1 /* GNU/Linux/AArch64 specific low level interface, for the remote server for
4 Copyright (C) 2009-2015 Free Software Foundation, Inc.
5 Contributed by ARM Ltd.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "linux-low.h"
24 #include "nat/aarch64-linux-hw-point.h"
25 #include "linux-aarch32-low.h"
26 #include "elf/common.h"
30 #include "nat/gdb_ptrace.h"
31 #include <asm/ptrace.h>
34 #include "gdb_proc_service.h"
36 /* Defined in auto-generated files. */
37 void init_registers_aarch64 (void);
38 extern const struct target_desc *tdesc_aarch64;
44 #define AARCH64_X_REGS_NUM 31
45 #define AARCH64_V_REGS_NUM 32
46 #define AARCH64_X0_REGNO 0
47 #define AARCH64_SP_REGNO 31
48 #define AARCH64_PC_REGNO 32
49 #define AARCH64_CPSR_REGNO 33
50 #define AARCH64_V0_REGNO 34
51 #define AARCH64_FPSR_REGNO (AARCH64_V0_REGNO + AARCH64_V_REGS_NUM)
52 #define AARCH64_FPCR_REGNO (AARCH64_V0_REGNO + AARCH64_V_REGS_NUM + 1)
54 #define AARCH64_NUM_REGS (AARCH64_V0_REGNO + AARCH64_V_REGS_NUM + 2)
56 /* Per-process arch-specific data we want to keep. */
58 struct arch_process_info
60 /* Hardware breakpoint/watchpoint data.
61 The reason for them to be per-process rather than per-thread is
62 due to the lack of information in the gdbserver environment;
63 gdbserver is not told that whether a requested hardware
64 breakpoint/watchpoint is thread specific or not, so it has to set
65 each hw bp/wp for every thread in the current process. The
66 higher level bp/wp management in gdb will resume a thread if a hw
67 bp/wp trap is not expected for it. Since the hw bp/wp setting is
68 same for each thread, it is reasonable for the data to live here.
70 struct aarch64_debug_reg_state debug_reg_state;
73 /* Return true if the size of register 0 is 8 byte. */
78 struct regcache *regcache = get_thread_regcache (current_thread, 0);
80 return register_size (regcache->tdesc, 0) == 8;
83 /* Implementation of linux_target_ops method "cannot_store_register". */
86 aarch64_cannot_store_register (int regno)
88 return regno >= AARCH64_NUM_REGS;
91 /* Implementation of linux_target_ops method "cannot_fetch_register". */
94 aarch64_cannot_fetch_register (int regno)
96 return regno >= AARCH64_NUM_REGS;
100 aarch64_fill_gregset (struct regcache *regcache, void *buf)
102 struct user_pt_regs *regset = buf;
105 for (i = 0; i < AARCH64_X_REGS_NUM; i++)
106 collect_register (regcache, AARCH64_X0_REGNO + i, ®set->regs[i]);
107 collect_register (regcache, AARCH64_SP_REGNO, ®set->sp);
108 collect_register (regcache, AARCH64_PC_REGNO, ®set->pc);
109 collect_register (regcache, AARCH64_CPSR_REGNO, ®set->pstate);
113 aarch64_store_gregset (struct regcache *regcache, const void *buf)
115 const struct user_pt_regs *regset = buf;
118 for (i = 0; i < AARCH64_X_REGS_NUM; i++)
119 supply_register (regcache, AARCH64_X0_REGNO + i, ®set->regs[i]);
120 supply_register (regcache, AARCH64_SP_REGNO, ®set->sp);
121 supply_register (regcache, AARCH64_PC_REGNO, ®set->pc);
122 supply_register (regcache, AARCH64_CPSR_REGNO, ®set->pstate);
126 aarch64_fill_fpregset (struct regcache *regcache, void *buf)
128 struct user_fpsimd_state *regset = buf;
131 for (i = 0; i < AARCH64_V_REGS_NUM; i++)
132 collect_register (regcache, AARCH64_V0_REGNO + i, ®set->vregs[i]);
133 collect_register (regcache, AARCH64_FPSR_REGNO, ®set->fpsr);
134 collect_register (regcache, AARCH64_FPCR_REGNO, ®set->fpcr);
138 aarch64_store_fpregset (struct regcache *regcache, const void *buf)
140 const struct user_fpsimd_state *regset = buf;
143 for (i = 0; i < AARCH64_V_REGS_NUM; i++)
144 supply_register (regcache, AARCH64_V0_REGNO + i, ®set->vregs[i]);
145 supply_register (regcache, AARCH64_FPSR_REGNO, ®set->fpsr);
146 supply_register (regcache, AARCH64_FPCR_REGNO, ®set->fpcr);
149 /* Enable miscellaneous debugging output. The name is historical - it
150 was originally used to debug LinuxThreads support. */
151 extern int debug_threads;
153 /* Implementation of linux_target_ops method "get_pc". */
156 aarch64_get_pc (struct regcache *regcache)
158 if (register_size (regcache->tdesc, 0) == 8)
162 collect_register_by_name (regcache, "pc", &pc);
164 debug_printf ("stop pc is %08lx\n", pc);
171 collect_register_by_name (regcache, "pc", &pc);
173 debug_printf ("stop pc is %04x\n", pc);
178 /* Implementation of linux_target_ops method "set_pc". */
181 aarch64_set_pc (struct regcache *regcache, CORE_ADDR pc)
183 if (register_size (regcache->tdesc, 0) == 8)
185 unsigned long newpc = pc;
186 supply_register_by_name (regcache, "pc", &newpc);
190 unsigned int newpc = pc;
191 supply_register_by_name (regcache, "pc", &newpc);
195 #define aarch64_breakpoint_len 4
197 /* AArch64 BRK software debug mode instruction.
198 This instruction needs to match gdb/aarch64-tdep.c
199 (aarch64_default_breakpoint). */
200 static const gdb_byte aarch64_breakpoint[] = {0x00, 0x00, 0x20, 0xd4};
202 /* Implementation of linux_target_ops method "breakpoint_at". */
205 aarch64_breakpoint_at (CORE_ADDR where)
207 gdb_byte insn[aarch64_breakpoint_len];
209 (*the_target->read_memory) (where, (unsigned char *) &insn,
210 aarch64_breakpoint_len);
211 if (memcmp (insn, aarch64_breakpoint, aarch64_breakpoint_len) == 0)
218 aarch64_init_debug_reg_state (struct aarch64_debug_reg_state *state)
222 for (i = 0; i < AARCH64_HBP_MAX_NUM; ++i)
224 state->dr_addr_bp[i] = 0;
225 state->dr_ctrl_bp[i] = 0;
226 state->dr_ref_count_bp[i] = 0;
229 for (i = 0; i < AARCH64_HWP_MAX_NUM; ++i)
231 state->dr_addr_wp[i] = 0;
232 state->dr_ctrl_wp[i] = 0;
233 state->dr_ref_count_wp[i] = 0;
237 struct aarch64_dr_update_callback_param
243 /* Callback for iterate_over_lwps. Records the
244 information about the change of one hardware breakpoint/watchpoint
245 setting for the thread LWP.
246 The information is passed in via PTR.
247 N.B. The actual updating of hardware debug registers is not
248 carried out until the moment the thread is resumed. */
251 debug_reg_change_callback (struct lwp_info *lwp, void *ptr)
253 struct aarch64_dr_update_callback_param *param_p
254 = (struct aarch64_dr_update_callback_param *) ptr;
255 int pid = ptid_get_pid (ptid_of_lwp (lwp));
256 int idx = param_p->idx;
257 int is_watchpoint = param_p->is_watchpoint;
258 struct arch_lwp_info *info = lwp->arch_private;
259 dr_changed_t *dr_changed_ptr;
260 dr_changed_t dr_changed;
264 debug_printf ("debug_reg_change_callback: \n\tOn entry:\n");
265 debug_printf ("\tpid%d, dr_changed_bp=0x%s, "
266 "dr_changed_wp=0x%s\n", pid,
267 phex (info->dr_changed_bp, 8),
268 phex (info->dr_changed_wp, 8));
271 dr_changed_ptr = is_watchpoint ? &info->dr_changed_wp
272 : &info->dr_changed_bp;
273 dr_changed = *dr_changed_ptr;
276 && (idx <= (is_watchpoint ? aarch64_num_wp_regs
277 : aarch64_num_bp_regs)));
279 /* The actual update is done later just before resuming the lwp,
280 we just mark that one register pair needs updating. */
281 DR_MARK_N_CHANGED (dr_changed, idx);
282 *dr_changed_ptr = dr_changed;
284 /* If the lwp isn't stopped, force it to momentarily pause, so
285 we can update its debug registers. */
287 linux_stop_lwp (lwp);
291 debug_printf ("\tOn exit:\n\tpid%d, dr_changed_bp=0x%s, "
292 "dr_changed_wp=0x%s\n", pid,
293 phex (info->dr_changed_bp, 8),
294 phex (info->dr_changed_wp, 8));
300 /* Notify each thread that their IDXth breakpoint/watchpoint register
301 pair needs to be updated. The message will be recorded in each
302 thread's arch-specific data area, the actual updating will be done
303 when the thread is resumed. */
306 aarch64_notify_debug_reg_change (const struct aarch64_debug_reg_state *state,
307 int is_watchpoint, unsigned int idx)
309 struct aarch64_dr_update_callback_param param;
310 ptid_t pid_ptid = pid_to_ptid (ptid_get_pid (current_lwp_ptid ()));
312 param.is_watchpoint = is_watchpoint;
315 iterate_over_lwps (pid_ptid, debug_reg_change_callback, (void *) ¶m);
319 /* Return the pointer to the debug register state structure in the
320 current process' arch-specific data area. */
322 static struct aarch64_debug_reg_state *
323 aarch64_get_debug_reg_state ()
325 struct process_info *proc;
327 proc = current_process ();
328 return &proc->priv->arch_private->debug_reg_state;
331 /* Implementation of linux_target_ops method "supports_z_point_type". */
334 aarch64_supports_z_point_type (char z_type)
340 if (!extended_protocol && is_64bit_tdesc ())
342 /* Only enable Z0 packet in non-multi-arch debugging. If
343 extended protocol is used, don't enable Z0 packet because
344 GDBserver may attach to 32-bit process. */
349 /* Disable Z0 packet so that GDBserver doesn't have to handle
350 different breakpoint instructions (aarch64, arm, thumb etc)
351 in multi-arch debugging. */
356 case Z_PACKET_WRITE_WP:
357 case Z_PACKET_READ_WP:
358 case Z_PACKET_ACCESS_WP:
365 /* Implementation of linux_target_ops method "insert_point".
367 It actually only records the info of the to-be-inserted bp/wp;
368 the actual insertion will happen when threads are resumed. */
371 aarch64_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
372 int len, struct raw_breakpoint *bp)
375 enum target_hw_bp_type targ_type;
376 struct aarch64_debug_reg_state *state = aarch64_get_debug_reg_state ();
379 fprintf (stderr, "insert_point on entry (addr=0x%08lx, len=%d)\n",
380 (unsigned long) addr, len);
382 /* Determine the type from the raw breakpoint type. */
383 targ_type = raw_bkpt_type_to_target_hw_bp_type (type);
385 if (targ_type != hw_execute)
387 aarch64_handle_watchpoint (targ_type, addr, len, 1 /* is_insert */,
391 aarch64_handle_breakpoint (targ_type, addr, len, 1 /* is_insert */,
395 aarch64_show_debug_reg_state (aarch64_get_debug_reg_state (),
396 "insert_point", addr, len, targ_type);
401 /* Implementation of linux_target_ops method "remove_point".
403 It actually only records the info of the to-be-removed bp/wp,
404 the actual removal will be done when threads are resumed. */
407 aarch64_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
408 int len, struct raw_breakpoint *bp)
411 enum target_hw_bp_type targ_type;
412 struct aarch64_debug_reg_state *state = aarch64_get_debug_reg_state ();
415 fprintf (stderr, "remove_point on entry (addr=0x%08lx, len=%d)\n",
416 (unsigned long) addr, len);
418 /* Determine the type from the raw breakpoint type. */
419 targ_type = raw_bkpt_type_to_target_hw_bp_type (type);
421 /* Set up state pointers. */
422 if (targ_type != hw_execute)
424 aarch64_handle_watchpoint (targ_type, addr, len, 0 /* is_insert */,
428 aarch64_handle_breakpoint (targ_type, addr, len, 0 /* is_insert */,
432 aarch64_show_debug_reg_state (aarch64_get_debug_reg_state (),
433 "remove_point", addr, len, targ_type);
438 /* Implementation of linux_target_ops method "stopped_data_address". */
441 aarch64_stopped_data_address (void)
445 struct aarch64_debug_reg_state *state;
447 pid = lwpid_of (current_thread);
449 /* Get the siginfo. */
450 if (ptrace (PTRACE_GETSIGINFO, pid, NULL, &siginfo) != 0)
451 return (CORE_ADDR) 0;
453 /* Need to be a hardware breakpoint/watchpoint trap. */
454 if (siginfo.si_signo != SIGTRAP
455 || (siginfo.si_code & 0xffff) != 0x0004 /* TRAP_HWBKPT */)
456 return (CORE_ADDR) 0;
458 /* Check if the address matches any watched address. */
459 state = aarch64_get_debug_reg_state ();
460 for (i = aarch64_num_wp_regs - 1; i >= 0; --i)
462 const unsigned int len = aarch64_watchpoint_length (state->dr_ctrl_wp[i]);
463 const CORE_ADDR addr_trap = (CORE_ADDR) siginfo.si_addr;
464 const CORE_ADDR addr_watch = state->dr_addr_wp[i];
465 if (state->dr_ref_count_wp[i]
466 && DR_CONTROL_ENABLED (state->dr_ctrl_wp[i])
467 && addr_trap >= addr_watch
468 && addr_trap < addr_watch + len)
472 return (CORE_ADDR) 0;
475 /* Implementation of linux_target_ops method "stopped_by_watchpoint". */
478 aarch64_stopped_by_watchpoint (void)
480 if (aarch64_stopped_data_address () != 0)
486 /* Fetch the thread-local storage pointer for libthread_db. */
489 ps_get_thread_area (const struct ps_prochandle *ph,
490 lwpid_t lwpid, int idx, void **base)
495 iovec.iov_base = ®
496 iovec.iov_len = sizeof (reg);
498 if (ptrace (PTRACE_GETREGSET, lwpid, NT_ARM_TLS, &iovec) != 0)
501 /* IDX is the bias from the thread pointer to the beginning of the
502 thread descriptor. It has to be subtracted due to implementation
503 quirks in libthread_db. */
504 *base = (void *) (reg - idx);
509 /* Implementation of linux_target_ops method "linux_new_process". */
511 static struct arch_process_info *
512 aarch64_linux_new_process (void)
514 struct arch_process_info *info = xcalloc (1, sizeof (*info));
516 aarch64_init_debug_reg_state (&info->debug_reg_state);
521 /* Implementation of linux_target_ops method "linux_new_thread". */
524 aarch64_linux_new_thread (struct lwp_info *lwp)
526 struct arch_lwp_info *info = xcalloc (1, sizeof (*info));
528 /* Mark that all the hardware breakpoint/watchpoint register pairs
529 for this thread need to be initialized (with data from
530 aarch_process_info.debug_reg_state). */
531 DR_MARK_ALL_CHANGED (info->dr_changed_bp, aarch64_num_bp_regs);
532 DR_MARK_ALL_CHANGED (info->dr_changed_wp, aarch64_num_wp_regs);
534 lwp->arch_private = info;
537 /* Implementation of linux_target_ops method "linux_new_fork". */
540 aarch64_linux_new_fork (struct process_info *parent,
541 struct process_info *child)
543 /* These are allocated by linux_add_process. */
544 gdb_assert (parent->priv != NULL
545 && parent->priv->arch_private != NULL);
546 gdb_assert (child->priv != NULL
547 && child->priv->arch_private != NULL);
549 /* Linux kernel before 2.6.33 commit
550 72f674d203cd230426437cdcf7dd6f681dad8b0d
551 will inherit hardware debug registers from parent
552 on fork/vfork/clone. Newer Linux kernels create such tasks with
553 zeroed debug registers.
555 GDB core assumes the child inherits the watchpoints/hw
556 breakpoints of the parent, and will remove them all from the
557 forked off process. Copy the debug registers mirrors into the
558 new process so that all breakpoints and watchpoints can be
559 removed together. The debug registers mirror will become zeroed
560 in the end before detaching the forked off process, thus making
561 this compatible with older Linux kernels too. */
563 *child->priv->arch_private = *parent->priv->arch_private;
566 /* Implementation of linux_target_ops method "linux_prepare_to_resume".
568 If the debug regs have changed, update the thread's copies. */
571 aarch64_linux_prepare_to_resume (struct lwp_info *lwp)
573 struct thread_info *thread = get_lwp_thread (lwp);
574 ptid_t ptid = ptid_of (thread);
575 struct arch_lwp_info *info = lwp->arch_private;
577 if (DR_HAS_CHANGED (info->dr_changed_bp)
578 || DR_HAS_CHANGED (info->dr_changed_wp))
580 int tid = ptid_get_lwp (ptid);
581 struct process_info *proc = find_process_pid (ptid_get_pid (ptid));
582 struct aarch64_debug_reg_state *state
583 = &proc->priv->arch_private->debug_reg_state;
586 fprintf (stderr, "prepare_to_resume thread %ld\n", lwpid_of (thread));
589 if (DR_HAS_CHANGED (info->dr_changed_wp))
591 aarch64_linux_set_debug_regs (state, tid, 1);
592 DR_CLEAR_CHANGED (info->dr_changed_wp);
596 if (DR_HAS_CHANGED (info->dr_changed_bp))
598 aarch64_linux_set_debug_regs (state, tid, 0);
599 DR_CLEAR_CHANGED (info->dr_changed_bp);
604 /* Return the right target description according to the ELF file of
607 static const struct target_desc *
608 aarch64_linux_read_description (void)
610 unsigned int machine;
614 tid = lwpid_of (current_thread);
616 is_elf64 = linux_pid_exe_is_elf_64_file (tid, &machine);
619 return tdesc_aarch64;
621 return tdesc_arm_with_neon;
624 /* Implementation of linux_target_ops method "arch_setup". */
627 aarch64_arch_setup (void)
629 current_process ()->tdesc = aarch64_linux_read_description ();
631 aarch64_linux_get_debug_reg_capacity (lwpid_of (current_thread));
634 static struct regset_info aarch64_regsets[] =
636 { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PRSTATUS,
637 sizeof (struct user_pt_regs), GENERAL_REGS,
638 aarch64_fill_gregset, aarch64_store_gregset },
639 { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_FPREGSET,
640 sizeof (struct user_fpsimd_state), FP_REGS,
641 aarch64_fill_fpregset, aarch64_store_fpregset
643 { 0, 0, 0, -1, -1, NULL, NULL }
646 static struct regsets_info aarch64_regsets_info =
648 aarch64_regsets, /* regsets */
650 NULL, /* disabled_regsets */
653 static struct regs_info regs_info_aarch64 =
655 NULL, /* regset_bitmap */
657 &aarch64_regsets_info,
660 /* Implementation of linux_target_ops method "regs_info". */
662 static const struct regs_info *
663 aarch64_regs_info (void)
665 if (is_64bit_tdesc ())
666 return ®s_info_aarch64;
668 return ®s_info_aarch32;
671 /* Implementation of linux_target_ops method "supports_tracepoints". */
674 aarch64_supports_tracepoints (void)
676 if (current_thread == NULL)
680 /* We don't support tracepoints on aarch32 now. */
681 return is_64bit_tdesc ();
685 /* Implementation of linux_target_ops method "supports_range_stepping". */
688 aarch64_supports_range_stepping (void)
693 struct linux_target_ops the_low_target =
697 aarch64_cannot_fetch_register,
698 aarch64_cannot_store_register,
699 NULL, /* fetch_register */
702 (const unsigned char *) &aarch64_breakpoint,
703 aarch64_breakpoint_len,
704 NULL, /* breakpoint_reinsert_addr */
705 0, /* decr_pc_after_break */
706 aarch64_breakpoint_at,
707 aarch64_supports_z_point_type,
708 aarch64_insert_point,
709 aarch64_remove_point,
710 aarch64_stopped_by_watchpoint,
711 aarch64_stopped_data_address,
712 NULL, /* collect_ptrace_register */
713 NULL, /* supply_ptrace_register */
714 NULL, /* siginfo_fixup */
715 aarch64_linux_new_process,
716 aarch64_linux_new_thread,
717 aarch64_linux_new_fork,
718 aarch64_linux_prepare_to_resume,
719 NULL, /* process_qsupported */
720 aarch64_supports_tracepoints,
721 NULL, /* get_thread_area */
722 NULL, /* install_fast_tracepoint_jump_pad */
724 NULL, /* get_min_fast_tracepoint_insn_len */
725 aarch64_supports_range_stepping,
729 initialize_low_arch (void)
731 init_registers_aarch64 ();
733 initialize_low_arch_aarch32 ();
735 initialize_regsets_info (&aarch64_regsets_info);