1 /* Target-dependent code for OpenBSD/amd64.
3 Copyright 2003, 2004, 2005 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 2 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, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
32 #include "gdb_assert.h"
33 #include "gdb_string.h"
35 #include "amd64-tdep.h"
36 #include "i387-tdep.h"
37 #include "solib-svr4.h"
38 #include "bsd-uthread.h"
40 /* Support for core dumps. */
43 amd64obsd_supply_regset (const struct regset
*regset
,
44 struct regcache
*regcache
, int regnum
,
45 const void *regs
, size_t len
)
47 const struct gdbarch_tdep
*tdep
= gdbarch_tdep (regset
->arch
);
49 gdb_assert (len
>= tdep
->sizeof_gregset
+ I387_SIZEOF_FXSAVE
);
51 i386_supply_gregset (regset
, regcache
, regnum
, regs
, tdep
->sizeof_gregset
);
52 amd64_supply_fxsave (regcache
, regnum
,
53 ((const gdb_byte
*)regs
) + tdep
->sizeof_gregset
);
56 static const struct regset
*
57 amd64obsd_regset_from_core_section (struct gdbarch
*gdbarch
,
58 const char *sect_name
, size_t sect_size
)
60 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
62 /* OpenBSD core dumps don't use seperate register sets for the
63 general-purpose and floating-point registers. */
65 if (strcmp (sect_name
, ".reg") == 0
66 && sect_size
>= tdep
->sizeof_gregset
+ I387_SIZEOF_FXSAVE
)
68 if (tdep
->gregset
== NULL
)
69 tdep
->gregset
= regset_alloc (gdbarch
, amd64obsd_supply_regset
, NULL
);
77 /* Support for signal handlers. */
79 /* Default page size. */
80 static const int amd64obsd_page_size
= 4096;
82 /* Return whether the frame preceding NEXT_FRAME corresponds to an
83 OpenBSD sigtramp routine. */
86 amd64obsd_sigtramp_p (struct frame_info
*next_frame
)
88 CORE_ADDR pc
= frame_pc_unwind (next_frame
);
89 CORE_ADDR start_pc
= (pc
& ~(amd64obsd_page_size
- 1));
90 const gdb_byte sigreturn
[] =
93 0x67, 0x00, 0x00, 0x00, /* movq $SYS_sigreturn, %rax */
94 0xcd, 0x80 /* int $0x80 */
96 size_t buflen
= (sizeof sigreturn
) + 1;
100 /* If the function has a valid symbol name, it isn't a
102 find_pc_partial_function (pc
, &name
, NULL
, NULL
);
106 /* If the function lives in a valid section (even without a starting
107 point) it isn't a trampoline. */
108 if (find_pc_section (pc
) != NULL
)
111 /* If we can't read the instructions at START_PC, return zero. */
112 buf
= alloca ((sizeof sigreturn
) + 1);
113 if (!safe_frame_unwind_memory (next_frame
, start_pc
+ 6, buf
, buflen
))
116 /* Check for sigreturn(2). Depending on how the assembler encoded
117 the `movq %rsp, %rdi' instruction, the code starts at offset 6 or
119 if (memcmp (buf
, sigreturn
, sizeof sigreturn
)
120 && memcpy (buf
+ 1, sigreturn
, sizeof sigreturn
))
126 /* Assuming NEXT_FRAME is for a frame following a BSD sigtramp
127 routine, return the address of the associated sigcontext structure. */
130 amd64obsd_sigcontext_addr (struct frame_info
*next_frame
)
132 CORE_ADDR pc
= frame_pc_unwind (next_frame
);
133 ULONGEST offset
= (pc
& (amd64obsd_page_size
- 1));
135 /* The %rsp register points at `struct sigcontext' upon entry of a
136 signal trampoline. The relevant part of the trampoline is
141 movq $SYS_sigreturn,%rax
144 (see /usr/src/sys/arch/amd64/amd64/locore.S). The `pushq'
145 instruction clobbers %rsp, but its value is saved in `%rdi'. */
148 return frame_unwind_register_unsigned (next_frame
, AMD64_RDI_REGNUM
);
150 return frame_unwind_register_unsigned (next_frame
, AMD64_RSP_REGNUM
);
153 /* OpenBSD 3.5 or later. */
155 /* Mapping between the general-purpose registers in `struct reg'
156 format and GDB's register cache layout. */
158 /* From <machine/reg.h>. */
159 int amd64obsd_r_reg_offset
[] =
176 11 * 8, /* ... %r15 */
178 17 * 8, /* %eflags */
187 /* From <machine/signal.h>. */
188 static int amd64obsd_sc_reg_offset
[] =
205 11 * 8, /* ... %r15 */
207 23 * 8, /* %eflags */
216 /* From /usr/src/lib/libpthread/arch/amd64/uthread_machdep.c. */
217 static int amd64obsd_uthread_reg_offset
[] =
227 12 * 8, /* %r8 ... */
234 5 * 8, /* ... %r15 */
245 /* Offset within the thread structure where we can find the saved
246 stack pointer (%esp). */
247 #define AMD64OBSD_UTHREAD_RSP_OFFSET 400
250 amd64obsd_supply_uthread (struct regcache
*regcache
,
251 int regnum
, CORE_ADDR addr
)
253 CORE_ADDR sp_addr
= addr
+ AMD64OBSD_UTHREAD_RSP_OFFSET
;
258 gdb_assert (regnum
>= -1);
260 if (regnum
== -1 || regnum
== AMD64_RSP_REGNUM
)
264 /* Fetch stack pointer from thread structure. */
265 sp
= read_memory_unsigned_integer (sp_addr
, 8);
267 /* Adjust the stack pointer such that it looks as if we just
268 returned from _thread_machdep_switch. */
269 offset
= amd64obsd_uthread_reg_offset
[AMD64_RIP_REGNUM
] + 8;
270 store_unsigned_integer (buf
, 8, sp
+ offset
);
271 regcache_raw_supply (regcache
, AMD64_RSP_REGNUM
, buf
);
274 for (i
= 0; i
< ARRAY_SIZE (amd64obsd_uthread_reg_offset
); i
++)
276 if (amd64obsd_uthread_reg_offset
[i
] != -1
277 && (regnum
== -1 || regnum
== i
))
279 /* Fetch stack pointer from thread structure (if we didn't
282 sp
= read_memory_unsigned_integer (sp_addr
, 8);
284 /* Read the saved register from the stack frame. */
285 read_memory (sp
+ amd64obsd_uthread_reg_offset
[i
], buf
, 8);
286 regcache_raw_supply (regcache
, i
, buf
);
292 amd64obsd_collect_uthread (const struct regcache
*regcache
,
293 int regnum
, CORE_ADDR addr
)
295 CORE_ADDR sp_addr
= addr
+ AMD64OBSD_UTHREAD_RSP_OFFSET
;
300 gdb_assert (regnum
>= -1);
302 if (regnum
== -1 || regnum
== AMD64_RSP_REGNUM
)
306 /* Calculate the stack pointer (frame pointer) that will be
307 stored into the thread structure. */
308 offset
= amd64obsd_uthread_reg_offset
[AMD64_RIP_REGNUM
] + 8;
309 regcache_raw_collect (regcache
, AMD64_RSP_REGNUM
, buf
);
310 sp
= extract_unsigned_integer (buf
, 8) - offset
;
312 /* Store the stack pointer. */
313 write_memory_unsigned_integer (sp_addr
, 8, sp
);
315 /* The stack pointer was (potentially) modified. Make sure we
316 build a proper stack frame. */
320 for (i
= 0; i
< ARRAY_SIZE (amd64obsd_uthread_reg_offset
); i
++)
322 if (amd64obsd_uthread_reg_offset
[i
] != -1
323 && (regnum
== -1 || regnum
== i
))
325 /* Fetch stack pointer from thread structure (if we didn't
326 calculate it already). */
328 sp
= read_memory_unsigned_integer (sp_addr
, 8);
330 /* Write the register into the stack frame. */
331 regcache_raw_collect (regcache
, i
, buf
);
332 write_memory (sp
+ amd64obsd_uthread_reg_offset
[i
], buf
, 8);
338 amd64obsd_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
340 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
342 amd64_init_abi (info
, gdbarch
);
344 /* Initialize general-purpose register set details. */
345 tdep
->gregset_reg_offset
= amd64obsd_r_reg_offset
;
346 tdep
->gregset_num_regs
= ARRAY_SIZE (amd64obsd_r_reg_offset
);
347 tdep
->sizeof_gregset
= 24 * 8;
349 set_gdbarch_regset_from_core_section (gdbarch
,
350 amd64obsd_regset_from_core_section
);
352 tdep
->jb_pc_offset
= 7 * 8;
354 tdep
->sigtramp_p
= amd64obsd_sigtramp_p
;
355 tdep
->sigcontext_addr
= amd64obsd_sigcontext_addr
;
356 tdep
->sc_reg_offset
= amd64obsd_sc_reg_offset
;
357 tdep
->sc_num_regs
= ARRAY_SIZE (amd64obsd_sc_reg_offset
);
359 /* OpenBSD provides a user-level threads implementation. */
360 bsd_uthread_set_supply_uthread (gdbarch
, amd64obsd_supply_uthread
);
361 bsd_uthread_set_collect_uthread (gdbarch
, amd64obsd_collect_uthread
);
363 /* OpenBSD uses SVR4-style shared libraries. */
364 set_solib_svr4_fetch_link_map_offsets
365 (gdbarch
, svr4_lp64_fetch_link_map_offsets
);
369 /* Provide a prototype to silence -Wmissing-prototypes. */
370 void _initialize_amd64obsd_tdep (void);
373 _initialize_amd64obsd_tdep (void)
375 /* The OpenBSD/amd64 native dependent code makes this assumption. */
376 gdb_assert (ARRAY_SIZE (amd64obsd_r_reg_offset
) == AMD64_NUM_GREGS
);
378 gdbarch_register_osabi (bfd_arch_i386
, bfd_mach_x86_64
,
379 GDB_OSABI_OPENBSD_ELF
, amd64obsd_init_abi
);
381 /* OpenBSD uses traditional (a.out) NetBSD-style core dumps. */
382 gdbarch_register_osabi (bfd_arch_i386
, bfd_mach_x86_64
,
383 GDB_OSABI_NETBSD_AOUT
, amd64obsd_init_abi
);