xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/ia64-linux-nat.c (revision c38e7cc395b1472a774ff828e46123de44c628e9)
1 /* Functions specific to running gdb native on IA-64 running
2    GNU/Linux.
3 
4    Copyright (C) 1999-2016 Free Software Foundation, Inc.
5 
6    This file is part of GDB.
7 
8    This program is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 3 of the License, or
11    (at your option) any later version.
12 
13    This program is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17 
18    You should have received a copy of the GNU General Public License
19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
20 
21 #include "defs.h"
22 #include "inferior.h"
23 #include "target.h"
24 #include "gdbcore.h"
25 #include "regcache.h"
26 #include "ia64-tdep.h"
27 #include "linux-nat.h"
28 
29 #include <signal.h>
30 #include "nat/gdb_ptrace.h"
31 #include "gdb_wait.h"
32 #ifdef HAVE_SYS_REG_H
33 #include <sys/reg.h>
34 #endif
35 #include <sys/syscall.h>
36 #include <sys/user.h>
37 
38 #include <asm/ptrace_offsets.h>
39 #include <sys/procfs.h>
40 
41 /* Prototypes for supply_gregset etc.  */
42 #include "gregset.h"
43 
44 /* These must match the order of the register names.
45 
46    Some sort of lookup table is needed because the offsets associated
47    with the registers are all over the board.  */
48 
49 static int u_offsets[] =
50   {
51     /* general registers */
52     -1,		/* gr0 not available; i.e, it's always zero.  */
53     PT_R1,
54     PT_R2,
55     PT_R3,
56     PT_R4,
57     PT_R5,
58     PT_R6,
59     PT_R7,
60     PT_R8,
61     PT_R9,
62     PT_R10,
63     PT_R11,
64     PT_R12,
65     PT_R13,
66     PT_R14,
67     PT_R15,
68     PT_R16,
69     PT_R17,
70     PT_R18,
71     PT_R19,
72     PT_R20,
73     PT_R21,
74     PT_R22,
75     PT_R23,
76     PT_R24,
77     PT_R25,
78     PT_R26,
79     PT_R27,
80     PT_R28,
81     PT_R29,
82     PT_R30,
83     PT_R31,
84     /* gr32 through gr127 not directly available via the ptrace interface.  */
85     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
86     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
87     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
88     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
89     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
90     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
91     /* Floating point registers */
92     -1, -1,	/* f0 and f1 not available (f0 is +0.0 and f1 is +1.0).  */
93     PT_F2,
94     PT_F3,
95     PT_F4,
96     PT_F5,
97     PT_F6,
98     PT_F7,
99     PT_F8,
100     PT_F9,
101     PT_F10,
102     PT_F11,
103     PT_F12,
104     PT_F13,
105     PT_F14,
106     PT_F15,
107     PT_F16,
108     PT_F17,
109     PT_F18,
110     PT_F19,
111     PT_F20,
112     PT_F21,
113     PT_F22,
114     PT_F23,
115     PT_F24,
116     PT_F25,
117     PT_F26,
118     PT_F27,
119     PT_F28,
120     PT_F29,
121     PT_F30,
122     PT_F31,
123     PT_F32,
124     PT_F33,
125     PT_F34,
126     PT_F35,
127     PT_F36,
128     PT_F37,
129     PT_F38,
130     PT_F39,
131     PT_F40,
132     PT_F41,
133     PT_F42,
134     PT_F43,
135     PT_F44,
136     PT_F45,
137     PT_F46,
138     PT_F47,
139     PT_F48,
140     PT_F49,
141     PT_F50,
142     PT_F51,
143     PT_F52,
144     PT_F53,
145     PT_F54,
146     PT_F55,
147     PT_F56,
148     PT_F57,
149     PT_F58,
150     PT_F59,
151     PT_F60,
152     PT_F61,
153     PT_F62,
154     PT_F63,
155     PT_F64,
156     PT_F65,
157     PT_F66,
158     PT_F67,
159     PT_F68,
160     PT_F69,
161     PT_F70,
162     PT_F71,
163     PT_F72,
164     PT_F73,
165     PT_F74,
166     PT_F75,
167     PT_F76,
168     PT_F77,
169     PT_F78,
170     PT_F79,
171     PT_F80,
172     PT_F81,
173     PT_F82,
174     PT_F83,
175     PT_F84,
176     PT_F85,
177     PT_F86,
178     PT_F87,
179     PT_F88,
180     PT_F89,
181     PT_F90,
182     PT_F91,
183     PT_F92,
184     PT_F93,
185     PT_F94,
186     PT_F95,
187     PT_F96,
188     PT_F97,
189     PT_F98,
190     PT_F99,
191     PT_F100,
192     PT_F101,
193     PT_F102,
194     PT_F103,
195     PT_F104,
196     PT_F105,
197     PT_F106,
198     PT_F107,
199     PT_F108,
200     PT_F109,
201     PT_F110,
202     PT_F111,
203     PT_F112,
204     PT_F113,
205     PT_F114,
206     PT_F115,
207     PT_F116,
208     PT_F117,
209     PT_F118,
210     PT_F119,
211     PT_F120,
212     PT_F121,
213     PT_F122,
214     PT_F123,
215     PT_F124,
216     PT_F125,
217     PT_F126,
218     PT_F127,
219     /* Predicate registers - we don't fetch these individually.  */
220     -1, -1, -1, -1, -1, -1, -1, -1,
221     -1, -1, -1, -1, -1, -1, -1, -1,
222     -1, -1, -1, -1, -1, -1, -1, -1,
223     -1, -1, -1, -1, -1, -1, -1, -1,
224     -1, -1, -1, -1, -1, -1, -1, -1,
225     -1, -1, -1, -1, -1, -1, -1, -1,
226     -1, -1, -1, -1, -1, -1, -1, -1,
227     -1, -1, -1, -1, -1, -1, -1, -1,
228     /* branch registers */
229     PT_B0,
230     PT_B1,
231     PT_B2,
232     PT_B3,
233     PT_B4,
234     PT_B5,
235     PT_B6,
236     PT_B7,
237     /* Virtual frame pointer and virtual return address pointer.  */
238     -1, -1,
239     /* other registers */
240     PT_PR,
241     PT_CR_IIP,	/* ip */
242     PT_CR_IPSR, /* psr */
243     PT_CFM,	/* cfm */
244     /* kernel registers not visible via ptrace interface (?)  */
245     -1, -1, -1, -1, -1, -1, -1, -1,
246     /* hole */
247     -1, -1, -1, -1, -1, -1, -1, -1,
248     PT_AR_RSC,
249     PT_AR_BSP,
250     PT_AR_BSPSTORE,
251     PT_AR_RNAT,
252     -1,
253     -1,		/* Not available: FCR, IA32 floating control register.  */
254     -1, -1,
255     -1,		/* Not available: EFLAG */
256     -1,		/* Not available: CSD */
257     -1,		/* Not available: SSD */
258     -1,		/* Not available: CFLG */
259     -1,		/* Not available: FSR */
260     -1,		/* Not available: FIR */
261     -1,		/* Not available: FDR */
262     -1,
263     PT_AR_CCV,
264     -1, -1, -1,
265     PT_AR_UNAT,
266     -1, -1, -1,
267     PT_AR_FPSR,
268     -1, -1, -1,
269     -1,		/* Not available: ITC */
270     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
271     -1, -1, -1, -1, -1, -1, -1, -1, -1,
272     PT_AR_PFS,
273     PT_AR_LC,
274     PT_AR_EC,
275     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
276     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
277     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
278     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
279     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
280     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
281     -1,
282     /* nat bits - not fetched directly; instead we obtain these bits from
283        either rnat or unat or from memory.  */
284     -1, -1, -1, -1, -1, -1, -1, -1,
285     -1, -1, -1, -1, -1, -1, -1, -1,
286     -1, -1, -1, -1, -1, -1, -1, -1,
287     -1, -1, -1, -1, -1, -1, -1, -1,
288     -1, -1, -1, -1, -1, -1, -1, -1,
289     -1, -1, -1, -1, -1, -1, -1, -1,
290     -1, -1, -1, -1, -1, -1, -1, -1,
291     -1, -1, -1, -1, -1, -1, -1, -1,
292     -1, -1, -1, -1, -1, -1, -1, -1,
293     -1, -1, -1, -1, -1, -1, -1, -1,
294     -1, -1, -1, -1, -1, -1, -1, -1,
295     -1, -1, -1, -1, -1, -1, -1, -1,
296     -1, -1, -1, -1, -1, -1, -1, -1,
297     -1, -1, -1, -1, -1, -1, -1, -1,
298     -1, -1, -1, -1, -1, -1, -1, -1,
299     -1, -1, -1, -1, -1, -1, -1, -1,
300   };
301 
302 static CORE_ADDR
303 ia64_register_addr (struct gdbarch *gdbarch, int regno)
304 {
305   CORE_ADDR addr;
306 
307   if (regno < 0 || regno >= gdbarch_num_regs (gdbarch))
308     error (_("Invalid register number %d."), regno);
309 
310   if (u_offsets[regno] == -1)
311     addr = 0;
312   else
313     addr = (CORE_ADDR) u_offsets[regno];
314 
315   return addr;
316 }
317 
318 static int
319 ia64_cannot_fetch_register (struct gdbarch *gdbarch, int regno)
320 {
321   return regno < 0
322 	 || regno >= gdbarch_num_regs (gdbarch)
323 	 || u_offsets[regno] == -1;
324 }
325 
326 static int
327 ia64_cannot_store_register (struct gdbarch *gdbarch, int regno)
328 {
329   /* Rationale behind not permitting stores to bspstore...
330 
331      The IA-64 architecture provides bspstore and bsp which refer
332      memory locations in the RSE's backing store.  bspstore is the
333      next location which will be written when the RSE needs to write
334      to memory.  bsp is the address at which r32 in the current frame
335      would be found if it were written to the backing store.
336 
337      The IA-64 architecture provides read-only access to bsp and
338      read/write access to bspstore (but only when the RSE is in
339      the enforced lazy mode).  It should be noted that stores
340      to bspstore also affect the value of bsp.  Changing bspstore
341      does not affect the number of dirty entries between bspstore
342      and bsp, so changing bspstore by N words will also cause bsp
343      to be changed by (roughly) N as well.  (It could be N-1 or N+1
344      depending upon where the NaT collection bits fall.)
345 
346      OTOH, the Linux kernel provides read/write access to bsp (and
347      currently read/write access to bspstore as well).  But it
348      is definitely the case that if you change one, the other
349      will change at the same time.  It is more useful to gdb to
350      be able to change bsp.  So in order to prevent strange and
351      undesirable things from happening when a dummy stack frame
352      is popped (after calling an inferior function), we allow
353      bspstore to be read, but not written.  (Note that popping
354      a (generic) dummy stack frame causes all registers that
355      were previously read from the inferior process to be written
356      back.)  */
357 
358   return regno < 0
359 	 || regno >= gdbarch_num_regs (gdbarch)
360 	 || u_offsets[regno] == -1
361          || regno == IA64_BSPSTORE_REGNUM;
362 }
363 
364 void
365 supply_gregset (struct regcache *regcache, const gregset_t *gregsetp)
366 {
367   int regi;
368   const greg_t *regp = (const greg_t *) gregsetp;
369 
370   for (regi = IA64_GR0_REGNUM; regi <= IA64_GR31_REGNUM; regi++)
371     {
372       regcache_raw_supply (regcache, regi, regp + (regi - IA64_GR0_REGNUM));
373     }
374 
375   /* FIXME: NAT collection bits are at index 32; gotta deal with these
376      somehow...  */
377 
378   regcache_raw_supply (regcache, IA64_PR_REGNUM, regp + 33);
379 
380   for (regi = IA64_BR0_REGNUM; regi <= IA64_BR7_REGNUM; regi++)
381     {
382       regcache_raw_supply (regcache, regi,
383 			   regp + 34 + (regi - IA64_BR0_REGNUM));
384     }
385 
386   regcache_raw_supply (regcache, IA64_IP_REGNUM, regp + 42);
387   regcache_raw_supply (regcache, IA64_CFM_REGNUM, regp + 43);
388   regcache_raw_supply (regcache, IA64_PSR_REGNUM, regp + 44);
389   regcache_raw_supply (regcache, IA64_RSC_REGNUM, regp + 45);
390   regcache_raw_supply (regcache, IA64_BSP_REGNUM, regp + 46);
391   regcache_raw_supply (regcache, IA64_BSPSTORE_REGNUM, regp + 47);
392   regcache_raw_supply (regcache, IA64_RNAT_REGNUM, regp + 48);
393   regcache_raw_supply (regcache, IA64_CCV_REGNUM, regp + 49);
394   regcache_raw_supply (regcache, IA64_UNAT_REGNUM, regp + 50);
395   regcache_raw_supply (regcache, IA64_FPSR_REGNUM, regp + 51);
396   regcache_raw_supply (regcache, IA64_PFS_REGNUM, regp + 52);
397   regcache_raw_supply (regcache, IA64_LC_REGNUM, regp + 53);
398   regcache_raw_supply (regcache, IA64_EC_REGNUM, regp + 54);
399 }
400 
401 void
402 fill_gregset (const struct regcache *regcache, gregset_t *gregsetp, int regno)
403 {
404   int regi;
405   greg_t *regp = (greg_t *) gregsetp;
406 
407 #define COPY_REG(_idx_,_regi_) \
408   if ((regno == -1) || regno == _regi_) \
409     regcache_raw_collect (regcache, _regi_, regp + _idx_)
410 
411   for (regi = IA64_GR0_REGNUM; regi <= IA64_GR31_REGNUM; regi++)
412     {
413       COPY_REG (regi - IA64_GR0_REGNUM, regi);
414     }
415 
416   /* FIXME: NAT collection bits at index 32?  */
417 
418   COPY_REG (33, IA64_PR_REGNUM);
419 
420   for (regi = IA64_BR0_REGNUM; regi <= IA64_BR7_REGNUM; regi++)
421     {
422       COPY_REG (34 + (regi - IA64_BR0_REGNUM), regi);
423     }
424 
425   COPY_REG (42, IA64_IP_REGNUM);
426   COPY_REG (43, IA64_CFM_REGNUM);
427   COPY_REG (44, IA64_PSR_REGNUM);
428   COPY_REG (45, IA64_RSC_REGNUM);
429   COPY_REG (46, IA64_BSP_REGNUM);
430   COPY_REG (47, IA64_BSPSTORE_REGNUM);
431   COPY_REG (48, IA64_RNAT_REGNUM);
432   COPY_REG (49, IA64_CCV_REGNUM);
433   COPY_REG (50, IA64_UNAT_REGNUM);
434   COPY_REG (51, IA64_FPSR_REGNUM);
435   COPY_REG (52, IA64_PFS_REGNUM);
436   COPY_REG (53, IA64_LC_REGNUM);
437   COPY_REG (54, IA64_EC_REGNUM);
438 }
439 
440 /*  Given a pointer to a floating point register set in /proc format
441    (fpregset_t *), unpack the register contents and supply them as gdb's
442    idea of the current floating point register values.  */
443 
444 void
445 supply_fpregset (struct regcache *regcache, const fpregset_t *fpregsetp)
446 {
447   int regi;
448   const char *from;
449   const gdb_byte f_zero[16] = { 0 };
450   const gdb_byte f_one[16] =
451     { 0, 0, 0, 0, 0, 0, 0, 0x80, 0xff, 0xff, 0, 0, 0, 0, 0, 0 };
452 
453   /* Kernel generated cores have fr1==0 instead of 1.0.  Older GDBs
454      did the same.  So ignore whatever might be recorded in fpregset_t
455      for fr0/fr1 and always supply their expected values.  */
456 
457   /* fr0 is always read as zero.  */
458   regcache_raw_supply (regcache, IA64_FR0_REGNUM, f_zero);
459   /* fr1 is always read as one (1.0).  */
460   regcache_raw_supply (regcache, IA64_FR1_REGNUM, f_one);
461 
462   for (regi = IA64_FR2_REGNUM; regi <= IA64_FR127_REGNUM; regi++)
463     {
464       from = (const char *) &((*fpregsetp)[regi - IA64_FR0_REGNUM]);
465       regcache_raw_supply (regcache, regi, from);
466     }
467 }
468 
469 /*  Given a pointer to a floating point register set in /proc format
470    (fpregset_t *), update the register specified by REGNO from gdb's idea
471    of the current floating point register set.  If REGNO is -1, update
472    them all.  */
473 
474 void
475 fill_fpregset (const struct regcache *regcache,
476 	       fpregset_t *fpregsetp, int regno)
477 {
478   int regi;
479 
480   for (regi = IA64_FR0_REGNUM; regi <= IA64_FR127_REGNUM; regi++)
481     {
482       if ((regno == -1) || (regno == regi))
483 	regcache_raw_collect (regcache, regi,
484 			      &((*fpregsetp)[regi - IA64_FR0_REGNUM]));
485     }
486 }
487 
488 #define IA64_PSR_DB (1UL << 24)
489 #define IA64_PSR_DD (1UL << 39)
490 
491 static void
492 enable_watchpoints_in_psr (ptid_t ptid)
493 {
494   struct regcache *regcache = get_thread_regcache (ptid);
495   ULONGEST psr;
496 
497   regcache_cooked_read_unsigned (regcache, IA64_PSR_REGNUM, &psr);
498   if (!(psr & IA64_PSR_DB))
499     {
500       psr |= IA64_PSR_DB;	/* Set the db bit - this enables hardware
501 			           watchpoints and breakpoints.  */
502       regcache_cooked_write_unsigned (regcache, IA64_PSR_REGNUM, psr);
503     }
504 }
505 
506 static long debug_registers[8];
507 
508 static void
509 store_debug_register (ptid_t ptid, int idx, long val)
510 {
511   int tid;
512 
513   tid = ptid_get_lwp (ptid);
514   if (tid == 0)
515     tid = ptid_get_pid (ptid);
516 
517   (void) ptrace (PT_WRITE_U, tid, (PTRACE_TYPE_ARG3) (PT_DBR + 8 * idx), val);
518 }
519 
520 static void
521 store_debug_register_pair (ptid_t ptid, int idx, long *dbr_addr,
522 			   long *dbr_mask)
523 {
524   if (dbr_addr)
525     store_debug_register (ptid, 2 * idx, *dbr_addr);
526   if (dbr_mask)
527     store_debug_register (ptid, 2 * idx + 1, *dbr_mask);
528 }
529 
530 static int
531 is_power_of_2 (int val)
532 {
533   int i, onecount;
534 
535   onecount = 0;
536   for (i = 0; i < 8 * sizeof (val); i++)
537     if (val & (1 << i))
538       onecount++;
539 
540   return onecount <= 1;
541 }
542 
543 static int
544 ia64_linux_insert_watchpoint (struct target_ops *self,
545 			      CORE_ADDR addr, int len,
546 			      enum target_hw_bp_type type,
547 			      struct expression *cond)
548 {
549   struct lwp_info *lp;
550   int idx;
551   long dbr_addr, dbr_mask;
552   int max_watchpoints = 4;
553 
554   if (len <= 0 || !is_power_of_2 (len))
555     return -1;
556 
557   for (idx = 0; idx < max_watchpoints; idx++)
558     {
559       dbr_mask = debug_registers[idx * 2 + 1];
560       if ((dbr_mask & (0x3UL << 62)) == 0)
561 	{
562 	  /* Exit loop if both r and w bits clear.  */
563 	  break;
564 	}
565     }
566 
567   if (idx == max_watchpoints)
568     return -1;
569 
570   dbr_addr = (long) addr;
571   dbr_mask = (~(len - 1) & 0x00ffffffffffffffL);  /* construct mask to match */
572   dbr_mask |= 0x0800000000000000L;           /* Only match privilege level 3 */
573   switch (type)
574     {
575     case hw_write:
576       dbr_mask |= (1L << 62);			/* Set w bit */
577       break;
578     case hw_read:
579       dbr_mask |= (1L << 63);			/* Set r bit */
580       break;
581     case hw_access:
582       dbr_mask |= (3L << 62);			/* Set both r and w bits */
583       break;
584     default:
585       return -1;
586     }
587 
588   debug_registers[2 * idx] = dbr_addr;
589   debug_registers[2 * idx + 1] = dbr_mask;
590   ALL_LWPS (lp)
591     {
592       store_debug_register_pair (lp->ptid, idx, &dbr_addr, &dbr_mask);
593       enable_watchpoints_in_psr (lp->ptid);
594     }
595 
596   return 0;
597 }
598 
599 static int
600 ia64_linux_remove_watchpoint (struct target_ops *self,
601 			      CORE_ADDR addr, int len,
602 			      enum target_hw_bp_type type,
603 			      struct expression *cond)
604 {
605   int idx;
606   long dbr_addr, dbr_mask;
607   int max_watchpoints = 4;
608 
609   if (len <= 0 || !is_power_of_2 (len))
610     return -1;
611 
612   for (idx = 0; idx < max_watchpoints; idx++)
613     {
614       dbr_addr = debug_registers[2 * idx];
615       dbr_mask = debug_registers[2 * idx + 1];
616       if ((dbr_mask & (0x3UL << 62)) && addr == (CORE_ADDR) dbr_addr)
617 	{
618 	  struct lwp_info *lp;
619 
620 	  debug_registers[2 * idx] = 0;
621 	  debug_registers[2 * idx + 1] = 0;
622 	  dbr_addr = 0;
623 	  dbr_mask = 0;
624 
625 	  ALL_LWPS (lp)
626 	    store_debug_register_pair (lp->ptid, idx, &dbr_addr, &dbr_mask);
627 
628 	  return 0;
629 	}
630     }
631   return -1;
632 }
633 
634 static void
635 ia64_linux_new_thread (struct lwp_info *lp)
636 {
637   int i, any;
638 
639   any = 0;
640   for (i = 0; i < 8; i++)
641     {
642       if (debug_registers[i] != 0)
643 	any = 1;
644       store_debug_register (lp->ptid, i, debug_registers[i]);
645     }
646 
647   if (any)
648     enable_watchpoints_in_psr (lp->ptid);
649 }
650 
651 static int
652 ia64_linux_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
653 {
654   CORE_ADDR psr;
655   siginfo_t siginfo;
656   struct regcache *regcache = get_current_regcache ();
657 
658   if (!linux_nat_get_siginfo (inferior_ptid, &siginfo))
659     return 0;
660 
661   if (siginfo.si_signo != SIGTRAP
662       || (siginfo.si_code & 0xffff) != 0x0004 /* TRAP_HWBKPT */)
663     return 0;
664 
665   regcache_cooked_read_unsigned (regcache, IA64_PSR_REGNUM, &psr);
666   psr |= IA64_PSR_DD;	/* Set the dd bit - this will disable the watchpoint
667                            for the next instruction.  */
668   regcache_cooked_write_unsigned (regcache, IA64_PSR_REGNUM, psr);
669 
670   *addr_p = (CORE_ADDR) siginfo.si_addr;
671   return 1;
672 }
673 
674 static int
675 ia64_linux_stopped_by_watchpoint (struct target_ops *ops)
676 {
677   CORE_ADDR addr;
678   return ia64_linux_stopped_data_address (ops, &addr);
679 }
680 
681 static int
682 ia64_linux_can_use_hw_breakpoint (struct target_ops *self,
683 				  enum bptype type,
684 				  int cnt, int othertype)
685 {
686   return 1;
687 }
688 
689 
690 /* Fetch register REGNUM from the inferior.  */
691 
692 static void
693 ia64_linux_fetch_register (struct regcache *regcache, int regnum)
694 {
695   struct gdbarch *gdbarch = get_regcache_arch (regcache);
696   CORE_ADDR addr;
697   size_t size;
698   PTRACE_TYPE_RET *buf;
699   int pid, i;
700 
701   /* r0 cannot be fetched but is always zero.  */
702   if (regnum == IA64_GR0_REGNUM)
703     {
704       const gdb_byte zero[8] = { 0 };
705 
706       gdb_assert (sizeof (zero) == register_size (gdbarch, regnum));
707       regcache_raw_supply (regcache, regnum, zero);
708       return;
709     }
710 
711   /* fr0 cannot be fetched but is always zero.  */
712   if (regnum == IA64_FR0_REGNUM)
713     {
714       const gdb_byte f_zero[16] = { 0 };
715 
716       gdb_assert (sizeof (f_zero) == register_size (gdbarch, regnum));
717       regcache_raw_supply (regcache, regnum, f_zero);
718       return;
719     }
720 
721   /* fr1 cannot be fetched but is always one (1.0).  */
722   if (regnum == IA64_FR1_REGNUM)
723     {
724       const gdb_byte f_one[16] =
725 	{ 0, 0, 0, 0, 0, 0, 0, 0x80, 0xff, 0xff, 0, 0, 0, 0, 0, 0 };
726 
727       gdb_assert (sizeof (f_one) == register_size (gdbarch, regnum));
728       regcache_raw_supply (regcache, regnum, f_one);
729       return;
730     }
731 
732   if (ia64_cannot_fetch_register (gdbarch, regnum))
733     {
734       regcache_raw_supply (regcache, regnum, NULL);
735       return;
736     }
737 
738   /* Cater for systems like GNU/Linux, that implement threads as
739      separate processes.  */
740   pid = ptid_get_lwp (inferior_ptid);
741   if (pid == 0)
742     pid = ptid_get_pid (inferior_ptid);
743 
744   /* This isn't really an address, but ptrace thinks of it as one.  */
745   addr = ia64_register_addr (gdbarch, regnum);
746   size = register_size (gdbarch, regnum);
747 
748   gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0);
749   buf = (PTRACE_TYPE_RET *) alloca (size);
750 
751   /* Read the register contents from the inferior a chunk at a time.  */
752   for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++)
753     {
754       errno = 0;
755       buf[i] = ptrace (PT_READ_U, pid, (PTRACE_TYPE_ARG3)addr, 0);
756       if (errno != 0)
757 	error (_("Couldn't read register %s (#%d): %s."),
758 	       gdbarch_register_name (gdbarch, regnum),
759 	       regnum, safe_strerror (errno));
760 
761       addr += sizeof (PTRACE_TYPE_RET);
762     }
763   regcache_raw_supply (regcache, regnum, buf);
764 }
765 
766 /* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
767    for all registers.  */
768 
769 static void
770 ia64_linux_fetch_registers (struct target_ops *ops,
771 			    struct regcache *regcache, int regnum)
772 {
773   if (regnum == -1)
774     for (regnum = 0;
775 	 regnum < gdbarch_num_regs (get_regcache_arch (regcache));
776 	 regnum++)
777       ia64_linux_fetch_register (regcache, regnum);
778   else
779     ia64_linux_fetch_register (regcache, regnum);
780 }
781 
782 /* Store register REGNUM into the inferior.  */
783 
784 static void
785 ia64_linux_store_register (const struct regcache *regcache, int regnum)
786 {
787   struct gdbarch *gdbarch = get_regcache_arch (regcache);
788   CORE_ADDR addr;
789   size_t size;
790   PTRACE_TYPE_RET *buf;
791   int pid, i;
792 
793   if (ia64_cannot_store_register (gdbarch, regnum))
794     return;
795 
796   /* Cater for systems like GNU/Linux, that implement threads as
797      separate processes.  */
798   pid = ptid_get_lwp (inferior_ptid);
799   if (pid == 0)
800     pid = ptid_get_pid (inferior_ptid);
801 
802   /* This isn't really an address, but ptrace thinks of it as one.  */
803   addr = ia64_register_addr (gdbarch, regnum);
804   size = register_size (gdbarch, regnum);
805 
806   gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0);
807   buf = (PTRACE_TYPE_RET *) alloca (size);
808 
809   /* Write the register contents into the inferior a chunk at a time.  */
810   regcache_raw_collect (regcache, regnum, buf);
811   for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++)
812     {
813       errno = 0;
814       ptrace (PT_WRITE_U, pid, (PTRACE_TYPE_ARG3)addr, buf[i]);
815       if (errno != 0)
816 	error (_("Couldn't write register %s (#%d): %s."),
817 	       gdbarch_register_name (gdbarch, regnum),
818 	       regnum, safe_strerror (errno));
819 
820       addr += sizeof (PTRACE_TYPE_RET);
821     }
822 }
823 
824 /* Store register REGNUM back into the inferior.  If REGNUM is -1, do
825    this for all registers.  */
826 
827 static void
828 ia64_linux_store_registers (struct target_ops *ops,
829 			    struct regcache *regcache, int regnum)
830 {
831   if (regnum == -1)
832     for (regnum = 0;
833 	 regnum < gdbarch_num_regs (get_regcache_arch (regcache));
834 	 regnum++)
835       ia64_linux_store_register (regcache, regnum);
836   else
837     ia64_linux_store_register (regcache, regnum);
838 }
839 
840 
841 static target_xfer_partial_ftype *super_xfer_partial;
842 
843 /* Implement the to_xfer_partial target_ops method.  */
844 
845 static enum target_xfer_status
846 ia64_linux_xfer_partial (struct target_ops *ops,
847 			 enum target_object object,
848 			 const char *annex,
849 			 gdb_byte *readbuf, const gdb_byte *writebuf,
850 			 ULONGEST offset, ULONGEST len,
851 			 ULONGEST *xfered_len)
852 {
853   if (object == TARGET_OBJECT_UNWIND_TABLE && readbuf != NULL)
854     {
855       static long gate_table_size;
856       gdb_byte *tmp_buf;
857       long res;
858 
859       /* Probe for the table size once.  */
860       if (gate_table_size == 0)
861         gate_table_size = syscall (__NR_getunwind, NULL, 0);
862       if (gate_table_size < 0)
863 	return TARGET_XFER_E_IO;
864 
865       if (offset >= gate_table_size)
866 	return TARGET_XFER_EOF;
867 
868       tmp_buf = (gdb_byte *) alloca (gate_table_size);
869       res = syscall (__NR_getunwind, tmp_buf, gate_table_size);
870       if (res < 0)
871 	return TARGET_XFER_E_IO;
872       gdb_assert (res == gate_table_size);
873 
874       if (offset + len > gate_table_size)
875 	len = gate_table_size - offset;
876 
877       memcpy (readbuf, tmp_buf + offset, len);
878       *xfered_len = len;
879       return TARGET_XFER_OK;
880     }
881 
882   return super_xfer_partial (ops, object, annex, readbuf, writebuf,
883 			     offset, len, xfered_len);
884 }
885 
886 /* For break.b instruction ia64 CPU forgets the immediate value and generates
887    SIGILL with ILL_ILLOPC instead of more common SIGTRAP with TRAP_BRKPT.
888    ia64 does not use gdbarch_decr_pc_after_break so we do not have to make any
889    difference for the signals here.  */
890 
891 static int
892 ia64_linux_status_is_event (int status)
893 {
894   return WIFSTOPPED (status) && (WSTOPSIG (status) == SIGTRAP
895 				 || WSTOPSIG (status) == SIGILL);
896 }
897 
898 void _initialize_ia64_linux_nat (void);
899 
900 void
901 _initialize_ia64_linux_nat (void)
902 {
903   struct target_ops *t;
904 
905   /* Fill in the generic GNU/Linux methods.  */
906   t = linux_target ();
907 
908   /* Override the default fetch/store register routines.  */
909   t->to_fetch_registers = ia64_linux_fetch_registers;
910   t->to_store_registers = ia64_linux_store_registers;
911 
912   /* Override the default to_xfer_partial.  */
913   super_xfer_partial = t->to_xfer_partial;
914   t->to_xfer_partial = ia64_linux_xfer_partial;
915 
916   /* Override watchpoint routines.  */
917 
918   /* The IA-64 architecture can step over a watch point (without triggering
919      it again) if the "dd" (data debug fault disable) bit in the processor
920      status word is set.
921 
922      This PSR bit is set in ia64_linux_stopped_by_watchpoint when the
923      code there has determined that a hardware watchpoint has indeed
924      been hit.  The CPU will then be able to execute one instruction
925      without triggering a watchpoint.  */
926 
927   t->to_have_steppable_watchpoint = 1;
928   t->to_can_use_hw_breakpoint = ia64_linux_can_use_hw_breakpoint;
929   t->to_stopped_by_watchpoint = ia64_linux_stopped_by_watchpoint;
930   t->to_stopped_data_address = ia64_linux_stopped_data_address;
931   t->to_insert_watchpoint = ia64_linux_insert_watchpoint;
932   t->to_remove_watchpoint = ia64_linux_remove_watchpoint;
933 
934   /* Register the target.  */
935   linux_nat_add_target (t);
936   linux_nat_set_new_thread (t, ia64_linux_new_thread);
937   linux_nat_set_status_is_event (t, ia64_linux_status_is_event);
938 }
939