xref: /freebsd/sys/amd64/amd64/ptrace_machdep.c (revision e0c4386e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2011 Konstantin Belousov <kib@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  */
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/elf.h>
33 #include <sys/lock.h>
34 #include <sys/malloc.h>
35 #include <sys/mutex.h>
36 #include <sys/proc.h>
37 #include <sys/ptrace.h>
38 #include <sys/reg.h>
39 #include <sys/sysent.h>
40 #include <vm/vm.h>
41 #include <vm/pmap.h>
42 #include <machine/md_var.h>
43 #include <machine/pcb.h>
44 #include <machine/frame.h>
45 #include <machine/vmparam.h>
46 
47 #ifdef COMPAT_FREEBSD32
48 struct ptrace_xstate_info32 {
49 	uint32_t	xsave_mask1, xsave_mask2;
50 	uint32_t	xsave_len;
51 };
52 #endif
53 
54 static bool
55 get_segbases(struct regset *rs, struct thread *td, void *buf,
56     size_t *sizep)
57 {
58 	struct segbasereg *reg;
59 	struct pcb *pcb;
60 
61 	if (buf != NULL) {
62 		KASSERT(*sizep == sizeof(*reg), ("%s: invalid size", __func__));
63 		reg = buf;
64 
65 		pcb = td->td_pcb;
66 		if (td == curthread)
67 			update_pcb_bases(pcb);
68 		reg->r_fsbase = pcb->pcb_fsbase;
69 		reg->r_gsbase = pcb->pcb_gsbase;
70 	}
71 	*sizep = sizeof(*reg);
72 	return (true);
73 }
74 
75 static bool
76 set_segbases(struct regset *rs, struct thread *td, void *buf,
77     size_t size)
78 {
79 	struct segbasereg *reg;
80 	struct pcb *pcb;
81 
82 	KASSERT(size == sizeof(*reg), ("%s: invalid size", __func__));
83 	reg = buf;
84 
85 	pcb = td->td_pcb;
86 	set_pcb_flags(pcb, PCB_FULL_IRET);
87 	pcb->pcb_fsbase = reg->r_fsbase;
88 	td->td_frame->tf_fs = _ufssel;
89 	pcb->pcb_gsbase = reg->r_gsbase;
90 	td->td_frame->tf_gs = _ugssel;
91 
92 	return (true);
93 }
94 
95 static struct regset regset_segbases = {
96 	.note = NT_X86_SEGBASES,
97 	.size = sizeof(struct segbasereg),
98 	.get = get_segbases,
99 	.set = set_segbases,
100 };
101 ELF_REGSET(regset_segbases);
102 
103 #ifdef COMPAT_FREEBSD32
104 static bool
105 get_segbases32(struct regset *rs, struct thread *td, void *buf,
106     size_t *sizep)
107 {
108 	struct segbasereg32 *reg;
109 	struct pcb *pcb;
110 
111 	if (buf != NULL) {
112 		KASSERT(*sizep == sizeof(*reg), ("%s: invalid size", __func__));
113 		reg = buf;
114 
115 		pcb = td->td_pcb;
116 		if (td == curthread)
117 			update_pcb_bases(pcb);
118 		reg->r_fsbase = (uint32_t)pcb->pcb_fsbase;
119 		reg->r_gsbase = (uint32_t)pcb->pcb_gsbase;
120 	}
121 	*sizep = sizeof(*reg);
122 	return (true);
123 }
124 
125 static bool
126 set_segbases32(struct regset *rs, struct thread *td, void *buf,
127     size_t size)
128 {
129 	struct segbasereg32 *reg;
130 	struct pcb *pcb;
131 
132 	KASSERT(size == sizeof(*reg), ("%s: invalid size", __func__));
133 	reg = buf;
134 
135 	pcb = td->td_pcb;
136 	set_pcb_flags(pcb, PCB_FULL_IRET);
137 	pcb->pcb_fsbase = reg->r_fsbase;
138 	td->td_frame->tf_fs = _ufssel;
139 	pcb->pcb_gsbase = reg->r_gsbase;
140 	td->td_frame->tf_gs = _ugssel;
141 
142 	return (true);
143 }
144 
145 static struct regset regset_segbases32 = {
146 	.note = NT_X86_SEGBASES,
147 	.size = sizeof(struct segbasereg32),
148 	.get = get_segbases32,
149 	.set = set_segbases32,
150 };
151 ELF32_REGSET(regset_segbases32);
152 #endif
153 
154 static int
155 cpu_ptrace_xstate(struct thread *td, int req, void *addr, int data)
156 {
157 	struct ptrace_xstate_info info;
158 #ifdef COMPAT_FREEBSD32
159 	struct ptrace_xstate_info32 info32;
160 #endif
161 	char *savefpu;
162 	int error;
163 
164 	if (!use_xsave)
165 		return (EOPNOTSUPP);
166 
167 	switch (req) {
168 	case PT_GETXSTATE_OLD:
169 		fpugetregs(td);
170 		savefpu = (char *)(get_pcb_user_save_td(td) + 1);
171 		error = copyout(savefpu, addr,
172 		    cpu_max_ext_state_size - sizeof(struct savefpu));
173 		break;
174 
175 	case PT_SETXSTATE_OLD:
176 		if (data > cpu_max_ext_state_size - sizeof(struct savefpu)) {
177 			error = EINVAL;
178 			break;
179 		}
180 		savefpu = malloc(data, M_TEMP, M_WAITOK);
181 		error = copyin(addr, savefpu, data);
182 		if (error == 0) {
183 			fpugetregs(td);
184 			error = fpusetxstate(td, savefpu, data);
185 		}
186 		free(savefpu, M_TEMP);
187 		break;
188 
189 	case PT_GETXSTATE_INFO:
190 #ifdef COMPAT_FREEBSD32
191 		if (SV_CURPROC_FLAG(SV_ILP32)) {
192 			if (data != sizeof(info32)) {
193 				error = EINVAL;
194 			} else {
195 				info32.xsave_len = cpu_max_ext_state_size;
196 				info32.xsave_mask1 = xsave_mask;
197 				info32.xsave_mask2 = xsave_mask >> 32;
198 				error = copyout(&info32, addr, data);
199 			}
200 		} else
201 #endif
202 		{
203 			if (data != sizeof(info)) {
204 				error  = EINVAL;
205 			} else {
206 				bzero(&info, sizeof(info));
207 				info.xsave_len = cpu_max_ext_state_size;
208 				info.xsave_mask = xsave_mask;
209 				error = copyout(&info, addr, data);
210 			}
211 		}
212 		break;
213 
214 	case PT_GETXSTATE:
215 		fpugetregs(td);
216 		savefpu = (char *)(get_pcb_user_save_td(td));
217 		error = copyout(savefpu, addr, cpu_max_ext_state_size);
218 		break;
219 
220 	case PT_SETXSTATE:
221 		if (data < sizeof(struct savefpu) ||
222 		    data > cpu_max_ext_state_size) {
223 			error = EINVAL;
224 			break;
225 		}
226 		savefpu = malloc(data, M_TEMP, M_WAITOK);
227 		error = copyin(addr, savefpu, data);
228 		if (error == 0)
229 			error = fpusetregs(td, (struct savefpu *)savefpu,
230 			    savefpu + sizeof(struct savefpu), data -
231 			    sizeof(struct savefpu));
232 		free(savefpu, M_TEMP);
233 		break;
234 
235 	default:
236 		error = EINVAL;
237 		break;
238 	}
239 
240 	return (error);
241 }
242 
243 static void
244 cpu_ptrace_setbase(struct thread *td, int req, register_t r)
245 {
246 	struct pcb *pcb;
247 
248 	pcb = td->td_pcb;
249 	set_pcb_flags(pcb, PCB_FULL_IRET);
250 	if (req == PT_SETFSBASE) {
251 		pcb->pcb_fsbase = r;
252 		td->td_frame->tf_fs = _ufssel;
253 	} else {
254 		pcb->pcb_gsbase = r;
255 		td->td_frame->tf_gs = _ugssel;
256 	}
257 }
258 
259 #ifdef COMPAT_FREEBSD32
260 #define PT_I386_GETXMMREGS	(PT_FIRSTMACH + 0)
261 #define PT_I386_SETXMMREGS	(PT_FIRSTMACH + 1)
262 
263 static int
264 cpu32_ptrace(struct thread *td, int req, void *addr, int data)
265 {
266 	struct savefpu *fpstate;
267 	struct pcb *pcb;
268 	uint32_t r;
269 	int error;
270 
271 	switch (req) {
272 	case PT_I386_GETXMMREGS:
273 		fpugetregs(td);
274 		error = copyout(get_pcb_user_save_td(td), addr,
275 		    sizeof(*fpstate));
276 		break;
277 
278 	case PT_I386_SETXMMREGS:
279 		fpugetregs(td);
280 		fpstate = get_pcb_user_save_td(td);
281 		error = copyin(addr, fpstate, sizeof(*fpstate));
282 		fpstate->sv_env.en_mxcsr &= cpu_mxcsr_mask;
283 		break;
284 
285 	case PT_GETXSTATE_OLD:
286 	case PT_SETXSTATE_OLD:
287 	case PT_GETXSTATE_INFO:
288 	case PT_GETXSTATE:
289 	case PT_SETXSTATE:
290 		error = cpu_ptrace_xstate(td, req, addr, data);
291 		break;
292 
293 	case PT_GETFSBASE:
294 	case PT_GETGSBASE:
295 		if (!SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
296 			error = EINVAL;
297 			break;
298 		}
299 		pcb = td->td_pcb;
300 		if (td == curthread)
301 			update_pcb_bases(pcb);
302 		r = req == PT_GETFSBASE ? pcb->pcb_fsbase : pcb->pcb_gsbase;
303 		error = copyout(&r, addr, sizeof(r));
304 		break;
305 
306 	case PT_SETFSBASE:
307 	case PT_SETGSBASE:
308 		if (!SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
309 			error = EINVAL;
310 			break;
311 		}
312 		error = copyin(addr, &r, sizeof(r));
313 		if (error != 0)
314 			break;
315 		cpu_ptrace_setbase(td, req, r);
316 		break;
317 
318 	default:
319 		error = EINVAL;
320 		break;
321 	}
322 
323 	return (error);
324 }
325 #endif
326 
327 int
328 cpu_ptrace(struct thread *td, int req, void *addr, int data)
329 {
330 	register_t *r, rv;
331 	struct pcb *pcb;
332 	int error;
333 
334 #ifdef COMPAT_FREEBSD32
335 	if (SV_CURPROC_FLAG(SV_ILP32))
336 		return (cpu32_ptrace(td, req, addr, data));
337 #endif
338 
339 	/* Support old values of PT_GETXSTATE_OLD and PT_SETXSTATE_OLD. */
340 	if (req == PT_FIRSTMACH + 0)
341 		req = PT_GETXSTATE_OLD;
342 	if (req == PT_FIRSTMACH + 1)
343 		req = PT_SETXSTATE_OLD;
344 
345 	switch (req) {
346 	case PT_GETXSTATE_OLD:
347 	case PT_SETXSTATE_OLD:
348 	case PT_GETXSTATE_INFO:
349 	case PT_GETXSTATE:
350 	case PT_SETXSTATE:
351 		error = cpu_ptrace_xstate(td, req, addr, data);
352 		break;
353 
354 	case PT_GETFSBASE:
355 	case PT_GETGSBASE:
356 		pcb = td->td_pcb;
357 		if (td == curthread)
358 			update_pcb_bases(pcb);
359 		r = req == PT_GETFSBASE ? &pcb->pcb_fsbase : &pcb->pcb_gsbase;
360 		error = copyout(r, addr, sizeof(*r));
361 		break;
362 
363 	case PT_SETFSBASE:
364 	case PT_SETGSBASE:
365 		error = copyin(addr, &rv, sizeof(rv));
366 		if (error != 0)
367 			break;
368 		if (rv >= td->td_proc->p_sysent->sv_maxuser) {
369 			error = EINVAL;
370 			break;
371 		}
372 		cpu_ptrace_setbase(td, req, rv);
373 		break;
374 
375 	default:
376 		error = EINVAL;
377 		break;
378 	}
379 
380 	return (error);
381 }
382 
383 int
384 ptrace_set_pc(struct thread *td, unsigned long addr)
385 {
386 
387 	td->td_frame->tf_rip = addr;
388 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
389 	return (0);
390 }
391 
392 int
393 ptrace_single_step(struct thread *td)
394 {
395 
396 	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
397 	if ((td->td_frame->tf_rflags & PSL_T) == 0) {
398 		td->td_frame->tf_rflags |= PSL_T;
399 		td->td_dbgflags |= TDB_STEP;
400 	}
401 	return (0);
402 }
403 
404 int
405 ptrace_clear_single_step(struct thread *td)
406 {
407 
408 	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
409 	td->td_frame->tf_rflags &= ~PSL_T;
410 	td->td_dbgflags &= ~TDB_STEP;
411 	return (0);
412 }
413