Introduce current_lwp_ptid

This commit introduces a new function, current_lwp_ptid, that
shared Linux code can use to obtain the ptid of the current
lightweight process.

gdb/ChangeLog:

	* nat/linux-nat.h (current_lwp_ptid): New declaration.
	* linux-nat.c (current_lwp_ptid): New function.
	* x86-linux-nat.c: Include nat/linux-nat.h.
	(x86_linux_dr_get_addr): Use current_lwp_ptid.
	(x86_linux_dr_get_control): Likewise.
	(x86_linux_dr_get_status): Likewise.
	(x86_linux_dr_set_control): Likewise.
	(x86_linux_dr_set_addr): Likewise.

gdb/gdbserver/ChangeLog:

	* linux-low.c (current_lwp_ptid): New function.
	* linux-x86-low.c: Include nat/linux-nat.h.
	(x86_dr_low_get_addr): Use current_lwp_ptid.
	(x86_dr_low_get_control): Likewise.
	(x86_dr_low_get_status): Likewise.
Add x86_debug_reg_state to gdbserver

This commit introduces a new function, x86_debug_reg_state, that
shared x86 code can use to access the local mirror of a process's
debug registers.  This function already existed in GDB and was
in use by GDB's x86_linux_prepare_to_resume.  An equivalent was
written for gdbserver and gdbserver's x86_linux_prepare_to_resume
was modified to use it.

gdb/ChangeLog:

	* x86-nat.h (x86_debug_reg_state): Move declaration to...
	* nat/x86-dregs.h (x86_debug_reg_state): New declaration.

gdb/gdbserver/ChangeLog:

	* linux-x86-low.c (x86_debug_reg_state): New function.
	(x86_linux_prepare_to_resume): Use the above.
Add iterate_over_lwps to gdbserver

This commit introduces a new function, iterate_over_lwps, that
shared Linux code can use to call a function for each LWP that
matches certain criteria.  This function already existed in GDB
and was in use by GDB's various low-level Linux x86 debug register
setters.  An equivalent was written for gdbserver and gdbserver's
low-level Linux x86 debug register setters were modified to use
it.

gdb/ChangeLog:

	* linux-nat.h: Include nat/linux-nat.h.
	(iterate_over_lwps): Move declaration to nat/linux-nat.h.
	* nat/linux-nat.h (struct lwp_info): New forward declaration.
	(iterate_over_lwps_ftype): New typedef.
	(iterate_over_lwps): New declaration.
	* linux-nat.h (iterate_over_lwps): Update comment.  Use
	iterate_over_lwps_ftype.  Update callback return value check.

gdb/gdbserver/ChangeLog:

	* linux-low.h: Include nat/linux-nat.h.
	* linux-low.c (iterate_over_lwps_args): New structure.
	(iterate_over_lwps_filter): New function.
	(iterate_over_lwps): Likewise.
	* linux-x86-low.c (update_debug_registers_callback):
	Updated signature to what iterate_over_lwps expects.
	Remove PID check that iterate_over_lwps now performs.
	(x86_dr_low_set_addr): Use iterate_over_lwps.
	(x86_dr_low_set_control): Likewise.
Make linux_stop_lwp be a shared function

Both GDB and gdbserver had linux_stop_lwp functions with identical
declarations.  This commit moves these to nat/linux-nat.h to allow
shared code to use the function.

gdb/ChangeLog:

	* linux-nat.h (linux_stop_lwp): Move declaration to...
	* nat/linux-nat.h (linux_stop_lwp): New declaration.

gdb/gdbserver/ChangeLog:

	* linux-low.h (linux_stop_lwp): Remove declaration.
Introduce basic LWP accessors

This commit introduces three accessors that shared Linux code can
use to access fields of struct lwp_info.  The GDB and gdbserver
Linux x86 code is modified to use them.

gdb/ChangeLog:

	* nat/linux-nat.h (ptid_of_lwp): New declaration.
	(lwp_is_stopped): Likewise.
	(lwp_is_stopped_by_watchpoint): Likewise.
	* linux-nat.c (ptid_of_lwp): New function.
	(lwp_is_stopped): Likewise.
	(lwp_is_stopped_by_watchpoint): Likewise.
	* x86-linux-nat.c (update_debug_registers_callback):
	Use lwp_is_stopped.
	(x86_linux_prepare_to_resume): Use ptid_of_lwp and
	lwp_is_stopped_by_watchpoint.

gdb/gdbserver/ChangeLog:

	* linux-low.c (ptid_of_lwp): New function.
	(lwp_is_stopped): Likewise.
	(lwp_is_stopped_by_watchpoint): Likewise.
	* linux-x86-low.c (update_debug_registers_callback):
	Use lwp_is_stopped.
	(x86_linux_prepare_to_resume): Use ptid_of_lwp and
	lwp_is_stopped_by_watchpoint.
Change signature of linux_target_ops.new_thread

This commit changes the signature of linux_target_ops.new_thread in
gdbserver to match that used in GDB's equivalent.

gdb/gdbserver/ChangeLog:

	* linux-low.h (linux_target_ops) <new_thread>: Changed signature.
	* linux-arm-low.c (arm_new_thread): Likewise.
	* linux-aarch64-low.c (aarch64_linux_new_thread): Likewise.
	* linux-mips-low.c (mips_linux_new_thread): Likewise.
	* linux-x86-low.c (x86_linux_new_thread): Likewise.
	* linux-low.c (add_lwp): Update the_low_target.new_thread call.
Make lwp_info.arch_private handling shared

This commit moves the code to handle lwp_info.arch_private for
Linux x86 into a new shared file, nat/x86-linux.c.

gdb/ChangeLog:

	* nat/x86-linux.h: New file.
	* nat/x86-linux.c: Likewise.
	* Makefile.in (HFILES_NO_SRCDIR): Add nat/x86-linux.h.
	(x86-linux.o): New rule.
	* config/i386/linux.mh (NATDEPFILES): Add x86-linux.o.
	* config/i386/linux64.mh (NATDEPFILES): Likewise.
	* nat/linux-nat.h (struct arch_lwp_info): New forward declaration.
	(lwp_set_arch_private_info): New declaration.
	(lwp_arch_private_info): Likewise.
	* linux-nat.c (lwp_set_arch_private_info): New function.
	(lwp_arch_private_info): Likewise.
	* x86-linux-nat.c: Include nat/x86-linux.h.
	(arch_lwp_info): Removed structure.
	(update_debug_registers_callback):
	Use lwp_set_debug_registers_changed.
	(x86_linux_prepare_to_resume): Use lwp_debug_registers_changed
	and lwp_set_debug_registers_changed.
	(x86_linux_new_thread): Use lwp_set_debug_registers_changed.

gdb/gdbserver/ChangeLog:

	* Makefile.in (x86-linux.o): New rule.
	* configure.srv: Add x86-linux.o to relevant targets.
	* linux-low.c (lwp_set_arch_private_info): New function.
	(lwp_arch_private_info): Likewise.
	* linux-x86-low.c: Include nat/x86-linux.h.
	(arch_lwp_info): Removed structure.
	(update_debug_registers_callback):
	Use lwp_set_debug_registers_changed.
	(x86_linux_prepare_to_resume): Use lwp_debug_registers_changed
	and lwp_set_debug_registers_changed.
	(x86_linux_new_thread): Use lwp_set_debug_registers_changed.
Rename gdbserver's low-level Linux x86 debug register accessors

This commit renames gdbserver's low-level Linux x86 debug register
accessors to the same names used by GDB.

gdb/gdbserver/ChangeLog:

	* linux-x86-low.c (x86_dr_low_set_addr): Renamed as...
	(x86_linux_dr_set_addr): New function.
	(x86_dr_low_get_addr): Renamed as...
	(x86_linux_dr_get_addr): New function.
	(x86_dr_low_set_control): Renamed as...
	(x86_linux_dr_set_control): New function.
	(x86_dr_low_get_control): Renamed as...
	(x86_linux_dr_get_control): New function.
	(x86_dr_low_get_status): Renamed as...
	(x86_linux_dr_get_status): New function.
	(x86_dr_low): Updated with new function names.
Linux x86 low-level debug register code synchronization

This commit makes several small changes to the low-level debug
register code for Linux x86, making the code in the GDB and
gdbserver implementations identical.

gdb/ChangeLog:

	* x86-linux-nat.c (x86_linux_dr_set_addr): Updated assertion.
	(x86_linux_new_thread): Renamed argument.

gdb/gdbserver/ChangeLog:

	* linux-x86-low.c (x86_linux_dr_get): Add assertion.
	Use perror_with_name.
	(x86_linux_dr_set): Likewise.
Linux x86 low-level debug register comment synchronization

This commit updates comments in the low-level debug register code for
Linux x86, making GDB's and gdbserver's implementations identical.

gdb/ChangeLog:

	* x86-linux-nat.c (x86_linux_dr_get): Updated comments.
	(x86_linux_dr_set): Likewise.
	(x86_linux_dr_get_addr): Likewise.
	(x86_linux_dr_get_control): Likewise.
	(x86_linux_dr_get_status): Likewise.
	(update_debug_registers_callback): Likewise.
	(x86_linux_dr_set_control): Likewise.
	(x86_linux_dr_set_addr): Likewise.
	(x86_linux_prepare_to_resume): Likewise.
	(x86_linux_new_thread): Likewise.

gdb/gdbserver/ChangeLog:

	* linux-x86-low.c (x86_linux_dr_get): Updated comments.
	(x86_linux_dr_set): Likewise.
	(update_debug_registers_callback): Likewise.
	(x86_linux_dr_set_addr): Likewise.
	(x86_linux_dr_get_addr): Likewise.
	(x86_linux_dr_set_control): Likewise.
	(x86_linux_dr_get_control): Likewise.
	(x86_linux_dr_get_status): Likewise.
	(x86_linux_prepare_to_resume): Likewise.
Introduce x86_linux_update_debug_registers

This commit moves the entire body of both GDB's and gdbserver's
x86_linux_prepare_to_resume functions into new functions,
x86_linux_update_debug_registers.  This reorganisation allows
all Linux x86 low-level debug register code to be placed in one
shared file, separate from general Linux x86 shared code.

gdb/ChangeLog:

	* x86-linux-nat.c (x86_linux_update_debug_registers):
	New function.
	(x86_linux_prepare_to_resume): Call the above.

gdb/gdbserver/ChangeLog:

	* linux-x86-low.c (x86_linux_update_debug_registers):
	New function.
	(x86_linux_prepare_to_resume): Call the above.
Move low-level Linux x86 debug register code to a shared file

This commit moves the now-identical low-level Linux x86 debug register
code from gdb/x86-linux-nat.c and gdb/gdbserver/linux-x86-low.c into a
new shared file gdb/nat/x86-linux-dregs.c.

gdb/ChangeLog:

	* nat/x86-linux-dregs.h: New file.
	* nat/x86-linux-dregs.c: Likewise.
	* Makefile.in (HFILES_NO_SRCDIR): Add nat/x86-linux-dregs.h.
	(x86-linux-dregs.o): New rule.
	* config/i386/linux.mh (NATDEPFILES): Add x86-linux-dregs.o.
	* config/i386/linux64.mh (NATDEPFILES): Likewise.
	* x86-linux-nat.c: Include nat/x86-linux-dregs.h.
	(x86_linux_dr_get): Moved to nat/x86-linux-dregs.c.
	(x86_linux_dr_set): Likewise.
	(x86_linux_dr_get_addr): Likewise.
	(x86_linux_dr_get_control): Likewise.
	(x86_linux_dr_get_status): Likewise.
	(update_debug_registers_callback): Likewise.
	(x86_linux_dr_set_control): Likewise.
	(x86_linux_dr_set_addr): Likewise.
	(x86_linux_update_debug_registers): Likewise.

gdb/gdbserver/ChangeLog:

	* Makefile.in (x86-linux-dregs.o): New rule.
	* configure.srv: Add x86-linux-dregs.o to relevant targets.
	* linux-x86-low.c: Include nat/x86-linux-dregs.h.
	(x86_linux_dr_get): Removed.
	(x86_linux_dr_set): Likewise.
	(update_debug_registers_callback): Likewise.
	(x86_linux_dr_set_addr): Likewise.
	(x86_linux_dr_get_addr): Likewise.
	(x86_linux_dr_set_control): Likewise.
	(x86_linux_dr_get_control): Likewise.
	(x86_linux_dr_get_status): Likewise.
	(x86_linux_update_debug_registers): Likewise.
Move duplicated Linux x86 code to nat/x86-linux.c

This commit moves two identical functions from gdb/x86-linux-nat.c and
gdb/gdbserver/linux-x86-low.c into the shared file gdb/nat/x86-linux.c.

gdb/ChangeLog:

	* nat/x86-linux.h (x86_linux_new_thread): New declaration.
	(x86_linux_prepare_to_resume): Likewise.
	* x86-linux-nat.c (x86_linux_new_thread):
	Moved to nat/x86-linux.c.
	(x86_linux_prepare_to_resume): Likewise.
	* nat/x86-linux.c (x86_linux_new_thread): New function.
	(x86_linux_prepare_to_resume): Likewise.

gdb/gdbserver/ChangeLog:

	* linux-x86-low.c (x86_linux_new_thread): Removed.
	(x86_linux_prepare_to_resume): Likewise.