1/* Low level interface to ptrace, for the remote server for GDB.
2   Copyright (C) 1995-2020 Free Software Foundation, Inc.
3
4   This file is part of GDB.
5
6   This program is free software; you can redistribute it and/or modify
7   it under the terms of the GNU General Public License as published by
8   the Free Software Foundation; either version 3 of the License, or
9   (at your option) any later version.
10
11   This program is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14   GNU General Public License for more details.
15
16   You should have received a copy of the GNU General Public License
17   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
18
19#include "server.h"
20#include "linux-low.h"
21
22#include "nat/gdb_ptrace.h"
23
24#include "gdb_proc_service.h"
25
26/* The stack pointer is offset from the stack frame by a BIAS of 2047
27   (0x7ff) for 64-bit code.  BIAS is likely to be defined on SPARC
28   hosts, so undefine it first.  */
29#undef BIAS
30#define BIAS 2047
31
32#ifdef HAVE_SYS_REG_H
33#include <sys/reg.h>
34#endif
35
36#define INSN_SIZE 4
37
38#define SPARC_R_REGS_NUM 32
39#define SPARC_F_REGS_NUM 48
40#define SPARC_CONTROL_REGS_NUM 6
41
42#define sparc_num_regs \
43  (SPARC_R_REGS_NUM + SPARC_F_REGS_NUM + SPARC_CONTROL_REGS_NUM)
44
45/* Linux target op definitions for the SPARC architecture.  */
46
47class sparc_target : public linux_process_target
48{
49public:
50
51  const regs_info *get_regs_info () override;
52
53  const gdb_byte *sw_breakpoint_from_kind (int kind, int *size) override;
54
55protected:
56
57  void low_arch_setup () override;
58
59  bool low_cannot_fetch_register (int regno) override;
60
61  bool low_cannot_store_register (int regno) override;
62
63  bool low_supports_breakpoints () override;
64
65  CORE_ADDR low_get_pc (regcache *regcache) override;
66
67  /* No low_set_pc is needed.  */
68
69  bool low_breakpoint_at (CORE_ADDR pc) override;
70};
71
72/* The singleton target ops object.  */
73
74static sparc_target the_sparc_target;
75
76bool
77sparc_target::low_supports_breakpoints ()
78{
79  return true;
80}
81
82CORE_ADDR
83sparc_target::low_get_pc (regcache *regcache)
84{
85  return linux_get_pc_64bit (regcache);
86}
87
88/* Each offset is multiplied by 8, because of the register size.
89   These offsets apply to the buffer sent/filled by ptrace.
90   Additionally, the array elements order corresponds to the .dat file, and the
91   gdb's registers enumeration order.  */
92
93static int sparc_regmap[] = {
94  /* These offsets correspond to GET/SETREGSET.  */
95	-1,  0*8,  1*8,  2*8,  3*8,  4*8,  5*8,  6*8,	 /* g0 .. g7 */
96	7*8,  8*8,  9*8, 10*8, 11*8, 12*8, 13*8, 14*8,	 /* o0 .. o5, sp, o7 */
97	-1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,	 /* l0 .. l7 */
98	-1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,	 /* i0 .. i5, fp, i7 */
99
100  /* Floating point registers offsets correspond to GET/SETFPREGSET.  */
101    0*4,  1*4,  2*4,  3*4,  4*4,  5*4,  6*4,  7*4,	   /*  f0 ..  f7 */
102    8*4,  9*4, 10*4, 11*4, 12*4, 13*4, 14*4, 15*4,	   /*  f8 .. f15 */
103   16*4, 17*4, 18*4, 19*4, 20*4, 21*4, 22*4, 23*4,	   /* f16 .. f23 */
104   24*4, 25*4, 26*4, 27*4, 28*4, 29*4, 30*4, 31*4,	   /* f24 .. f31 */
105
106  /* F32 offset starts next to f31: 31*4+4 = 16 * 8.  */
107   16*8, 17*8, 18*8, 19*8, 20*8, 21*8, 22*8, 23*8,	   /* f32 .. f46 */
108   24*8, 25*8, 26*8, 27*8, 28*8, 29*8, 30*8, 31*8,	   /* f48 .. f62 */
109
110   17 *8, /*    pc */
111   18 *8, /*   npc */
112   16 *8, /* state */
113  /* FSR offset also corresponds to GET/SETFPREGSET, ans is placed
114     next to f62.  */
115   32 *8, /*   fsr */
116      -1, /*  fprs */
117  /* Y register is 32-bits length, but gdb takes care of that.  */
118   19 *8, /*     y */
119
120};
121
122
123struct regs_range_t
124{
125  int regno_start;
126  int regno_end;
127};
128
129static const struct regs_range_t gregs_ranges[] = {
130 {  0, 31 }, /*   g0 .. i7  */
131 { 80, 82 }, /*   pc .. state */
132 { 84, 85 }  /* fprs .. y */
133};
134
135#define N_GREGS_RANGES (sizeof (gregs_ranges) / sizeof (struct regs_range_t))
136
137static const struct regs_range_t fpregs_ranges[] = {
138 { 32, 79 }, /* f0 .. f62  */
139 { 83, 83 }  /* fsr */
140};
141
142#define N_FPREGS_RANGES (sizeof (fpregs_ranges) / sizeof (struct regs_range_t))
143
144/* Defined in auto-generated file reg-sparc64.c.  */
145void init_registers_sparc64 (void);
146extern const struct target_desc *tdesc_sparc64;
147
148bool
149sparc_target::low_cannot_store_register (int regno)
150{
151  return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
152}
153
154bool
155sparc_target::low_cannot_fetch_register (int regno)
156{
157  return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
158}
159
160static void
161sparc_fill_gregset_to_stack (struct regcache *regcache, const void *buf)
162{
163  int i;
164  CORE_ADDR addr = 0;
165  unsigned char tmp_reg_buf[8];
166  const int l0_regno = find_regno (regcache->tdesc, "l0");
167  const int i7_regno = l0_regno + 15;
168
169  /* These registers have to be stored in the stack.  */
170  memcpy (&addr,
171	  ((char *) buf) + sparc_regmap[find_regno (regcache->tdesc, "sp")],
172	  sizeof (addr));
173
174  addr += BIAS;
175
176  for (i = l0_regno; i <= i7_regno; i++)
177    {
178      collect_register (regcache, i, tmp_reg_buf);
179      the_target->write_memory (addr, tmp_reg_buf, sizeof (tmp_reg_buf));
180      addr += sizeof (tmp_reg_buf);
181    }
182}
183
184static void
185sparc_fill_gregset (struct regcache *regcache, void *buf)
186{
187  int i;
188  int range;
189
190  for (range = 0; range < N_GREGS_RANGES; range++)
191    for (i = gregs_ranges[range].regno_start;
192	 i <= gregs_ranges[range].regno_end; i++)
193      if (sparc_regmap[i] != -1)
194	collect_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
195
196  sparc_fill_gregset_to_stack (regcache, buf);
197}
198
199static void
200sparc_fill_fpregset (struct regcache *regcache, void *buf)
201{
202  int i;
203  int range;
204
205  for (range = 0; range < N_FPREGS_RANGES; range++)
206    for (i = fpregs_ranges[range].regno_start;
207	 i <= fpregs_ranges[range].regno_end; i++)
208      collect_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
209
210}
211
212static void
213sparc_store_gregset_from_stack (struct regcache *regcache, const void *buf)
214{
215  int i;
216  CORE_ADDR addr = 0;
217  unsigned char tmp_reg_buf[8];
218  const int l0_regno = find_regno (regcache->tdesc, "l0");
219  const int i7_regno = l0_regno + 15;
220
221  /* These registers have to be obtained from the stack.  */
222  memcpy (&addr,
223	  ((char *) buf) + sparc_regmap[find_regno (regcache->tdesc, "sp")],
224	  sizeof (addr));
225
226  addr += BIAS;
227
228  for (i = l0_regno; i <= i7_regno; i++)
229    {
230      the_target->read_memory (addr, tmp_reg_buf, sizeof (tmp_reg_buf));
231      supply_register (regcache, i, tmp_reg_buf);
232      addr += sizeof (tmp_reg_buf);
233    }
234}
235
236static void
237sparc_store_gregset (struct regcache *regcache, const void *buf)
238{
239  int i;
240  char zerobuf[8];
241  int range;
242
243  memset (zerobuf, 0, sizeof (zerobuf));
244
245  for (range = 0; range < N_GREGS_RANGES; range++)
246    for (i = gregs_ranges[range].regno_start;
247	 i <= gregs_ranges[range].regno_end; i++)
248      if (sparc_regmap[i] != -1)
249	supply_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
250      else
251	supply_register (regcache, i, zerobuf);
252
253  sparc_store_gregset_from_stack (regcache, buf);
254}
255
256static void
257sparc_store_fpregset (struct regcache *regcache, const void *buf)
258{
259  int i;
260  int range;
261
262  for (range = 0; range < N_FPREGS_RANGES; range++)
263    for (i = fpregs_ranges[range].regno_start;
264	 i <= fpregs_ranges[range].regno_end;
265	 i++)
266      supply_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
267}
268
269static const gdb_byte sparc_breakpoint[INSN_SIZE] = {
270  0x91, 0xd0, 0x20, 0x01
271};
272#define sparc_breakpoint_len INSN_SIZE
273
274/* Implementation of target ops method "sw_breakpoint_from_kind".  */
275
276const gdb_byte *
277sparc_target::sw_breakpoint_from_kind (int kind, int *size)
278{
279  *size = sparc_breakpoint_len;
280  return sparc_breakpoint;
281}
282
283bool
284sparc_target::low_breakpoint_at (CORE_ADDR where)
285{
286  unsigned char insn[INSN_SIZE];
287
288  read_memory (where, (unsigned char *) insn, sizeof (insn));
289
290  if (memcmp (sparc_breakpoint, insn, sizeof (insn)) == 0)
291    return true;
292
293  /* If necessary, recognize more trap instructions here.  GDB only
294     uses TRAP Always.  */
295
296  return false;
297}
298
299void
300sparc_target::low_arch_setup ()
301{
302  current_process ()->tdesc = tdesc_sparc64;
303}
304
305static struct regset_info sparc_regsets[] = {
306  { PTRACE_GETREGS, PTRACE_SETREGS, 0, sizeof (elf_gregset_t),
307    GENERAL_REGS,
308    sparc_fill_gregset, sparc_store_gregset },
309  { PTRACE_GETFPREGS, PTRACE_SETFPREGS, 0, sizeof (fpregset_t),
310    FP_REGS,
311    sparc_fill_fpregset, sparc_store_fpregset },
312  NULL_REGSET
313};
314
315static struct regsets_info sparc_regsets_info =
316  {
317    sparc_regsets, /* regsets */
318    0, /* num_regsets */
319    NULL, /* disabled_regsets */
320  };
321
322static struct usrregs_info sparc_usrregs_info =
323  {
324    sparc_num_regs,
325    /* No regmap needs to be provided since this impl. doesn't use
326       USRREGS.  */
327    NULL
328  };
329
330static struct regs_info myregs_info =
331  {
332    NULL, /* regset_bitmap */
333    &sparc_usrregs_info,
334    &sparc_regsets_info
335  };
336
337const regs_info *
338sparc_target::get_regs_info ()
339{
340  return &myregs_info;
341}
342
343/* The linux target ops object.  */
344
345linux_process_target *the_linux_target = &the_sparc_target;
346
347void
348initialize_low_arch (void)
349{
350  /* Initialize the Linux target descriptions.  */
351  init_registers_sparc64 ();
352
353  initialize_regsets_info (&sparc_regsets_info);
354}
355