1 /* Native-dependent code for GNU/Linux on MIPS processors.
3 Copyright (C) 2001-2018 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "mips-tdep.h"
27 #include "linux-nat-trad.h"
28 #include "mips-linux-tdep.h"
29 #include "target-descriptions.h"
31 #include "gdb_proc_service.h"
35 #include "nat/gdb_ptrace.h"
36 #include <asm/ptrace.h>
37 #include "inf-ptrace.h"
39 #include "nat/mips-linux-watch.h"
41 #ifndef PTRACE_GET_THREAD_AREA
42 #define PTRACE_GET_THREAD_AREA 25
45 class mips_linux_nat_target final : public linux_nat_trad_target
48 /* Add our register access methods. */
49 void fetch_registers (struct regcache *, int) override;
50 void store_registers (struct regcache *, int) override;
52 void close () override;
54 int can_use_hw_breakpoint (enum bptype, int, int) override;
56 int remove_watchpoint (CORE_ADDR, int, enum target_hw_bp_type,
57 struct expression *) override;
59 int insert_watchpoint (CORE_ADDR, int, enum target_hw_bp_type,
60 struct expression *) override;
62 bool stopped_by_watchpoint () override;
64 bool stopped_data_address (CORE_ADDR *) override;
66 int region_ok_for_hw_watchpoint (CORE_ADDR, int) override;
68 const struct target_desc *read_description () override;
71 /* Override linux_nat_trad_target methods. */
72 CORE_ADDR register_u_offset (struct gdbarch *gdbarch,
73 int regno, int store_p) override;
75 /* Override linux_nat_target low methods. */
76 void low_new_thread (struct lwp_info *lp) override;
79 /* Helpers. See definitions. */
80 void mips64_regsets_store_registers (struct regcache *regcache,
82 void mips64_regsets_fetch_registers (struct regcache *regcache,
86 static mips_linux_nat_target the_mips_linux_nat_target;
88 /* Assume that we have PTRACE_GETREGS et al. support. If we do not,
89 we'll clear this and use PTRACE_PEEKUSER instead. */
90 static int have_ptrace_regsets = 1;
92 /* Map gdb internal register number to ptrace ``address''.
93 These ``addresses'' are normally defined in <asm/ptrace.h>.
95 ptrace does not provide a way to read (or set) MIPS_PS_REGNUM,
96 and there's no point in reading or setting MIPS_ZERO_REGNUM.
97 We also can not set BADVADDR, CAUSE, or FCRIR via ptrace(). */
100 mips_linux_register_addr (struct gdbarch *gdbarch, int regno, int store)
104 if (regno < 0 || regno >= gdbarch_num_regs (gdbarch))
105 error (_("Bogon register number %d."), regno);
107 if (regno > MIPS_ZERO_REGNUM && regno < MIPS_ZERO_REGNUM + 32)
109 else if ((regno >= mips_regnum (gdbarch)->fp0)
110 && (regno < mips_regnum (gdbarch)->fp0 + 32))
111 regaddr = FPR_BASE + (regno - mips_regnum (gdbarch)->fp0);
112 else if (regno == mips_regnum (gdbarch)->pc)
114 else if (regno == mips_regnum (gdbarch)->cause)
115 regaddr = store? (CORE_ADDR) -1 : CAUSE;
116 else if (regno == mips_regnum (gdbarch)->badvaddr)
117 regaddr = store? (CORE_ADDR) -1 : BADVADDR;
118 else if (regno == mips_regnum (gdbarch)->lo)
120 else if (regno == mips_regnum (gdbarch)->hi)
122 else if (regno == mips_regnum (gdbarch)->fp_control_status)
124 else if (regno == mips_regnum (gdbarch)->fp_implementation_revision)
125 regaddr = store? (CORE_ADDR) -1 : FPC_EIR;
126 else if (mips_regnum (gdbarch)->dspacc != -1
127 && regno >= mips_regnum (gdbarch)->dspacc
128 && regno < mips_regnum (gdbarch)->dspacc + 6)
129 regaddr = DSP_BASE + (regno - mips_regnum (gdbarch)->dspacc);
130 else if (regno == mips_regnum (gdbarch)->dspctl)
131 regaddr = DSP_CONTROL;
132 else if (mips_linux_restart_reg_p (gdbarch) && regno == MIPS_RESTART_REGNUM)
135 regaddr = (CORE_ADDR) -1;
141 mips64_linux_register_addr (struct gdbarch *gdbarch, int regno, int store)
145 if (regno < 0 || regno >= gdbarch_num_regs (gdbarch))
146 error (_("Bogon register number %d."), regno);
148 /* On n32 we can't access 64-bit registers via PTRACE_PEEKUSR
149 or PTRACE_POKEUSR. */
150 if (register_size (gdbarch, regno) > sizeof (PTRACE_TYPE_RET))
151 return (CORE_ADDR) -1;
153 if (regno > MIPS_ZERO_REGNUM && regno < MIPS_ZERO_REGNUM + 32)
155 else if ((regno >= mips_regnum (gdbarch)->fp0)
156 && (regno < mips_regnum (gdbarch)->fp0 + 32))
157 regaddr = MIPS64_FPR_BASE + (regno - gdbarch_fp0_regnum (gdbarch));
158 else if (regno == mips_regnum (gdbarch)->pc)
160 else if (regno == mips_regnum (gdbarch)->cause)
161 regaddr = store? (CORE_ADDR) -1 : MIPS64_CAUSE;
162 else if (regno == mips_regnum (gdbarch)->badvaddr)
163 regaddr = store? (CORE_ADDR) -1 : MIPS64_BADVADDR;
164 else if (regno == mips_regnum (gdbarch)->lo)
165 regaddr = MIPS64_MMLO;
166 else if (regno == mips_regnum (gdbarch)->hi)
167 regaddr = MIPS64_MMHI;
168 else if (regno == mips_regnum (gdbarch)->fp_control_status)
169 regaddr = MIPS64_FPC_CSR;
170 else if (regno == mips_regnum (gdbarch)->fp_implementation_revision)
171 regaddr = store? (CORE_ADDR) -1 : MIPS64_FPC_EIR;
172 else if (mips_regnum (gdbarch)->dspacc != -1
173 && regno >= mips_regnum (gdbarch)->dspacc
174 && regno < mips_regnum (gdbarch)->dspacc + 6)
175 regaddr = DSP_BASE + (regno - mips_regnum (gdbarch)->dspacc);
176 else if (regno == mips_regnum (gdbarch)->dspctl)
177 regaddr = DSP_CONTROL;
178 else if (mips_linux_restart_reg_p (gdbarch) && regno == MIPS_RESTART_REGNUM)
181 regaddr = (CORE_ADDR) -1;
186 /* Fetch the thread-local storage pointer for libthread_db. */
189 ps_get_thread_area (struct ps_prochandle *ph,
190 lwpid_t lwpid, int idx, void **base)
192 if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
195 /* IDX is the bias from the thread pointer to the beginning of the
196 thread descriptor. It has to be subtracted due to implementation
197 quirks in libthread_db. */
198 *base = (void *) ((char *)*base - idx);
203 /* Wrapper functions. These are only used by libthread_db. */
206 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregsetp)
208 if (mips_isa_regsize (regcache->arch ()) == 4)
209 mips_supply_gregset (regcache, (const mips_elf_gregset_t *) gregsetp);
211 mips64_supply_gregset (regcache, (const mips64_elf_gregset_t *) gregsetp);
215 fill_gregset (const struct regcache *regcache,
216 gdb_gregset_t *gregsetp, int regno)
218 if (mips_isa_regsize (regcache->arch ()) == 4)
219 mips_fill_gregset (regcache, (mips_elf_gregset_t *) gregsetp, regno);
221 mips64_fill_gregset (regcache, (mips64_elf_gregset_t *) gregsetp, regno);
225 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregsetp)
227 if (mips_isa_regsize (regcache->arch ()) == 4)
228 mips_supply_fpregset (regcache, (const mips_elf_fpregset_t *) fpregsetp);
230 mips64_supply_fpregset (regcache,
231 (const mips64_elf_fpregset_t *) fpregsetp);
235 fill_fpregset (const struct regcache *regcache,
236 gdb_fpregset_t *fpregsetp, int regno)
238 if (mips_isa_regsize (regcache->arch ()) == 4)
239 mips_fill_fpregset (regcache, (mips_elf_fpregset_t *) fpregsetp, regno);
241 mips64_fill_fpregset (regcache,
242 (mips64_elf_fpregset_t *) fpregsetp, regno);
246 /* Fetch REGNO (or all registers if REGNO == -1) from the target
247 using PTRACE_GETREGS et al. */
250 mips_linux_nat_target::mips64_regsets_fetch_registers
251 (struct regcache *regcache, int regno)
253 struct gdbarch *gdbarch = regcache->arch ();
259 if (regno >= mips_regnum (gdbarch)->fp0
260 && regno <= mips_regnum (gdbarch)->fp0 + 32)
262 else if (regno == mips_regnum (gdbarch)->fp_control_status)
264 else if (regno == mips_regnum (gdbarch)->fp_implementation_revision)
269 /* DSP registers are optional and not a part of any set. */
270 have_dsp = mips_regnum (gdbarch)->dspctl != -1;
273 else if (regno >= mips_regnum (gdbarch)->dspacc
274 && regno < mips_regnum (gdbarch)->dspacc + 6)
276 else if (regno == mips_regnum (gdbarch)->dspctl)
281 tid = get_ptrace_pid (regcache_get_ptid (regcache));
283 if (regno == -1 || (!is_fp && !is_dsp))
285 mips64_elf_gregset_t regs;
287 if (ptrace (PTRACE_GETREGS, tid, 0L, (PTRACE_TYPE_ARG3) ®s) == -1)
291 have_ptrace_regsets = 0;
294 perror_with_name (_("Couldn't get registers"));
297 mips64_supply_gregset (regcache,
298 (const mips64_elf_gregset_t *) ®s);
301 if (regno == -1 || is_fp)
303 mips64_elf_fpregset_t fp_regs;
305 if (ptrace (PTRACE_GETFPREGS, tid, 0L,
306 (PTRACE_TYPE_ARG3) &fp_regs) == -1)
310 have_ptrace_regsets = 0;
313 perror_with_name (_("Couldn't get FP registers"));
316 mips64_supply_fpregset (regcache,
317 (const mips64_elf_fpregset_t *) &fp_regs);
321 linux_nat_trad_target::fetch_registers (regcache, regno);
322 else if (regno == -1 && have_dsp)
324 for (regi = mips_regnum (gdbarch)->dspacc;
325 regi < mips_regnum (gdbarch)->dspacc + 6;
327 linux_nat_trad_target::fetch_registers (regcache, regi);
328 linux_nat_trad_target::fetch_registers (regcache,
329 mips_regnum (gdbarch)->dspctl);
333 /* Store REGNO (or all registers if REGNO == -1) to the target
334 using PTRACE_SETREGS et al. */
337 mips_linux_nat_target::mips64_regsets_store_registers
338 (struct regcache *regcache, int regno)
340 struct gdbarch *gdbarch = regcache->arch ();
346 if (regno >= mips_regnum (gdbarch)->fp0
347 && regno <= mips_regnum (gdbarch)->fp0 + 32)
349 else if (regno == mips_regnum (gdbarch)->fp_control_status)
351 else if (regno == mips_regnum (gdbarch)->fp_implementation_revision)
356 /* DSP registers are optional and not a part of any set. */
357 have_dsp = mips_regnum (gdbarch)->dspctl != -1;
360 else if (regno >= mips_regnum (gdbarch)->dspacc
361 && regno < mips_regnum (gdbarch)->dspacc + 6)
363 else if (regno == mips_regnum (gdbarch)->dspctl)
368 tid = get_ptrace_pid (regcache_get_ptid (regcache));
370 if (regno == -1 || (!is_fp && !is_dsp))
372 mips64_elf_gregset_t regs;
374 if (ptrace (PTRACE_GETREGS, tid, 0L, (PTRACE_TYPE_ARG3) ®s) == -1)
375 perror_with_name (_("Couldn't get registers"));
377 mips64_fill_gregset (regcache, ®s, regno);
379 if (ptrace (PTRACE_SETREGS, tid, 0L, (PTRACE_TYPE_ARG3) ®s) == -1)
380 perror_with_name (_("Couldn't set registers"));
383 if (regno == -1 || is_fp)
385 mips64_elf_fpregset_t fp_regs;
387 if (ptrace (PTRACE_GETFPREGS, tid, 0L,
388 (PTRACE_TYPE_ARG3) &fp_regs) == -1)
389 perror_with_name (_("Couldn't get FP registers"));
391 mips64_fill_fpregset (regcache, &fp_regs, regno);
393 if (ptrace (PTRACE_SETFPREGS, tid, 0L,
394 (PTRACE_TYPE_ARG3) &fp_regs) == -1)
395 perror_with_name (_("Couldn't set FP registers"));
399 linux_nat_trad_target::store_registers (regcache, regno);
400 else if (regno == -1 && have_dsp)
402 for (regi = mips_regnum (gdbarch)->dspacc;
403 regi < mips_regnum (gdbarch)->dspacc + 6;
405 linux_nat_trad_target::store_registers (regcache, regi);
406 linux_nat_trad_target::store_registers (regcache,
407 mips_regnum (gdbarch)->dspctl);
411 /* Fetch REGNO (or all registers if REGNO == -1) from the target
412 using any working method. */
415 mips_linux_nat_target::fetch_registers (struct regcache *regcache, int regnum)
417 /* Unless we already know that PTRACE_GETREGS does not work, try it. */
418 if (have_ptrace_regsets)
419 mips64_regsets_fetch_registers (regcache, regnum);
421 /* If we know, or just found out, that PTRACE_GETREGS does not work, fall
422 back to PTRACE_PEEKUSER. */
423 if (!have_ptrace_regsets)
425 linux_nat_trad_target::fetch_registers (regcache, regnum);
427 /* Fill the inaccessible zero register with zero. */
428 if (regnum == MIPS_ZERO_REGNUM || regnum == -1)
429 regcache->raw_supply_zeroed (MIPS_ZERO_REGNUM);
433 /* Store REGNO (or all registers if REGNO == -1) to the target
434 using any working method. */
437 mips_linux_nat_target::store_registers (struct regcache *regcache, int regnum)
439 /* Unless we already know that PTRACE_GETREGS does not work, try it. */
440 if (have_ptrace_regsets)
441 mips64_regsets_store_registers (regcache, regnum);
443 /* If we know, or just found out, that PTRACE_GETREGS does not work, fall
444 back to PTRACE_PEEKUSER. */
445 if (!have_ptrace_regsets)
446 linux_nat_trad_target::store_registers (regcache, regnum);
449 /* Return the address in the core dump or inferior of register
453 mips_linux_nat_target::register_u_offset (struct gdbarch *gdbarch,
454 int regno, int store_p)
456 if (mips_abi_regsize (gdbarch) == 8)
457 return mips64_linux_register_addr (gdbarch, regno, store_p);
459 return mips_linux_register_addr (gdbarch, regno, store_p);
462 const struct target_desc *
463 mips_linux_nat_target::read_description ()
465 static int have_dsp = -1;
471 tid = ptid_get_lwp (inferior_ptid);
473 tid = ptid_get_pid (inferior_ptid);
476 ptrace (PTRACE_PEEKUSER, tid, DSP_CONTROL, 0);
486 perror_with_name (_("Couldn't check DSP support"));
491 /* Report that target registers are a size we know for sure
492 that we can get from ptrace. */
493 if (_MIPS_SIM == _ABIO32)
494 return have_dsp ? tdesc_mips_dsp_linux : tdesc_mips_linux;
496 return have_dsp ? tdesc_mips64_dsp_linux : tdesc_mips64_linux;
499 /* -1 if the kernel and/or CPU do not support watch registers.
500 1 if watch_readback is valid and we can read style, num_valid
502 0 if we need to read the watch_readback. */
504 static int watch_readback_valid;
506 /* Cached watch register read values. */
508 static struct pt_watch_regs watch_readback;
510 static struct mips_watchpoint *current_watches;
512 /* The current set of watch register values for writing the
515 static struct pt_watch_regs watch_mirror;
518 mips_show_dr (const char *func, CORE_ADDR addr,
519 int len, enum target_hw_bp_type type)
523 puts_unfiltered (func);
525 printf_unfiltered (" (addr=%s, len=%d, type=%s)",
526 paddress (target_gdbarch (), addr), len,
527 type == hw_write ? "data-write"
528 : (type == hw_read ? "data-read"
529 : (type == hw_access ? "data-read/write"
530 : (type == hw_execute ? "instruction-execute"
532 puts_unfiltered (":\n");
534 for (i = 0; i < MAX_DEBUG_REGISTER; i++)
535 printf_unfiltered ("\tDR%d: lo=%s, hi=%s\n", i,
536 paddress (target_gdbarch (),
537 mips_linux_watch_get_watchlo (&watch_mirror,
539 paddress (target_gdbarch (),
540 mips_linux_watch_get_watchhi (&watch_mirror,
544 /* Target to_can_use_hw_breakpoint implementation. Return 1 if we can
545 handle the specified watch type. */
548 mips_linux_nat_target::can_use_hw_breakpoint (enum bptype type,
552 uint32_t wanted_mask, irw_mask;
554 if (!mips_linux_read_watch_registers (ptid_get_lwp (inferior_ptid),
556 &watch_readback_valid, 0))
561 case bp_hardware_watchpoint:
562 wanted_mask = W_MASK;
564 case bp_read_watchpoint:
565 wanted_mask = R_MASK;
567 case bp_access_watchpoint:
568 wanted_mask = R_MASK | W_MASK;
575 i < mips_linux_watch_get_num_valid (&watch_readback) && cnt;
578 irw_mask = mips_linux_watch_get_irw_mask (&watch_readback, i);
579 if ((irw_mask & wanted_mask) == wanted_mask)
582 return (cnt == 0) ? 1 : 0;
585 /* Target to_stopped_by_watchpoint implementation. Return 1 if
586 stopped by watchpoint. The watchhi R and W bits indicate the watch
587 register triggered. */
590 mips_linux_nat_target::stopped_by_watchpoint ()
595 if (!mips_linux_read_watch_registers (ptid_get_lwp (inferior_ptid),
597 &watch_readback_valid, 1))
600 num_valid = mips_linux_watch_get_num_valid (&watch_readback);
602 for (n = 0; n < MAX_DEBUG_REGISTER && n < num_valid; n++)
603 if (mips_linux_watch_get_watchhi (&watch_readback, n) & (R_MASK | W_MASK))
609 /* Target to_stopped_data_address implementation. Set the address
610 where the watch triggered (if known). Return 1 if the address was
614 mips_linux_nat_target::stopped_data_address (CORE_ADDR *paddr)
616 /* On mips we don't know the low order 3 bits of the data address,
617 so we must return false. */
621 /* Target to_region_ok_for_hw_watchpoint implementation. Return 1 if
622 the specified region can be covered by the watch registers. */
625 mips_linux_nat_target::region_ok_for_hw_watchpoint (CORE_ADDR addr, int len)
627 struct pt_watch_regs dummy_regs;
630 if (!mips_linux_read_watch_registers (ptid_get_lwp (inferior_ptid),
632 &watch_readback_valid, 0))
635 dummy_regs = watch_readback;
636 /* Clear them out. */
637 for (i = 0; i < mips_linux_watch_get_num_valid (&dummy_regs); i++)
638 mips_linux_watch_set_watchlo (&dummy_regs, i, 0);
639 return mips_linux_watch_try_one_watch (&dummy_regs, addr, len, 0);
642 /* Write the mirrored watch register values for each thread. */
645 write_watchpoint_regs (void)
652 tid = ptid_get_lwp (lp->ptid);
653 if (ptrace (PTRACE_SET_WATCH_REGS, tid, &watch_mirror, NULL) == -1)
654 perror_with_name (_("Couldn't write debug register"));
659 /* linux_nat_target::low_new_thread implementation. Write the
660 mirrored watch register values for the new thread. */
663 mips_linux_nat_target::low_new_thread (struct lwp_info *lp)
665 long tid = lp->ptid.lwp ();
667 if (!mips_linux_read_watch_registers (tid,
669 &watch_readback_valid, 0))
672 if (ptrace (PTRACE_SET_WATCH_REGS, tid, &watch_mirror, NULL) == -1)
673 perror_with_name (_("Couldn't write debug register"));
676 /* Target to_insert_watchpoint implementation. Try to insert a new
677 watch. Return zero on success. */
680 mips_linux_nat_target::insert_watchpoint (CORE_ADDR addr, int len,
681 enum target_hw_bp_type type,
682 struct expression *cond)
684 struct pt_watch_regs regs;
685 struct mips_watchpoint *new_watch;
686 struct mips_watchpoint **pw;
691 if (!mips_linux_read_watch_registers (ptid_get_lwp (inferior_ptid),
693 &watch_readback_valid, 0))
699 regs = watch_readback;
700 /* Add the current watches. */
701 mips_linux_watch_populate_regs (current_watches, ®s);
703 /* Now try to add the new watch. */
704 if (!mips_linux_watch_try_one_watch (®s, addr, len,
705 mips_linux_watch_type_to_irw (type)))
708 /* It fit. Stick it on the end of the list. */
709 new_watch = XNEW (struct mips_watchpoint);
710 new_watch->addr = addr;
711 new_watch->len = len;
712 new_watch->type = type;
713 new_watch->next = NULL;
715 pw = ¤t_watches;
721 retval = write_watchpoint_regs ();
724 mips_show_dr ("insert_watchpoint", addr, len, type);
729 /* Target to_remove_watchpoint implementation. Try to remove a watch.
730 Return zero on success. */
733 mips_linux_nat_target::remove_watchpoint (CORE_ADDR addr, int len,
734 enum target_hw_bp_type type,
735 struct expression *cond)
740 struct mips_watchpoint **pw;
741 struct mips_watchpoint *w;
743 /* Search for a known watch that matches. Then unlink and free
746 pw = ¤t_watches;
749 if (w->addr == addr && w->len == len && w->type == type)
760 return -1; /* We don't know about it, fail doing nothing. */
762 /* At this point watch_readback is known to be valid because we
763 could not have added the watch without reading it. */
764 gdb_assert (watch_readback_valid == 1);
766 watch_mirror = watch_readback;
767 mips_linux_watch_populate_regs (current_watches, &watch_mirror);
769 retval = write_watchpoint_regs ();
772 mips_show_dr ("remove_watchpoint", addr, len, type);
777 /* Target to_close implementation. Free any watches and call the
778 super implementation. */
781 mips_linux_nat_target::close ()
783 struct mips_watchpoint *w;
784 struct mips_watchpoint *nw;
786 /* Clean out the current_watches list. */
794 current_watches = NULL;
796 linux_nat_trad_target::close ();
800 _initialize_mips_linux_nat (void)
802 add_setshow_boolean_cmd ("show-debug-regs", class_maintenance,
803 &show_debug_regs, _("\
804 Set whether to show variables that mirror the mips debug registers."), _("\
805 Show whether to show variables that mirror the mips debug registers."), _("\
806 Use \"on\" to enable, \"off\" to disable.\n\
807 If enabled, the debug registers values are shown when GDB inserts\n\
808 or removes a hardware breakpoint or watchpoint, and when the inferior\n\
809 triggers a breakpoint or watchpoint."),
812 &maintenance_set_cmdlist,
813 &maintenance_show_cmdlist);
815 linux_target = &the_mips_linux_nat_target;
816 add_inf_child_target (&the_mips_linux_nat_target);