1 /* Native-dependent code for FreeBSD/i386.
3 Copyright (C) 2001-2022 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 "gdbsupport/x86-xstate.h"
35 #include "x86-fbsd-nat.h"
37 class i386_fbsd_nat_target final
: public x86_fbsd_nat_target
40 void fetch_registers (struct regcache
*, int) override
;
41 void store_registers (struct regcache
*, int) override
;
43 const struct target_desc
*read_description () override
;
45 void resume (ptid_t
, int, enum gdb_signal
) override
;
48 static i386_fbsd_nat_target the_i386_fbsd_nat_target
;
50 #ifdef PT_GETXSTATE_INFO
51 static size_t xsave_len
;
54 static int have_ptrace_xmmregs
;
56 /* Fetch register REGNUM from the inferior. If REGNUM is -1, do this
60 i386_fbsd_nat_target::fetch_registers (struct regcache
*regcache
, int regnum
)
62 struct gdbarch
*gdbarch
= regcache
->arch ();
63 #if defined(PT_GETFSBASE) || defined(PT_GETGSBASE)
64 const struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
66 pid_t pid
= get_ptrace_pid (regcache
->ptid ());
68 if (fetch_register_set
<struct reg
> (regcache
, regnum
, PT_GETREGS
,
76 if (regnum
== -1 || regnum
== I386_FSBASE_REGNUM
)
80 if (ptrace (PT_GETFSBASE
, pid
, (PTRACE_TYPE_ARG3
) &base
, 0) == -1)
81 perror_with_name (_("Couldn't get segment register fs_base"));
83 regcache
->raw_supply (I386_FSBASE_REGNUM
, &base
);
89 if (regnum
== -1 || regnum
== I386_GSBASE_REGNUM
)
93 if (ptrace (PT_GETGSBASE
, pid
, (PTRACE_TYPE_ARG3
) &base
, 0) == -1)
94 perror_with_name (_("Couldn't get segment register gs_base"));
96 regcache
->raw_supply (I386_GSBASE_REGNUM
, &base
);
102 /* There is no i386_fxsave_supplies or i386_xsave_supplies.
103 Instead, the earlier register sets return early if the request
104 was for a specific register that was already satisified to avoid
105 fetching the FPU/XSAVE state unnecessarily. */
107 #ifdef PT_GETXSTATE_INFO
110 void *xstateregs
= alloca (xsave_len
);
112 if (ptrace (PT_GETXSTATE
, pid
, (PTRACE_TYPE_ARG3
) xstateregs
, 0) == -1)
113 perror_with_name (_("Couldn't get extended state status"));
115 i387_supply_xsave (regcache
, regnum
, xstateregs
);
119 if (have_ptrace_xmmregs
!= 0)
121 char xmmregs
[I387_SIZEOF_FXSAVE
];
123 if (ptrace(PT_GETXMMREGS
, pid
, (PTRACE_TYPE_ARG3
) xmmregs
, 0) == -1)
124 perror_with_name (_("Couldn't get XMM registers"));
126 i387_supply_fxsave (regcache
, regnum
, xmmregs
);
132 if (ptrace (PT_GETFPREGS
, pid
, (PTRACE_TYPE_ARG3
) &fpregs
, 0) == -1)
133 perror_with_name (_("Couldn't get floating point status"));
135 i387_supply_fsave (regcache
, regnum
, &fpregs
);
138 /* Store register REGNUM back into the inferior. If REGNUM is -1, do
139 this for all registers. */
142 i386_fbsd_nat_target::store_registers (struct regcache
*regcache
, int regnum
)
144 struct gdbarch
*gdbarch
= regcache
->arch ();
145 #if defined(PT_GETFSBASE) || defined(PT_GETGSBASE)
146 const struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
148 pid_t pid
= get_ptrace_pid (regcache
->ptid ());
150 if (store_register_set
<struct reg
> (regcache
, regnum
, PT_GETREGS
, PT_SETREGS
,
158 if (regnum
== -1 || regnum
== I386_FSBASE_REGNUM
)
162 regcache
->raw_collect (I386_FSBASE_REGNUM
, &base
);
164 if (ptrace (PT_SETFSBASE
, pid
, (PTRACE_TYPE_ARG3
) &base
, 0) == -1)
165 perror_with_name (_("Couldn't write segment register fs_base"));
171 if (regnum
== -1 || regnum
== I386_GSBASE_REGNUM
)
175 regcache
->raw_collect (I386_GSBASE_REGNUM
, &base
);
177 if (ptrace (PT_SETGSBASE
, pid
, (PTRACE_TYPE_ARG3
) &base
, 0) == -1)
178 perror_with_name (_("Couldn't write segment register gs_base"));
184 /* There is no i386_fxsave_supplies or i386_xsave_supplies.
185 Instead, the earlier register sets return early if the request
186 was for a specific register that was already satisified to avoid
187 fetching the FPU/XSAVE state unnecessarily. */
189 #ifdef PT_GETXSTATE_INFO
192 void *xstateregs
= alloca (xsave_len
);
194 if (ptrace (PT_GETXSTATE
, pid
, (PTRACE_TYPE_ARG3
) xstateregs
, 0) == -1)
195 perror_with_name (_("Couldn't get extended state status"));
197 i387_collect_xsave (regcache
, regnum
, xstateregs
, 0);
199 if (ptrace (PT_SETXSTATE
, pid
, (PTRACE_TYPE_ARG3
) xstateregs
, xsave_len
)
201 perror_with_name (_("Couldn't write extended state status"));
205 if (have_ptrace_xmmregs
!= 0)
207 char xmmregs
[I387_SIZEOF_FXSAVE
];
209 if (ptrace(PT_GETXMMREGS
, pid
, (PTRACE_TYPE_ARG3
) xmmregs
, 0) == -1)
210 perror_with_name (_("Couldn't get XMM registers"));
212 i387_collect_fxsave (regcache
, regnum
, xmmregs
);
214 if (ptrace (PT_SETXMMREGS
, pid
, (PTRACE_TYPE_ARG3
) xmmregs
, 0) == -1)
215 perror_with_name (_("Couldn't write XMM registers"));
221 if (ptrace (PT_GETFPREGS
, pid
, (PTRACE_TYPE_ARG3
) &fpregs
, 0) == -1)
222 perror_with_name (_("Couldn't get floating point status"));
224 i387_collect_fsave (regcache
, regnum
, &fpregs
);
226 if (ptrace (PT_SETFPREGS
, pid
, (PTRACE_TYPE_ARG3
) &fpregs
, 0) == -1)
227 perror_with_name (_("Couldn't write floating point status"));
230 /* Resume execution of the inferior process. If STEP is nonzero,
231 single-step it. If SIGNAL is nonzero, give it that signal. */
234 i386_fbsd_nat_target::resume (ptid_t ptid
, int step
, enum gdb_signal signal
)
236 pid_t pid
= ptid
.pid ();
237 int request
= PT_STEP
;
240 /* Resume all threads. This only gets used in the non-threaded
241 case, where "resume all threads" and "resume inferior_ptid" are
243 pid
= inferior_ptid
.pid ();
247 struct regcache
*regcache
= get_current_regcache ();
250 /* Workaround for a bug in FreeBSD. Make sure that the trace
251 flag is off when doing a continue. There is a code path
252 through the kernel which leaves the flag set when it should
253 have been cleared. If a process has a signal pending (such
254 as SIGALRM) and we do a PT_STEP, the process never really has
255 a chance to run because the kernel needs to notify the
256 debugger that a signal is being sent. Therefore, the process
257 never goes through the kernel's trap() function which would
258 normally clear it. */
260 regcache_cooked_read_unsigned (regcache
, I386_EFLAGS_REGNUM
,
263 regcache_cooked_write_unsigned (regcache
, I386_EFLAGS_REGNUM
,
266 request
= PT_CONTINUE
;
269 /* An addres of (caddr_t) 1 tells ptrace to continue from where it
270 was. (If GDB wanted it to start some other way, we have already
271 written a new PC value to the child.) */
272 if (ptrace (request
, pid
, (caddr_t
) 1,
273 gdb_signal_to_host (signal
)) == -1)
274 perror_with_name (("ptrace"));
278 /* Support for debugging kernel virtual memory images. */
280 #include <machine/pcb.h>
285 i386fbsd_supply_pcb (struct regcache
*regcache
, struct pcb
*pcb
)
287 /* The following is true for FreeBSD 4.7:
289 The pcb contains %eip, %ebx, %esp, %ebp, %esi, %edi and %gs.
290 This accounts for all callee-saved registers specified by the
291 psABI and then some. Here %esp contains the stack pointer at the
292 point just after the call to cpu_switch(). From this information
293 we reconstruct the register state as it would look when we just
294 returned from cpu_switch(). */
296 /* The stack pointer shouldn't be zero. */
297 if (pcb
->pcb_esp
== 0)
301 regcache
->raw_supply (I386_EDI_REGNUM
, &pcb
->pcb_edi
);
302 regcache
->raw_supply (I386_ESI_REGNUM
, &pcb
->pcb_esi
);
303 regcache
->raw_supply (I386_EBP_REGNUM
, &pcb
->pcb_ebp
);
304 regcache
->raw_supply (I386_ESP_REGNUM
, &pcb
->pcb_esp
);
305 regcache
->raw_supply (I386_EBX_REGNUM
, &pcb
->pcb_ebx
);
306 regcache
->raw_supply (I386_EIP_REGNUM
, &pcb
->pcb_eip
);
307 regcache
->raw_supply (I386_GS_REGNUM
, &pcb
->pcb_gs
);
313 /* Implement the read_description method. */
315 const struct target_desc
*
316 i386_fbsd_nat_target::read_description ()
318 #ifdef PT_GETXSTATE_INFO
319 static int xsave_probed
;
320 static uint64_t xcr0
;
322 static int xmm_probed
;
324 #ifdef PT_GETXSTATE_INFO
327 struct ptrace_xstate_info info
;
329 if (ptrace (PT_GETXSTATE_INFO
, inferior_ptid
.pid (),
330 (PTRACE_TYPE_ARG3
) &info
, sizeof (info
)) == 0)
332 xsave_len
= info
.xsave_len
;
333 xcr0
= info
.xsave_mask
;
339 return i386_target_description (xcr0
, true);
344 char xmmregs
[I387_SIZEOF_FXSAVE
];
346 if (ptrace (PT_GETXMMREGS
, inferior_ptid
.pid (),
347 (PTRACE_TYPE_ARG3
) xmmregs
, 0) == 0)
348 have_ptrace_xmmregs
= 1;
352 if (have_ptrace_xmmregs
)
353 return i386_target_description (X86_XSTATE_SSE_MASK
, true);
355 return i386_target_description (X86_XSTATE_X87_MASK
, true);
358 void _initialize_i386fbsd_nat ();
360 _initialize_i386fbsd_nat ()
362 add_inf_child_target (&the_i386_fbsd_nat_target
);
364 /* Support debugging kernel virtual memory images. */
365 bsd_kvm_add_target (i386fbsd_supply_pcb
);