1 /* Native-dependent code for FreeBSD/amd64.
3 Copyright (C) 2003-2017 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/>. */
26 #include <sys/types.h>
27 #include <sys/ptrace.h>
28 #include <sys/sysctl.h>
30 #include <machine/reg.h>
33 #include "amd64-tdep.h"
34 #include "amd64-nat.h"
35 #include "x86-bsd-nat.h"
37 #include "x86-xstate.h"
40 /* Offset in `struct reg' where MEMBER is stored. */
41 #define REG_OFFSET(member) offsetof (struct reg, member)
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
[] =
65 REG_OFFSET (r_rflags
),
75 /* Mapping between the general-purpose registers in FreeBSD/amd64
76 `struct reg' format and GDB's register cache layout for
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. */
83 /* From <machine/reg.h>. */
84 static int amd64fbsd32_r_reg_offset
[I386_NUM_GREGS
] =
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 */
96 /* Support for debugging kernel virtual memory images. */
98 #include <machine/pcb.h>
99 #include <osreldate.h>
104 amd64fbsd_supply_pcb (struct regcache
*regcache
, struct pcb
*pcb
)
106 /* The following is true for FreeBSD 5.2:
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(). */
115 /* The stack pointer shouldn't be zero. */
116 if (pcb
->pcb_rsp
== 0)
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 #if (__FreeBSD_version < 800075) && (__FreeBSD_kernel_version < 800075)
129 /* struct pcb provides the pcb_ds/pcb_es/pcb_fs/pcb_gs fields only
130 up until __FreeBSD_version 800074: The removal of these fields
131 occurred on 2009-04-01 while the __FreeBSD_version number was
132 bumped to 800075 on 2009-04-06. So 800075 is the closest version
133 number where we should not try to access these fields. */
134 regcache_raw_supply (regcache
, AMD64_DS_REGNUM
, &pcb
->pcb_ds
);
135 regcache_raw_supply (regcache
, AMD64_ES_REGNUM
, &pcb
->pcb_es
);
136 regcache_raw_supply (regcache
, AMD64_FS_REGNUM
, &pcb
->pcb_fs
);
137 regcache_raw_supply (regcache
, AMD64_GS_REGNUM
, &pcb
->pcb_gs
);
144 /* Implement the to_read_description method. */
146 static const struct target_desc
*
147 amd64fbsd_read_description (struct target_ops
*ops
)
149 #ifdef PT_GETXSTATE_INFO
150 static int xsave_probed
;
151 static uint64_t xcr0
;
156 if (ptrace (PT_GETREGS
, ptid_get_pid (inferior_ptid
),
157 (PTRACE_TYPE_ARG3
) ®s
, 0) == -1)
158 perror_with_name (_("Couldn't get registers"));
159 is64
= (regs
.r_cs
== GSEL (GUCODE_SEL
, SEL_UPL
));
160 #ifdef PT_GETXSTATE_INFO
163 struct ptrace_xstate_info info
;
165 if (ptrace (PT_GETXSTATE_INFO
, ptid_get_pid (inferior_ptid
),
166 (PTRACE_TYPE_ARG3
) &info
, sizeof (info
)) == 0)
168 x86bsd_xsave_len
= info
.xsave_len
;
169 xcr0
= info
.xsave_mask
;
174 if (x86bsd_xsave_len
!= 0)
177 return amd64_target_description (xcr0
);
179 return i386_target_description (xcr0
);
183 return amd64_target_description (X86_XSTATE_SSE_MASK
);
185 return i386_target_description (X86_XSTATE_SSE_MASK
);
188 /* Provide a prototype to silence -Wmissing-prototypes. */
189 void _initialize_amd64fbsd_nat (void);
192 _initialize_amd64fbsd_nat (void)
194 struct target_ops
*t
;
197 amd64_native_gregset32_reg_offset
= amd64fbsd32_r_reg_offset
;
198 amd64_native_gregset64_reg_offset
= amd64fbsd64_r_reg_offset
;
200 /* Add some extra features to the common *BSD/i386 target. */
201 t
= amd64bsd_target ();
202 t
->to_read_description
= amd64fbsd_read_description
;
204 fbsd_nat_add_target (t
);
206 /* Support debugging kernel virtual memory images. */
207 bsd_kvm_add_target (amd64fbsd_supply_pcb
);
209 /* To support the recognition of signal handlers, i386-bsd-tdep.c
210 hardcodes some constants. Inclusion of this file means that we
211 are compiling a native debugger, which means that we can use the
212 system header files and sysctl(3) to get at the relevant
215 #define SC_REG_OFFSET amd64fbsd_sc_reg_offset
217 /* We only check the program counter, stack pointer and frame
218 pointer since these members of `struct sigcontext' are essential
219 for providing backtraces. */
221 #define SC_RIP_OFFSET SC_REG_OFFSET[AMD64_RIP_REGNUM]
222 #define SC_RSP_OFFSET SC_REG_OFFSET[AMD64_RSP_REGNUM]
223 #define SC_RBP_OFFSET SC_REG_OFFSET[AMD64_RBP_REGNUM]
225 /* Override the default value for the offset of the program counter
226 in the sigcontext structure. */
227 offset
= offsetof (struct sigcontext
, sc_rip
);
229 if (SC_RIP_OFFSET
!= offset
)
232 offsetof (struct sigcontext, sc_rip) yields %d instead of %d.\n\
233 Please report this to <bug-gdb@gnu.org>."),
234 offset
, SC_RIP_OFFSET
);
237 SC_RIP_OFFSET
= offset
;
239 /* Likewise for the stack pointer. */
240 offset
= offsetof (struct sigcontext
, sc_rsp
);
242 if (SC_RSP_OFFSET
!= offset
)
245 offsetof (struct sigcontext, sc_rsp) yields %d instead of %d.\n\
246 Please report this to <bug-gdb@gnu.org>."),
247 offset
, SC_RSP_OFFSET
);
250 SC_RSP_OFFSET
= offset
;
252 /* And the frame pointer. */
253 offset
= offsetof (struct sigcontext
, sc_rbp
);
255 if (SC_RBP_OFFSET
!= offset
)
258 offsetof (struct sigcontext, sc_rbp) yields %d instead of %d.\n\
259 Please report this to <bug-gdb@gnu.org>."),
260 offset
, SC_RBP_OFFSET
);
263 SC_RBP_OFFSET
= offset
;
265 #ifdef KERN_PROC_SIGTRAMP
266 /* Normally signal frames are detected via amd64fbsd_sigtramp_p.
267 However, FreeBSD 9.2 through 10.1 do not include the page holding
268 the signal code in core dumps. These releases do provide a
269 kern.proc.sigtramp.<pid> sysctl that returns the location of the
270 signal trampoline for a running process. We fetch the location
271 of the current (gdb) process and use this to identify signal
272 frames in core dumps from these releases. Note that this only
273 works for core dumps of 64-bit (FreeBSD/amd64) processes and does
274 not handle core dumps of 32-bit (FreeBSD/i386) processes. */
277 struct kinfo_sigtramp kst
;
282 mib
[2] = KERN_PROC_SIGTRAMP
;
285 if (sysctl (mib
, 4, &kst
, &len
, NULL
, 0) == 0)
287 amd64fbsd_sigtramp_start_addr
= (uintptr_t) kst
.ksigtramp_start
;
288 amd64fbsd_sigtramp_end_addr
= (uintptr_t) kst
.ksigtramp_end
;