1 /* Motorola m68k target-dependent support for GNU/Linux.
3 Copyright (C) 1996-2019 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/>. */
29 #include "m68k-tdep.h"
30 #include "trad-frame.h"
31 #include "frame-unwind.h"
32 #include "glibc-tdep.h"
33 #include "solib-svr4.h"
35 #include "observable.h"
36 #include "elf/common.h"
37 #include "linux-tdep.h"
40 /* Offsets (in target ints) into jmp_buf. */
42 #define M68K_LINUX_JB_ELEMENT_SIZE 4
43 #define M68K_LINUX_JB_PC 7
45 /* Check whether insn1 and insn2 are parts of a signal trampoline. */
47 #define IS_SIGTRAMP(insn1, insn2) \
48 (/* addaw #20,sp; moveq #119,d0; trap #0 */ \
49 (insn1 == 0xdefc0014 && insn2 == 0x70774e40) \
50 /* moveq #119,d0; trap #0 */ \
51 || insn1 == 0x70774e40)
53 #define IS_RT_SIGTRAMP(insn1, insn2) \
54 (/* movel #173,d0; trap #0 */ \
55 (insn1 == 0x203c0000 && insn2 == 0x00ad4e40) \
56 /* moveq #82,d0; notb d0; trap #0 */ \
57 || (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40))
59 /* Return non-zero if THIS_FRAME corresponds to a signal trampoline. For
60 the sake of m68k_linux_get_sigtramp_info we also distinguish between
61 non-RT and RT signal trampolines. */
64 m68k_linux_pc_in_sigtramp (struct frame_info
*this_frame
)
66 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
67 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
69 unsigned long insn0
, insn1
, insn2
;
70 CORE_ADDR pc
= get_frame_pc (this_frame
);
72 if (!safe_frame_unwind_memory (this_frame
, pc
- 4, buf
, sizeof (buf
)))
74 insn1
= extract_unsigned_integer (buf
+ 4, 4, byte_order
);
75 insn2
= extract_unsigned_integer (buf
+ 8, 4, byte_order
);
76 if (IS_SIGTRAMP (insn1
, insn2
))
78 if (IS_RT_SIGTRAMP (insn1
, insn2
))
81 insn0
= extract_unsigned_integer (buf
, 4, byte_order
);
82 if (IS_SIGTRAMP (insn0
, insn1
))
84 if (IS_RT_SIGTRAMP (insn0
, insn1
))
87 insn0
= ((insn0
<< 16) & 0xffffffff) | (insn1
>> 16);
88 insn1
= ((insn1
<< 16) & 0xffffffff) | (insn2
>> 16);
89 if (IS_SIGTRAMP (insn0
, insn1
))
91 if (IS_RT_SIGTRAMP (insn0
, insn1
))
97 /* From <asm/sigcontext.h>. */
98 static int m68k_linux_sigcontext_reg_offset
[M68K_NUM_REGS
] =
128 16 * 4 /* %fpiaddr */
131 static int m68k_uclinux_sigcontext_reg_offset
[M68K_NUM_REGS
] =
164 /* From <asm/ucontext.h>. */
165 static int m68k_linux_ucontext_reg_offset
[M68K_NUM_REGS
] =
195 26 * 4 /* %fpiaddr */
199 /* Get info about saved registers in sigtramp. */
201 struct m68k_linux_sigtramp_info
203 /* Address of sigcontext. */
204 CORE_ADDR sigcontext_addr
;
206 /* Offset of registers in `struct sigcontext'. */
210 /* Nonzero if running on uClinux. */
211 static int target_is_uclinux
;
214 m68k_linux_inferior_created (struct target_ops
*objfile
, int from_tty
)
216 /* Record that we will need to re-evaluate whether we are running on a
217 uClinux or normal GNU/Linux target (see m68k_linux_get_sigtramp_info). */
218 target_is_uclinux
= -1;
221 static struct m68k_linux_sigtramp_info
222 m68k_linux_get_sigtramp_info (struct frame_info
*this_frame
)
224 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
225 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
227 struct m68k_linux_sigtramp_info info
;
229 /* Determine whether we are running on a uClinux or normal GNU/Linux
230 target so we can use the correct sigcontext layouts. */
231 if (target_is_uclinux
== -1)
232 target_is_uclinux
= linux_is_uclinux ();
234 sp
= get_frame_register_unsigned (this_frame
, M68K_SP_REGNUM
);
236 /* Get sigcontext address, it is the third parameter on the stack. */
237 info
.sigcontext_addr
= read_memory_unsigned_integer (sp
+ 8, 4, byte_order
);
239 if (m68k_linux_pc_in_sigtramp (this_frame
) == 2)
240 info
.sc_reg_offset
= m68k_linux_ucontext_reg_offset
;
242 info
.sc_reg_offset
= (target_is_uclinux
243 ? m68k_uclinux_sigcontext_reg_offset
244 : m68k_linux_sigcontext_reg_offset
);
248 /* Signal trampolines. */
250 static struct trad_frame_cache
*
251 m68k_linux_sigtramp_frame_cache (struct frame_info
*this_frame
,
254 struct frame_id this_id
;
255 struct trad_frame_cache
*cache
;
256 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
257 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
258 struct m68k_linux_sigtramp_info info
;
263 return (struct trad_frame_cache
*) *this_cache
;
265 cache
= trad_frame_cache_zalloc (this_frame
);
267 /* FIXME: cagney/2004-05-01: This is is long standing broken code.
268 The frame ID's code address should be the start-address of the
269 signal trampoline and not the current PC within that
271 get_frame_register (this_frame
, M68K_SP_REGNUM
, buf
);
272 /* See the end of m68k_push_dummy_call. */
273 this_id
= frame_id_build (extract_unsigned_integer (buf
, 4, byte_order
)
274 - 4 + 8, get_frame_pc (this_frame
));
275 trad_frame_set_id (cache
, this_id
);
277 info
= m68k_linux_get_sigtramp_info (this_frame
);
279 for (i
= 0; i
< M68K_NUM_REGS
; i
++)
280 if (info
.sc_reg_offset
[i
] != -1)
281 trad_frame_set_reg_addr (cache
, i
,
282 info
.sigcontext_addr
+ info
.sc_reg_offset
[i
]);
289 m68k_linux_sigtramp_frame_this_id (struct frame_info
*this_frame
,
291 struct frame_id
*this_id
)
293 struct trad_frame_cache
*cache
=
294 m68k_linux_sigtramp_frame_cache (this_frame
, this_cache
);
295 trad_frame_get_id (cache
, this_id
);
298 static struct value
*
299 m68k_linux_sigtramp_frame_prev_register (struct frame_info
*this_frame
,
303 /* Make sure we've initialized the cache. */
304 struct trad_frame_cache
*cache
=
305 m68k_linux_sigtramp_frame_cache (this_frame
, this_cache
);
306 return trad_frame_get_register (cache
, this_frame
, regnum
);
310 m68k_linux_sigtramp_frame_sniffer (const struct frame_unwind
*self
,
311 struct frame_info
*this_frame
,
312 void **this_prologue_cache
)
314 return m68k_linux_pc_in_sigtramp (this_frame
);
317 static const struct frame_unwind m68k_linux_sigtramp_frame_unwind
=
320 default_frame_unwind_stop_reason
,
321 m68k_linux_sigtramp_frame_this_id
,
322 m68k_linux_sigtramp_frame_prev_register
,
324 m68k_linux_sigtramp_frame_sniffer
327 /* Register maps for supply/collect regset functions. */
329 static const struct regcache_map_entry m68k_linux_gregmap
[] =
331 { 7, M68K_D1_REGNUM
, 4 }, /* d1 ... d7 */
332 { 7, M68K_A0_REGNUM
, 4 }, /* a0 ... a6 */
333 { 1, M68K_D0_REGNUM
, 4 },
334 { 1, M68K_SP_REGNUM
, 4 },
335 { 1, REGCACHE_MAP_SKIP
, 4 }, /* orig_d0 (skip) */
336 { 1, M68K_PS_REGNUM
, 4 },
337 { 1, M68K_PC_REGNUM
, 4 },
338 /* Ignore 16-bit fields 'fmtvec' and '__fill'. */
342 #define M68K_LINUX_GREGS_SIZE (20 * 4)
344 static const struct regcache_map_entry m68k_linux_fpregmap
[] =
346 { 8, M68K_FP0_REGNUM
, 12 }, /* fp0 ... fp7 */
347 { 1, M68K_FPC_REGNUM
, 4 },
348 { 1, M68K_FPS_REGNUM
, 4 },
349 { 1, M68K_FPI_REGNUM
, 4 },
353 #define M68K_LINUX_FPREGS_SIZE (27 * 4)
357 static const struct regset m68k_linux_gregset
=
360 regcache_supply_regset
, regcache_collect_regset
363 static const struct regset m68k_linux_fpregset
=
366 regcache_supply_regset
, regcache_collect_regset
369 /* Iterate over core file register note sections. */
372 m68k_linux_iterate_over_regset_sections (struct gdbarch
*gdbarch
,
373 iterate_over_regset_sections_cb
*cb
,
375 const struct regcache
*regcache
)
377 cb (".reg", M68K_LINUX_GREGS_SIZE
, M68K_LINUX_GREGS_SIZE
, &m68k_linux_gregset
,
379 cb (".reg2", M68K_LINUX_FPREGS_SIZE
, M68K_LINUX_FPREGS_SIZE
,
380 &m68k_linux_fpregset
, NULL
, cb_data
);
384 m68k_linux_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
386 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
388 linux_init_abi (info
, gdbarch
);
390 tdep
->jb_pc
= M68K_LINUX_JB_PC
;
391 tdep
->jb_elt_size
= M68K_LINUX_JB_ELEMENT_SIZE
;
393 /* GNU/Linux uses a calling convention that's similar to SVR4. It
394 returns integer values in %d0/%d1, pointer values in %a0 and
395 floating values in %fp0, just like SVR4, but uses %a1 to pass the
396 address to store a structure value. It also returns small
397 structures in registers instead of memory. */
398 m68k_svr4_init_abi (info
, gdbarch
);
399 tdep
->struct_value_regnum
= M68K_A1_REGNUM
;
400 tdep
->struct_return
= reg_struct_return
;
402 set_gdbarch_decr_pc_after_break (gdbarch
, 2);
404 frame_unwind_append_unwinder (gdbarch
, &m68k_linux_sigtramp_frame_unwind
);
406 /* Shared library handling. */
408 /* GNU/Linux uses SVR4-style shared libraries. */
409 set_solib_svr4_fetch_link_map_offsets (gdbarch
,
410 svr4_ilp32_fetch_link_map_offsets
);
412 /* GNU/Linux uses the dynamic linker included in the GNU C Library. */
413 set_gdbarch_skip_solib_resolver (gdbarch
, glibc_skip_solib_resolver
);
415 set_gdbarch_skip_trampoline_code (gdbarch
, find_solib_trampoline_target
);
417 /* Core file support. */
418 set_gdbarch_iterate_over_regset_sections
419 (gdbarch
, m68k_linux_iterate_over_regset_sections
);
421 /* Enable TLS support. */
422 set_gdbarch_fetch_tls_load_module_address (gdbarch
,
423 svr4_fetch_objfile_link_map
);
427 _initialize_m68k_linux_tdep (void)
429 gdbarch_register_osabi (bfd_arch_m68k
, 0, GDB_OSABI_LINUX
,
430 m68k_linux_init_abi
);
431 gdb::observers::inferior_created
.attach (m68k_linux_inferior_created
);