xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/xtensa-linux-nat.c (revision 8b657b0747480f8989760d71343d6dd33f8d4cf9)
1 /* Xtensa GNU/Linux native support.
2 
3    Copyright (C) 2007-2023 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 3 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, see <http://www.gnu.org/licenses/>.  */
19 
20 #include "defs.h"
21 #include "frame.h"
22 #include "inferior.h"
23 #include "gdbcore.h"
24 #include "regcache.h"
25 #include "target.h"
26 #include "linux-nat.h"
27 #include <sys/types.h>
28 #include <signal.h>
29 #include <sys/user.h>
30 #include <sys/ioctl.h>
31 #include "gdbsupport/gdb_wait.h"
32 #include <fcntl.h>
33 #include <sys/procfs.h>
34 #include "nat/gdb_ptrace.h"
35 #include <asm/ptrace.h>
36 
37 #include "gregset.h"
38 #include "xtensa-tdep.h"
39 
40 /* Defines ps_err_e, struct ps_prochandle.  */
41 #include "gdb_proc_service.h"
42 
43 /* Extended register set depends on hardware configs.
44    Keeping these definitions separately allows to introduce
45    hardware-specific overlays.  */
46 #include "xtensa-xtregs.c"
47 
48 class xtensa_linux_nat_target final : public linux_nat_target
49 {
50 public:
51   /* Add our register access methods.  */
52   void fetch_registers (struct regcache *, int) override;
53   void store_registers (struct regcache *, int) override;
54 };
55 
56 static xtensa_linux_nat_target the_xtensa_linux_nat_target;
57 
58 void
59 fill_gregset (const struct regcache *regcache,
60 	      gdb_gregset_t *gregsetp, int regnum)
61 {
62   int i;
63   xtensa_elf_gregset_t *regs = (xtensa_elf_gregset_t *) gregsetp;
64   struct gdbarch *gdbarch = regcache->arch ();
65   xtensa_gdbarch_tdep *tdep = gdbarch_tdep<xtensa_gdbarch_tdep> (gdbarch);
66 
67   if (regnum == gdbarch_pc_regnum (gdbarch) || regnum == -1)
68     regcache->raw_collect (gdbarch_pc_regnum (gdbarch), &regs->pc);
69   if (regnum == gdbarch_ps_regnum (gdbarch) || regnum == -1)
70     regcache->raw_collect (gdbarch_ps_regnum (gdbarch), &regs->ps);
71 
72   if (regnum == tdep->wb_regnum || regnum == -1)
73     regcache->raw_collect (tdep->wb_regnum,
74 			   &regs->windowbase);
75   if (regnum == tdep->ws_regnum || regnum == -1)
76     regcache->raw_collect (tdep->ws_regnum,
77 			   &regs->windowstart);
78   if (regnum == tdep->lbeg_regnum || regnum == -1)
79     regcache->raw_collect (tdep->lbeg_regnum,
80 			   &regs->lbeg);
81   if (regnum == tdep->lend_regnum || regnum == -1)
82     regcache->raw_collect (tdep->lend_regnum,
83 			   &regs->lend);
84   if (regnum == tdep->lcount_regnum || regnum == -1)
85     regcache->raw_collect (tdep->lcount_regnum,
86 			   &regs->lcount);
87   if (regnum == tdep->sar_regnum || regnum == -1)
88     regcache->raw_collect (tdep->sar_regnum,
89 			   &regs->sar);
90   if (regnum == tdep->threadptr_regnum || regnum == -1)
91     regcache->raw_collect (tdep->threadptr_regnum,
92 			   &regs->threadptr);
93   if (regnum >=tdep->ar_base
94       && regnum < tdep->ar_base
95 		    + tdep->num_aregs)
96     regcache->raw_collect (regnum,
97 			   &regs->ar[regnum - tdep->ar_base]);
98   else if (regnum == -1)
99     {
100       for (i = 0; i < tdep->num_aregs; ++i)
101 	regcache->raw_collect (tdep->ar_base + i,
102 			       &regs->ar[i]);
103     }
104   if (regnum >= tdep->a0_base
105       && regnum < tdep->a0_base + C0_NREGS)
106     regcache->raw_collect (regnum,
107 			   &regs->ar[(4 * regs->windowbase + regnum
108 				      - tdep->a0_base)
109 			  % tdep->num_aregs]);
110   else if (regnum == -1)
111     {
112       for (i = 0; i < C0_NREGS; ++i)
113 	regcache->raw_collect (tdep->a0_base + i,
114 			       (&regs->ar[(4 * regs->windowbase + i)
115 				% tdep->num_aregs]));
116     }
117 }
118 
119 static void
120 supply_gregset_reg (struct regcache *regcache,
121 		    const gdb_gregset_t *gregsetp, int regnum)
122 {
123   int i;
124   xtensa_elf_gregset_t *regs = (xtensa_elf_gregset_t *) gregsetp;
125 
126   struct gdbarch *gdbarch = regcache->arch ();
127   xtensa_gdbarch_tdep *tdep = gdbarch_tdep<xtensa_gdbarch_tdep> (gdbarch);
128 
129   if (regnum == gdbarch_pc_regnum (gdbarch) || regnum == -1)
130     regcache->raw_supply (gdbarch_pc_regnum (gdbarch), &regs->pc);
131   if (regnum == gdbarch_ps_regnum (gdbarch) || regnum == -1)
132     regcache->raw_supply (gdbarch_ps_regnum (gdbarch), &regs->ps);
133 
134   if (regnum == tdep->wb_regnum || regnum == -1)
135     regcache->raw_supply (tdep->wb_regnum,
136 			  &regs->windowbase);
137   if (regnum == tdep->ws_regnum || regnum == -1)
138     regcache->raw_supply (tdep->ws_regnum,
139 			  &regs->windowstart);
140   if (regnum == tdep->lbeg_regnum || regnum == -1)
141     regcache->raw_supply (tdep->lbeg_regnum,
142 			  &regs->lbeg);
143   if (regnum == tdep->lend_regnum || regnum == -1)
144     regcache->raw_supply (tdep->lend_regnum,
145 			  &regs->lend);
146   if (regnum == tdep->lcount_regnum || regnum == -1)
147     regcache->raw_supply (tdep->lcount_regnum,
148 			  &regs->lcount);
149   if (regnum == tdep->sar_regnum || regnum == -1)
150     regcache->raw_supply (tdep->sar_regnum,
151 			  &regs->sar);
152   if (regnum == tdep->threadptr_regnum || regnum == -1)
153     regcache->raw_supply (tdep->threadptr_regnum,
154 			  &regs->threadptr);
155   if (regnum >=tdep->ar_base
156       && regnum < tdep->ar_base
157 		    + tdep->num_aregs)
158     regcache->raw_supply (regnum,
159 			  &regs->ar[regnum - tdep->ar_base]);
160   else if (regnum == -1)
161     {
162       for (i = 0; i < tdep->num_aregs; ++i)
163 	regcache->raw_supply (tdep->ar_base + i,
164 			      &regs->ar[i]);
165     }
166   if (regnum >= tdep->a0_base
167       && regnum < tdep->a0_base + C0_NREGS)
168     regcache->raw_supply (regnum,
169 			  &regs->ar[(4 * regs->windowbase + regnum
170 				     - tdep->a0_base)
171 			 % tdep->num_aregs]);
172   else if (regnum == -1)
173     {
174       for (i = 0; i < C0_NREGS; ++i)
175 	regcache->raw_supply (tdep->a0_base + i,
176 			      &regs->ar[(4 * regs->windowbase + i)
177 					% tdep->num_aregs]);
178     }
179 }
180 
181 void
182 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregsetp)
183 {
184   supply_gregset_reg (regcache, gregsetp, -1);
185 }
186 
187 void
188 fill_fpregset (const struct regcache *regcache,
189 	       gdb_fpregset_t *fpregsetp, int regnum)
190 {
191   return;
192 }
193 
194 void
195 supply_fpregset (struct regcache *regcache,
196 		 const gdb_fpregset_t *fpregsetp)
197 {
198   return;
199 }
200 
201 /* Fetch greg-register(s) from process/thread TID
202    and store value(s) in GDB's register array.  */
203 
204 static void
205 fetch_gregs (struct regcache *regcache, int regnum)
206 {
207   int tid = regcache->ptid ().lwp ();
208   gdb_gregset_t regs;
209 
210   if (ptrace (PTRACE_GETREGS, tid, 0, (long) &regs) < 0)
211     {
212       perror_with_name (_("Couldn't get registers"));
213       return;
214     }
215 
216   supply_gregset_reg (regcache, &regs, regnum);
217 }
218 
219 /* Store greg-register(s) in GDB's register
220    array into the process/thread specified by TID.  */
221 
222 static void
223 store_gregs (struct regcache *regcache, int regnum)
224 {
225   int tid = regcache->ptid ().lwp ();
226   gdb_gregset_t regs;
227 
228   if (ptrace (PTRACE_GETREGS, tid, 0, (long) &regs) < 0)
229     {
230       perror_with_name (_("Couldn't get registers"));
231       return;
232     }
233 
234   fill_gregset (regcache, &regs, regnum);
235 
236   if (ptrace (PTRACE_SETREGS, tid, 0, (long) &regs) < 0)
237     {
238       perror_with_name (_("Couldn't write registers"));
239       return;
240     }
241 }
242 
243 static int xtreg_lo;
244 static int xtreg_high;
245 
246 /* Fetch/Store Xtensa TIE registers.  Xtensa GNU/Linux PTRACE
247    interface provides special requests for this.  */
248 
249 static void
250 fetch_xtregs (struct regcache *regcache, int regnum)
251 {
252   int tid = regcache->ptid ().lwp ();
253   const xtensa_regtable_t *ptr;
254   char xtregs [XTENSA_ELF_XTREG_SIZE];
255 
256   if (ptrace (PTRACE_GETXTREGS, tid, 0, (long)&xtregs) < 0)
257     perror_with_name (_("Couldn't get extended registers"));
258 
259   for (ptr = xtensa_regmap_table; ptr->name; ptr++)
260     if (regnum == ptr->gdb_regnum || regnum == -1)
261       regcache->raw_supply (ptr->gdb_regnum, xtregs + ptr->ptrace_offset);
262 }
263 
264 static void
265 store_xtregs (struct regcache *regcache, int regnum)
266 {
267   int tid = regcache->ptid ().lwp ();
268   const xtensa_regtable_t *ptr;
269   char xtregs [XTENSA_ELF_XTREG_SIZE];
270 
271   if (ptrace (PTRACE_GETXTREGS, tid, 0, (long)&xtregs) < 0)
272     perror_with_name (_("Couldn't get extended registers"));
273 
274   for (ptr = xtensa_regmap_table; ptr->name; ptr++)
275     if (regnum == ptr->gdb_regnum || regnum == -1)
276       regcache->raw_collect (ptr->gdb_regnum, xtregs + ptr->ptrace_offset);
277 
278   if (ptrace (PTRACE_SETXTREGS, tid, 0, (long)&xtregs) < 0)
279     perror_with_name (_("Couldn't write extended registers"));
280 }
281 
282 void
283 xtensa_linux_nat_target::fetch_registers (struct regcache *regcache,
284 					  int regnum)
285 {
286   if (regnum == -1)
287     {
288       fetch_gregs (regcache, regnum);
289       fetch_xtregs (regcache, regnum);
290     }
291   else if ((regnum < xtreg_lo) || (regnum > xtreg_high))
292     fetch_gregs (regcache, regnum);
293   else
294     fetch_xtregs (regcache, regnum);
295 }
296 
297 void
298 xtensa_linux_nat_target::store_registers (struct regcache *regcache,
299 					  int regnum)
300 {
301   if (regnum == -1)
302     {
303       store_gregs (regcache, regnum);
304       store_xtregs (regcache, regnum);
305     }
306   else if ((regnum < xtreg_lo) || (regnum > xtreg_high))
307     store_gregs (regcache, regnum);
308   else
309     store_xtregs (regcache, regnum);
310 }
311 
312 /* Called by libthread_db.  */
313 
314 ps_err_e
315 ps_get_thread_area (struct ps_prochandle *ph,
316 		    lwpid_t lwpid, int idx, void **base)
317 {
318   xtensa_elf_gregset_t regs;
319 
320   if (ptrace (PTRACE_GETREGS, lwpid, NULL, &regs) != 0)
321     return PS_ERR;
322 
323   /* IDX is the bias from the thread pointer to the beginning of the
324      thread descriptor.  It has to be subtracted due to implementation
325      quirks in libthread_db.  */
326   *base = (void *) ((char *) regs.threadptr - idx);
327 
328   return PS_OK;
329 }
330 
331 void _initialize_xtensa_linux_nat ();
332 void
333 _initialize_xtensa_linux_nat ()
334 {
335   const xtensa_regtable_t *ptr;
336 
337   /* Calculate the number range for extended registers.  */
338   xtreg_lo = 1000000000;
339   xtreg_high = -1;
340   for (ptr = xtensa_regmap_table; ptr->name; ptr++)
341     {
342       if (ptr->gdb_regnum < xtreg_lo)
343 	xtreg_lo = ptr->gdb_regnum;
344       if (ptr->gdb_regnum > xtreg_high)
345 	xtreg_high = ptr->gdb_regnum;
346     }
347 
348   linux_target = &the_xtensa_linux_nat_target;
349   add_inf_child_target (&the_xtensa_linux_nat_target);
350 }
351