1 /* Native-dependent code for FreeBSD/amd64.
2
3 Copyright 2003, 2004 Free Software Foundation, Inc.
4
5 This file is part of GDB.
6
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.
11
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.
16
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. */
21
22 #include "defs.h"
23 #include "inferior.h"
24 #include "regcache.h"
25 #include "target.h"
26
27 #include "gdb_assert.h"
28 #include <signal.h>
29 #include <stddef.h>
30 #include <sys/types.h>
31 #include <sys/ptrace.h>
32 #include <sys/sysctl.h>
33 #include <machine/reg.h>
34
35 #include "fbsd-nat.h"
36 #include "amd64-tdep.h"
37 #include "amd64-nat.h"
38
39
40 /* Offset in `struct reg' where MEMBER is stored. */
41 #define REG_OFFSET(member) offsetof (struct reg, member)
42
43 /* At amd64fbsd64_r_reg_offset[REGNUM] you'll find the offset in
44 `struct reg' location where the GDB register REGNUM is stored.
45 Unsupported registers are marked with `-1'. */
46 static int amd64fbsd64_r_reg_offset[] =
47 {
48 REG_OFFSET (r_rax),
49 REG_OFFSET (r_rbx),
50 REG_OFFSET (r_rcx),
51 REG_OFFSET (r_rdx),
52 REG_OFFSET (r_rsi),
53 REG_OFFSET (r_rdi),
54 REG_OFFSET (r_rbp),
55 REG_OFFSET (r_rsp),
56 REG_OFFSET (r_r8),
57 REG_OFFSET (r_r9),
58 REG_OFFSET (r_r10),
59 REG_OFFSET (r_r11),
60 REG_OFFSET (r_r12),
61 REG_OFFSET (r_r13),
62 REG_OFFSET (r_r14),
63 REG_OFFSET (r_r15),
64 REG_OFFSET (r_rip),
65 REG_OFFSET (r_rflags),
66 REG_OFFSET (r_cs),
67 REG_OFFSET (r_ss),
68 -1,
69 -1,
70 -1,
71 -1
72 };
73
74
75 /* Mapping between the general-purpose registers in FreeBSD/amd64
76 `struct reg' format and GDB's register cache layout for
77 FreeBSD/i386.
78
79 Note that most FreeBSD/amd64 registers are 64-bit, while the
80 FreeBSD/i386 registers are all 32-bit, but since we're
81 little-endian we get away with that. */
82
83 /* From <machine/reg.h>. */
84 static int amd64fbsd32_r_reg_offset[I386_NUM_GREGS] =
85 {
86 14 * 8, 13 * 8, /* %eax, %ecx */
87 12 * 8, 11 * 8, /* %edx, %ebx */
88 20 * 8, 10 * 8, /* %esp, %ebp */
89 9 * 8, 8 * 8, /* %esi, %edi */
90 17 * 8, 19 * 8, /* %eip, %eflags */
91 18 * 8, 21 * 8, /* %cs, %ss */
92 -1, -1, -1, -1 /* %ds, %es, %fs, %gs */
93 };
94
95
96 /* Support for debugging kernel virtual memory images. */
97
98 #include <sys/types.h>
99 #include <machine/pcb.h>
100
101 #include "bsd-kvm.h"
102
103 static int
amd64fbsd_supply_pcb(struct regcache * regcache,struct pcb * pcb)104 amd64fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
105 {
106 /* The following is true for FreeBSD 5.2:
107
108 The pcb contains %rip, %rbx, %rsp, %rbp, %r12, %r13, %r14, %r15,
109 %ds, %es, %fs and %gs. This accounts for all callee-saved
110 registers specified by the psABI and then some. Here %esp
111 contains the stack pointer at the point just after the call to
112 cpu_switch(). From this information we reconstruct the register
113 state as it would like when we just returned from cpu_switch(). */
114
115 /* The stack pointer shouldn't be zero. */
116 if (pcb->pcb_rsp == 0)
117 return 0;
118
119 pcb->pcb_rsp += 8;
120 regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &pcb->pcb_rip);
121 regcache_raw_supply (regcache, AMD64_RBX_REGNUM, &pcb->pcb_rbx);
122 regcache_raw_supply (regcache, AMD64_RSP_REGNUM, &pcb->pcb_rsp);
123 regcache_raw_supply (regcache, AMD64_RBP_REGNUM, &pcb->pcb_rbp);
124 regcache_raw_supply (regcache, 12, &pcb->pcb_r12);
125 regcache_raw_supply (regcache, 13, &pcb->pcb_r13);
126 regcache_raw_supply (regcache, 14, &pcb->pcb_r14);
127 regcache_raw_supply (regcache, 15, &pcb->pcb_r15);
128 regcache_raw_supply (regcache, AMD64_DS_REGNUM, &pcb->pcb_ds);
129 regcache_raw_supply (regcache, AMD64_ES_REGNUM, &pcb->pcb_es);
130 regcache_raw_supply (regcache, AMD64_FS_REGNUM, &pcb->pcb_fs);
131 regcache_raw_supply (regcache, AMD64_GS_REGNUM, &pcb->pcb_gs);
132
133 return 1;
134 }
135
136
137 /* Provide a prototype to silence -Wmissing-prototypes. */
138 void _initialize_amd64fbsd_nat (void);
139
140 void
_initialize_amd64fbsd_nat(void)141 _initialize_amd64fbsd_nat (void)
142 {
143 struct target_ops *t;
144 int offset;
145
146 amd64_native_gregset32_reg_offset = amd64fbsd32_r_reg_offset;
147 amd64_native_gregset64_reg_offset = amd64fbsd64_r_reg_offset;
148
149 /* Add some extra features to the common *BSD/i386 target. */
150 t = amd64bsd_target ();
151 t->to_pid_to_exec_file = fbsd_pid_to_exec_file;
152 t->to_find_memory_regions = fbsd_find_memory_regions;
153 t->to_make_corefile_notes = fbsd_make_corefile_notes;
154 add_target (t);
155
156 /* Support debugging kernel virtual memory images. */
157 bsd_kvm_add_target (amd64fbsd_supply_pcb);
158
159 /* To support the recognition of signal handlers, i386bsd-tdep.c
160 hardcodes some constants. Inclusion of this file means that we
161 are compiling a native debugger, which means that we can use the
162 system header files and sysctl(3) to get at the relevant
163 information. */
164
165 #define SC_REG_OFFSET amd64fbsd_sc_reg_offset
166
167 /* We only check the program counter, stack pointer and frame
168 pointer since these members of `struct sigcontext' are essential
169 for providing backtraces. */
170
171 #define SC_RIP_OFFSET SC_REG_OFFSET[AMD64_RIP_REGNUM]
172 #define SC_RSP_OFFSET SC_REG_OFFSET[AMD64_RSP_REGNUM]
173 #define SC_RBP_OFFSET SC_REG_OFFSET[AMD64_RBP_REGNUM]
174
175 /* Override the default value for the offset of the program counter
176 in the sigcontext structure. */
177 offset = offsetof (struct sigcontext, sc_rip);
178
179 if (SC_RIP_OFFSET != offset)
180 {
181 warning ("\
182 offsetof (struct sigcontext, sc_rip) yields %d instead of %d.\n\
183 Please report this to <bug-gdb@gnu.org>.",
184 offset, SC_RIP_OFFSET);
185 }
186
187 SC_RIP_OFFSET = offset;
188
189 /* Likewise for the stack pointer. */
190 offset = offsetof (struct sigcontext, sc_rsp);
191
192 if (SC_RSP_OFFSET != offset)
193 {
194 warning ("\
195 offsetof (struct sigcontext, sc_rsp) yields %d instead of %d.\n\
196 Please report this to <bug-gdb@gnu.org>.",
197 offset, SC_RSP_OFFSET);
198 }
199
200 SC_RSP_OFFSET = offset;
201
202 /* And the frame pointer. */
203 offset = offsetof (struct sigcontext, sc_rbp);
204
205 if (SC_RBP_OFFSET != offset)
206 {
207 warning ("\
208 offsetof (struct sigcontext, sc_rbp) yields %d instead of %d.\n\
209 Please report this to <bug-gdb@gnu.org>.",
210 offset, SC_RBP_OFFSET);
211 }
212
213 SC_RBP_OFFSET = offset;
214
215 /* FreeBSD provides a kern.ps_strings sysctl that we can use to
216 locate the sigtramp. That way we can still recognize a sigtramp
217 if its location is changed in a new kernel. Of course this is
218 still based on the assumption that the sigtramp is placed
219 directly under the location where the program arguments and
220 environment can be found. */
221 {
222 int mib[2];
223 long ps_strings;
224 size_t len;
225
226 mib[0] = CTL_KERN;
227 mib[1] = KERN_PS_STRINGS;
228 len = sizeof (ps_strings);
229 if (sysctl (mib, 2, &ps_strings, &len, NULL, 0) == 0)
230 {
231 amd64fbsd_sigtramp_start_addr = ps_strings - 32;
232 amd64fbsd_sigtramp_end_addr = ps_strings;
233 }
234 }
235 }
236