1 /* Motorola m68k native support for GNU/Linux.
3 Copyright (C) 1996-2018 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/>. */
27 #include "linux-nat.h"
29 #include "m68k-tdep.h"
33 #include "nat/gdb_ptrace.h"
35 #include <sys/ioctl.h>
37 #include <sys/procfs.h>
46 #include "floatformat.h"
48 /* Prototypes for supply_gregset etc. */
51 /* Defines ps_err_e, struct ps_prochandle. */
52 #include "gdb_proc_service.h"
54 #include "inf-ptrace.h"
56 #ifndef PTRACE_GET_THREAD_AREA
57 #define PTRACE_GET_THREAD_AREA 25
61 class m68k_linux_nat_target final : public linux_nat_target
64 /* Add our register access methods. */
65 void fetch_registers (struct regcache *, int) override;
66 void store_registers (struct regcache *, int) override;
69 static m68k_linux_nat_target the_m68k_linux_nat_target;
71 /* This table must line up with gdbarch_register_name in "m68k-tdep.c". */
72 static const int regmap[] =
74 PT_D0, PT_D1, PT_D2, PT_D3, PT_D4, PT_D5, PT_D6, PT_D7,
75 PT_A0, PT_A1, PT_A2, PT_A3, PT_A4, PT_A5, PT_A6, PT_USP,
77 /* PT_FP0, ..., PT_FP7 */
78 21, 24, 27, 30, 33, 36, 39, 42,
79 /* PT_FPCR, PT_FPSR, PT_FPIAR */
83 /* Which ptrace request retrieves which registers?
84 These apply to the corresponding SET requests as well. */
85 #define NUM_GREGS (18)
86 #define MAX_NUM_REGS (NUM_GREGS + 11)
89 getregs_supplies (int regno)
91 return 0 <= regno && regno < NUM_GREGS;
95 getfpregs_supplies (int regno)
97 return M68K_FP0_REGNUM <= regno && regno <= M68K_FPI_REGNUM;
100 /* Does the current host support the GETREGS request? */
101 static int have_ptrace_getregs =
102 #ifdef HAVE_PTRACE_GETREGS
111 /* Fetching registers directly from the U area, one at a time. */
113 /* Fetch one register. */
116 fetch_register (struct regcache *regcache, int regno)
118 struct gdbarch *gdbarch = regcache->arch ();
121 gdb_byte buf[M68K_MAX_REGISTER_SIZE];
122 pid_t tid = get_ptrace_pid (regcache->ptid ());
124 regaddr = 4 * regmap[regno];
125 for (i = 0; i < register_size (gdbarch, regno); i += sizeof (long))
128 val = ptrace (PTRACE_PEEKUSER, tid, regaddr, 0);
129 memcpy (&buf[i], &val, sizeof (long));
130 regaddr += sizeof (long);
132 error (_("Couldn't read register %s (#%d): %s."),
133 gdbarch_register_name (gdbarch, regno),
134 regno, safe_strerror (errno));
136 regcache_raw_supply (regcache, regno, buf);
139 /* Fetch register values from the inferior.
140 If REGNO is negative, do this for all registers.
141 Otherwise, REGNO specifies which register (so we can save time). */
144 old_fetch_inferior_registers (struct regcache *regcache, int regno)
148 fetch_register (regcache, regno);
153 regno < gdbarch_num_regs (regcache->arch ());
156 fetch_register (regcache, regno);
161 /* Store one register. */
164 store_register (const struct regcache *regcache, int regno)
166 struct gdbarch *gdbarch = regcache->arch ();
169 gdb_byte buf[M68K_MAX_REGISTER_SIZE];
170 pid_t tid = get_ptrace_pid (regcache->ptid ());
172 regaddr = 4 * regmap[regno];
174 /* Put the contents of regno into a local buffer. */
175 regcache_raw_collect (regcache, regno, buf);
177 /* Store the local buffer into the inferior a chunk at the time. */
178 for (i = 0; i < register_size (gdbarch, regno); i += sizeof (long))
181 memcpy (&val, &buf[i], sizeof (long));
182 ptrace (PTRACE_POKEUSER, tid, regaddr, val);
183 regaddr += sizeof (long);
185 error (_("Couldn't write register %s (#%d): %s."),
186 gdbarch_register_name (gdbarch, regno),
187 regno, safe_strerror (errno));
191 /* Store our register values back into the inferior.
192 If REGNO is negative, do this for all registers.
193 Otherwise, REGNO specifies which register (so we can save time). */
196 old_store_inferior_registers (const struct regcache *regcache, int regno)
200 store_register (regcache, regno);
205 regno < gdbarch_num_regs (regcache->arch ());
208 store_register (regcache, regno);
213 /* Given a pointer to a general register set in /proc format
214 (elf_gregset_t *), unpack the register contents and supply
215 them as gdb's idea of the current register values. */
218 supply_gregset (struct regcache *regcache, const elf_gregset_t *gregsetp)
220 struct gdbarch *gdbarch = regcache->arch ();
221 const elf_greg_t *regp = (const elf_greg_t *) gregsetp;
224 for (regi = M68K_D0_REGNUM;
225 regi <= gdbarch_sp_regnum (gdbarch);
227 regcache_raw_supply (regcache, regi, ®p[regmap[regi]]);
228 regcache_raw_supply (regcache, gdbarch_ps_regnum (gdbarch),
230 regcache_raw_supply (regcache,
231 gdbarch_pc_regnum (gdbarch), ®p[PT_PC]);
234 /* Fill register REGNO (if it is a general-purpose register) in
235 *GREGSETPS with the value in GDB's register array. If REGNO is -1,
236 do this for all registers. */
238 fill_gregset (const struct regcache *regcache,
239 elf_gregset_t *gregsetp, int regno)
241 elf_greg_t *regp = (elf_greg_t *) gregsetp;
244 for (i = 0; i < NUM_GREGS; i++)
245 if (regno == -1 || regno == i)
246 regcache_raw_collect (regcache, i, regp + regmap[i]);
249 #ifdef HAVE_PTRACE_GETREGS
251 /* Fetch all general-purpose registers from process/thread TID and
252 store their values in GDB's register array. */
255 fetch_regs (struct regcache *regcache, int tid)
259 if (ptrace (PTRACE_GETREGS, tid, 0, (int) ®s) < 0)
263 /* The kernel we're running on doesn't support the GETREGS
264 request. Reset `have_ptrace_getregs'. */
265 have_ptrace_getregs = 0;
269 perror_with_name (_("Couldn't get registers"));
272 supply_gregset (regcache, (const elf_gregset_t *) ®s);
275 /* Store all valid general-purpose registers in GDB's register array
276 into the process/thread specified by TID. */
279 store_regs (const struct regcache *regcache, int tid, int regno)
283 if (ptrace (PTRACE_GETREGS, tid, 0, (int) ®s) < 0)
284 perror_with_name (_("Couldn't get registers"));
286 fill_gregset (regcache, ®s, regno);
288 if (ptrace (PTRACE_SETREGS, tid, 0, (int) ®s) < 0)
289 perror_with_name (_("Couldn't write registers"));
294 static void fetch_regs (struct regcache *regcache, int tid)
298 static void store_regs (const struct regcache *regcache, int tid, int regno)
305 /* Transfering floating-point registers between GDB, inferiors and cores. */
307 /* What is the address of fpN within the floating-point register set F? */
308 #define FPREG_ADDR(f, n) (&(f)->fpregs[(n) * 3])
310 /* Fill GDB's register array with the floating-point register values in
314 supply_fpregset (struct regcache *regcache, const elf_fpregset_t *fpregsetp)
316 struct gdbarch *gdbarch = regcache->arch ();
319 for (regi = gdbarch_fp0_regnum (gdbarch);
320 regi < gdbarch_fp0_regnum (gdbarch) + 8; regi++)
321 regcache_raw_supply (regcache, regi,
322 FPREG_ADDR (fpregsetp,
323 regi - gdbarch_fp0_regnum (gdbarch)));
324 regcache_raw_supply (regcache, M68K_FPC_REGNUM, &fpregsetp->fpcntl[0]);
325 regcache_raw_supply (regcache, M68K_FPS_REGNUM, &fpregsetp->fpcntl[1]);
326 regcache_raw_supply (regcache, M68K_FPI_REGNUM, &fpregsetp->fpcntl[2]);
329 /* Fill register REGNO (if it is a floating-point register) in
330 *FPREGSETP with the value in GDB's register array. If REGNO is -1,
331 do this for all registers. */
334 fill_fpregset (const struct regcache *regcache,
335 elf_fpregset_t *fpregsetp, int regno)
337 struct gdbarch *gdbarch = regcache->arch ();
340 /* Fill in the floating-point registers. */
341 for (i = gdbarch_fp0_regnum (gdbarch);
342 i < gdbarch_fp0_regnum (gdbarch) + 8; i++)
343 if (regno == -1 || regno == i)
344 regcache_raw_collect (regcache, i,
345 FPREG_ADDR (fpregsetp,
346 i - gdbarch_fp0_regnum (gdbarch)));
348 /* Fill in the floating-point control registers. */
349 for (i = M68K_FPC_REGNUM; i <= M68K_FPI_REGNUM; i++)
350 if (regno == -1 || regno == i)
351 regcache_raw_collect (regcache, i,
352 &fpregsetp->fpcntl[i - M68K_FPC_REGNUM]);
355 #ifdef HAVE_PTRACE_GETREGS
357 /* Fetch all floating-point registers from process/thread TID and store
358 thier values in GDB's register array. */
361 fetch_fpregs (struct regcache *regcache, int tid)
363 elf_fpregset_t fpregs;
365 if (ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs) < 0)
366 perror_with_name (_("Couldn't get floating point status"));
368 supply_fpregset (regcache, (const elf_fpregset_t *) &fpregs);
371 /* Store all valid floating-point registers in GDB's register array
372 into the process/thread specified by TID. */
375 store_fpregs (const struct regcache *regcache, int tid, int regno)
377 elf_fpregset_t fpregs;
379 if (ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs) < 0)
380 perror_with_name (_("Couldn't get floating point status"));
382 fill_fpregset (regcache, &fpregs, regno);
384 if (ptrace (PTRACE_SETFPREGS, tid, 0, (int) &fpregs) < 0)
385 perror_with_name (_("Couldn't write floating point status"));
390 static void fetch_fpregs (struct regcache *regcache, int tid)
394 static void store_fpregs (const struct regcache *regcache, int tid, int regno)
400 /* Transferring arbitrary registers between GDB and inferior. */
402 /* Fetch register REGNO from the child process. If REGNO is -1, do
403 this for all registers (including the floating point and SSE
407 m68k_linux_nat_target::fetch_registers (struct regcache *regcache, int regno)
411 /* Use the old method of peeking around in `struct user' if the
412 GETREGS request isn't available. */
413 if (! have_ptrace_getregs)
415 old_fetch_inferior_registers (regcache, regno);
419 tid = get_ptrace_pid (regcache->ptid ());
421 /* Use the PTRACE_GETFPXREGS request whenever possible, since it
422 transfers more registers in one system call, and we'll cache the
423 results. But remember that fetch_fpxregs can fail, and return
427 fetch_regs (regcache, tid);
429 /* The call above might reset `have_ptrace_getregs'. */
430 if (! have_ptrace_getregs)
432 old_fetch_inferior_registers (regcache, -1);
436 fetch_fpregs (regcache, tid);
440 if (getregs_supplies (regno))
442 fetch_regs (regcache, tid);
446 if (getfpregs_supplies (regno))
448 fetch_fpregs (regcache, tid);
452 internal_error (__FILE__, __LINE__,
453 _("Got request for bad register number %d."), regno);
456 /* Store register REGNO back into the child process. If REGNO is -1,
457 do this for all registers (including the floating point and SSE
460 m68k_linux_nat_target::store_registers (struct regcache *regcache, int regno)
464 /* Use the old method of poking around in `struct user' if the
465 SETREGS request isn't available. */
466 if (! have_ptrace_getregs)
468 old_store_inferior_registers (regcache, regno);
472 tid = get_ptrace_pid (regcache->ptid ());
474 /* Use the PTRACE_SETFPREGS requests whenever possible, since it
475 transfers more registers in one system call. But remember that
476 store_fpregs can fail, and return zero. */
479 store_regs (regcache, tid, regno);
480 store_fpregs (regcache, tid, regno);
484 if (getregs_supplies (regno))
486 store_regs (regcache, tid, regno);
490 if (getfpregs_supplies (regno))
492 store_fpregs (regcache, tid, regno);
496 internal_error (__FILE__, __LINE__,
497 _("Got request to store bad register number %d."), regno);
501 /* Fetch the thread-local storage pointer for libthread_db. */
504 ps_get_thread_area (struct ps_prochandle *ph,
505 lwpid_t lwpid, int idx, void **base)
507 if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) < 0)
510 /* IDX is the bias from the thread pointer to the beginning of the
511 thread descriptor. It has to be subtracted due to implementation
512 quirks in libthread_db. */
513 *base = (char *) *base - idx;
519 _initialize_m68k_linux_nat (void)
521 /* Register the target. */
522 linux_target = &the_m68k_linux_nat_target;
523 add_inf_child_target (&the_m68k_linux_nat_target);