xref: /freebsd/sys/arm64/arm64/freebsd32_machdep.c (revision 4b9d6057)
1 /*-
2  * Copyright (c) 2018 Olivier Houchard
3  * Copyright (c) 2017 Nuxi, https://nuxi.nl/
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/param.h>
28 #include <sys/exec.h>
29 #include <sys/proc.h>
30 #include <sys/lock.h>
31 #include <sys/mutex.h>
32 #include <sys/syscallsubr.h>
33 #include <sys/ktr.h>
34 #include <sys/sysctl.h>
35 #include <sys/sysent.h>
36 #include <sys/sysproto.h>
37 #include <machine/armreg.h>
38 #include <machine/pcb.h>
39 #ifdef VFP
40 #include <machine/vfp.h>
41 #endif
42 #include <compat/freebsd32/freebsd32_proto.h>
43 #include <compat/freebsd32/freebsd32_signal.h>
44 
45 #include <vm/vm.h>
46 #include <vm/vm_param.h>
47 #include <vm/pmap.h>
48 #include <vm/vm_map.h>
49 
50 _Static_assert(sizeof(mcontext32_t) == 208, "mcontext32_t size incorrect");
51 _Static_assert(sizeof(ucontext32_t) == 260, "ucontext32_t size incorrect");
52 _Static_assert(sizeof(struct siginfo32) == 64, "struct siginfo32 size incorrect");
53 
54 extern void freebsd32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
55 
56 SYSCTL_NODE(_compat, OID_AUTO, arm, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
57     "32-bit mode");
58 
59 /*
60  * The first two fields of a ucontext_t are the signal mask and the machine
61  * context.  The next field is uc_link; we want to avoid destroying the link
62  * when copying out contexts.
63  */
64 #define UC32_COPY_SIZE  offsetof(ucontext32_t, uc_link)
65 
66 /*
67  * Stubs for machine dependent 32-bits system calls.
68  */
69 
70 int
71 freebsd32_sysarch(struct thread *td, struct freebsd32_sysarch_args *uap)
72 {
73 	int error;
74 
75 #define ARM_SYNC_ICACHE		0
76 #define ARM_DRAIN_WRITEBUF	1
77 #define ARM_SET_TP		2
78 #define ARM_GET_TP		3
79 #define ARM_GET_VFPSTATE	4
80 
81 	switch(uap->op) {
82 	case ARM_SET_TP:
83 		WRITE_SPECIALREG(tpidr_el0, uap->parms);
84 		WRITE_SPECIALREG(tpidrro_el0, uap->parms);
85 		return 0;
86 	case ARM_SYNC_ICACHE:
87 		{
88 			struct {
89 				uint32_t addr;
90 				uint32_t size;
91 			} args;
92 
93 			if ((error = copyin(uap->parms, &args, sizeof(args))) != 0)
94 				return (error);
95 			if ((uint64_t)args.addr + (uint64_t)args.size > 0xffffffff)
96 				return (EINVAL);
97 			cpu_icache_sync_range_checked(args.addr, args.size);
98 			return 0;
99 		}
100 	case ARM_GET_VFPSTATE:
101 		{
102 			mcontext32_vfp_t mcontext_vfp;
103 
104 			struct {
105 				uint32_t mc_vfp_size;
106 				uint32_t mc_vfp;
107 			} args;
108 			if ((error = copyin(uap->parms, &args, sizeof(args))) != 0)
109 				return (error);
110 			if (args.mc_vfp_size != sizeof(mcontext_vfp))
111 				return (EINVAL);
112 #ifdef VFP
113 			get_fpcontext32(td, &mcontext_vfp);
114 #else
115 			bzero(&mcontext_vfp, sizeof(mcontext_vfp));
116 #endif
117 			error = copyout(&mcontext_vfp,
118 				(void *)(uintptr_t)args.mc_vfp,
119 				sizeof(mcontext_vfp));
120 			return error;
121 		}
122 	}
123 
124 	return (EINVAL);
125 }
126 
127 #ifdef VFP
128 void
129 get_fpcontext32(struct thread *td, mcontext32_vfp_t *mcp)
130 {
131 	struct pcb *pcb;
132 	int i;
133 
134 	KASSERT(td == curthread || TD_IS_SUSPENDED(td) ||
135 	    P_SHOULDSTOP(td->td_proc),
136 	    ("not suspended thread %p", td));
137 
138 	memset(mcp, 0, sizeof(*mcp));
139 	pcb = td->td_pcb;
140 
141 	if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0) {
142 		/*
143 		 * If we have just been running VFP instructions we will
144 		 * need to save the state to memcpy it below.
145 		 */
146 		if (td == curthread)
147 			vfp_save_state(td, pcb);
148 
149 		KASSERT(pcb->pcb_fpusaved == &pcb->pcb_fpustate,
150 		    ("Called get_fpcontext32 while the kernel is using the VFP"));
151 		KASSERT((pcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0,
152 		    ("Non-userspace FPU flags set in get_fpcontext32"));
153 		for (i = 0; i < 16; i++) {
154 			uint64_t *tmpreg = (uint64_t *)&pcb->pcb_fpustate.vfp_regs[i];
155 
156 			mcp->mcv_reg[i * 2] = tmpreg[0];
157 			mcp->mcv_reg[i * 2 + 1] = tmpreg[1];
158 		}
159 		mcp->mcv_fpscr = VFP_FPSCR_FROM_SRCR(pcb->pcb_fpustate.vfp_fpcr,
160 		    pcb->pcb_fpustate.vfp_fpsr);
161 	}
162 }
163 
164 void
165 set_fpcontext32(struct thread *td, mcontext32_vfp_t *mcp)
166 {
167 	struct pcb *pcb;
168 	int i;
169 
170 	critical_enter();
171 	pcb = td->td_pcb;
172 	if (td == curthread)
173 		vfp_discard(td);
174 	for (i = 0; i < 16; i++) {
175 		uint64_t *tmpreg = (uint64_t *)&pcb->pcb_fpustate.vfp_regs[i];
176 
177 		tmpreg[0] = mcp->mcv_reg[i * 2];
178 		tmpreg[1] = mcp->mcv_reg[i * 2 + 1];
179 	}
180 	pcb->pcb_fpustate.vfp_fpsr = VFP_FPSR_FROM_FPSCR(mcp->mcv_fpscr);
181 	pcb->pcb_fpustate.vfp_fpcr = VFP_FPSR_FROM_FPSCR(mcp->mcv_fpscr);
182 	critical_exit();
183 }
184 #endif
185 
186 static void
187 get_mcontext32(struct thread *td, mcontext32_t *mcp, int flags)
188 {
189 	struct trapframe *tf;
190 	int i;
191 
192 	tf = td->td_frame;
193 
194 	if ((flags & GET_MC_CLEAR_RET) != 0) {
195 		mcp->mc_gregset[0] = 0;
196 		mcp->mc_gregset[16] = tf->tf_spsr & ~PSR_C;
197 	} else {
198 		mcp->mc_gregset[0] = tf->tf_x[0];
199 		mcp->mc_gregset[16] = tf->tf_spsr;
200 	}
201 	for (i = 1; i < 15; i++)
202 		mcp->mc_gregset[i] = tf->tf_x[i];
203 	mcp->mc_gregset[15] = tf->tf_elr;
204 
205 	mcp->mc_vfp_size = 0;
206 	mcp->mc_vfp_ptr = 0;
207 
208 	memset(mcp->mc_spare, 0, sizeof(mcp->mc_spare));
209 }
210 
211 static int
212 set_mcontext32(struct thread *td, mcontext32_t *mcp)
213 {
214 	struct trapframe *tf;
215 	mcontext32_vfp_t mc_vfp;
216 	uint32_t spsr;
217 	int i;
218 
219 	tf = td->td_frame;
220 
221 	spsr = mcp->mc_gregset[16];
222 	/*
223 	 * There is no PSR_SS in the 32-bit kernel so ignore it if it's set
224 	 * as we will set it later if needed.
225 	 */
226 	if ((spsr & ~(PSR_SETTABLE_32 | PSR_SS)) !=
227 	    (tf->tf_spsr & ~(PSR_SETTABLE_32 | PSR_SS)))
228 		return (EINVAL);
229 
230 	spsr &= PSR_SETTABLE_32;
231 	spsr |= tf->tf_spsr & ~PSR_SETTABLE_32;
232 
233 	if ((td->td_dbgflags & TDB_STEP) != 0) {
234 		spsr |= PSR_SS;
235 		td->td_pcb->pcb_flags |= PCB_SINGLE_STEP;
236 		WRITE_SPECIALREG(mdscr_el1,
237 		    READ_SPECIALREG(mdscr_el1) | MDSCR_SS);
238 	}
239 
240 	for (i = 0; i < 15; i++)
241 		tf->tf_x[i] = mcp->mc_gregset[i];
242 	tf->tf_elr = mcp->mc_gregset[15];
243 	tf->tf_spsr = spsr;
244 #ifdef VFP
245 	if (mcp->mc_vfp_size == sizeof(mc_vfp) && mcp->mc_vfp_ptr != 0) {
246 		if (copyin((void *)(uintptr_t)mcp->mc_vfp_ptr, &mc_vfp,
247 					sizeof(mc_vfp)) != 0)
248 			return (EFAULT);
249 		set_fpcontext32(td, &mc_vfp);
250 	}
251 #endif
252 
253 	return (0);
254 }
255 
256 #define UC_COPY_SIZE	offsetof(ucontext32_t, uc_link)
257 
258 int
259 freebsd32_getcontext(struct thread *td, struct freebsd32_getcontext_args *uap)
260 {
261 	ucontext32_t uc;
262 	int ret;
263 
264 	if (uap->ucp == NULL)
265 		ret = EINVAL;
266 	else {
267 		memset(&uc, 0, sizeof(uc));
268 		get_mcontext32(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
269 		PROC_LOCK(td->td_proc);
270 		uc.uc_sigmask = td->td_sigmask;
271 		PROC_UNLOCK(td->td_proc);
272 		ret = copyout(&uc, uap->ucp, UC_COPY_SIZE);
273 	}
274 	return (ret);
275 }
276 
277 int
278 freebsd32_setcontext(struct thread *td, struct freebsd32_setcontext_args *uap)
279 {
280 	ucontext32_t uc;
281 	int ret;
282 
283 	if (uap->ucp == NULL)
284 		ret = EINVAL;
285 	else {
286 		ret = copyin(uap->ucp, &uc, UC_COPY_SIZE);
287 		if (ret == 0) {
288 			ret = set_mcontext32(td, &uc.uc_mcontext);
289 			if (ret == 0)
290 				kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask,
291 						NULL, 0);
292 		}
293 	}
294 	return (ret);
295 }
296 
297 int
298 freebsd32_sigreturn(struct thread *td, struct freebsd32_sigreturn_args *uap)
299 {
300 	ucontext32_t uc;
301 	int error;
302 
303 	if (uap == NULL)
304 		return (EFAULT);
305 	if (copyin(uap->sigcntxp, &uc, sizeof(uc)))
306 		return (EFAULT);
307 	error = set_mcontext32(td, &uc.uc_mcontext);
308 	if (error != 0)
309 		return (0);
310 
311 	/* Restore signal mask. */
312 	kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);
313 
314 	return (EJUSTRETURN);
315 
316 }
317 
318 int
319 freebsd32_swapcontext(struct thread *td, struct freebsd32_swapcontext_args *uap)
320 {
321 	ucontext32_t uc;
322 	int ret;
323 
324 	if (uap->oucp == NULL || uap->ucp == NULL)
325 		ret = EINVAL;
326 	else {
327 		bzero(&uc, sizeof(uc));
328 		get_mcontext32(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
329 		PROC_LOCK(td->td_proc);
330 		uc.uc_sigmask = td->td_sigmask;
331 		PROC_UNLOCK(td->td_proc);
332 		ret = copyout(&uc, uap->oucp, UC32_COPY_SIZE);
333 		if (ret == 0) {
334 			ret = copyin(uap->ucp, &uc, UC32_COPY_SIZE);
335 			if (ret == 0) {
336 				ret = set_mcontext32(td, &uc.uc_mcontext);
337 				kern_sigprocmask(td, SIG_SETMASK,
338 						&uc.uc_sigmask, NULL, 0);
339 			}
340 		}
341 	}
342 	return (ret);
343 }
344 
345 void
346 freebsd32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
347 {
348 	struct thread *td;
349 	struct proc *p;
350 	struct trapframe *tf;
351 	struct sigframe32 *fp, frame;
352 	struct sigacts *psp;
353 	struct siginfo32 siginfo;
354 	struct sysentvec *sysent;
355 	int onstack;
356 	int sig;
357 
358 	siginfo_to_siginfo32(&ksi->ksi_info, &siginfo);
359 	td = curthread;
360 	p = td->td_proc;
361 	PROC_LOCK_ASSERT(p, MA_OWNED);
362 	sig = ksi->ksi_signo;
363 	psp = p->p_sigacts;
364 	mtx_assert(&psp->ps_mtx, MA_OWNED);
365 	tf = td->td_frame;
366 	onstack = sigonstack(tf->tf_x[13]);
367 
368 	CTR4(KTR_SIG, "sendsig: td=%p (%s) catcher=%p sig=%d", td, p->p_comm,
369 	    catcher, sig);
370 
371 	/* Allocate and validate space for the signal handler context. */
372 	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !(onstack) &&
373 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
374 		fp = (struct sigframe32 *)((uintptr_t)td->td_sigstk.ss_sp +
375 		    td->td_sigstk.ss_size);
376 #if defined(COMPAT_43)
377 		td->td_sigstk.ss_flags |= SS_ONSTACK;
378 #endif
379 	} else
380 		fp = (struct sigframe32 *)td->td_frame->tf_x[13];
381 
382 	/* make room on the stack */
383 	fp--;
384 
385 	/* make the stack aligned */
386 	fp = (struct sigframe32 *)((unsigned long)(fp) &~ (8 - 1));
387 	/* Populate the siginfo frame. */
388 	get_mcontext32(td, &frame.sf_uc.uc_mcontext, 0);
389 #ifdef VFP
390 	get_fpcontext32(td, &frame.sf_vfp);
391 	frame.sf_uc.uc_mcontext.mc_vfp_size = sizeof(fp->sf_vfp);
392 	frame.sf_uc.uc_mcontext.mc_vfp_ptr = (uint32_t)(uintptr_t)&fp->sf_vfp;
393 #else
394 	frame.sf_uc.uc_mcontext.mc_vfp_size = 0;
395 	frame.sf_uc.uc_mcontext.mc_vfp_ptr = (uint32_t)NULL;
396 #endif
397 	frame.sf_si = siginfo;
398 	frame.sf_uc.uc_sigmask = *mask;
399 	frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK )
400 	    ? ((onstack) ? SS_ONSTACK : 0) : SS_DISABLE;
401 	frame.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp;
402 	frame.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size;
403 
404 	mtx_unlock(&psp->ps_mtx);
405 	PROC_UNLOCK(td->td_proc);
406 
407 	/* Copy the sigframe out to the user's stack. */
408 	if (copyout(&frame, fp, sizeof(*fp)) != 0) {
409 		/* Process has trashed its stack. Kill it. */
410 		CTR2(KTR_SIG, "sendsig: sigexit td=%p fp=%p", td, fp);
411 		PROC_LOCK(p);
412 		sigexit(td, SIGILL);
413 	}
414 
415 	/*
416 	 * Build context to run handler in.  We invoke the handler
417 	 * directly, only returning via the trampoline.  Note the
418 	 * trampoline version numbers are coordinated with machine-
419 	 * dependent code in libc.
420 	 */
421 
422 	tf->tf_x[0] = sig;
423 	tf->tf_x[1] = (register_t)&fp->sf_si;
424 	tf->tf_x[2] = (register_t)&fp->sf_uc;
425 
426 	/* the trampoline uses r5 as the uc address */
427 	tf->tf_x[5] = (register_t)&fp->sf_uc;
428 	tf->tf_elr = (register_t)catcher;
429 	tf->tf_x[13] = (register_t)fp;
430 	sysent = p->p_sysent;
431 	if (PROC_HAS_SHP(p))
432 		tf->tf_x[14] = (register_t)PROC_SIGCODE(p);
433 	else
434 		tf->tf_x[14] = (register_t)(PROC_PS_STRINGS(p) -
435 		    *(sysent->sv_szsigcode));
436 	/* Set the mode to enter in the signal handler */
437 	if ((register_t)catcher & 1)
438 		tf->tf_spsr |= PSR_T;
439 	else
440 		tf->tf_spsr &= ~PSR_T;
441 
442 	/* Clear the single step flag while in the signal handler */
443 	if ((td->td_pcb->pcb_flags & PCB_SINGLE_STEP) != 0) {
444 		td->td_pcb->pcb_flags &= ~PCB_SINGLE_STEP;
445 		WRITE_SPECIALREG(mdscr_el1,
446 		    READ_SPECIALREG(mdscr_el1) & ~MDSCR_SS);
447 		isb();
448 	}
449 
450 	CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_x[14],
451 	    tf->tf_x[13]);
452 
453 	PROC_LOCK(p);
454 	mtx_lock(&psp->ps_mtx);
455 
456 }
457 
458 #ifdef COMPAT_43
459 /*
460  * Mirror the osigreturn definition in kern_sig.c for !i386 platforms. This
461  * mirrors what's connected to the FreeBSD/arm syscall.
462  */
463 int
464 ofreebsd32_sigreturn(struct thread *td, struct ofreebsd32_sigreturn_args *uap)
465 {
466 
467 	return (nosys(td, (struct nosys_args *)uap));
468 }
469 #endif
470