1 /* Motorola m68k target-dependent support for GNU/Linux.
3 Copyright (C) 1996, 1998, 2000, 2001, 2002, 2003, 2004, 2007, 2008, 2009,
4 2010, 2011 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"
41 #include "linux-tdep.h"
43 /* Offsets (in target ints) into jmp_buf. */
45 #define M68K_LINUX_JB_ELEMENT_SIZE 4
46 #define M68K_LINUX_JB_PC 7
48 /* Check whether insn1 and insn2 are parts of a signal trampoline. */
50 #define IS_SIGTRAMP(insn1, insn2) \
51 (/* addaw #20,sp; moveq #119,d0; trap #0 */ \
52 (insn1 == 0xdefc0014 && insn2 == 0x70774e40) \
53 /* moveq #119,d0; trap #0 */ \
54 || insn1 == 0x70774e40)
56 #define IS_RT_SIGTRAMP(insn1, insn2) \
57 (/* movel #173,d0; trap #0 */ \
58 (insn1 == 0x203c0000 && insn2 == 0x00ad4e40) \
59 /* moveq #82,d0; notb d0; trap #0 */ \
60 || (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40))
62 /* Return non-zero if THIS_FRAME corresponds to a signal trampoline. For
63 the sake of m68k_linux_get_sigtramp_info we also distinguish between
64 non-RT and RT signal trampolines. */
67 m68k_linux_pc_in_sigtramp (struct frame_info
*this_frame
)
69 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
70 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
73 unsigned long insn0
, insn1
, insn2
;
74 CORE_ADDR pc
= get_frame_pc (this_frame
);
76 if (!safe_frame_unwind_memory (this_frame
, pc
- 4, buf
, sizeof (buf
)))
78 insn1
= extract_unsigned_integer (buf
+ 4, 4, byte_order
);
79 insn2
= extract_unsigned_integer (buf
+ 8, 4, byte_order
);
80 if (IS_SIGTRAMP (insn1
, insn2
))
82 if (IS_RT_SIGTRAMP (insn1
, insn2
))
85 insn0
= extract_unsigned_integer (buf
, 4, byte_order
);
86 if (IS_SIGTRAMP (insn0
, insn1
))
88 if (IS_RT_SIGTRAMP (insn0
, insn1
))
91 insn0
= ((insn0
<< 16) & 0xffffffff) | (insn1
>> 16);
92 insn1
= ((insn1
<< 16) & 0xffffffff) | (insn2
>> 16);
93 if (IS_SIGTRAMP (insn0
, insn1
))
95 if (IS_RT_SIGTRAMP (insn0
, insn1
))
101 /* From <asm/sigcontext.h>. */
102 static int m68k_linux_sigcontext_reg_offset
[M68K_NUM_REGS
] =
132 16 * 4 /* %fpiaddr */
135 static int m68k_uclinux_sigcontext_reg_offset
[M68K_NUM_REGS
] =
168 /* From <asm/ucontext.h>. */
169 static int m68k_linux_ucontext_reg_offset
[M68K_NUM_REGS
] =
199 26 * 4 /* %fpiaddr */
203 /* Get info about saved registers in sigtramp. */
205 struct m68k_linux_sigtramp_info
207 /* Address of sigcontext. */
208 CORE_ADDR sigcontext_addr
;
210 /* Offset of registers in `struct sigcontext'. */
214 /* Nonzero if running on uClinux. */
215 static int target_is_uclinux
;
218 m68k_linux_inferior_created (struct target_ops
*objfile
, int from_tty
)
220 /* Record that we will need to re-evaluate whether we are running on a
221 uClinux or normal GNU/Linux target (see m68k_linux_get_sigtramp_info). */
222 target_is_uclinux
= -1;
225 static struct m68k_linux_sigtramp_info
226 m68k_linux_get_sigtramp_info (struct frame_info
*this_frame
)
228 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
229 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
231 struct m68k_linux_sigtramp_info info
;
233 if (target_is_uclinux
== -1)
235 /* Determine whether we are running on a uClinux or normal GNU/Linux
236 target so we can use the correct sigcontext layouts. */
240 = (target_auxv_search (¤t_target
, AT_NULL
, &dummy
) > 0
241 && target_auxv_search (¤t_target
, AT_PAGESZ
, &dummy
) == 0);
244 sp
= get_frame_register_unsigned (this_frame
, M68K_SP_REGNUM
);
246 /* Get sigcontext address, it is the third parameter on the stack. */
247 info
.sigcontext_addr
= read_memory_unsigned_integer (sp
+ 8, 4, byte_order
);
249 if (m68k_linux_pc_in_sigtramp (this_frame
) == 2)
250 info
.sc_reg_offset
= m68k_linux_ucontext_reg_offset
;
252 info
.sc_reg_offset
= (target_is_uclinux
253 ? m68k_uclinux_sigcontext_reg_offset
254 : m68k_linux_sigcontext_reg_offset
);
258 /* Signal trampolines. */
260 static struct trad_frame_cache
*
261 m68k_linux_sigtramp_frame_cache (struct frame_info
*this_frame
,
264 struct frame_id this_id
;
265 struct trad_frame_cache
*cache
;
266 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
267 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
268 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
269 struct m68k_linux_sigtramp_info info
;
276 cache
= trad_frame_cache_zalloc (this_frame
);
278 /* FIXME: cagney/2004-05-01: This is is long standing broken code.
279 The frame ID's code address should be the start-address of the
280 signal trampoline and not the current PC within that
282 get_frame_register (this_frame
, M68K_SP_REGNUM
, buf
);
283 /* See the end of m68k_push_dummy_call. */
284 this_id
= frame_id_build (extract_unsigned_integer (buf
, 4, byte_order
)
285 - 4 + 8, get_frame_pc (this_frame
));
286 trad_frame_set_id (cache
, this_id
);
288 info
= m68k_linux_get_sigtramp_info (this_frame
);
290 for (i
= 0; i
< M68K_NUM_REGS
; i
++)
291 if (info
.sc_reg_offset
[i
] != -1)
292 trad_frame_set_reg_addr (cache
, i
,
293 info
.sigcontext_addr
+ info
.sc_reg_offset
[i
]);
300 m68k_linux_sigtramp_frame_this_id (struct frame_info
*this_frame
,
302 struct frame_id
*this_id
)
304 struct trad_frame_cache
*cache
=
305 m68k_linux_sigtramp_frame_cache (this_frame
, this_cache
);
306 trad_frame_get_id (cache
, this_id
);
309 static struct value
*
310 m68k_linux_sigtramp_frame_prev_register (struct frame_info
*this_frame
,
314 /* Make sure we've initialized the cache. */
315 struct trad_frame_cache
*cache
=
316 m68k_linux_sigtramp_frame_cache (this_frame
, this_cache
);
317 return trad_frame_get_register (cache
, this_frame
, regnum
);
321 m68k_linux_sigtramp_frame_sniffer (const struct frame_unwind
*self
,
322 struct frame_info
*this_frame
,
323 void **this_prologue_cache
)
325 return m68k_linux_pc_in_sigtramp (this_frame
);
328 static const struct frame_unwind m68k_linux_sigtramp_frame_unwind
=
331 default_frame_unwind_stop_reason
,
332 m68k_linux_sigtramp_frame_this_id
,
333 m68k_linux_sigtramp_frame_prev_register
,
335 m68k_linux_sigtramp_frame_sniffer
339 m68k_linux_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
341 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
343 linux_init_abi (info
, gdbarch
);
345 tdep
->jb_pc
= M68K_LINUX_JB_PC
;
346 tdep
->jb_elt_size
= M68K_LINUX_JB_ELEMENT_SIZE
;
348 /* GNU/Linux uses a calling convention that's similar to SVR4. It
349 returns integer values in %d0/%d1, pointer values in %a0 and
350 floating values in %fp0, just like SVR4, but uses %a1 to pass the
351 address to store a structure value. It also returns small
352 structures in registers instead of memory. */
353 m68k_svr4_init_abi (info
, gdbarch
);
354 tdep
->struct_value_regnum
= M68K_A1_REGNUM
;
355 tdep
->struct_return
= reg_struct_return
;
357 set_gdbarch_decr_pc_after_break (gdbarch
, 2);
359 frame_unwind_append_unwinder (gdbarch
, &m68k_linux_sigtramp_frame_unwind
);
361 /* Shared library handling. */
363 /* GNU/Linux uses SVR4-style shared libraries. */
364 set_solib_svr4_fetch_link_map_offsets (gdbarch
,
365 svr4_ilp32_fetch_link_map_offsets
);
367 /* GNU/Linux uses the dynamic linker included in the GNU C Library. */
368 set_gdbarch_skip_solib_resolver (gdbarch
, glibc_skip_solib_resolver
);
370 set_gdbarch_skip_trampoline_code (gdbarch
, find_solib_trampoline_target
);
372 /* Enable TLS support. */
373 set_gdbarch_fetch_tls_load_module_address (gdbarch
,
374 svr4_fetch_objfile_link_map
);
377 /* Provide a prototype to silence -Wmissing-prototypes. */
378 extern initialize_file_ftype _initialize_m68k_linux_tdep
;
381 _initialize_m68k_linux_tdep (void)
383 gdbarch_register_osabi (bfd_arch_m68k
, 0, GDB_OSABI_LINUX
,
384 m68k_linux_init_abi
);
385 observer_attach_inferior_created (m68k_linux_inferior_created
);