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);
189 _initialize_amd64fbsd_nat (void)
191 struct target_ops *t;
194 amd64_native_gregset32_reg_offset = amd64fbsd32_r_reg_offset;
195 amd64_native_gregset64_reg_offset = amd64fbsd64_r_reg_offset;
197 /* Add some extra features to the common *BSD/i386 target. */
198 t = amd64bsd_target ();
199 t->to_read_description = amd64fbsd_read_description;
201 fbsd_nat_add_target (t);
203 /* Support debugging kernel virtual memory images. */
204 bsd_kvm_add_target (amd64fbsd_supply_pcb);
206 /* To support the recognition of signal handlers, i386-bsd-tdep.c
207 hardcodes some constants. Inclusion of this file means that we
208 are compiling a native debugger, which means that we can use the
209 system header files and sysctl(3) to get at the relevant
212 #define SC_REG_OFFSET amd64fbsd_sc_reg_offset
214 /* We only check the program counter, stack pointer and frame
215 pointer since these members of `struct sigcontext' are essential
216 for providing backtraces. */
218 #define SC_RIP_OFFSET SC_REG_OFFSET[AMD64_RIP_REGNUM]
219 #define SC_RSP_OFFSET SC_REG_OFFSET[AMD64_RSP_REGNUM]
220 #define SC_RBP_OFFSET SC_REG_OFFSET[AMD64_RBP_REGNUM]
222 /* Override the default value for the offset of the program counter
223 in the sigcontext structure. */
224 offset = offsetof (struct sigcontext, sc_rip);
226 if (SC_RIP_OFFSET != offset)
229 offsetof (struct sigcontext, sc_rip) yields %d instead of %d.\n\
230 Please report this to <bug-gdb@gnu.org>."),
231 offset, SC_RIP_OFFSET);
234 SC_RIP_OFFSET = offset;
236 /* Likewise for the stack pointer. */
237 offset = offsetof (struct sigcontext, sc_rsp);
239 if (SC_RSP_OFFSET != offset)
242 offsetof (struct sigcontext, sc_rsp) yields %d instead of %d.\n\
243 Please report this to <bug-gdb@gnu.org>."),
244 offset, SC_RSP_OFFSET);
247 SC_RSP_OFFSET = offset;
249 /* And the frame pointer. */
250 offset = offsetof (struct sigcontext, sc_rbp);
252 if (SC_RBP_OFFSET != offset)
255 offsetof (struct sigcontext, sc_rbp) yields %d instead of %d.\n\
256 Please report this to <bug-gdb@gnu.org>."),
257 offset, SC_RBP_OFFSET);
260 SC_RBP_OFFSET = offset;
262 #ifdef KERN_PROC_SIGTRAMP
263 /* Normally signal frames are detected via amd64fbsd_sigtramp_p.
264 However, FreeBSD 9.2 through 10.1 do not include the page holding
265 the signal code in core dumps. These releases do provide a
266 kern.proc.sigtramp.<pid> sysctl that returns the location of the
267 signal trampoline for a running process. We fetch the location
268 of the current (gdb) process and use this to identify signal
269 frames in core dumps from these releases. Note that this only
270 works for core dumps of 64-bit (FreeBSD/amd64) processes and does
271 not handle core dumps of 32-bit (FreeBSD/i386) processes. */
274 struct kinfo_sigtramp kst;
279 mib[2] = KERN_PROC_SIGTRAMP;
282 if (sysctl (mib, 4, &kst, &len, NULL, 0) == 0)
284 amd64fbsd_sigtramp_start_addr = (uintptr_t) kst.ksigtramp_start;
285 amd64fbsd_sigtramp_end_addr = (uintptr_t) kst.ksigtramp_end;