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)
160 collect_register_by_name (regcache, "pc", &pc);
162 debug_printf ("stop pc is %08lx\n", pc);
166 /* Implementation of linux_target_ops method "set_pc". */
169 aarch64_set_pc (struct regcache *regcache, CORE_ADDR pc)
171 unsigned long newpc = pc;
172 supply_register_by_name (regcache, "pc", &newpc);
175 #define aarch64_breakpoint_len 4
177 /* AArch64 BRK software debug mode instruction.
178 This instruction needs to match gdb/aarch64-tdep.c
179 (aarch64_default_breakpoint). */
180 static const gdb_byte aarch64_breakpoint[] = {0x00, 0x00, 0x20, 0xd4};
182 /* Implementation of linux_target_ops method "breakpoint_at". */
185 aarch64_breakpoint_at (CORE_ADDR where)
187 gdb_byte insn[aarch64_breakpoint_len];
189 (*the_target->read_memory) (where, (unsigned char *) &insn,
190 aarch64_breakpoint_len);
191 if (memcmp (insn, aarch64_breakpoint, aarch64_breakpoint_len) == 0)
198 aarch64_init_debug_reg_state (struct aarch64_debug_reg_state *state)
202 for (i = 0; i < AARCH64_HBP_MAX_NUM; ++i)
204 state->dr_addr_bp[i] = 0;
205 state->dr_ctrl_bp[i] = 0;
206 state->dr_ref_count_bp[i] = 0;
209 for (i = 0; i < AARCH64_HWP_MAX_NUM; ++i)
211 state->dr_addr_wp[i] = 0;
212 state->dr_ctrl_wp[i] = 0;
213 state->dr_ref_count_wp[i] = 0;
217 struct aarch64_dr_update_callback_param
224 /* Callback function which records the information about the change of
225 one hardware breakpoint/watchpoint setting for the thread ENTRY.
226 The information is passed in via PTR.
227 N.B. The actual updating of hardware debug registers is not
228 carried out until the moment the thread is resumed. */
231 debug_reg_change_callback (struct inferior_list_entry *entry, void *ptr)
233 struct thread_info *thread = (struct thread_info *) entry;
234 struct lwp_info *lwp = get_thread_lwp (thread);
235 struct aarch64_dr_update_callback_param *param_p
236 = (struct aarch64_dr_update_callback_param *) ptr;
237 int pid = param_p->pid;
238 int idx = param_p->idx;
239 int is_watchpoint = param_p->is_watchpoint;
240 struct arch_lwp_info *info = lwp->arch_private;
241 dr_changed_t *dr_changed_ptr;
242 dr_changed_t dr_changed;
246 fprintf (stderr, "debug_reg_change_callback: \n\tOn entry:\n");
247 fprintf (stderr, "\tpid%d, tid: %ld, dr_changed_bp=0x%llx, "
248 "dr_changed_wp=0x%llx\n",
249 pid, lwpid_of (thread), info->dr_changed_bp,
250 info->dr_changed_wp);
253 dr_changed_ptr = is_watchpoint ? &info->dr_changed_wp
254 : &info->dr_changed_bp;
255 dr_changed = *dr_changed_ptr;
257 /* Only update the threads of this process. */
258 if (pid_of (thread) == pid)
261 && (idx <= (is_watchpoint ? aarch64_num_wp_regs
262 : aarch64_num_bp_regs)));
264 /* The following assertion is not right, as there can be changes
265 that have not been made to the hardware debug registers
266 before new changes overwrite the old ones. This can happen,
267 for instance, when the breakpoint/watchpoint hit one of the
268 threads and the user enters continue; then what happens is:
269 1) all breakpoints/watchpoints are removed for all threads;
270 2) a single step is carried out for the thread that was hit;
271 3) all of the points are inserted again for all threads;
272 4) all threads are resumed.
273 The 2nd step will only affect the one thread in which the
274 bp/wp was hit, which means only that one thread is resumed;
275 remember that the actual updating only happen in
276 aarch64_linux_prepare_to_resume, so other threads remain
277 stopped during the removal and insertion of bp/wp. Therefore
278 for those threads, the change of insertion of the bp/wp
279 overwrites that of the earlier removals. (The situation may
280 be different when bp/wp is steppable, or in the non-stop
282 /* gdb_assert (DR_N_HAS_CHANGED (dr_changed, idx) == 0); */
284 /* The actual update is done later just before resuming the lwp,
285 we just mark that one register pair needs updating. */
286 DR_MARK_N_CHANGED (dr_changed, idx);
287 *dr_changed_ptr = dr_changed;
289 /* If the lwp isn't stopped, force it to momentarily pause, so
290 we can update its debug registers. */
292 linux_stop_lwp (lwp);
297 fprintf (stderr, "\tOn exit:\n\tpid%d, tid: %ld, dr_changed_bp=0x%llx, "
298 "dr_changed_wp=0x%llx\n",
299 pid, lwpid_of (thread), info->dr_changed_bp,
300 info->dr_changed_wp);
306 /* Notify each thread that their IDXth breakpoint/watchpoint register
307 pair needs to be updated. The message will be recorded in each
308 thread's arch-specific data area, the actual updating will be done
309 when the thread is resumed. */
312 aarch64_notify_debug_reg_change (const struct aarch64_debug_reg_state *state,
313 int is_watchpoint, unsigned int idx)
315 struct aarch64_dr_update_callback_param param;
317 /* Only update the threads of this process. */
318 param.pid = pid_of (current_thread);
320 param.is_watchpoint = is_watchpoint;
323 find_inferior (&all_threads, debug_reg_change_callback, (void *) ¶m);
327 /* Return the pointer to the debug register state structure in the
328 current process' arch-specific data area. */
330 static struct aarch64_debug_reg_state *
331 aarch64_get_debug_reg_state ()
333 struct process_info *proc;
335 proc = current_process ();
336 return &proc->priv->arch_private->debug_reg_state;
339 /* Implementation of linux_target_ops method "supports_z_point_type". */
342 aarch64_supports_z_point_type (char z_type)
348 case Z_PACKET_WRITE_WP:
349 case Z_PACKET_READ_WP:
350 case Z_PACKET_ACCESS_WP:
357 /* Implementation of linux_target_ops method "insert_point".
359 It actually only records the info of the to-be-inserted bp/wp;
360 the actual insertion will happen when threads are resumed. */
363 aarch64_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
364 int len, struct raw_breakpoint *bp)
367 enum target_hw_bp_type targ_type;
368 struct aarch64_debug_reg_state *state = aarch64_get_debug_reg_state ();
371 fprintf (stderr, "insert_point on entry (addr=0x%08lx, len=%d)\n",
372 (unsigned long) addr, len);
374 /* Determine the type from the raw breakpoint type. */
375 targ_type = raw_bkpt_type_to_target_hw_bp_type (type);
377 if (targ_type != hw_execute)
379 aarch64_handle_watchpoint (targ_type, addr, len, 1 /* is_insert */,
383 aarch64_handle_breakpoint (targ_type, addr, len, 1 /* is_insert */,
387 aarch64_show_debug_reg_state (aarch64_get_debug_reg_state (),
388 "insert_point", addr, len, targ_type);
393 /* Implementation of linux_target_ops method "remove_point".
395 It actually only records the info of the to-be-removed bp/wp,
396 the actual removal will be done when threads are resumed. */
399 aarch64_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
400 int len, struct raw_breakpoint *bp)
403 enum target_hw_bp_type targ_type;
404 struct aarch64_debug_reg_state *state = aarch64_get_debug_reg_state ();
407 fprintf (stderr, "remove_point on entry (addr=0x%08lx, len=%d)\n",
408 (unsigned long) addr, len);
410 /* Determine the type from the raw breakpoint type. */
411 targ_type = raw_bkpt_type_to_target_hw_bp_type (type);
413 /* Set up state pointers. */
414 if (targ_type != hw_execute)
416 aarch64_handle_watchpoint (targ_type, addr, len, 0 /* is_insert */,
420 aarch64_handle_breakpoint (targ_type, addr, len, 0 /* is_insert */,
424 aarch64_show_debug_reg_state (aarch64_get_debug_reg_state (),
425 "remove_point", addr, len, targ_type);
430 /* Implementation of linux_target_ops method "stopped_data_address". */
433 aarch64_stopped_data_address (void)
437 struct aarch64_debug_reg_state *state;
439 pid = lwpid_of (current_thread);
441 /* Get the siginfo. */
442 if (ptrace (PTRACE_GETSIGINFO, pid, NULL, &siginfo) != 0)
443 return (CORE_ADDR) 0;
445 /* Need to be a hardware breakpoint/watchpoint trap. */
446 if (siginfo.si_signo != SIGTRAP
447 || (siginfo.si_code & 0xffff) != 0x0004 /* TRAP_HWBKPT */)
448 return (CORE_ADDR) 0;
450 /* Check if the address matches any watched address. */
451 state = aarch64_get_debug_reg_state ();
452 for (i = aarch64_num_wp_regs - 1; i >= 0; --i)
454 const unsigned int len = aarch64_watchpoint_length (state->dr_ctrl_wp[i]);
455 const CORE_ADDR addr_trap = (CORE_ADDR) siginfo.si_addr;
456 const CORE_ADDR addr_watch = state->dr_addr_wp[i];
457 if (state->dr_ref_count_wp[i]
458 && DR_CONTROL_ENABLED (state->dr_ctrl_wp[i])
459 && addr_trap >= addr_watch
460 && addr_trap < addr_watch + len)
464 return (CORE_ADDR) 0;
467 /* Implementation of linux_target_ops method "stopped_by_watchpoint". */
470 aarch64_stopped_by_watchpoint (void)
472 if (aarch64_stopped_data_address () != 0)
478 /* Fetch the thread-local storage pointer for libthread_db. */
481 ps_get_thread_area (const struct ps_prochandle *ph,
482 lwpid_t lwpid, int idx, void **base)
487 iovec.iov_base = ®
488 iovec.iov_len = sizeof (reg);
490 if (ptrace (PTRACE_GETREGSET, lwpid, NT_ARM_TLS, &iovec) != 0)
493 /* IDX is the bias from the thread pointer to the beginning of the
494 thread descriptor. It has to be subtracted due to implementation
495 quirks in libthread_db. */
496 *base = (void *) (reg - idx);
501 /* Implementation of linux_target_ops method "linux_new_process". */
503 static struct arch_process_info *
504 aarch64_linux_new_process (void)
506 struct arch_process_info *info = xcalloc (1, sizeof (*info));
508 aarch64_init_debug_reg_state (&info->debug_reg_state);
513 /* Implementation of linux_target_ops method "linux_new_thread". */
516 aarch64_linux_new_thread (struct lwp_info *lwp)
518 struct arch_lwp_info *info = xcalloc (1, sizeof (*info));
520 /* Mark that all the hardware breakpoint/watchpoint register pairs
521 for this thread need to be initialized (with data from
522 aarch_process_info.debug_reg_state). */
523 DR_MARK_ALL_CHANGED (info->dr_changed_bp, aarch64_num_bp_regs);
524 DR_MARK_ALL_CHANGED (info->dr_changed_wp, aarch64_num_wp_regs);
526 lwp->arch_private = info;
529 /* Implementation of linux_target_ops method "linux_new_fork". */
532 aarch64_linux_new_fork (struct process_info *parent,
533 struct process_info *child)
535 /* These are allocated by linux_add_process. */
536 gdb_assert (parent->priv != NULL
537 && parent->priv->arch_private != NULL);
538 gdb_assert (child->priv != NULL
539 && child->priv->arch_private != NULL);
541 /* Linux kernel before 2.6.33 commit
542 72f674d203cd230426437cdcf7dd6f681dad8b0d
543 will inherit hardware debug registers from parent
544 on fork/vfork/clone. Newer Linux kernels create such tasks with
545 zeroed debug registers.
547 GDB core assumes the child inherits the watchpoints/hw
548 breakpoints of the parent, and will remove them all from the
549 forked off process. Copy the debug registers mirrors into the
550 new process so that all breakpoints and watchpoints can be
551 removed together. The debug registers mirror will become zeroed
552 in the end before detaching the forked off process, thus making
553 this compatible with older Linux kernels too. */
555 *child->priv->arch_private = *parent->priv->arch_private;
558 /* Implementation of linux_target_ops method "linux_prepare_to_resume".
560 If the debug regs have changed, update the thread's copies. */
563 aarch64_linux_prepare_to_resume (struct lwp_info *lwp)
565 struct thread_info *thread = get_lwp_thread (lwp);
566 ptid_t ptid = ptid_of (thread);
567 struct arch_lwp_info *info = lwp->arch_private;
569 if (DR_HAS_CHANGED (info->dr_changed_bp)
570 || DR_HAS_CHANGED (info->dr_changed_wp))
572 int tid = ptid_get_lwp (ptid);
573 struct process_info *proc = find_process_pid (ptid_get_pid (ptid));
574 struct aarch64_debug_reg_state *state
575 = &proc->priv->arch_private->debug_reg_state;
578 fprintf (stderr, "prepare_to_resume thread %ld\n", lwpid_of (thread));
581 if (DR_HAS_CHANGED (info->dr_changed_wp))
583 aarch64_linux_set_debug_regs (state, tid, 1);
584 DR_CLEAR_CHANGED (info->dr_changed_wp);
588 if (DR_HAS_CHANGED (info->dr_changed_bp))
590 aarch64_linux_set_debug_regs (state, tid, 0);
591 DR_CLEAR_CHANGED (info->dr_changed_bp);
596 /* Return the right target description according to the ELF file of
599 static const struct target_desc *
600 aarch64_linux_read_description (void)
602 unsigned int machine;
606 tid = lwpid_of (current_thread);
608 is_elf64 = linux_pid_exe_is_elf_64_file (tid, &machine);
611 return tdesc_aarch64;
613 return tdesc_arm_with_neon;
616 /* Implementation of linux_target_ops method "arch_setup". */
619 aarch64_arch_setup (void)
621 current_process ()->tdesc = aarch64_linux_read_description ();
623 aarch64_linux_get_debug_reg_capacity (lwpid_of (current_thread));
626 static struct regset_info aarch64_regsets[] =
628 { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PRSTATUS,
629 sizeof (struct user_pt_regs), GENERAL_REGS,
630 aarch64_fill_gregset, aarch64_store_gregset },
631 { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_FPREGSET,
632 sizeof (struct user_fpsimd_state), FP_REGS,
633 aarch64_fill_fpregset, aarch64_store_fpregset
635 { 0, 0, 0, -1, -1, NULL, NULL }
638 static struct regsets_info aarch64_regsets_info =
640 aarch64_regsets, /* regsets */
642 NULL, /* disabled_regsets */
645 static struct regs_info regs_info_aarch64 =
647 NULL, /* regset_bitmap */
649 &aarch64_regsets_info,
652 /* Implementation of linux_target_ops method "regs_info". */
654 static const struct regs_info *
655 aarch64_regs_info (void)
657 if (is_64bit_tdesc ())
658 return ®s_info_aarch64;
660 return ®s_info_aarch32;
663 /* Implementation of linux_target_ops method "supports_tracepoints". */
666 aarch64_supports_tracepoints (void)
671 /* Implementation of linux_target_ops method "supports_range_stepping". */
674 aarch64_supports_range_stepping (void)
679 struct linux_target_ops the_low_target =
683 aarch64_cannot_fetch_register,
684 aarch64_cannot_store_register,
685 NULL, /* fetch_register */
688 (const unsigned char *) &aarch64_breakpoint,
689 aarch64_breakpoint_len,
690 NULL, /* breakpoint_reinsert_addr */
691 0, /* decr_pc_after_break */
692 aarch64_breakpoint_at,
693 aarch64_supports_z_point_type,
694 aarch64_insert_point,
695 aarch64_remove_point,
696 aarch64_stopped_by_watchpoint,
697 aarch64_stopped_data_address,
698 NULL, /* collect_ptrace_register */
699 NULL, /* supply_ptrace_register */
700 NULL, /* siginfo_fixup */
701 aarch64_linux_new_process,
702 aarch64_linux_new_thread,
703 aarch64_linux_new_fork,
704 aarch64_linux_prepare_to_resume,
705 NULL, /* process_qsupported */
706 aarch64_supports_tracepoints,
707 NULL, /* get_thread_area */
708 NULL, /* install_fast_tracepoint_jump_pad */
710 NULL, /* get_min_fast_tracepoint_insn_len */
711 aarch64_supports_range_stepping,
715 initialize_low_arch (void)
717 init_registers_aarch64 ();
719 initialize_low_arch_aarch32 ();
721 initialize_regsets_info (&aarch64_regsets_info);