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Refactor queries for hardware and software single stepping support in GDBServer.

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Before this patch there was only one call: can_hardware_single_step. Its
implementation was a check on breakpoint_reinsert_addr if NULL it assumed
that the target could hardware single step.

This patch prepares for the case where this is not true anymore.

In order to improve software single stepping in GDBServer the
breakpoint_reinsert_addr operation of targets that had a very simple
software implementation used only for stepping over thread creation events
will be removed.

This will create a case where a target does not support hardware single
step and has the operation breakpoint_reinsert_addr set to NULL, thus
can_hardware_single_step needs to be implemented another way.

A new target operation supports_hardware_single_step is introduced and is
to return true if the target does support such a feature, support for the
feature is manually hardcoded.

Note that the hardware single step support was enabled as per the current
behavior, I did not check if tile for example really has ptrace singlestep
support but since the current implementation assumed it had, I kept it
that way.

No regressions on Ubuntu 14.04 on ARMv7 and x86.
With gdbserver-{native,extended} / { -marm -mthumb }

Compilation tested on: aarch64,arm,bfind,crisv32,m32r,ppc,s390,tic6x,tile,
xtensa.
Not tested : sh.

gdb/gdbserver/ChangeLog:

	* linux-aarch64-low.c (aarch64_supports_hardware_single_step):
	New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* linux-arm-low.c (arm_supports_hardware_single_step): New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* linux-bfin-low.c (bfin_supports_hardware_single_step): New function.
	(struct linux_target_ops) <bfin_supports_hardware_single_step>:
	Initialize.
	* linux-crisv32-low.c (cris_supports_hardware_single_step):
	New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* linux-low.c (can_hardware_single_step): Use
	supports_hardware_single_step.
	(can_software_single_step): New function.
	(start_step_over): Call can_software_single_step.
	(linux_supports_hardware_single_step): New function.
	(struct target_ops) <supports_software_single_step>: Initialize.
	* linux-low.h (struct linux_target_ops)
	<supports_hardware_single_step>: Initialize.
	* linux-m32r-low.c (m32r_supports_hardware_single_step): New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* linux-ppc-low.c (ppc_supports_hardware_single_step): New function.
	(struct linux_target_ops) <supports_hardware_single_step> Initialize.
	* linux-s390-low.c (s390_supports_hardware_single_step): New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* linux-sh-low.c (sh_supports_hardware_single_step): New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* linux-tic6x-low.c (tic6x_supports_hardware_single_step): New function.
	(struct linux_target_ops) <tic6x_supports_hardware_single_step>:
	Initialize.
	* linux-tile-low.c (tile_supports_hardware_single_step): New function.
	(struct linux_target_ops) <tile_supports_hardware_single_step>:
	Initialize.
	* linux-x86-low.c (x86_supports_hardware_single_step) New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* linux-xtensa-low.c (xtensa_supports_hardware_single_step):
	New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* target.h (struct target_ops): <supports_software_single_step>:
	New field.
	(target_supports_software_single_step): New macro.
This commit is contained in:
Antoine Tremblay 2015-11-19 11:29:10 -05:00
parent 2d97cd356e
commit 7d00775ece
16 changed files with 355 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
gdb/gdbserver/ChangeLog
View File

@ -1,3 +1,47 @@
2015-11-30 Antoine Tremblay <antoine.tremblay@ericsson.com>
* linux-aarch64-low.c (aarch64_supports_hardware_single_step):
New function.
(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
* linux-arm-low.c (arm_supports_hardware_single_step): New function.
(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
* linux-bfin-low.c (bfin_supports_hardware_single_step): New function.
(struct linux_target_ops) <bfin_supports_hardware_single_step>:
Initialize.
* linux-crisv32-low.c (cris_supports_hardware_single_step):
New function.
(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
* linux-low.c (can_hardware_single_step): Use
supports_hardware_single_step.
(can_software_single_step): New function.
(start_step_over): Call can_software_single_step.
(linux_supports_hardware_single_step): New function.
(struct target_ops) <supports_software_single_step>: Initialize.
* linux-low.h (struct linux_target_ops)
<supports_hardware_single_step>: Initialize.
* linux-m32r-low.c (m32r_supports_hardware_single_step): New function.
(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
* linux-ppc-low.c (ppc_supports_hardware_single_step): New function.
(struct linux_target_ops) <supports_hardware_single_step> Initialize.
* linux-s390-low.c (s390_supports_hardware_single_step): New function.
(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
* linux-sh-low.c (sh_supports_hardware_single_step): New function.
(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
* linux-tic6x-low.c (tic6x_supports_hardware_single_step): New function.
(struct linux_target_ops) <tic6x_supports_hardware_single_step>:
Initialize.
* linux-tile-low.c (tile_supports_hardware_single_step): New function.
(struct linux_target_ops) <tile_supports_hardware_single_step>:
Initialize.
* linux-x86-low.c (x86_supports_hardware_single_step) New function.
(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
* linux-xtensa-low.c (xtensa_supports_hardware_single_step):
New function.
(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
* target.h (struct target_ops): <supports_software_single_step>:
New field.
(target_supports_software_single_step): New macro.
2015-11-30 Antoine Tremblay <antoine.tremblay@ericsson.com>
* linux-low.c (linux_wait_1): Fix pc advance condition.

10
gdb/gdbserver/linux-aarch64-low.c
View File

@ -2944,6 +2944,14 @@ aarch64_sw_breakpoint_from_kind (int kind, int *size)
return aarch64_breakpoint;
}
/* Support for hardware single step. */
static int
aarch64_supports_hardware_single_step (void)
{
return 1;
}
struct linux_target_ops the_low_target =
{
aarch64_arch_setup,
@ -2977,6 +2985,8 @@ struct linux_target_ops the_low_target =
aarch64_emit_ops,
aarch64_get_min_fast_tracepoint_insn_len,
aarch64_supports_range_stepping,
NULL, /* breakpoint_kind_from_current_state */
aarch64_supports_hardware_single_step,
};
void

11
gdb/gdbserver/linux-arm-low.c
View File

@ -902,6 +902,14 @@ arm_arch_setup (void)
have_ptrace_getregset = 0;
}
/* Support for hardware single step. */
static int
arm_supports_hardware_single_step (void)
{
return 0;
}
/* Register sets without using PTRACE_GETREGSET. */
static struct regset_info arm_regsets[] = {
@ -1058,7 +1066,8 @@ struct linux_target_ops the_low_target = {
NULL, /* emit_ops */
NULL, /* get_min_fast_tracepoint_insn_len */
NULL, /* supports_range_stepping */
arm_breakpoint_kind_from_current_state
arm_breakpoint_kind_from_current_state,
arm_supports_hardware_single_step
};
void

29
gdb/gdbserver/linux-bfin-low.c
View File

@ -105,6 +105,14 @@ bfin_arch_setup (void)
current_process ()->tdesc = tdesc_bfin;
}
/* Support for hardware single step. */
static int
bfin_supports_hardware_single_step (void)
{
return 1;
}
static struct usrregs_info bfin_usrregs_info =
{
bfin_num_regs,
@ -136,6 +144,27 @@ struct linux_target_ops the_low_target = {
NULL, /* breakpoint_reinsert_addr */
2,
bfin_breakpoint_at,
NULL, /* supports_z_point_type */
NULL, /* insert_point */
NULL, /* remove_point */
NULL, /* stopped_by_watchpoint */
NULL, /* stopped_data_address */
NULL, /* collect_ptrace_register */
NULL, /* supply_ptrace_register */
NULL, /* siginfo_fixup */
NULL, /* new_process */
NULL, /* new_thread */
NULL, /* new_fork */
NULL, /* prepare_to_resume */
NULL, /* process_qsupported */
NULL, /* supports_tracepoints */
NULL, /* get_thread_area */
NULL, /* install_fast_tracepoint_jump_pad */
NULL, /* emit_ops */
NULL, /* get_min_fast_tracepoint_insn_len */
NULL, /* supports_range_stepping */
NULL, /* breakpoint_kind_from_current_state */
bfin_supports_hardware_single_step,
};

24
gdb/gdbserver/linux-crisv32-low.c
View File

@ -388,6 +388,14 @@ cris_arch_setup (void)
current_process ()->tdesc = tdesc_crisv32;
}
/* Support for hardware single step. */
static int
cris_supports_hardware_single_step (void)
{
return 1;
}
static struct regset_info cris_regsets[] = {
{ PTRACE_GETREGS, PTRACE_SETREGS, 0, cris_num_regs * 4,
GENERAL_REGS, cris_fill_gregset, cris_store_gregset },
@ -439,6 +447,22 @@ struct linux_target_ops the_low_target = {
cris_remove_point,
cris_stopped_by_watchpoint,
cris_stopped_data_address,
NULL, /* collect_ptrace_register */
NULL, /* supply_ptrace_register */
NULL, /* siginfo_fixup */
NULL, /* new_process */
NULL, /* new_thread */
NULL, /* new_fork */
NULL, /* prepare_to_resume */
NULL, /* process_qsupported */
NULL, /* supports_tracepoints */
NULL, /* get_thread_area */
NULL, /* install_fast_tracepoint_jump_pad */
NULL, /* emit_ops */
NULL, /* get_min_fast_tracepoint_insn_len */
NULL, /* supports_range_stepping */
NULL, /* breakpoint_kind_from_current_state */
cris_supports_hardware_single_step,
};
void

33
gdb/gdbserver/linux-low.c
View File

@ -269,13 +269,24 @@ static void complete_ongoing_step_over (void);
being stepped. */
ptid_t step_over_bkpt;
/* True if the low target can hardware single-step. Such targets
don't need a BREAKPOINT_REINSERT_ADDR callback. */
/* True if the low target can hardware single-step. */
static int
can_hardware_single_step (void)
{
return (the_low_target.breakpoint_reinsert_addr == NULL);
if (the_low_target.supports_hardware_single_step != NULL)
return the_low_target.supports_hardware_single_step ();
else
return 0;
}
/* True if the low target can software single-step. Such targets
implement the BREAKPOINT_REINSERT_ADDR callback. */
static int
can_software_single_step (void)
{
return (the_low_target.breakpoint_reinsert_addr != NULL);
}
/* True if the low target supports memory breakpoints. If so, we'll
@ -4509,12 +4520,17 @@ start_step_over (struct lwp_info *lwp)
{
step = 1;
}
else
else if (can_software_single_step ())
{
CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
set_reinsert_breakpoint (raddr);
step = 0;
}
else
{
internal_error (__FILE__, __LINE__,
"stepping is not implemented on this target");
}
current_thread = saved_thread;
@ -5713,6 +5729,12 @@ linux_supports_hardware_single_step (void)
return can_hardware_single_step ();
}
static int
linux_supports_software_single_step (void)
{
return can_software_single_step ();
}
static int
linux_stopped_by_watchpoint (void)
{
@ -7153,7 +7175,8 @@ static struct target_ops linux_target_ops = {
linux_breakpoint_kind_from_pc,
linux_sw_breakpoint_from_kind,
linux_proc_tid_get_name,
linux_breakpoint_kind_from_current_state
linux_breakpoint_kind_from_current_state,
linux_supports_software_single_step
};
static void

3
gdb/gdbserver/linux-low.h
View File

@ -236,6 +236,9 @@ struct linux_target_ops
/* See target.h. */
int (*breakpoint_kind_from_current_state) (CORE_ADDR *pcptr);
/* See target.h. */
int (*supports_hardware_single_step) (void);
};
extern struct linux_target_ops the_low_target;

29
gdb/gdbserver/linux-m32r-low.c
View File

@ -103,6 +103,14 @@ m32r_arch_setup (void)
current_process ()->tdesc = tdesc_m32r;
}
/* Support for hardware single step. */
static int
m32r_supports_hardware_single_step (void)
{
return 1;
}
static struct usrregs_info m32r_usrregs_info =
{
m32r_num_regs,
@ -134,6 +142,27 @@ struct linux_target_ops the_low_target = {
NULL,
0,
m32r_breakpoint_at,
NULL, /* supports_z_point_type */
NULL, /* insert_point */
NULL, /* remove_point */
NULL, /* stopped_by_watchpoint */
NULL, /* stopped_data_address */
NULL, /* collect_ptrace_register */
NULL, /* supply_ptrace_register */
NULL, /* siginfo_fixup */
NULL, /* new_process */
NULL, /* new_thread */
NULL, /* new_fork */
NULL, /* prepare_to_resume */
NULL, /* process_qsupported */
NULL, /* supports_tracepoints */
NULL, /* get_thread_area */
NULL, /* install_fast_tracepoint_jump_pad */
NULL, /* emit_ops */
NULL, /* get_min_fast_tracepoint_insn_len */
NULL, /* supports_range_stepping */
NULL, /* breakpoint_kind_from_current_state */
m32r_supports_hardware_single_step,
};
void

22
gdb/gdbserver/linux-ppc-low.c
View File

@ -547,6 +547,14 @@ ppc_store_evrregset (struct regcache *regcache, const void *buf)
supply_register_by_name (regcache, "spefscr", &regset->spefscr);
}
/* Support for hardware single step. */
static int
ppc_supports_hardware_single_step (void)
{
return 1;
}
static struct regset_info ppc_regsets[] = {
/* List the extra register sets before GENERAL_REGS. That way we will
fetch them every time, but still fall back to PTRACE_PEEKUSER for the
@ -705,6 +713,20 @@ struct linux_target_ops the_low_target = {
NULL,
ppc_collect_ptrace_register,
ppc_supply_ptrace_register,
NULL, /* siginfo_fixup */
NULL, /* new_process */
NULL, /* new_thread */
NULL, /* new_fork */
NULL, /* prepare_to_resume */
NULL, /* process_qsupported */
NULL, /* supports_tracepoints */
NULL, /* get_thread_area */
NULL, /* install_fast_tracepoint_jump_pad */
NULL, /* emit_ops */
NULL, /* get_min_fast_tracepoint_insn_len */
NULL, /* supports_range_stepping */
NULL, /* breakpoint_kind_from_current_state */
ppc_supports_hardware_single_step,
};
void

22
gdb/gdbserver/linux-s390-low.c
View File

@ -609,6 +609,14 @@ s390_breakpoint_at (CORE_ADDR pc)
return memcmp (c, s390_breakpoint, s390_breakpoint_len) == 0;
}
/* Support for hardware single step. */
static int
s390_supports_hardware_single_step (void)
{
return 1;
}
static struct usrregs_info s390_usrregs_info =
{
s390_num_regs,
@ -686,6 +694,20 @@ struct linux_target_ops the_low_target = {
NULL,
s390_collect_ptrace_register,
s390_supply_ptrace_register,
NULL, /* siginfo_fixup */
NULL, /* new_process */
NULL, /* new_thread */
NULL, /* new_fork */
NULL, /* prepare_to_resume */
NULL, /* process_qsupported */
NULL, /* supports_tracepoints */
NULL, /* get_thread_area */
NULL, /* install_fast_tracepoint_jump_pad */
NULL, /* emit_ops */
NULL, /* get_min_fast_tracepoint_insn_len */
NULL, /* supports_range_stepping */
NULL, /* breakpoint_kind_from_current_state */
s390_supports_hardware_single_step,
};
void

29
gdb/gdbserver/linux-sh-low.c
View File

@ -100,6 +100,14 @@ sh_breakpoint_at (CORE_ADDR where)
return 0;
}
/* Support for hardware single step. */
static int
sh_supports_hardware_single_step (void)
{
return 1;
}
/* Provide only a fill function for the general register set. ps_lgetregs
will use this for NPTL support. */
@ -162,6 +170,27 @@ struct linux_target_ops the_low_target = {
NULL,
0,
sh_breakpoint_at,
NULL, /* supports_z_point_type */
NULL, /* insert_point */
NULL, /* remove_point */
NULL, /* stopped_by_watchpoint */
NULL, /* stopped_data_address */
NULL, /* collect_ptrace_register */
NULL, /* supply_ptrace_register */
NULL, /* siginfo_fixup */
NULL, /* new_process */
NULL, /* new_thread */
NULL, /* new_fork */
NULL, /* prepare_to_resume */
NULL, /* process_qsupported */
NULL, /* supports_tracepoints */
NULL, /* get_thread_area */
NULL, /* install_fast_tracepoint_jump_pad */
NULL, /* emit_ops */
NULL, /* get_min_fast_tracepoint_insn_len */
NULL, /* supports_range_stepping */
NULL, /* breakpoint_kind_from_current_state */
sh_supports_hardware_single_step,
};
void

29
gdb/gdbserver/linux-tic6x-low.c
View File

@ -341,6 +341,14 @@ tic6x_arch_setup (void)
current_process ()->tdesc = tic6x_read_description ();
}
/* Support for hardware single step. */
static int
tic6x_supports_hardware_single_step (void)
{
return 1;
}
static struct regsets_info tic6x_regsets_info =
{
tic6x_regsets, /* regsets */
@ -380,6 +388,27 @@ struct linux_target_ops the_low_target = {
NULL,
0,
tic6x_breakpoint_at,
NULL, /* supports_z_point_type */
NULL, /* insert_point */
NULL, /* remove_point */
NULL, /* stopped_by_watchpoint */
NULL, /* stopped_data_address */
NULL, /* collect_ptrace_register */
NULL, /* supply_ptrace_register */
NULL, /* siginfo_fixup */
NULL, /* new_process */
NULL, /* new_thread */
NULL, /* new_fork */
NULL, /* prepare_to_resume */
NULL, /* process_qsupported */
NULL, /* supports_tracepoints */
NULL, /* get_thread_area */
NULL, /* install_fast_tracepoint_jump_pad */
NULL, /* emit_ops */
NULL, /* get_min_fast_tracepoint_insn_len */
NULL, /* supports_range_stepping */
NULL, /* breakpoint_kind_from_current_state */
tic6x_supports_hardware_single_step,
};
void

29
gdb/gdbserver/linux-tile-low.c
View File

@ -181,6 +181,14 @@ tile_arch_setup (void)
current_process ()->tdesc = tdesc_tilegx;
}
/* Support for hardware single step. */
static int
tile_supports_hardware_single_step (void)
{
return 1;
}
struct linux_target_ops the_low_target =
{
@ -196,6 +204,27 @@ struct linux_target_ops the_low_target =
NULL,
0,
tile_breakpoint_at,
NULL, /* supports_z_point_type */
NULL, /* insert_point */
NULL, /* remove_point */
NULL, /* stopped_by_watchpoint */
NULL, /* stopped_data_address */
NULL, /* collect_ptrace_register */
NULL, /* supply_ptrace_register */
NULL, /* siginfo_fixup */
NULL, /* new_process */
NULL, /* new_thread */
NULL, /* new_fork */
NULL, /* prepare_to_resume */
NULL, /* process_qsupported */
NULL, /* supports_tracepoints */
NULL, /* get_thread_area */
NULL, /* install_fast_tracepoint_jump_pad */
NULL, /* emit_ops */
NULL, /* get_min_fast_tracepoint_insn_len */
NULL, /* supports_range_stepping */
NULL, /* breakpoint_kind_from_current_state */
tile_supports_hardware_single_step,
};
void

11
gdb/gdbserver/linux-x86-low.c
View File

@ -3264,6 +3264,15 @@ x86_supports_range_stepping (void)
return 1;
}
/* Implementation of linux_target_ops method "supports_hardware_single_step".
*/
static int
x86_supports_hardware_single_step (void)
{
return 1;
}
/* This is initialized assuming an amd64 target.
x86_arch_setup will correct it for i386 or amd64 targets. */
@ -3304,6 +3313,8 @@ struct linux_target_ops the_low_target =
x86_emit_ops,
x86_get_min_fast_tracepoint_insn_len,
x86_supports_range_stepping,
NULL, /* breakpoint_kind_from_current_state */
x86_supports_hardware_single_step,
};
void

29
gdb/gdbserver/linux-xtensa-low.c
View File

@ -229,6 +229,14 @@ xtensa_arch_setup (void)
current_process ()->tdesc = tdesc_xtensa;
}
/* Support for hardware single step. */
static int
xtensa_supports_hardware_single_step (void)
{
return 1;
}
static const struct regs_info *
xtensa_regs_info (void)
{
@ -248,6 +256,27 @@ struct linux_target_ops the_low_target = {
NULL,
0,
xtensa_breakpoint_at,
NULL, /* supports_z_point_type */
NULL, /* insert_point */
NULL, /* remove_point */
NULL, /* stopped_by_watchpoint */
NULL, /* stopped_data_address */
NULL, /* collect_ptrace_register */
NULL, /* supply_ptrace_register */
NULL, /* siginfo_fixup */
NULL, /* new_process */
NULL, /* new_thread */
NULL, /* new_fork */
NULL, /* prepare_to_resume */
NULL, /* process_qsupported */
NULL, /* supports_tracepoints */
NULL, /* get_thread_area */
NULL, /* install_fast_tracepoint_jump_pad */
NULL, /* emit_ops */
NULL, /* get_min_fast_tracepoint_insn_len */
NULL, /* supports_range_stepping */
NULL, /* breakpoint_kind_from_current_state */
xtensa_supports_hardware_single_step,
};

7
gdb/gdbserver/target.h
View File

@ -463,6 +463,9 @@ struct target_ops
PC. The PCPTR is adjusted to the real memory location in case a flag
(e.g., the Thumb bit on ARM) is present in the PC. */
int (*breakpoint_kind_from_current_state) (CORE_ADDR *pcptr);
/* Returns true if the target can software single step. */
int (*supports_software_single_step) (void);
};
extern struct target_ops *the_target;
@ -655,6 +658,10 @@ int kill_inferior (int);
? (*the_target->breakpoint_kind_from_current_state) (pcptr) \
: target_breakpoint_kind_from_pc (pcptr))
#define target_supports_software_single_step() \
(the_target->supports_software_single_step ? \
(*the_target->supports_software_single_step) () : 0)
/* Start non-stop mode, returns 0 on success, -1 on failure. */
int start_non_stop (int nonstop);