1/* Native-dependent code for SPARC.
2
3   Copyright 2003, 2004 Free Software Foundation, Inc.
4
5   This file is part of GDB.
6
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 2 of the License, or
10   (at your option) any later version.
11
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.
16
17   You should have received a copy of the GNU General Public License
18   along with this program; if not, write to the Free Software
19   Foundation, Inc., 59 Temple Place - Suite 330,
20   Boston, MA 02111-1307, USA.  */
21
22#include "defs.h"
23#include "inferior.h"
24#include "regcache.h"
25#include "target.h"
26
27#include "gdb_assert.h"
28#include <signal.h>
29#include "gdb_string.h"
30#include <sys/ptrace.h>
31#include "gdb_wait.h"
32#ifdef HAVE_MACHINE_REG_H
33#include <machine/reg.h>
34#endif
35
36#include "sparc-tdep.h"
37#include "sparc-nat.h"
38
39/* With some trickery we can use the code in this file for most (if
40   not all) ptrace(2) based SPARC systems, which includes SunOS 4,
41   GNU/Linux and the various SPARC BSD's.
42
43   First, we need a data structure for use with ptrace(2).  SunOS has
44   `struct regs' and `struct fp_status' in <machine/reg.h>.  BSD's
45   have `struct reg' and `struct fpreg' in <machine/reg.h>.  GNU/Linux
46   has the same structures as SunOS 4, but they're in <asm/reg.h>,
47   which is a kernel header.  As a general rule we avoid including
48   GNU/Linux kernel headers.  Fortunately GNU/Linux has a `gregset_t'
49   and a `fpregset_t' that are equivalent to `struct regs' and `struct
50   fp_status' in <sys/ucontext.h>, which is automatically included by
51   <signal.h>.  Settling on using the `gregset_t' and `fpregset_t'
52   typedefs, providing them for the other systems, therefore solves
53   the puzzle.  */
54
55#ifdef HAVE_MACHINE_REG_H
56#ifdef HAVE_STRUCT_REG
57typedef struct reg gregset_t;
58typedef struct fpreg fpregset_t;
59#else
60typedef struct regs gregset_t;
61typedef struct fp_status fpregset_t;
62#endif
63#endif
64
65/* Second, we need to remap the BSD ptrace(2) requests to their SunOS
66   equivalents.  GNU/Linux already follows SunOS here.  */
67
68#ifndef PTRACE_GETREGS
69#define PTRACE_GETREGS PT_GETREGS
70#endif
71
72#ifndef PTRACE_SETREGS
73#define PTRACE_SETREGS PT_SETREGS
74#endif
75
76#ifndef PTRACE_GETFPREGS
77#define PTRACE_GETFPREGS PT_GETFPREGS
78#endif
79
80#ifndef PTRACE_SETFPREGS
81#define PTRACE_SETFPREGS PT_SETFPREGS
82#endif
83
84/* Register set description.  */
85const struct sparc_gregset *sparc_gregset;
86void (*sparc_supply_gregset) (const struct sparc_gregset *,
87			      struct regcache *, int , const void *);
88void (*sparc_collect_gregset) (const struct sparc_gregset *,
89			       const struct regcache *, int, void *);
90void (*sparc_supply_fpregset) (struct regcache *, int , const void *);
91void (*sparc_collect_fpregset) (const struct regcache *, int , void *);
92int (*sparc_gregset_supplies_p) (int);
93int (*sparc_fpregset_supplies_p) (int);
94
95/* Determine whether `gregset_t' contains register REGNUM.  */
96
97int
98sparc32_gregset_supplies_p (int regnum)
99{
100  /* Integer registers.  */
101  if ((regnum >= SPARC_G1_REGNUM && regnum <= SPARC_G7_REGNUM)
102      || (regnum >= SPARC_O0_REGNUM && regnum <= SPARC_O7_REGNUM)
103      || (regnum >= SPARC_L0_REGNUM && regnum <= SPARC_L7_REGNUM)
104      || (regnum >= SPARC_I0_REGNUM && regnum <= SPARC_I7_REGNUM))
105    return 1;
106
107  /* Control registers.  */
108  if (regnum == SPARC32_PC_REGNUM
109      || regnum == SPARC32_NPC_REGNUM
110      || regnum == SPARC32_PSR_REGNUM
111      || regnum == SPARC32_Y_REGNUM)
112    return 1;
113
114  return 0;
115}
116
117/* Determine whether `fpregset_t' contains register REGNUM.  */
118
119int
120sparc32_fpregset_supplies_p (int regnum)
121{
122  /* Floating-point registers.  */
123  if (regnum >= SPARC_F0_REGNUM && regnum <= SPARC_F31_REGNUM)
124    return 1;
125
126  /* Control registers.  */
127  if (regnum == SPARC32_FSR_REGNUM)
128    return 1;
129
130  return 0;
131}
132
133/* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
134   for all registers (including the floating-point registers).  */
135
136void
137fetch_inferior_registers (int regnum)
138{
139  struct regcache *regcache = current_regcache;
140  int pid;
141
142  /* NOTE: cagney/2002-12-03: This code assumes that the currently
143     selected light weight processes' registers can be written
144     directly into the selected thread's register cache.  This works
145     fine when given an 1:1 LWP:thread model (such as found on
146     GNU/Linux) but will, likely, have problems when used on an N:1
147     (userland threads) or N:M (userland multiple LWP) model.  In the
148     case of the latter two, the LWP's registers do not necessarily
149     belong to the selected thread (the LWP could be in the middle of
150     executing the thread switch code).
151
152     These functions should instead be paramaterized with an explicit
153     object (struct regcache, struct thread_info?) into which the LWPs
154     registers can be written.  */
155  pid = TIDGET (inferior_ptid);
156  if (pid == 0)
157    pid = PIDGET (inferior_ptid);
158
159  if (regnum == SPARC_G0_REGNUM)
160    {
161      regcache_raw_supply (regcache, SPARC_G0_REGNUM, NULL);
162      return;
163    }
164
165  if (regnum == -1 || sparc_gregset_supplies_p (regnum))
166    {
167      gregset_t regs;
168
169      if (ptrace (PTRACE_GETREGS, pid, (PTRACE_ARG3_TYPE) &regs, 0) == -1)
170	perror_with_name ("Couldn't get registers");
171
172      sparc_supply_gregset (sparc_gregset, regcache, -1, &regs);
173      if (regnum != -1)
174	return;
175    }
176
177  if (regnum == -1 || sparc_fpregset_supplies_p (regnum))
178    {
179      fpregset_t fpregs;
180
181      if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
182	perror_with_name ("Couldn't get floating point status");
183
184      sparc_supply_fpregset (regcache, -1, &fpregs);
185    }
186}
187
188void
189store_inferior_registers (int regnum)
190{
191  struct regcache *regcache = current_regcache;
192  int pid;
193
194  /* NOTE: cagney/2002-12-02: See comment in fetch_inferior_registers
195     about threaded assumptions.  */
196  pid = TIDGET (inferior_ptid);
197  if (pid == 0)
198    pid = PIDGET (inferior_ptid);
199
200  if (regnum == -1 || sparc_gregset_supplies_p (regnum))
201    {
202      gregset_t regs;
203
204      if (ptrace (PTRACE_GETREGS, pid, (PTRACE_ARG3_TYPE) &regs, 0) == -1)
205	perror_with_name ("Couldn't get registers");
206
207      sparc_collect_gregset (sparc_gregset, regcache, regnum, &regs);
208
209      if (ptrace (PTRACE_SETREGS, pid, (PTRACE_ARG3_TYPE) &regs, 0) == -1)
210	perror_with_name ("Couldn't write registers");
211
212      /* Deal with the stack regs.  */
213      if (regnum == -1 || regnum == SPARC_SP_REGNUM
214	  || (regnum >= SPARC_L0_REGNUM && regnum <= SPARC_I7_REGNUM))
215	{
216	  ULONGEST sp;
217
218	  regcache_cooked_read_unsigned (regcache, SPARC_SP_REGNUM, &sp);
219	  sparc_collect_rwindow (regcache, sp, regnum);
220	}
221
222      if (regnum != -1)
223	return;
224    }
225
226  if (regnum == -1 || sparc_fpregset_supplies_p (regnum))
227    {
228      fpregset_t fpregs, saved_fpregs;
229
230      if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
231	perror_with_name ("Couldn't get floating-point registers");
232
233      memcpy (&saved_fpregs, &fpregs, sizeof (fpregs));
234      sparc_collect_fpregset (regcache, regnum, &fpregs);
235
236      /* Writing the floating-point registers will fail on NetBSD with
237	 EINVAL if the inferior process doesn't have an FPU state
238	 (i.e. if it didn't use the FPU yet).  Therefore we don't try
239	 to write the registers if nothing changed.  */
240      if (memcmp (&saved_fpregs, &fpregs, sizeof (fpregs)) != 0)
241	{
242	  if (ptrace (PTRACE_SETFPREGS, pid,
243		      (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
244	    perror_with_name ("Couldn't write floating-point registers");
245	}
246
247      if (regnum != -1)
248	return;
249    }
250}
251
252
253/* Fetch StackGhost Per-Process XOR cookie.  */
254
255LONGEST
256sparc_xfer_wcookie (struct target_ops *ops, enum target_object object,
257		    const char *annex, void *readbuf, const void *writebuf,
258		    ULONGEST offset, LONGEST len)
259{
260  unsigned long wcookie = 0;
261  char *buf = (char *)&wcookie;
262
263  gdb_assert (object == TARGET_OBJECT_WCOOKIE);
264  gdb_assert (readbuf && writebuf == NULL);
265
266  if (offset >= sizeof (unsigned long))
267    return -1;
268
269#ifdef PT_WCOOKIE
270  /* If PT_WCOOKIE is defined (by <sys/ptrace.h>), assume we're
271     running on an OpenBSD release that uses StackGhost (3.1 or
272     later).  As of release 3.4, OpenBSD doesn't use a randomized
273     cookie yet, but a future release probably will.  */
274  {
275    int pid;
276
277    pid = TIDGET (inferior_ptid);
278    if (pid == 0)
279      pid = PIDGET (inferior_ptid);
280
281    /* Sanity check.  The proper type for a cookie is register_t, but
282       we can't assume that this type exists on all systems supported
283       by the code in this file.  */
284    gdb_assert (sizeof (wcookie) == sizeof (register_t));
285
286    /* Fetch the cookie.  */
287    if (ptrace (PT_WCOOKIE, pid, (PTRACE_ARG3_TYPE) &wcookie, 0) == -1)
288      {
289	if (errno != EINVAL)
290	  perror_with_name ("Couldn't get StackGhost cookie");
291
292	/* Although PT_WCOOKIE is defined on OpenBSD 3.1 and later,
293	   the request wasn't implemented until after OpenBSD 3.4.  If
294	   the kernel doesn't support the PT_WCOOKIE request, assume
295	   we're running on a kernel that uses non-randomized cookies.  */
296	wcookie = 0x3;
297      }
298  }
299#endif /* PT_WCOOKIE */
300
301  if (len > sizeof (unsigned long) - offset)
302    len = sizeof (unsigned long) - offset;
303
304  memcpy (readbuf, buf + offset, len);
305  return len;
306}
307
308
309/* Provide a prototype to silence -Wmissing-prototypes.  */
310void _initialize_sparc_nat (void);
311
312void
313_initialize_sparc_nat (void)
314{
315  /* Deafult to using SunOS 4 register sets.  */
316  if (sparc_gregset == NULL)
317    sparc_gregset = &sparc32_sunos4_gregset;
318  if (sparc_supply_gregset == NULL)
319    sparc_supply_gregset = sparc32_supply_gregset;
320  if (sparc_collect_gregset == NULL)
321    sparc_collect_gregset = sparc32_collect_gregset;
322  if (sparc_supply_fpregset == NULL)
323    sparc_supply_fpregset = sparc32_supply_fpregset;
324  if (sparc_collect_fpregset == NULL)
325    sparc_collect_fpregset = sparc32_collect_fpregset;
326  if (sparc_gregset_supplies_p == NULL)
327    sparc_gregset_supplies_p = sparc32_gregset_supplies_p;
328  if (sparc_fpregset_supplies_p == NULL)
329    sparc_fpregset_supplies_p = sparc32_fpregset_supplies_p;
330}
331