction_changes_pc): Likewise.
(thumb_instruction_changes_pc): Likewise.
(thumb2_instruction_changes_pc): Likewise.
(shifted_reg_val): Likewise.
* arm-linux-tdep.c: Include arch/arm.h, arch/arm-get-next-pcs.h
arch/arm-linux.h.
(arm_linux_get_next_pcs_ops): New struct.
(ARM_SIGCONTEXT_R0, ARM_UCONTEXT_SIGCONTEXT,
ARM_OLD_RT_SIGFRAME_SIGINFO, ARM_OLD_RT_SIGFRAME_UCONTEXT,
ARM_NEW_RT_SIGFRAME_UCONTEXT, ARM_NEW_SIGFRAME_MAGIC): Move stack
layout defines to arch/arm-linux.h.
(arm_linux_sigreturn_next_pc_offset): Move to arch/arm-linux.c.
(arm_linux_software_single_step): Adjust for arm_get_next_pcs
implementation.
* arm-tdep.c: Include arch/arm-get-next-pcs.h.
(arm_get_next_pcs_ops): New struct.
(submask): Move macro to arm.h.
(bit): Likewise.
(bits): Likewise.
(sbits): Likewise.
(BranchDest): Likewise.
(thumb_instruction_changes_pc): Move to arm.c
(thumb2_instruction_changes_pc): Likewise.
(arm_instruction_changes_pc): Likewise.
(shifted_reg_val): Likewise.
(thumb_advance_itstate): Likewise.
(thumb_get_next_pc_raw): Move to arm-get-next-pcs.c.
(arm_get_next_pc_raw): Likewise.
(arm_get_next_pc): Likewise.
(thumb_deal_with_atomic_sequence_raw): Likewise.
(arm_deal_with_atomic_sequence_raw): Likewise.
(arm_deal_with_atomic_sequence): Likewise.
(arm_get_next_pcs_read_memory_unsigned_integer): New function.
(arm_get_next_pcs_addr_bits_remove): Likewise.
(arm_get_next_pcs_syscall_next_pc): Likewise.
(arm_get_next_pcs_is_thumb): Likewise.
(arm_software_single_step): Adjust for arm_get_next_pcs
implementation.
* arm-tdep.h: (arm_get_next_pc): Remove declaration.
(arm_get_next_pcs_read_memory_unsigned_integer):
New declaration.
(arm_get_next_pcs_addr_bits_remove): Likewise.
(arm_get_next_pcs_syscall_next_pc): Likewise.
(arm_get_next_pcs_is_thumb): Likewise.
(arm_deal_with_atomic_sequence: Remove declaration.
* common/gdb_vecs.h: Add CORE_ADDR vector definition.
* configure.tgt (aarch64*-*-linux): Add arm-get-next-pcs.o,
arm-linux.o.
(arm*-wince-pe): Add arm-get-next-pcs.o.
(arm*-*-linux*): Add arm-get-next-pcs.o, arm-linux.o,
arm-get-next-pcs.o
(arm*-*-netbsd*,arm*-*-knetbsd*-gnu): Add arm-get-next-pcs.o.
(arm*-*-openbsd*): Likewise.
(arm*-*-symbianelf*): Likewise.
(arm*-*-*): Likewise.
* symtab.h: Move CORE_ADDR vector definition to gdb_vecs.h.
gdb/gdbserver/ChangeLog:
* Makefile.in (SFILES): Append arch/arm-linux.c,
arch/arm-get-next-pcs.c.
(arm-linux.o): New rule.
(arm-get-next-pcs.o): New rule.
* configure.srv (arm*-*-linux*): Add arm-get-next-pcs.o,
arm-linux.o.
* linux-aarch32-low.c (arm_abi_breakpoint): Remove macro. Moved
to linux-aarch32-low.c.
(arm_eabi_breakpoint, arm_breakpoint): Likewise.
(arm_breakpoint_len, thumb_breakpoint): Likewise.
(thumb_breakpoint_len, thumb2_breakpoint): Likewise.
(thumb2_breakpoint_len): Likewise.
(arm_is_thumb_mode): Make non-static.
* linux-aarch32-low.h (arm_abi_breakpoint): New macro. Moved
from linux-aarch32-low.c.
(arm_eabi_breakpoint, arm_breakpoint): Likewise.
(arm_breakpoint_len, thumb_breakpoint): Likewise.
(thumb_breakpoint_len, thumb2_breakpoint): Likewise.
(thumb2_breakpoint_len): Likewise.
(arm_is_thumb_mode): New declaration.
* linux-arm-low.c: Include arch/arm-linux.h
aarch/arm-get-next-pcs.h, sys/syscall.h.
(get_next_pcs_ops): New struct.
(get_next_pcs_addr_bits_remove): New function.
(get_next_pcs_is_thumb): New function.
(get_next_pcs_read_memory_unsigned_integer): Likewise.
(arm_sigreturn_next_pc): Likewise.
(get_next_pcs_syscall_next_pc): Likewise.
(arm_gdbserver_get_next_pcs): Likewise.
(struct linux_target_ops) <arm_gdbserver_get_next_pcs>:
Initialize.
* linux-low.h: Move CORE_ADDR vector definition to gdb_vecs.h.
* server.h: Include gdb_vecs.h.
In commit 6085d6f6, Z0 packet is disabled in aarch64 GDBserver if
the inferior is 32-bit or there may be multiple inferiors, because
Z0 packet isn't supported for arm then. Recently, Z0 packet
is supported in arm target, so we don't have such limitation in
aarch64 GDBserver, that is to say, aarch64 GDBserver can use Z0
packet in multi-arch/multi-inferior debugging when the inferior's
arch is arm.
Part of this patch is to revert 6085d6f6, and the rest of the patch
is to move some breakpoint related arm_* functions into
linux-aarch32-low.c in order to share them between arm and aarch64.
This patch is regression tested on aarch64-linux for debugging both
aarch64 programs and arm programs respectively.
gdb/gdbserver:
2015-12-07 Yao Qi <yao.qi@linaro.org>
* configure.srv: Append arm.o to srv_tgtobj for
aarch64*-*-linux* target.
* linux-aarch32-low.c (arm_abi_breakpoint): New macro. Moved
from linux-arm-low.c.
(arm_eabi_breakpoint, arm_breakpoint): Likewise.
(arm_breakpoint_len, thumb_breakpoint): Likewise.
(thumb_breakpoint_len, thumb2_breakpoint): Likewise.
(thumb2_breakpoint_len): Likewise.
(arm_is_thumb_mode, arm_breakpoint_at): Likewise.
(arm_breakpoint_kinds): Likewise.
(arm_breakpoint_kind_from_pc): Likewise.
(arm_sw_breakpoint_from_kind): Likewise.
(arm_breakpoint_kind_from_current_state): Likewise.
* linux-aarch32-low.h (arm_breakpoint_kind_from_pc): Declare.
(arm_sw_breakpoint_from_kind): Declare.
(arm_breakpoint_kind_from_current_state): Declare.
(arm_breakpoint_at): Declare.
* linux-aarch64-low.c (aarch64_sw_breakpoint_from_kind): Call
arm_sw_breakpoint_from_kind if process is 32-bit.
(aarch64_breakpoint_kind_from_pc): New function.
(aarch64_breakpoint_kind_from_current_state): New function.
(the_low_target): Initialize fields breakpoint_kind_from_pc
and breakpoint_kind_from_current_state.
* linux-arm-low.c (arm_breakpoint_kinds): Move to
linux-aarch32-low.c.
(arm_abi_breakpoint, arm_eabi_breakpoint): Likewise.
(arm_breakpoint, arm_breakpoint_len): Likewise.
(thumb_breakpoint, thumb_breakpoint_len): Likewise.
(thumb2_breakpoint, thumb2_breakpoint_len): Likewise.
(arm_is_thumb_mode): Likewise.
(arm_breakpoint_at): Likewise.
(arm_breakpoint_kind_from_pc): Likewise.
(arm_sw_breakpoint_from_kind): Likewise.
(arm_breakpoint_kind_from_current_state): Likewise.
Revert:
2015-08-04 Yao Qi <yao.qi@linaro.org>
* linux-aarch64-low.c (aarch64_supports_z_point_type): Return
0 for Z_PACKET_SW_BP if it may be used in multi-arch debugging.
* server.c (extended_protocol): Remove "static".
* server.h (extended_protocol): Declare it.
This patch adds a new regs_info regs_info_aarch32 for aarch32, which
can be used by both aarch64 and arm backend.
gdb/gdbserver:
2015-08-04 Yao Qi <yao.qi@linaro.org>
* configure.srv (srv_tgtobj): Add linux-aarch32-low.o.
* linux-aarch32-low.c: New file.
* linux-aarch32-low.h: New file.
* linux-arm-low.c (arm_fill_gregset): Move it to
linux-aarch32-low.c.
(arm_store_gregset): Likewise.
(arm_fill_vfpregset): Call arm_fill_vfpregset_num
(arm_store_vfpregset): Caa arm_store_vfpregset_num.
(arm_arch_setup): Check if PTRACE_GETREGSET works.
(regs_info): Rename to regs_info_arm.
(arm_regs_info): Return regs_info_aarch32 if
have_ptrace_getregset is 1 and target description is
arm_with_neon or arm_with_vfpv3.
(initialize_low_arch): Don't call init_registers_arm_with_neon.
Call initialize_low_arch_aarch32 instead.
Yao Qi