xref: /freebsd/sys/arm64/arm64/freebsd32_machdep.c (revision 1323ec57) 
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/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/exec.h>
32 #include <sys/proc.h>
33 #include <sys/lock.h>
34 #include <sys/mutex.h>
35 #include <sys/syscallsubr.h>
36 #include <sys/ktr.h>
37 #include <sys/sysent.h>
38 #include <sys/sysproto.h>
39 #include <machine/armreg.h>
40 #ifdef VFP
41 #include <machine/vfp.h>
42 #endif
43 #include <compat/freebsd32/freebsd32_proto.h>
44 #include <compat/freebsd32/freebsd32_signal.h>
45 
46 #include <vm/vm.h>
47 #include <vm/vm_param.h>
48 #include <vm/pmap.h>
49 #include <vm/vm_map.h>
50 
51 _Static_assert(sizeof(mcontext32_t) == 208, "mcontext32_t size incorrect");
52 _Static_assert(sizeof(ucontext32_t) == 260, "ucontext32_t size incorrect");
53 _Static_assert(sizeof(struct siginfo32) == 64, "struct siginfo32 size incorrect");
54 
55 extern void freebsd32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
56 
57 /*
58  * The first two fields of a ucontext_t are the signal mask and the machine
59  * context.  The next field is uc_link; we want to avoid destroying the link
60  * when copying out contexts.
61  */
62 #define UC32_COPY_SIZE  offsetof(ucontext32_t, uc_link)
63 
64 /*
65  * Stubs for machine dependent 32-bits system calls.
66  */
67 
68 int
69 freebsd32_sysarch(struct thread *td, struct freebsd32_sysarch_args *uap)
70 {
71 	int error;
72 
73 #define ARM_SYNC_ICACHE		0
74 #define ARM_DRAIN_WRITEBUF	1
75 #define ARM_SET_TP		2
76 #define ARM_GET_TP		3
77 #define ARM_GET_VFPSTATE	4
78 
79 	switch(uap->op) {
80 	case ARM_SET_TP:
81 		WRITE_SPECIALREG(tpidr_el0, uap->parms);
82 		WRITE_SPECIALREG(tpidrro_el0, uap->parms);
83 		return 0;
84 	case ARM_SYNC_ICACHE:
85 		{
86 			struct {
87 				uint32_t addr;
88 				uint32_t size;
89 			} args;
90 
91 			if ((error = copyin(uap->parms, &args, sizeof(args))) != 0)
92 				return (error);
93 			if ((uint64_t)args.addr + (uint64_t)args.size > 0xffffffff)
94 				return (EINVAL);
95 			cpu_icache_sync_range_checked(args.addr, args.size);
96 			return 0;
97 		}
98 	case ARM_GET_VFPSTATE:
99 		{
100 			mcontext32_vfp_t mcontext_vfp;
101 
102 			struct {
103 				uint32_t mc_vfp_size;
104 				uint32_t mc_vfp;
105 			} args;
106 			if ((error = copyin(uap->parms, &args, sizeof(args))) != 0)
107 				return (error);
108 			if (args.mc_vfp_size != sizeof(mcontext_vfp))
109 				return (EINVAL);
110 #ifdef VFP
111 			get_fpcontext32(td, &mcontext_vfp);
112 #else
113 			bzero(&mcontext_vfp, sizeof(mcontext_vfp));
114 #endif
115 			error = copyout(&mcontext_vfp,
116 				(void *)(uintptr_t)args.mc_vfp,
117 				sizeof(mcontext_vfp));
118 			return error;
119 		}
120 	}
121 
122 	return (EINVAL);
123 }
124 
125 #ifdef VFP
126 void
127 get_fpcontext32(struct thread *td, mcontext32_vfp_t *mcp)
128 {
129 	struct pcb *pcb;
130 	int i;
131 
132 	KASSERT(td == curthread || TD_IS_SUSPENDED(td) ||
133 	    P_SHOULDSTOP(td->td_proc),
134 	    ("not suspended thread %p", td));
135 
136 	memset(mcp, 0, sizeof(*mcp));
137 	pcb = td->td_pcb;
138 
139 	if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0) {
140 		/*
141 		 * If we have just been running VFP instructions we will
142 		 * need to save the state to memcpy it below.
143 		 */
144 		if (td == curthread)
145 			vfp_save_state(td, pcb);
146 
147 		KASSERT(pcb->pcb_fpusaved == &pcb->pcb_fpustate,
148 		    ("Called get_fpcontext32 while the kernel is using the VFP"));
149 		KASSERT((pcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0,
150 		    ("Non-userspace FPU flags set in get_fpcontext32"));
151 		for (i = 0; i < 32; i++)
152 			mcp->mcv_reg[i] = (uint64_t)pcb->pcb_fpustate.vfp_regs[i];
153 		mcp->mcv_fpscr = VFP_FPSCR_FROM_SRCR(pcb->pcb_fpustate.vfp_fpcr,
154 		    pcb->pcb_fpustate.vfp_fpsr);
155 	}
156 }
157 
158 void
159 set_fpcontext32(struct thread *td, mcontext32_vfp_t *mcp)
160 {
161 	struct pcb *pcb;
162 	int i;
163 
164 	critical_enter();
165 	pcb = td->td_pcb;
166 	if (td == curthread)
167 		vfp_discard(td);
168 	for (i = 0; i < 32; i++)
169 		pcb->pcb_fpustate.vfp_regs[i] = mcp->mcv_reg[i];
170 	pcb->pcb_fpustate.vfp_fpsr = VFP_FPSR_FROM_FPSCR(mcp->mcv_fpscr);
171 	pcb->pcb_fpustate.vfp_fpcr = VFP_FPSR_FROM_FPSCR(mcp->mcv_fpscr);
172 	critical_exit();
173 }
174 #endif
175 
176 static void
177 get_mcontext32(struct thread *td, mcontext32_t *mcp, int flags)
178 {
179 	struct trapframe *tf;
180 	int i;
181 
182 	tf = td->td_frame;
183 
184 	if ((flags & GET_MC_CLEAR_RET) != 0) {
185 		mcp->mc_gregset[0] = 0;
186 		mcp->mc_gregset[16] = tf->tf_spsr & ~PSR_C;
187 	} else {
188 		mcp->mc_gregset[0] = tf->tf_x[0];
189 		mcp->mc_gregset[16] = tf->tf_spsr;
190 	}
191 	for (i = 1; i < 15; i++)
192 		mcp->mc_gregset[i] = tf->tf_x[i];
193 	mcp->mc_gregset[15] = tf->tf_elr;
194 
195 	mcp->mc_vfp_size = 0;
196 	mcp->mc_vfp_ptr = 0;
197 
198 	memset(mcp->mc_spare, 0, sizeof(mcp->mc_spare));
199 }
200 
201 static int
202 set_mcontext32(struct thread *td, mcontext32_t *mcp)
203 {
204 	struct trapframe *tf;
205 	mcontext32_vfp_t mc_vfp;
206 	uint32_t spsr;
207 	int i;
208 
209 	tf = td->td_frame;
210 
211 	spsr = mcp->mc_gregset[16];
212 	/*
213 	 * There is no PSR_SS in the 32-bit kernel so ignore it if it's set
214 	 * as we will set it later if needed.
215 	 */
216 	if ((spsr & ~(PSR_SETTABLE_32 | PSR_SS)) !=
217 	    (tf->tf_spsr & ~(PSR_SETTABLE_32 | PSR_SS)))
218 		return (EINVAL);
219 
220 	spsr &= PSR_SETTABLE_32;
221 	spsr |= tf->tf_spsr & ~PSR_SETTABLE_32;
222 
223 	if ((td->td_dbgflags & TDB_STEP) != 0) {
224 		spsr |= PSR_SS;
225 		td->td_pcb->pcb_flags |= PCB_SINGLE_STEP;
226 		WRITE_SPECIALREG(mdscr_el1,
227 		    READ_SPECIALREG(mdscr_el1) | MDSCR_SS);
228 	}
229 
230 	for (i = 0; i < 15; i++)
231 		tf->tf_x[i] = mcp->mc_gregset[i];
232 	tf->tf_elr = mcp->mc_gregset[15];
233 	tf->tf_spsr = spsr;
234 #ifdef VFP
235 	if (mcp->mc_vfp_size == sizeof(mc_vfp) && mcp->mc_vfp_ptr != 0) {
236 		if (copyin((void *)(uintptr_t)mcp->mc_vfp_ptr, &mc_vfp,
237 					sizeof(mc_vfp)) != 0)
238 			return (EFAULT);
239 		set_fpcontext32(td, &mc_vfp);
240 	}
241 #endif
242 
243 	return (0);
244 }
245 
246 #define UC_COPY_SIZE	offsetof(ucontext32_t, uc_link)
247 
248 int
249 freebsd32_getcontext(struct thread *td, struct freebsd32_getcontext_args *uap)
250 {
251 	ucontext32_t uc;
252 	int ret;
253 
254 	if (uap->ucp == NULL)
255 		ret = EINVAL;
256 	else {
257 		memset(&uc, 0, sizeof(uc));
258 		get_mcontext32(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
259 		PROC_LOCK(td->td_proc);
260 		uc.uc_sigmask = td->td_sigmask;
261 		PROC_UNLOCK(td->td_proc);
262 		ret = copyout(&uc, uap->ucp, UC_COPY_SIZE);
263 	}
264 	return (ret);
265 }
266 
267 int
268 freebsd32_setcontext(struct thread *td, struct freebsd32_setcontext_args *uap)
269 {
270 	ucontext32_t uc;
271 	int ret;
272 
273 	if (uap->ucp == NULL)
274 		ret = EINVAL;
275 	else {
276 		ret = copyin(uap->ucp, &uc, UC_COPY_SIZE);
277 		if (ret == 0) {
278 			ret = set_mcontext32(td, &uc.uc_mcontext);
279 			if (ret == 0)
280 				kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask,
281 						NULL, 0);
282 		}
283 	}
284 	return (ret);
285 }
286 
287 int
288 freebsd32_sigreturn(struct thread *td, struct freebsd32_sigreturn_args *uap)
289 {
290 	ucontext32_t uc;
291 	int error;
292 
293 	if (uap == NULL)
294 		return (EFAULT);
295 	if (copyin(uap->sigcntxp, &uc, sizeof(uc)))
296 		return (EFAULT);
297 	error = set_mcontext32(td, &uc.uc_mcontext);
298 	if (error != 0)
299 		return (0);
300 
301 	/* Restore signal mask. */
302 	kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);
303 
304 	return (EJUSTRETURN);
305 
306 }
307 
308 int
309 freebsd32_swapcontext(struct thread *td, struct freebsd32_swapcontext_args *uap)
310 {
311 	ucontext32_t uc;
312 	int ret;
313 
314 	if (uap->oucp == NULL || uap->ucp == NULL)
315 		ret = EINVAL;
316 	else {
317 		bzero(&uc, sizeof(uc));
318 		get_mcontext32(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
319 		PROC_LOCK(td->td_proc);
320 		uc.uc_sigmask = td->td_sigmask;
321 		PROC_UNLOCK(td->td_proc);
322 		ret = copyout(&uc, uap->oucp, UC32_COPY_SIZE);
323 		if (ret == 0) {
324 			ret = copyin(uap->ucp, &uc, UC32_COPY_SIZE);
325 			if (ret == 0) {
326 				ret = set_mcontext32(td, &uc.uc_mcontext);
327 				kern_sigprocmask(td, SIG_SETMASK,
328 						&uc.uc_sigmask, NULL, 0);
329 			}
330 		}
331 	}
332 	return (ret);
333 }
334 
335 void
336 freebsd32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
337 {
338 	struct thread *td;
339 	struct proc *p;
340 	struct trapframe *tf;
341 	struct sigframe32 *fp, frame;
342 	struct sigacts *psp;
343 	struct siginfo32 siginfo;
344 	struct sysentvec *sysent;
345 	int onstack;
346 	int sig;
347 
348 	siginfo_to_siginfo32(&ksi->ksi_info, &siginfo);
349 	td = curthread;
350 	p = td->td_proc;
351 	PROC_LOCK_ASSERT(p, MA_OWNED);
352 	sig = ksi->ksi_signo;
353 	psp = p->p_sigacts;
354 	mtx_assert(&psp->ps_mtx, MA_OWNED);
355 	tf = td->td_frame;
356 	onstack = sigonstack(tf->tf_x[13]);
357 
358 	CTR4(KTR_SIG, "sendsig: td=%p (%s) catcher=%p sig=%d", td, p->p_comm,
359 	    catcher, sig);
360 
361 	/* Allocate and validate space for the signal handler context. */
362 	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !(onstack) &&
363 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
364 		fp = (struct sigframe32 *)((uintptr_t)td->td_sigstk.ss_sp +
365 		    td->td_sigstk.ss_size);
366 #if defined(COMPAT_43)
367 		td->td_sigstk.ss_flags |= SS_ONSTACK;
368 #endif
369 	} else
370 		fp = (struct sigframe32 *)td->td_frame->tf_x[13];
371 
372 	/* make room on the stack */
373 	fp--;
374 
375 	/* make the stack aligned */
376 	fp = (struct sigframe32 *)((unsigned long)(fp) &~ (8 - 1));
377 	/* Populate the siginfo frame. */
378 	get_mcontext32(td, &frame.sf_uc.uc_mcontext, 0);
379 #ifdef VFP
380 	get_fpcontext32(td, &frame.sf_vfp);
381 	frame.sf_uc.uc_mcontext.mc_vfp_size = sizeof(fp->sf_vfp);
382 	frame.sf_uc.uc_mcontext.mc_vfp_ptr = (uint32_t)(uintptr_t)&fp->sf_vfp;
383 #else
384 	frame.sf_uc.uc_mcontext.mc_vfp_size = 0;
385 	frame.sf_uc.uc_mcontext.mc_vfp_ptr = (uint32_t)NULL;
386 #endif
387 	frame.sf_si = siginfo;
388 	frame.sf_uc.uc_sigmask = *mask;
389 	frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK )
390 	    ? ((onstack) ? SS_ONSTACK : 0) : SS_DISABLE;
391 	frame.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp;
392 	frame.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size;
393 
394 	mtx_unlock(&psp->ps_mtx);
395 	PROC_UNLOCK(td->td_proc);
396 
397 	/* Copy the sigframe out to the user's stack. */
398 	if (copyout(&frame, fp, sizeof(*fp)) != 0) {
399 		/* Process has trashed its stack. Kill it. */
400 		CTR2(KTR_SIG, "sendsig: sigexit td=%p fp=%p", td, fp);
401 		PROC_LOCK(p);
402 		sigexit(td, SIGILL);
403 	}
404 
405 	/*
406 	 * Build context to run handler in.  We invoke the handler
407 	 * directly, only returning via the trampoline.  Note the
408 	 * trampoline version numbers are coordinated with machine-
409 	 * dependent code in libc.
410 	 */
411 
412 	tf->tf_x[0] = sig;
413 	tf->tf_x[1] = (register_t)&fp->sf_si;
414 	tf->tf_x[2] = (register_t)&fp->sf_uc;
415 
416 	/* the trampoline uses r5 as the uc address */
417 	tf->tf_x[5] = (register_t)&fp->sf_uc;
418 	tf->tf_elr = (register_t)catcher;
419 	tf->tf_x[13] = (register_t)fp;
420 	sysent = p->p_sysent;
421 	if (sysent->sv_sigcode_base != 0)
422 		tf->tf_x[14] = (register_t)sysent->sv_sigcode_base;
423 	else
424 		tf->tf_x[14] = (register_t)(PROC_PS_STRINGS(p) -
425 		    *(sysent->sv_szsigcode));
426 	/* Set the mode to enter in the signal handler */
427 	if ((register_t)catcher & 1)
428 		tf->tf_spsr |= PSR_T;
429 	else
430 		tf->tf_spsr &= ~PSR_T;
431 
432 	/* Clear the single step flag while in the signal handler */
433 	if ((td->td_pcb->pcb_flags & PCB_SINGLE_STEP) != 0) {
434 		td->td_pcb->pcb_flags &= ~PCB_SINGLE_STEP;
435 		WRITE_SPECIALREG(mdscr_el1,
436 		    READ_SPECIALREG(mdscr_el1) & ~MDSCR_SS);
437 		isb();
438 	}
439 
440 	CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_x[14],
441 	    tf->tf_x[13]);
442 
443 	PROC_LOCK(p);
444 	mtx_lock(&psp->ps_mtx);
445 
446 }
447 
448 #ifdef COMPAT_43
449 /*
450  * Mirror the osigreturn definition in kern_sig.c for !i386 platforms. This
451  * mirrors what's connected to the FreeBSD/arm syscall.
452  */
453 int
454 ofreebsd32_sigreturn(struct thread *td, struct ofreebsd32_sigreturn_args *uap)
455 {
456 
457 	return (nosys(td, (struct nosys_args *)uap));
458 }
459 #endif
460