]> git.ipfire.org Git - thirdparty/binutils-gdb.git/blame - gdb/amd64fbsd-nat.c
Fix potential buffer overflows with sprintf and very large integer values.
[thirdparty/binutils-gdb.git] / gdb / amd64fbsd-nat.c
CommitLineData
68cc0bfb 1/* Native-dependent code for FreeBSD/amd64.
2a6d284d 2
618f726f 3 Copyright (C) 2003-2016 Free Software Foundation, Inc.
68cc0bfb
MK
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
a9762ec7 9 the Free Software Foundation; either version 3 of the License, or
68cc0bfb
MK
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
a9762ec7 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
68cc0bfb
MK
19
20#include "defs.h"
21#include "inferior.h"
22#include "regcache.h"
6a5c78a3 23#include "target.h"
68cc0bfb 24
68cc0bfb 25#include <signal.h>
68cc0bfb
MK
26#include <sys/types.h>
27#include <sys/ptrace.h>
28#include <sys/sysctl.h>
cf424aef 29#include <sys/user.h>
68cc0bfb
MK
30#include <machine/reg.h>
31
6a5c78a3 32#include "fbsd-nat.h"
85be1ca6 33#include "amd64-tdep.h"
2a6d284d 34#include "amd64-nat.h"
1916efaf 35#include "amd64bsd-nat.h"
df7e5265 36#include "x86-nat.h"
68cc0bfb
MK
37\f
38
cb461069
MK
39/* Offset in `struct reg' where MEMBER is stored. */
40#define REG_OFFSET(member) offsetof (struct reg, member)
68cc0bfb 41
cb461069
MK
42/* At amd64fbsd64_r_reg_offset[REGNUM] you'll find the offset in
43 `struct reg' location where the GDB register REGNUM is stored.
44 Unsupported registers are marked with `-1'. */
45static int amd64fbsd64_r_reg_offset[] =
68cc0bfb
MK
46{
47 REG_OFFSET (r_rax),
48 REG_OFFSET (r_rbx),
49 REG_OFFSET (r_rcx),
50 REG_OFFSET (r_rdx),
51 REG_OFFSET (r_rsi),
52 REG_OFFSET (r_rdi),
53 REG_OFFSET (r_rbp),
54 REG_OFFSET (r_rsp),
55 REG_OFFSET (r_r8),
56 REG_OFFSET (r_r9),
57 REG_OFFSET (r_r10),
58 REG_OFFSET (r_r11),
59 REG_OFFSET (r_r12),
60 REG_OFFSET (r_r13),
61 REG_OFFSET (r_r14),
62 REG_OFFSET (r_r15),
63 REG_OFFSET (r_rip),
64 REG_OFFSET (r_rflags),
af233647
MK
65 REG_OFFSET (r_cs),
66 REG_OFFSET (r_ss),
68cc0bfb
MK
67 -1,
68 -1,
69 -1,
70 -1
71};
2a6d284d
MK
72\f
73
74/* Mapping between the general-purpose registers in FreeBSD/amd64
75 `struct reg' format and GDB's register cache layout for
76 FreeBSD/i386.
68cc0bfb 77
2a6d284d
MK
78 Note that most FreeBSD/amd64 registers are 64-bit, while the
79 FreeBSD/i386 registers are all 32-bit, but since we're
80 little-endian we get away with that. */
68cc0bfb 81
2a6d284d
MK
82/* From <machine/reg.h>. */
83static int amd64fbsd32_r_reg_offset[I386_NUM_GREGS] =
84{
85 14 * 8, 13 * 8, /* %eax, %ecx */
86 12 * 8, 11 * 8, /* %edx, %ebx */
87 20 * 8, 10 * 8, /* %esp, %ebp */
88 9 * 8, 8 * 8, /* %esi, %edi */
89 17 * 8, 19 * 8, /* %eip, %eflags */
90 18 * 8, 21 * 8, /* %cs, %ss */
91 -1, -1, -1, -1 /* %ds, %es, %fs, %gs */
92};
68cc0bfb
MK
93\f
94
315c4276
MK
95/* Support for debugging kernel virtual memory images. */
96
315c4276 97#include <machine/pcb.h>
1f596238 98#include <osreldate.h>
315c4276
MK
99
100#include "bsd-kvm.h"
101
102static int
103amd64fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
104{
105 /* The following is true for FreeBSD 5.2:
106
107 The pcb contains %rip, %rbx, %rsp, %rbp, %r12, %r13, %r14, %r15,
108 %ds, %es, %fs and %gs. This accounts for all callee-saved
109 registers specified by the psABI and then some. Here %esp
110 contains the stack pointer at the point just after the call to
111 cpu_switch(). From this information we reconstruct the register
112 state as it would like when we just returned from cpu_switch(). */
113
114 /* The stack pointer shouldn't be zero. */
115 if (pcb->pcb_rsp == 0)
116 return 0;
117
118 pcb->pcb_rsp += 8;
119 regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &pcb->pcb_rip);
120 regcache_raw_supply (regcache, AMD64_RBX_REGNUM, &pcb->pcb_rbx);
121 regcache_raw_supply (regcache, AMD64_RSP_REGNUM, &pcb->pcb_rsp);
122 regcache_raw_supply (regcache, AMD64_RBP_REGNUM, &pcb->pcb_rbp);
123 regcache_raw_supply (regcache, 12, &pcb->pcb_r12);
124 regcache_raw_supply (regcache, 13, &pcb->pcb_r13);
125 regcache_raw_supply (regcache, 14, &pcb->pcb_r14);
126 regcache_raw_supply (regcache, 15, &pcb->pcb_r15);
c1dec97b 127#if (__FreeBSD_version < 800075) && (__FreeBSD_kernel_version < 800075)
ffeecffa
JB
128 /* struct pcb provides the pcb_ds/pcb_es/pcb_fs/pcb_gs fields only
129 up until __FreeBSD_version 800074: The removal of these fields
130 occurred on 2009-04-01 while the __FreeBSD_version number was
131 bumped to 800075 on 2009-04-06. So 800075 is the closest version
132 number where we should not try to access these fields. */
315c4276
MK
133 regcache_raw_supply (regcache, AMD64_DS_REGNUM, &pcb->pcb_ds);
134 regcache_raw_supply (regcache, AMD64_ES_REGNUM, &pcb->pcb_es);
135 regcache_raw_supply (regcache, AMD64_FS_REGNUM, &pcb->pcb_fs);
136 regcache_raw_supply (regcache, AMD64_GS_REGNUM, &pcb->pcb_gs);
1f596238 137#endif
315c4276
MK
138
139 return 1;
140}
141\f
142
26cb8b7c
PA
143static void (*super_mourn_inferior) (struct target_ops *ops);
144
145static void
146amd64fbsd_mourn_inferior (struct target_ops *ops)
147{
148#ifdef HAVE_PT_GETDBREGS
df7e5265 149 x86_cleanup_dregs ();
26cb8b7c
PA
150#endif
151 super_mourn_inferior (ops);
152}
153
97de3545
JB
154/* Implement the to_read_description method. */
155
156static const struct target_desc *
157amd64fbsd_read_description (struct target_ops *ops)
158{
159#ifdef PT_GETXSTATE_INFO
160 static int xsave_probed;
161 static uint64_t xcr0;
162#endif
163 struct reg regs;
164 int is64;
165
166 if (ptrace (PT_GETREGS, ptid_get_pid (inferior_ptid),
167 (PTRACE_TYPE_ARG3) &regs, 0) == -1)
168 perror_with_name (_("Couldn't get registers"));
169 is64 = (regs.r_cs == GSEL (GUCODE_SEL, SEL_UPL));
170#ifdef PT_GETXSTATE_INFO
171 if (!xsave_probed)
172 {
173 struct ptrace_xstate_info info;
174
175 if (ptrace (PT_GETXSTATE_INFO, ptid_get_pid (inferior_ptid),
176 (PTRACE_TYPE_ARG3) &info, sizeof (info)) == 0)
177 {
178 amd64bsd_xsave_len = info.xsave_len;
179 xcr0 = info.xsave_mask;
180 }
181 xsave_probed = 1;
182 }
183
184 if (amd64bsd_xsave_len != 0)
185 {
186 if (is64)
187 return amd64_target_description (xcr0);
188 else
189 return i386_target_description (xcr0);
190 }
191#endif
192 if (is64)
193 return tdesc_amd64;
194 else
195 return tdesc_i386;
196}
197
68cc0bfb
MK
198/* Provide a prototype to silence -Wmissing-prototypes. */
199void _initialize_amd64fbsd_nat (void);
200
201void
1c671366 202_initialize_amd64fbsd_nat (void)
68cc0bfb 203{
6a5c78a3 204 struct target_ops *t;
68cc0bfb
MK
205 int offset;
206
2a6d284d 207 amd64_native_gregset32_reg_offset = amd64fbsd32_r_reg_offset;
cb461069 208 amd64_native_gregset64_reg_offset = amd64fbsd64_r_reg_offset;
2a6d284d 209
6a5c78a3
MK
210 /* Add some extra features to the common *BSD/i386 target. */
211 t = amd64bsd_target ();
1916efaf
PA
212
213#ifdef HAVE_PT_GETDBREGS
214
df7e5265 215 x86_use_watchpoints (t);
1916efaf 216
df7e5265
GB
217 x86_dr_low.set_control = amd64bsd_dr_set_control;
218 x86_dr_low.set_addr = amd64bsd_dr_set_addr;
219 x86_dr_low.get_addr = amd64bsd_dr_get_addr;
220 x86_dr_low.get_status = amd64bsd_dr_get_status;
221 x86_dr_low.get_control = amd64bsd_dr_get_control;
222 x86_set_debug_register_length (8);
1916efaf
PA
223
224#endif /* HAVE_PT_GETDBREGS */
225
26cb8b7c
PA
226 super_mourn_inferior = t->to_mourn_inferior;
227 t->to_mourn_inferior = amd64fbsd_mourn_inferior;
97de3545 228 t->to_read_description = amd64fbsd_read_description;
26cb8b7c 229
8f60fe01 230 fbsd_nat_add_target (t);
6a5c78a3
MK
231
232 /* Support debugging kernel virtual memory images. */
233 bsd_kvm_add_target (amd64fbsd_supply_pcb);
234
68cc0bfb
MK
235 /* To support the recognition of signal handlers, i386bsd-tdep.c
236 hardcodes some constants. Inclusion of this file means that we
237 are compiling a native debugger, which means that we can use the
238 system header files and sysctl(3) to get at the relevant
239 information. */
240
68cc0bfb
MK
241#define SC_REG_OFFSET amd64fbsd_sc_reg_offset
242
243 /* We only check the program counter, stack pointer and frame
244 pointer since these members of `struct sigcontext' are essential
245 for providing backtraces. */
246
90f90721
MK
247#define SC_RIP_OFFSET SC_REG_OFFSET[AMD64_RIP_REGNUM]
248#define SC_RSP_OFFSET SC_REG_OFFSET[AMD64_RSP_REGNUM]
249#define SC_RBP_OFFSET SC_REG_OFFSET[AMD64_RBP_REGNUM]
68cc0bfb
MK
250
251 /* Override the default value for the offset of the program counter
252 in the sigcontext structure. */
253 offset = offsetof (struct sigcontext, sc_rip);
254
255 if (SC_RIP_OFFSET != offset)
256 {
edefbb7c 257 warning (_("\
68cc0bfb 258offsetof (struct sigcontext, sc_rip) yields %d instead of %d.\n\
edefbb7c 259Please report this to <bug-gdb@gnu.org>."),
68cc0bfb
MK
260 offset, SC_RIP_OFFSET);
261 }
262
263 SC_RIP_OFFSET = offset;
264
265 /* Likewise for the stack pointer. */
266 offset = offsetof (struct sigcontext, sc_rsp);
267
268 if (SC_RSP_OFFSET != offset)
269 {
edefbb7c 270 warning (_("\
68cc0bfb 271offsetof (struct sigcontext, sc_rsp) yields %d instead of %d.\n\
edefbb7c 272Please report this to <bug-gdb@gnu.org>."),
68cc0bfb
MK
273 offset, SC_RSP_OFFSET);
274 }
275
276 SC_RSP_OFFSET = offset;
277
278 /* And the frame pointer. */
279 offset = offsetof (struct sigcontext, sc_rbp);
280
281 if (SC_RBP_OFFSET != offset)
282 {
edefbb7c 283 warning (_("\
68cc0bfb 284offsetof (struct sigcontext, sc_rbp) yields %d instead of %d.\n\
edefbb7c 285Please report this to <bug-gdb@gnu.org>."),
68cc0bfb
MK
286 offset, SC_RBP_OFFSET);
287 }
288
289 SC_RBP_OFFSET = offset;
290
cf424aef
JB
291#ifdef KERN_PROC_SIGTRAMP
292 /* Normally signal frames are detected via amd64fbsd_sigtramp_p.
293 However, FreeBSD 9.2 through 10.1 do not include the page holding
294 the signal code in core dumps. These releases do provide a
295 kern.proc.sigtramp.<pid> sysctl that returns the location of the
296 signal trampoline for a running process. We fetch the location
297 of the current (gdb) process and use this to identify signal
298 frames in core dumps from these releases. Note that this only
299 works for core dumps of 64-bit (FreeBSD/amd64) processes and does
300 not handle core dumps of 32-bit (FreeBSD/i386) processes. */
68cc0bfb 301 {
cf424aef
JB
302 int mib[4];
303 struct kinfo_sigtramp kst;
68cc0bfb
MK
304 size_t len;
305
68cc0bfb 306 mib[0] = CTL_KERN;
cf424aef
JB
307 mib[1] = KERN_PROC;
308 mib[2] = KERN_PROC_SIGTRAMP;
309 mib[3] = getpid ();
310 len = sizeof (kst);
311 if (sysctl (mib, 4, &kst, &len, NULL, 0) == 0)
68cc0bfb 312 {
cf424aef
JB
313 amd64fbsd_sigtramp_start_addr = (uintptr_t) kst.ksigtramp_start;
314 amd64fbsd_sigtramp_end_addr = (uintptr_t) kst.ksigtramp_end;
68cc0bfb
MK
315 }
316 }
cf424aef 317#endif
68cc0bfb 318}