1 /* Target-dependent code for FreeBSD/i386.
3 Copyright (C) 2003-2015 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/>. */
21 #include "arch-utils.h"
26 #include "i386fbsd-tdep.h"
27 #include "x86-xstate.h"
29 #include "i386-tdep.h"
30 #include "i387-tdep.h"
31 #include "bsd-uthread.h"
32 #include "fbsd-tdep.h"
33 #include "solib-svr4.h"
35 /* Support for signal handlers. */
37 /* Return whether THIS_FRAME corresponds to a FreeBSD sigtramp
40 /* FreeBSD/i386 supports three different signal trampolines, one for
41 versions before 4.0, a second for 4.x, and a third for 5.0 and
42 later. To complicate matters, FreeBSD/i386 binaries running under
43 an amd64 kernel use a different set of trampolines. These
44 trampolines differ from the i386 kernel trampolines in that they
45 omit a middle section that conditionally restores %gs. */
47 static const gdb_byte i386fbsd_sigtramp_start
[] =
49 0x8d, 0x44, 0x24, 0x20, /* lea SIGF_UC(%esp),%eax */
53 static const gdb_byte i386fbsd_sigtramp_middle
[] =
55 0xf7, 0x40, 0x54, 0x00, 0x00, 0x02, 0x00,
56 /* testl $PSL_VM,UC_EFLAGS(%eax) */
57 0x75, 0x03, /* jne +3 */
58 0x8e, 0x68, 0x14 /* mov UC_GS(%eax),%gs */
61 static const gdb_byte i386fbsd_sigtramp_end
[] =
63 0xb8, 0xa1, 0x01, 0x00, 0x00, /* movl $SYS_sigreturn,%eax */
64 0x50, /* pushl %eax */
65 0xcd, 0x80 /* int $0x80 */
68 static const gdb_byte i386fbsd_freebsd4_sigtramp_start
[] =
70 0x8d, 0x44, 0x24, 0x14, /* lea SIGF_UC4(%esp),%eax */
74 static const gdb_byte i386fbsd_freebsd4_sigtramp_middle
[] =
76 0xf7, 0x40, 0x54, 0x00, 0x00, 0x02, 0x00,
77 /* testl $PSL_VM,UC4_EFLAGS(%eax) */
78 0x75, 0x03, /* jne +3 */
79 0x8e, 0x68, 0x14 /* mov UC4_GS(%eax),%gs */
82 static const gdb_byte i386fbsd_freebsd4_sigtramp_end
[] =
84 0xb8, 0x58, 0x01, 0x00, 0x00, /* movl $344,%eax */
85 0x50, /* pushl %eax */
86 0xcd, 0x80 /* int $0x80 */
89 static const gdb_byte i386fbsd_osigtramp_start
[] =
91 0x8d, 0x44, 0x24, 0x14, /* lea SIGF_SC(%esp),%eax */
95 static const gdb_byte i386fbsd_osigtramp_middle
[] =
97 0xf7, 0x40, 0x18, 0x00, 0x00, 0x02, 0x00,
98 /* testl $PSL_VM,SC_PS(%eax) */
99 0x75, 0x03, /* jne +3 */
100 0x8e, 0x68, 0x44 /* mov SC_GS(%eax),%gs */
103 static const gdb_byte i386fbsd_osigtramp_end
[] =
105 0xb8, 0x67, 0x00, 0x00, 0x00, /* movl $103,%eax */
106 0x50, /* pushl %eax */
107 0xcd, 0x80 /* int $0x80 */
110 /* The three different trampolines are all the same size. */
111 gdb_static_assert (sizeof i386fbsd_sigtramp_start
112 == sizeof i386fbsd_freebsd4_sigtramp_start
);
113 gdb_static_assert (sizeof i386fbsd_sigtramp_start
114 == sizeof i386fbsd_osigtramp_start
);
115 gdb_static_assert (sizeof i386fbsd_sigtramp_middle
116 == sizeof i386fbsd_freebsd4_sigtramp_middle
);
117 gdb_static_assert (sizeof i386fbsd_sigtramp_middle
118 == sizeof i386fbsd_osigtramp_middle
);
119 gdb_static_assert (sizeof i386fbsd_sigtramp_end
120 == sizeof i386fbsd_freebsd4_sigtramp_end
);
121 gdb_static_assert (sizeof i386fbsd_sigtramp_end
122 == sizeof i386fbsd_osigtramp_end
);
124 /* We assume that the middle is the largest chunk below. */
125 gdb_static_assert (sizeof i386fbsd_sigtramp_middle
126 > sizeof i386fbsd_sigtramp_start
);
127 gdb_static_assert (sizeof i386fbsd_sigtramp_middle
128 > sizeof i386fbsd_sigtramp_end
);
131 i386fbsd_sigtramp_p (struct frame_info
*this_frame
)
133 CORE_ADDR pc
= get_frame_pc (this_frame
);
134 gdb_byte buf
[sizeof i386fbsd_sigtramp_middle
];
135 const gdb_byte
*middle
, *end
;
137 /* Look for a matching start. */
138 if (!safe_frame_unwind_memory (this_frame
, pc
, buf
,
139 sizeof i386fbsd_sigtramp_start
))
141 if (memcmp (buf
, i386fbsd_sigtramp_start
, sizeof i386fbsd_sigtramp_start
)
144 middle
= i386fbsd_sigtramp_middle
;
145 end
= i386fbsd_sigtramp_end
;
147 else if (memcmp (buf
, i386fbsd_freebsd4_sigtramp_start
,
148 sizeof i386fbsd_freebsd4_sigtramp_start
) == 0)
150 middle
= i386fbsd_freebsd4_sigtramp_middle
;
151 end
= i386fbsd_freebsd4_sigtramp_end
;
153 else if (memcmp (buf
, i386fbsd_osigtramp_start
,
154 sizeof i386fbsd_osigtramp_start
) == 0)
156 middle
= i386fbsd_osigtramp_middle
;
157 end
= i386fbsd_osigtramp_end
;
162 /* Since the end is shorter than the middle, check for a matching end
164 pc
+= sizeof i386fbsd_sigtramp_start
;
165 if (!safe_frame_unwind_memory (this_frame
, pc
, buf
,
166 sizeof i386fbsd_sigtramp_end
))
168 if (memcmp (buf
, end
, sizeof i386fbsd_sigtramp_end
) == 0)
171 /* If the end didn't match, check for a matching middle. */
172 if (!safe_frame_unwind_memory (this_frame
, pc
, buf
,
173 sizeof i386fbsd_sigtramp_middle
))
175 if (memcmp (buf
, middle
, sizeof i386fbsd_sigtramp_middle
) != 0)
178 /* The middle matched, check for a matching end. */
179 pc
+= sizeof i386fbsd_sigtramp_middle
;
180 if (!safe_frame_unwind_memory (this_frame
, pc
, buf
,
181 sizeof i386fbsd_sigtramp_end
))
183 if (memcmp (buf
, end
, sizeof i386fbsd_sigtramp_end
) != 0)
189 /* FreeBSD 3.0-RELEASE or later. */
191 /* From <machine/reg.h>. */
192 static int i386fbsd_r_reg_offset
[] =
194 9 * 4, 8 * 4, 7 * 4, 6 * 4, /* %eax, %ecx, %edx, %ebx */
195 15 * 4, 4 * 4, /* %esp, %ebp */
196 3 * 4, 2 * 4, /* %esi, %edi */
197 12 * 4, 14 * 4, /* %eip, %eflags */
198 13 * 4, 16 * 4, /* %cs, %ss */
199 1 * 4, 0 * 4, -1, -1 /* %ds, %es, %fs, %gs */
202 /* Sigtramp routine location. */
203 CORE_ADDR i386fbsd_sigtramp_start_addr
;
204 CORE_ADDR i386fbsd_sigtramp_end_addr
;
206 /* From <machine/signal.h>. */
207 int i386fbsd_sc_reg_offset
[] =
209 8 + 14 * 4, /* %eax */
210 8 + 13 * 4, /* %ecx */
211 8 + 12 * 4, /* %edx */
212 8 + 11 * 4, /* %ebx */
213 8 + 0 * 4, /* %esp */
214 8 + 1 * 4, /* %ebp */
215 8 + 10 * 4, /* %esi */
216 8 + 9 * 4, /* %edi */
217 8 + 3 * 4, /* %eip */
218 8 + 4 * 4, /* %eflags */
223 8 + 15 * 4, /* %fs */
227 /* From /usr/src/lib/libc/i386/gen/_setjmp.S. */
228 static int i386fbsd_jmp_buf_reg_offset
[] =
241 /* Get XSAVE extended state xcr0 from core dump. */
244 i386fbsd_core_read_xcr0 (bfd
*abfd
)
246 asection
*xstate
= bfd_get_section_by_name (abfd
, ".reg-xstate");
251 size_t size
= bfd_section_size (abfd
, xstate
);
253 /* Check extended state size. */
254 if (size
< X86_XSTATE_AVX_SIZE
)
255 xcr0
= X86_XSTATE_SSE_MASK
;
260 if (! bfd_get_section_contents (abfd
, xstate
, contents
,
261 I386_FBSD_XSAVE_XCR0_OFFSET
,
264 warning (_("Couldn't read `xcr0' bytes from "
265 "`.reg-xstate' section in core file."));
269 xcr0
= bfd_get_64 (abfd
, contents
);
278 /* Implement the core_read_description gdbarch method. */
280 static const struct target_desc
*
281 i386fbsd_core_read_description (struct gdbarch
*gdbarch
,
282 struct target_ops
*target
,
285 return i386_target_description (i386fbsd_core_read_xcr0 (abfd
));
288 /* Similar to i386_supply_fpregset, but use XSAVE extended state. */
291 i386fbsd_supply_xstateregset (const struct regset
*regset
,
292 struct regcache
*regcache
, int regnum
,
293 const void *xstateregs
, size_t len
)
295 i387_supply_xsave (regcache
, regnum
, xstateregs
);
298 /* Similar to i386_collect_fpregset, but use XSAVE extended state. */
301 i386fbsd_collect_xstateregset (const struct regset
*regset
,
302 const struct regcache
*regcache
,
303 int regnum
, void *xstateregs
, size_t len
)
305 i387_collect_xsave (regcache
, regnum
, xstateregs
, 1);
308 /* Register set definitions. */
310 static const struct regset i386fbsd_xstateregset
=
313 i386fbsd_supply_xstateregset
,
314 i386fbsd_collect_xstateregset
317 /* Iterate over core file register note sections. */
320 i386fbsd_iterate_over_regset_sections (struct gdbarch
*gdbarch
,
321 iterate_over_regset_sections_cb
*cb
,
323 const struct regcache
*regcache
)
325 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
327 cb (".reg", tdep
->sizeof_gregset
, &i386_gregset
, NULL
, cb_data
);
328 cb (".reg2", tdep
->sizeof_fpregset
, &i386_fpregset
, NULL
, cb_data
);
330 if (tdep
->xcr0
& X86_XSTATE_AVX
)
331 cb (".reg-xstate", X86_XSTATE_SIZE(tdep
->xcr0
),
332 &i386fbsd_xstateregset
, "XSAVE extended state", cb_data
);
336 i386fbsd_supply_uthread (struct regcache
*regcache
,
337 int regnum
, CORE_ADDR addr
)
342 gdb_assert (regnum
>= -1);
344 for (i
= 0; i
< ARRAY_SIZE (i386fbsd_jmp_buf_reg_offset
); i
++)
346 if (i386fbsd_jmp_buf_reg_offset
[i
] != -1
347 && (regnum
== -1 || regnum
== i
))
349 read_memory (addr
+ i386fbsd_jmp_buf_reg_offset
[i
], buf
, 4);
350 regcache_raw_supply (regcache
, i
, buf
);
356 i386fbsd_collect_uthread (const struct regcache
*regcache
,
357 int regnum
, CORE_ADDR addr
)
362 gdb_assert (regnum
>= -1);
364 for (i
= 0; i
< ARRAY_SIZE (i386fbsd_jmp_buf_reg_offset
); i
++)
366 if (i386fbsd_jmp_buf_reg_offset
[i
] != -1
367 && (regnum
== -1 || regnum
== i
))
369 regcache_raw_collect (regcache
, i
, buf
);
370 write_memory (addr
+ i386fbsd_jmp_buf_reg_offset
[i
], buf
, 4);
376 i386fbsdaout_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
378 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
380 /* Obviously FreeBSD is BSD-based. */
381 i386bsd_init_abi (info
, gdbarch
);
383 /* FreeBSD has a different `struct reg', and reserves some space for
384 its FPU emulator in `struct fpreg'. */
385 tdep
->gregset_reg_offset
= i386fbsd_r_reg_offset
;
386 tdep
->gregset_num_regs
= ARRAY_SIZE (i386fbsd_r_reg_offset
);
387 tdep
->sizeof_gregset
= 18 * 4;
388 tdep
->sizeof_fpregset
= 176;
390 /* FreeBSD uses -freg-struct-return by default. */
391 tdep
->struct_return
= reg_struct_return
;
393 tdep
->sigtramp_p
= i386fbsd_sigtramp_p
;
395 /* FreeBSD uses a different memory layout. */
396 tdep
->sigtramp_start
= i386fbsd_sigtramp_start_addr
;
397 tdep
->sigtramp_end
= i386fbsd_sigtramp_end_addr
;
399 /* FreeBSD has a more complete `struct sigcontext'. */
400 tdep
->sc_reg_offset
= i386fbsd_sc_reg_offset
;
401 tdep
->sc_num_regs
= ARRAY_SIZE (i386fbsd_sc_reg_offset
);
403 /* FreeBSD provides a user-level threads implementation. */
404 bsd_uthread_set_supply_uthread (gdbarch
, i386fbsd_supply_uthread
);
405 bsd_uthread_set_collect_uthread (gdbarch
, i386fbsd_collect_uthread
);
409 i386fbsd_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
411 /* It's almost identical to FreeBSD a.out. */
412 i386fbsdaout_init_abi (info
, gdbarch
);
414 /* Except that it uses ELF. */
415 i386_elf_init_abi (info
, gdbarch
);
417 /* FreeBSD ELF uses SVR4-style shared libraries. */
418 set_solib_svr4_fetch_link_map_offsets
419 (gdbarch
, svr4_ilp32_fetch_link_map_offsets
);
422 /* FreeBSD 4.0-RELEASE or later. */
424 /* From <machine/reg.h>. */
425 static int i386fbsd4_r_reg_offset
[] =
427 10 * 4, 9 * 4, 8 * 4, 7 * 4, /* %eax, %ecx, %edx, %ebx */
428 16 * 4, 5 * 4, /* %esp, %ebp */
429 4 * 4, 3 * 4, /* %esi, %edi */
430 13 * 4, 15 * 4, /* %eip, %eflags */
431 14 * 4, 17 * 4, /* %cs, %ss */
432 2 * 4, 1 * 4, 0 * 4, 18 * 4 /* %ds, %es, %fs, %gs */
435 /* From <machine/signal.h>. */
436 int i386fbsd4_sc_reg_offset
[] =
438 20 + 11 * 4, /* %eax */
439 20 + 10 * 4, /* %ecx */
440 20 + 9 * 4, /* %edx */
441 20 + 8 * 4, /* %ebx */
442 20 + 17 * 4, /* %esp */
443 20 + 6 * 4, /* %ebp */
444 20 + 5 * 4, /* %esi */
445 20 + 4 * 4, /* %edi */
446 20 + 14 * 4, /* %eip */
447 20 + 16 * 4, /* %eflags */
448 20 + 15 * 4, /* %cs */
449 20 + 18 * 4, /* %ss */
450 20 + 3 * 4, /* %ds */
451 20 + 2 * 4, /* %es */
452 20 + 1 * 4, /* %fs */
457 i386fbsd4_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
459 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
461 /* Generic FreeBSD support. */
462 fbsd_init_abi (info
, gdbarch
);
464 /* Inherit stuff from older releases. We assume that FreeBSD
465 4.0-RELEASE always uses ELF. */
466 i386fbsd_init_abi (info
, gdbarch
);
468 /* FreeBSD 4.0 introduced a new `struct reg'. */
469 tdep
->gregset_reg_offset
= i386fbsd4_r_reg_offset
;
470 tdep
->gregset_num_regs
= ARRAY_SIZE (i386fbsd4_r_reg_offset
);
471 tdep
->sizeof_gregset
= 19 * 4;
473 /* FreeBSD 4.0 introduced a new `struct sigcontext'. */
474 tdep
->sc_reg_offset
= i386fbsd4_sc_reg_offset
;
475 tdep
->sc_num_regs
= ARRAY_SIZE (i386fbsd4_sc_reg_offset
);
477 tdep
->xsave_xcr0_offset
= I386_FBSD_XSAVE_XCR0_OFFSET
;
479 /* Iterate over core file register note sections. */
480 set_gdbarch_iterate_over_regset_sections
481 (gdbarch
, i386fbsd_iterate_over_regset_sections
);
483 set_gdbarch_core_read_description (gdbarch
,
484 i386fbsd_core_read_description
);
488 /* Provide a prototype to silence -Wmissing-prototypes. */
489 void _initialize_i386fbsd_tdep (void);
492 _initialize_i386fbsd_tdep (void)
494 gdbarch_register_osabi (bfd_arch_i386
, 0, GDB_OSABI_FREEBSD_AOUT
,
495 i386fbsdaout_init_abi
);
496 gdbarch_register_osabi (bfd_arch_i386
, 0, GDB_OSABI_FREEBSD_ELF
,