1 /* Motorola m68k target-dependent support for GNU/Linux.
3 Copyright (C) 1996, 1998, 2000, 2001, 2002, 2003, 2004, 2007, 2008, 2009,
4 2010 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "floatformat.h"
27 #include "gdb_string.h"
33 #include "m68k-tdep.h"
34 #include "trad-frame.h"
35 #include "frame-unwind.h"
36 #include "glibc-tdep.h"
37 #include "solib-svr4.h"
40 #include "elf/common.h"
42 /* Offsets (in target ints) into jmp_buf. */
44 #define M68K_LINUX_JB_ELEMENT_SIZE 4
45 #define M68K_LINUX_JB_PC 7
47 /* Check whether insn1 and insn2 are parts of a signal trampoline. */
49 #define IS_SIGTRAMP(insn1, insn2) \
50 (/* addaw #20,sp; moveq #119,d0; trap #0 */ \
51 (insn1 == 0xdefc0014 && insn2 == 0x70774e40) \
52 /* moveq #119,d0; trap #0 */ \
53 || insn1 == 0x70774e40)
55 #define IS_RT_SIGTRAMP(insn1, insn2) \
56 (/* movel #173,d0; trap #0 */ \
57 (insn1 == 0x203c0000 && insn2 == 0x00ad4e40) \
58 /* moveq #82,d0; notb d0; trap #0 */ \
59 || (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40))
61 /* Return non-zero if THIS_FRAME corresponds to a signal trampoline. For
62 the sake of m68k_linux_get_sigtramp_info we also distinguish between
63 non-RT and RT signal trampolines. */
66 m68k_linux_pc_in_sigtramp (struct frame_info
*this_frame
)
68 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
69 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
72 unsigned long insn0
, insn1
, insn2
;
73 CORE_ADDR pc
= get_frame_pc (this_frame
);
75 if (!safe_frame_unwind_memory (this_frame
, pc
- 4, buf
, sizeof (buf
)))
77 insn1
= extract_unsigned_integer (buf
+ 4, 4, byte_order
);
78 insn2
= extract_unsigned_integer (buf
+ 8, 4, byte_order
);
79 if (IS_SIGTRAMP (insn1
, insn2
))
81 if (IS_RT_SIGTRAMP (insn1
, insn2
))
84 insn0
= extract_unsigned_integer (buf
, 4, byte_order
);
85 if (IS_SIGTRAMP (insn0
, insn1
))
87 if (IS_RT_SIGTRAMP (insn0
, insn1
))
90 insn0
= ((insn0
<< 16) & 0xffffffff) | (insn1
>> 16);
91 insn1
= ((insn1
<< 16) & 0xffffffff) | (insn2
>> 16);
92 if (IS_SIGTRAMP (insn0
, insn1
))
94 if (IS_RT_SIGTRAMP (insn0
, insn1
))
100 /* From <asm/sigcontext.h>. */
101 static int m68k_linux_sigcontext_reg_offset
[M68K_NUM_REGS
] =
131 16 * 4 /* %fpiaddr */
134 static int m68k_uclinux_sigcontext_reg_offset
[M68K_NUM_REGS
] =
167 /* From <asm/ucontext.h>. */
168 static int m68k_linux_ucontext_reg_offset
[M68K_NUM_REGS
] =
198 26 * 4 /* %fpiaddr */
202 /* Get info about saved registers in sigtramp. */
204 struct m68k_linux_sigtramp_info
206 /* Address of sigcontext. */
207 CORE_ADDR sigcontext_addr
;
209 /* Offset of registers in `struct sigcontext'. */
213 /* Nonzero if running on uClinux. */
214 static int target_is_uclinux
;
217 m68k_linux_inferior_created (struct target_ops
*objfile
, int from_tty
)
219 /* Record that we will need to re-evaluate whether we are running on a
220 uClinux or normal GNU/Linux target (see m68k_linux_get_sigtramp_info). */
221 target_is_uclinux
= -1;
224 static struct m68k_linux_sigtramp_info
225 m68k_linux_get_sigtramp_info (struct frame_info
*this_frame
)
227 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
228 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
230 struct m68k_linux_sigtramp_info info
;
232 if (target_is_uclinux
== -1)
234 /* Determine whether we are running on a uClinux or normal GNU/Linux
235 target so we can use the correct sigcontext layouts. */
239 = (target_auxv_search (¤t_target
, AT_NULL
, &dummy
) > 0
240 && target_auxv_search (¤t_target
, AT_PAGESZ
, &dummy
) == 0);
243 sp
= get_frame_register_unsigned (this_frame
, M68K_SP_REGNUM
);
245 /* Get sigcontext address, it is the third parameter on the stack. */
246 info
.sigcontext_addr
= read_memory_unsigned_integer (sp
+ 8, 4, byte_order
);
248 if (m68k_linux_pc_in_sigtramp (this_frame
) == 2)
249 info
.sc_reg_offset
= m68k_linux_ucontext_reg_offset
;
251 info
.sc_reg_offset
= (target_is_uclinux
252 ? m68k_uclinux_sigcontext_reg_offset
253 : m68k_linux_sigcontext_reg_offset
);
257 /* Signal trampolines. */
259 static struct trad_frame_cache
*
260 m68k_linux_sigtramp_frame_cache (struct frame_info
*this_frame
,
263 struct frame_id this_id
;
264 struct trad_frame_cache
*cache
;
265 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
266 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
267 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
268 struct m68k_linux_sigtramp_info info
;
275 cache
= trad_frame_cache_zalloc (this_frame
);
277 /* FIXME: cagney/2004-05-01: This is is long standing broken code.
278 The frame ID's code address should be the start-address of the
279 signal trampoline and not the current PC within that
281 get_frame_register (this_frame
, M68K_SP_REGNUM
, buf
);
282 /* See the end of m68k_push_dummy_call. */
283 this_id
= frame_id_build (extract_unsigned_integer (buf
, 4, byte_order
)
284 - 4 + 8, get_frame_pc (this_frame
));
285 trad_frame_set_id (cache
, this_id
);
287 info
= m68k_linux_get_sigtramp_info (this_frame
);
289 for (i
= 0; i
< M68K_NUM_REGS
; i
++)
290 if (info
.sc_reg_offset
[i
] != -1)
291 trad_frame_set_reg_addr (cache
, i
,
292 info
.sigcontext_addr
+ info
.sc_reg_offset
[i
]);
299 m68k_linux_sigtramp_frame_this_id (struct frame_info
*this_frame
,
301 struct frame_id
*this_id
)
303 struct trad_frame_cache
*cache
=
304 m68k_linux_sigtramp_frame_cache (this_frame
, this_cache
);
305 trad_frame_get_id (cache
, this_id
);
308 static struct value
*
309 m68k_linux_sigtramp_frame_prev_register (struct frame_info
*this_frame
,
313 /* Make sure we've initialized the cache. */
314 struct trad_frame_cache
*cache
=
315 m68k_linux_sigtramp_frame_cache (this_frame
, this_cache
);
316 return trad_frame_get_register (cache
, this_frame
, regnum
);
320 m68k_linux_sigtramp_frame_sniffer (const struct frame_unwind
*self
,
321 struct frame_info
*this_frame
,
322 void **this_prologue_cache
)
324 return m68k_linux_pc_in_sigtramp (this_frame
);
327 static const struct frame_unwind m68k_linux_sigtramp_frame_unwind
=
330 m68k_linux_sigtramp_frame_this_id
,
331 m68k_linux_sigtramp_frame_prev_register
,
333 m68k_linux_sigtramp_frame_sniffer
337 m68k_linux_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
339 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
341 tdep
->jb_pc
= M68K_LINUX_JB_PC
;
342 tdep
->jb_elt_size
= M68K_LINUX_JB_ELEMENT_SIZE
;
344 /* GNU/Linux uses a calling convention that's similar to SVR4. It
345 returns integer values in %d0/%d1, pointer values in %a0 and
346 floating values in %fp0, just like SVR4, but uses %a1 to pass the
347 address to store a structure value. It also returns small
348 structures in registers instead of memory. */
349 m68k_svr4_init_abi (info
, gdbarch
);
350 tdep
->struct_value_regnum
= M68K_A1_REGNUM
;
351 tdep
->struct_return
= reg_struct_return
;
353 set_gdbarch_decr_pc_after_break (gdbarch
, 2);
355 frame_unwind_append_unwinder (gdbarch
, &m68k_linux_sigtramp_frame_unwind
);
357 /* Shared library handling. */
359 /* GNU/Linux uses SVR4-style shared libraries. */
360 set_solib_svr4_fetch_link_map_offsets (gdbarch
,
361 svr4_ilp32_fetch_link_map_offsets
);
363 /* GNU/Linux uses the dynamic linker included in the GNU C Library. */
364 set_gdbarch_skip_solib_resolver (gdbarch
, glibc_skip_solib_resolver
);
366 set_gdbarch_skip_trampoline_code (gdbarch
, find_solib_trampoline_target
);
368 /* Enable TLS support. */
369 set_gdbarch_fetch_tls_load_module_address (gdbarch
,
370 svr4_fetch_objfile_link_map
);
373 /* Provide a prototype to silence -Wmissing-prototypes. */
374 extern initialize_file_ftype _initialize_m68k_linux_tdep
;
377 _initialize_m68k_linux_tdep (void)
379 gdbarch_register_osabi (bfd_arch_m68k
, 0, GDB_OSABI_LINUX
,
380 m68k_linux_init_abi
);
381 observer_attach_inferior_created (m68k_linux_inferior_created
);