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/tmp/gdb-8.1/gdb/i386-bsd-nat.c
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1 /* Native-dependent code for modern i386 BSD's.
2
3 Copyright (C) 2000-2018 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 3 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, see <http://www.gnu.org/licenses/>. */
19
20 #include "defs.h"
21 #include "inferior.h"
22 #include "regcache.h"
23
24 #include <signal.h>
25 #include <sys/types.h>
26 #include <sys/ptrace.h>
27 #include <machine/reg.h>
28 #include <machine/frame.h>
29
30 #include "i386-tdep.h"
31 #include "i387-tdep.h"
32 #include "x86-bsd-nat.h"
33 #include "i386-bsd-nat.h"
34 #include "inf-ptrace.h"
35
36
37 /* In older BSD versions we cannot get at some of the segment
38 registers. FreeBSD for example didn't support the %fs and %gs
39 registers until the 3.0 release. We have autoconf checks for their
40 presence, and deal gracefully with their absence. */
41
42 /* Offset in `struct reg' where MEMBER is stored. */
43 #define REG_OFFSET(member) offsetof (struct reg, member)
44
45 /* At i386bsd_reg_offset[REGNUM] you'll find the offset in `struct
46 reg' where the GDB register REGNUM is stored. Unsupported
47 registers are marked with `-1'. */
48 static int i386bsd_r_reg_offset[] =
49 {
50 REG_OFFSET (r_eax),
51 REG_OFFSET (r_ecx),
52 REG_OFFSET (r_edx),
53 REG_OFFSET (r_ebx),
54 REG_OFFSET (r_esp),
55 REG_OFFSET (r_ebp),
56 REG_OFFSET (r_esi),
57 REG_OFFSET (r_edi),
58 REG_OFFSET (r_eip),
59 REG_OFFSET (r_eflags),
60 REG_OFFSET (r_cs),
61 REG_OFFSET (r_ss),
62 REG_OFFSET (r_ds),
63 REG_OFFSET (r_es),
64 #ifdef HAVE_STRUCT_REG_R_FS
65 REG_OFFSET (r_fs),
66 #else
67 -1,
68 #endif
69 #ifdef HAVE_STRUCT_REG_R_GS
70 REG_OFFSET (r_gs)
71 #else
72 -1
73 #endif
74 };
75
76 /* Macro to determine if a register is fetched with PT_GETREGS. */
77 #define GETREGS_SUPPLIES(regnum) \
78 ((0 <= (regnum) && (regnum) <= 15))
79
80 #ifdef HAVE_PT_GETXMMREGS
81 /* Set to 1 if the kernel supports PT_GETXMMREGS. Initialized to -1
82 so that we try PT_GETXMMREGS the first time around. */
83 static int have_ptrace_xmmregs = -1;
84 #endif
85
86
87 /* Supply the general-purpose registers in GREGS, to REGCACHE. */
88
89 static void
90 i386bsd_supply_gregset (struct regcache *regcache, const void *gregs)
91 {
92 const char *regs = (const char *) gregs;
93 int regnum;
94
95 for (regnum = 0; regnum < ARRAY_SIZE (i386bsd_r_reg_offset); regnum++)
96 {
97 int offset = i386bsd_r_reg_offset[regnum];
98
99 if (offset != -1)
100 regcache_raw_supply (regcache, regnum, regs + offset);
101 }
102 }
103
104 /* Collect register REGNUM from REGCACHE and store its contents in
105 GREGS. If REGNUM is -1, collect and store all appropriate
106 registers. */
107
108 static void
109 i386bsd_collect_gregset (const struct regcache *regcache,
110 void *gregs, int regnum)
111 {
112 char *regs = (char *) gregs;
113 int i;
114
115 for (i = 0; i < ARRAY_SIZE (i386bsd_r_reg_offset); i++)
116 {
117 if (regnum == -1 || regnum == i)
118 {
119 int offset = i386bsd_r_reg_offset[i];
120
121 if (offset != -1)
122 regcache_raw_collect (regcache, i, regs + offset);
123 }
124 }
125 }
126
127 /* Fetch register REGNUM from the inferior. If REGNUM is -1, do this
128 for all registers (including the floating point registers). */
129
130 static void
131 i386bsd_fetch_inferior_registers (struct target_ops *ops,
132 struct regcache *regcache, int regnum)
133 {
134 pid_t pid = get_ptrace_pid (regcache_get_ptid (regcache));
135
136 if (regnum == -1 || GETREGS_SUPPLIES (regnum))
137 {
138 struct reg regs;
139
140 if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
141 perror_with_name (_("Couldn't get registers"));
142
143 i386bsd_supply_gregset (regcache, &regs);
144 if (regnum != -1)
145 return;
146 }
147
148 if (regnum == -1 || regnum >= I386_ST0_REGNUM)
149 {
150 struct fpreg fpregs;
151 #ifdef HAVE_PT_GETXMMREGS
152 char xmmregs[512];
153 #endif
154
155 #ifdef PT_GETXSTATE_INFO
156 if (x86bsd_xsave_len != 0)
157 {
158 void *xstateregs;
159
160 xstateregs = alloca (x86bsd_xsave_len);
161 if (ptrace (PT_GETXSTATE, pid,
162 (PTRACE_TYPE_ARG3) xstateregs, 0) == -1)
163 perror_with_name (_("Couldn't get extended state status"));
164
165 i387_supply_xsave (regcache, -1, xstateregs);
166 return;
167 }
168 #endif
169
170 #ifdef HAVE_PT_GETXMMREGS
171 if (have_ptrace_xmmregs != 0
172 && ptrace(PT_GETXMMREGS, pid, (PTRACE_TYPE_ARG3) xmmregs, 0) == 0)
173 {
174 have_ptrace_xmmregs = 1;
175 i387_supply_fxsave (regcache, -1, xmmregs);
176 }
177 else
178 {
179 have_ptrace_xmmregs = 0;
180 #endif
181 if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
182 perror_with_name (_("Couldn't get floating point status"));
183
184 i387_supply_fsave (regcache, -1, &fpregs);
185 #ifdef HAVE_PT_GETXMMREGS
186 }
187 #endif
188 }
189 }
190
191 /* Store register REGNUM back into the inferior. If REGNUM is -1, do
192 this for all registers (including the floating point registers). */
193
194 static void
195 i386bsd_store_inferior_registers (struct target_ops *ops,
196 struct regcache *regcache, int regnum)
197 {
198 pid_t pid = get_ptrace_pid (regcache_get_ptid (regcache));
199
200 if (regnum == -1 || GETREGS_SUPPLIES (regnum))
201 {
202 struct reg regs;
203
204 if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
205 perror_with_name (_("Couldn't get registers"));
206
207 i386bsd_collect_gregset (regcache, &regs, regnum);
208
209 if (ptrace (PT_SETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
210 perror_with_name (_("Couldn't write registers"));
211
212 if (regnum != -1)
213 return;
214 }
215
216 if (regnum == -1 || regnum >= I386_ST0_REGNUM)
217 {
218 struct fpreg fpregs;
219 #ifdef HAVE_PT_GETXMMREGS
220 char xmmregs[512];
221 #endif
222
223 #ifdef PT_GETXSTATE_INFO
224 if (x86bsd_xsave_len != 0)
225 {
226 void *xstateregs;
227
228 xstateregs = alloca (x86bsd_xsave_len);
229 if (ptrace (PT_GETXSTATE, pid,
230 (PTRACE_TYPE_ARG3) xstateregs, 0) == -1)
231 perror_with_name (_("Couldn't get extended state status"));
232
233 i387_collect_xsave (regcache, -1, xstateregs, 0);
234
235 if (ptrace (PT_SETXSTATE, pid,
236 (PTRACE_TYPE_ARG3) xstateregs, x86bsd_xsave_len) == -1)
237 perror_with_name (_("Couldn't write extended state status"));
238 return;
239 }
240 #endif
241
242 #ifdef HAVE_PT_GETXMMREGS
243 if (have_ptrace_xmmregs != 0
244 && ptrace(PT_GETXMMREGS, pid, (PTRACE_TYPE_ARG3) xmmregs, 0) == 0)
245 {
246 have_ptrace_xmmregs = 1;
247
248 i387_collect_fxsave (regcache, regnum, xmmregs);
249
250 if (ptrace (PT_SETXMMREGS, pid, (PTRACE_TYPE_ARG3) xmmregs, 0) == -1)
251 perror_with_name (_("Couldn't write XMM registers"));
252 }
253 else
254 {
255 have_ptrace_xmmregs = 0;
256 #endif
257 if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
258 perror_with_name (_("Couldn't get floating point status"));
259
260 i387_collect_fsave (regcache, regnum, &fpregs);
261
262 if (ptrace (PT_SETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
263 perror_with_name (_("Couldn't write floating point status"));
264 #ifdef HAVE_PT_GETXMMREGS
265 }
266 #endif
267 }
268 }
269
270 /* Create a prototype *BSD/i386 target. The client can override it
271 with local methods. */
272
273 struct target_ops *
274 i386bsd_target (void)
275 {
276 struct target_ops *t;
277
278 t = x86bsd_target ();
279 t->to_fetch_registers = i386bsd_fetch_inferior_registers;
280 t->to_store_registers = i386bsd_store_inferior_registers;
281 return t;
282 }
283
284 void
285 _initialize_i386bsd_nat (void)
286 {
287 int offset;
288
289 /* To support the recognition of signal handlers, i386-bsd-tdep.c
290 hardcodes some constants. Inclusion of this file means that we
291 are compiling a native debugger, which means that we can use the
292 system header files and sysctl(3) to get at the relevant
293 information. */
294
295 #if defined (__FreeBSD_version) && __FreeBSD_version >= 400011
296 #define SC_REG_OFFSET i386fbsd4_sc_reg_offset
297 #elif defined (__FreeBSD_version) && __FreeBSD_version >= 300005
298 #define SC_REG_OFFSET i386fbsd_sc_reg_offset
299 #elif defined (NetBSD) || defined (__NetBSD_Version__)
300 #define SC_REG_OFFSET i386nbsd_sc_reg_offset
301 #elif defined (OpenBSD)
302 #define SC_REG_OFFSET i386obsd_sc_reg_offset
303 #endif
304
305 #ifdef SC_REG_OFFSET
306
307 /* We only check the program counter, stack pointer and frame
308 pointer since these members of `struct sigcontext' are essential
309 for providing backtraces. More checks could be added, but would
310 involve adding configure checks for the appropriate structure
311 members, since older BSD's don't provide all of them. */
312
313 #define SC_PC_OFFSET SC_REG_OFFSET[I386_EIP_REGNUM]
314 #define SC_SP_OFFSET SC_REG_OFFSET[I386_ESP_REGNUM]
315 #define SC_FP_OFFSET SC_REG_OFFSET[I386_EBP_REGNUM]
316
317 /* Override the default value for the offset of the program counter
318 in the sigcontext structure. */
319 offset = offsetof (struct sigcontext, sc_pc);
320
321 if (SC_PC_OFFSET != offset)
322 {
323 warning (_("\
324 offsetof (struct sigcontext, sc_pc) yields %d instead of %d.\n\
325 Please report this to <bug-gdb@gnu.org>."),
326 offset, SC_PC_OFFSET);
327 }
328
329 SC_PC_OFFSET = offset;
330
331 /* Likewise for the stack pointer. */
332 offset = offsetof (struct sigcontext, sc_sp);
333
334 if (SC_SP_OFFSET != offset)
335 {
336 warning (_("\
337 offsetof (struct sigcontext, sc_sp) yields %d instead of %d.\n\
338 Please report this to <bug-gdb@gnu.org>."),
339 offset, SC_SP_OFFSET);
340 }
341
342 SC_SP_OFFSET = offset;
343
344 /* And the frame pointer. */
345 offset = offsetof (struct sigcontext, sc_fp);
346
347 if (SC_FP_OFFSET != offset)
348 {
349 warning (_("\
350 offsetof (struct sigcontext, sc_fp) yields %d instead of %d.\n\
351 Please report this to <bug-gdb@gnu.org>."),
352 offset, SC_FP_OFFSET);
353 }
354
355 SC_FP_OFFSET = offset;
356
357 #endif /* SC_REG_OFFSET */
358 }
i387_collect_fsave
void i387_collect_fsave(const struct regcache *regcache, int regnum, void *fsave)
Definition: i387-tdep.c:493
pid
mach_port_t mach_port_t name mach_port_t mach_port_t name kern_return_t int int rusage_t pid_t pid
Definition: gnu-nat.c:1824
warning
void warning(const char *fmt,...)
Definition: errors.c:26
i387_supply_fxsave
void i387_supply_fxsave(struct regcache *regcache, int regnum, const void *fxsave)
Definition: i387-tdep.c:586
REG_OFFSET
#define REG_OFFSET(member)
Definition: i386-bsd-nat.c:43
regcache_get_ptid
ptid_t regcache_get_ptid(const struct regcache *regcache)
Definition: regcache.c:229
i387_supply_fsave
void i387_supply_fsave(struct regcache *regcache, int regnum, const void *fsave)
Definition: i387-tdep.c:438
i386bsd_supply_gregset
static void i386bsd_supply_gregset(struct regcache *regcache, const void *gregs)
Definition: i386-bsd-nat.c:90
_
#define _(String)
Definition: gdb_locale.h:35
defs.h
x86-bsd-nat.h
ptrace
PTRACE_TYPE_RET ptrace()
GETREGS_SUPPLIES
#define GETREGS_SUPPLIES(regnum)
Definition: i386-bsd-nat.c:77
_initialize_i386bsd_nat
void _initialize_i386bsd_nat(void)
Definition: i386-bsd-nat.c:285
x86bsd_target
struct target_ops * x86bsd_target(void)
Definition: x86-bsd-nat.c:141
i387_collect_fxsave
void i387_collect_fxsave(const struct regcache *regcache, int regnum, void *fxsave)
Definition: i387-tdep.c:669
inf-ptrace.h
target_ops
Definition: target.h:412
regcache.h
I386_ST0_REGNUM
Definition: i386-tdep.h:287
inferior.h
i386bsd_store_inferior_registers
static void i386bsd_store_inferior_registers(struct target_ops *ops, struct regcache *regcache, int regnum)
Definition: i386-bsd-nat.c:195
i386-bsd-nat.h
regnum
int regnum
Definition: aarch64-tdep.c:77
reg
Definition: regdef.h:22
i387_collect_xsave
void i387_collect_xsave(const struct regcache *regcache, int regnum, void *xsave, int gcore)
Definition: i387-tdep.c:1306
i386bsd_r_reg_offset
static int i386bsd_r_reg_offset[]
Definition: i386-bsd-nat.c:48
target_ops::to_fetch_registers
void(* to_fetch_registers)(struct target_ops *, struct regcache *, int) TARGET_DEFAULT_IGNORE()
Definition: target.h:457
perror_with_name
void void void void void void void void void perror_with_name(const char *string) ATTRIBUTE_NORETURN
Definition: utils.c:692
x86bsd_xsave_len
size_t x86bsd_xsave_len
offset
int offset
Definition: agent.c:65
i386bsd_collect_gregset
static void i386bsd_collect_gregset(const struct regcache *regcache, void *gregs, int regnum)
Definition: i386-bsd-nat.c:109
i386bsd_target
struct target_ops * i386bsd_target(void)
Definition: i386-bsd-nat.c:274
regcache_raw_supply
void regcache_raw_supply(struct regcache *regcache, int regnum, const void *buf)
Definition: regcache.c:1004
regcache
Definition: regcache.h:232
regcache_raw_collect
void regcache_raw_collect(const struct regcache *regcache, int regnum, void *buf)
Definition: regcache.c:1085
PTRACE_TYPE_ARG3
#define PTRACE_TYPE_ARG3
Definition: config.h:642
i386bsd_fetch_inferior_registers
static void i386bsd_fetch_inferior_registers(struct target_ops *ops, struct regcache *regcache, int regnum)
Definition: i386-bsd-nat.c:131
get_ptrace_pid
pid_t get_ptrace_pid(ptid_t ptid)
Definition: inf-ptrace.c:320
i386-tdep.h
i387-tdep.h
i387_supply_xsave
void i387_supply_xsave(struct regcache *regcache, int regnum, const void *xsave)
Definition: i387-tdep.c:898
target_ops::to_store_registers
void(* to_store_registers)(struct target_ops *, struct regcache *, int) TARGET_DEFAULT_NORETURN(noprocess())
Definition: target.h:459