1 /* Native-dependent code for FreeBSD/i386.
3 Copyright (C) 2001-2023 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/>. */
25 #include <sys/types.h>
26 #include <sys/ptrace.h>
27 #include <sys/sysctl.h>
30 #include "i386-tdep.h"
31 #include "i386-fbsd-tdep.h"
32 #include "i387-tdep.h"
34 #include "x86-fbsd-nat.h"
36 class i386_fbsd_nat_target final
: public x86_fbsd_nat_target
39 void fetch_registers (struct regcache
*, int) override
;
40 void store_registers (struct regcache
*, int) override
;
42 const struct target_desc
*read_description () override
;
44 void resume (ptid_t
, int, enum gdb_signal
) override
;
47 static i386_fbsd_nat_target the_i386_fbsd_nat_target
;
49 static int have_ptrace_xmmregs
;
51 /* Fetch register REGNUM from the inferior. If REGNUM is -1, do this
55 i386_fbsd_nat_target::fetch_registers (struct regcache
*regcache
, int regnum
)
57 struct gdbarch
*gdbarch
= regcache
->arch ();
58 pid_t pid
= get_ptrace_pid (regcache
->ptid ());
60 if (fetch_register_set
<struct reg
> (regcache
, regnum
, PT_GETREGS
,
68 if (regnum
== -1 || regnum
== I386_FSBASE_REGNUM
)
72 if (ptrace (PT_GETFSBASE
, pid
, (PTRACE_TYPE_ARG3
) &base
, 0) == -1)
73 perror_with_name (_("Couldn't get segment register fs_base"));
75 regcache
->raw_supply (I386_FSBASE_REGNUM
, &base
);
81 if (regnum
== -1 || regnum
== I386_GSBASE_REGNUM
)
85 if (ptrace (PT_GETGSBASE
, pid
, (PTRACE_TYPE_ARG3
) &base
, 0) == -1)
86 perror_with_name (_("Couldn't get segment register gs_base"));
88 regcache
->raw_supply (I386_GSBASE_REGNUM
, &base
);
94 /* There is no i386_fxsave_supplies or i386_xsave_supplies.
95 Instead, the earlier register sets return early if the request
96 was for a specific register that was already satisified to avoid
97 fetching the FPU/XSAVE state unnecessarily. */
99 #ifdef PT_GETXSTATE_INFO
100 if (m_xsave_info
.xsave_len
!= 0)
102 void *xstateregs
= alloca (m_xsave_info
.xsave_len
);
104 if (ptrace (PT_GETXSTATE
, pid
, (PTRACE_TYPE_ARG3
) xstateregs
, 0) == -1)
105 perror_with_name (_("Couldn't get extended state status"));
107 i387_supply_xsave (regcache
, regnum
, xstateregs
);
111 if (have_ptrace_xmmregs
!= 0)
113 char xmmregs
[I387_SIZEOF_FXSAVE
];
115 if (ptrace(PT_GETXMMREGS
, pid
, (PTRACE_TYPE_ARG3
) xmmregs
, 0) == -1)
116 perror_with_name (_("Couldn't get XMM registers"));
118 i387_supply_fxsave (regcache
, regnum
, xmmregs
);
124 if (ptrace (PT_GETFPREGS
, pid
, (PTRACE_TYPE_ARG3
) &fpregs
, 0) == -1)
125 perror_with_name (_("Couldn't get floating point status"));
127 i387_supply_fsave (regcache
, regnum
, &fpregs
);
130 /* Store register REGNUM back into the inferior. If REGNUM is -1, do
131 this for all registers. */
134 i386_fbsd_nat_target::store_registers (struct regcache
*regcache
, int regnum
)
136 struct gdbarch
*gdbarch
= regcache
->arch ();
137 pid_t pid
= get_ptrace_pid (regcache
->ptid ());
139 if (store_register_set
<struct reg
> (regcache
, regnum
, PT_GETREGS
, PT_SETREGS
,
147 if (regnum
== -1 || regnum
== I386_FSBASE_REGNUM
)
151 regcache
->raw_collect (I386_FSBASE_REGNUM
, &base
);
153 if (ptrace (PT_SETFSBASE
, pid
, (PTRACE_TYPE_ARG3
) &base
, 0) == -1)
154 perror_with_name (_("Couldn't write segment register fs_base"));
160 if (regnum
== -1 || regnum
== I386_GSBASE_REGNUM
)
164 regcache
->raw_collect (I386_GSBASE_REGNUM
, &base
);
166 if (ptrace (PT_SETGSBASE
, pid
, (PTRACE_TYPE_ARG3
) &base
, 0) == -1)
167 perror_with_name (_("Couldn't write segment register gs_base"));
173 /* There is no i386_fxsave_supplies or i386_xsave_supplies.
174 Instead, the earlier register sets return early if the request
175 was for a specific register that was already satisified to avoid
176 fetching the FPU/XSAVE state unnecessarily. */
178 #ifdef PT_GETXSTATE_INFO
179 if (m_xsave_info
.xsave_len
!= 0)
181 void *xstateregs
= alloca (m_xsave_info
.xsave_len
);
183 if (ptrace (PT_GETXSTATE
, pid
, (PTRACE_TYPE_ARG3
) xstateregs
, 0) == -1)
184 perror_with_name (_("Couldn't get extended state status"));
186 i387_collect_xsave (regcache
, regnum
, xstateregs
, 0);
188 if (ptrace (PT_SETXSTATE
, pid
, (PTRACE_TYPE_ARG3
) xstateregs
,
189 m_xsave_info
.xsave_len
) == -1)
190 perror_with_name (_("Couldn't write extended state status"));
194 if (have_ptrace_xmmregs
!= 0)
196 char xmmregs
[I387_SIZEOF_FXSAVE
];
198 if (ptrace(PT_GETXMMREGS
, pid
, (PTRACE_TYPE_ARG3
) xmmregs
, 0) == -1)
199 perror_with_name (_("Couldn't get XMM registers"));
201 i387_collect_fxsave (regcache
, regnum
, xmmregs
);
203 if (ptrace (PT_SETXMMREGS
, pid
, (PTRACE_TYPE_ARG3
) xmmregs
, 0) == -1)
204 perror_with_name (_("Couldn't write XMM registers"));
210 if (ptrace (PT_GETFPREGS
, pid
, (PTRACE_TYPE_ARG3
) &fpregs
, 0) == -1)
211 perror_with_name (_("Couldn't get floating point status"));
213 i387_collect_fsave (regcache
, regnum
, &fpregs
);
215 if (ptrace (PT_SETFPREGS
, pid
, (PTRACE_TYPE_ARG3
) &fpregs
, 0) == -1)
216 perror_with_name (_("Couldn't write floating point status"));
219 /* Resume execution of the inferior process. If STEP is nonzero,
220 single-step it. If SIGNAL is nonzero, give it that signal. */
223 i386_fbsd_nat_target::resume (ptid_t ptid
, int step
, enum gdb_signal signal
)
225 pid_t pid
= ptid
.pid ();
226 int request
= PT_STEP
;
229 /* Resume all threads. This only gets used in the non-threaded
230 case, where "resume all threads" and "resume inferior_ptid" are
232 pid
= inferior_ptid
.pid ();
236 regcache
*regcache
= get_thread_regcache (inferior_thread ());
239 /* Workaround for a bug in FreeBSD. Make sure that the trace
240 flag is off when doing a continue. There is a code path
241 through the kernel which leaves the flag set when it should
242 have been cleared. If a process has a signal pending (such
243 as SIGALRM) and we do a PT_STEP, the process never really has
244 a chance to run because the kernel needs to notify the
245 debugger that a signal is being sent. Therefore, the process
246 never goes through the kernel's trap() function which would
247 normally clear it. */
249 regcache_cooked_read_unsigned (regcache
, I386_EFLAGS_REGNUM
,
252 regcache_cooked_write_unsigned (regcache
, I386_EFLAGS_REGNUM
,
255 request
= PT_CONTINUE
;
258 /* An addres of (caddr_t) 1 tells ptrace to continue from where it
259 was. (If GDB wanted it to start some other way, we have already
260 written a new PC value to the child.) */
261 if (ptrace (request
, pid
, (caddr_t
) 1,
262 gdb_signal_to_host (signal
)) == -1)
263 perror_with_name (("ptrace"));
267 /* Support for debugging kernel virtual memory images. */
269 #include <machine/pcb.h>
274 i386fbsd_supply_pcb (struct regcache
*regcache
, struct pcb
*pcb
)
276 /* The following is true for FreeBSD 4.7:
278 The pcb contains %eip, %ebx, %esp, %ebp, %esi, %edi and %gs.
279 This accounts for all callee-saved registers specified by the
280 psABI and then some. Here %esp contains the stack pointer at the
281 point just after the call to cpu_switch(). From this information
282 we reconstruct the register state as it would look when we just
283 returned from cpu_switch(). */
285 /* The stack pointer shouldn't be zero. */
286 if (pcb
->pcb_esp
== 0)
290 regcache
->raw_supply (I386_EDI_REGNUM
, &pcb
->pcb_edi
);
291 regcache
->raw_supply (I386_ESI_REGNUM
, &pcb
->pcb_esi
);
292 regcache
->raw_supply (I386_EBP_REGNUM
, &pcb
->pcb_ebp
);
293 regcache
->raw_supply (I386_ESP_REGNUM
, &pcb
->pcb_esp
);
294 regcache
->raw_supply (I386_EBX_REGNUM
, &pcb
->pcb_ebx
);
295 regcache
->raw_supply (I386_EIP_REGNUM
, &pcb
->pcb_eip
);
296 regcache
->raw_supply (I386_GS_REGNUM
, &pcb
->pcb_gs
);
302 /* Implement the read_description method. */
304 const struct target_desc
*
305 i386_fbsd_nat_target::read_description ()
307 static int xmm_probed
;
309 if (inferior_ptid
== null_ptid
)
310 return this->beneath ()->read_description ();
312 #ifdef PT_GETXSTATE_INFO
313 probe_xsave_layout (inferior_ptid
.pid ());
314 if (m_xsave_info
.xsave_len
!= 0)
315 return i386_target_description (m_xsave_info
.xsave_mask
, true);
320 char xmmregs
[I387_SIZEOF_FXSAVE
];
322 if (ptrace (PT_GETXMMREGS
, inferior_ptid
.pid (),
323 (PTRACE_TYPE_ARG3
) xmmregs
, 0) == 0)
324 have_ptrace_xmmregs
= 1;
328 if (have_ptrace_xmmregs
)
329 return i386_target_description (X86_XSTATE_SSE_MASK
, true);
331 return i386_target_description (X86_XSTATE_X87_MASK
, true);
334 void _initialize_i386fbsd_nat ();
336 _initialize_i386fbsd_nat ()
338 add_inf_child_target (&the_i386_fbsd_nat_target
);
340 /* Support debugging kernel virtual memory images. */
341 bsd_kvm_add_target (i386fbsd_supply_pcb
);