xref: /freebsd/sys/arm64/arm64/freebsd32_machdep.c (revision c1d255d3)
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/types.h>
31 #include <sys/proc.h>
32 #include <sys/lock.h>
33 #include <sys/mutex.h>
34 #include <sys/syscallsubr.h>
35 #include <sys/ktr.h>
36 #include <sys/sysent.h>
37 #include <sys/sysproto.h>
38 #include <machine/armreg.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 extern void freebsd32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
46 
47 /*
48  * The first two fields of a ucontext_t are the signal mask and the machine
49  * context.  The next field is uc_link; we want to avoid destroying the link
50  * when copying out contexts.
51  */
52 #define UC32_COPY_SIZE  offsetof(ucontext32_t, uc_link)
53 
54 #ifdef VFP
55 static void get_fpcontext32(struct thread *td, mcontext32_vfp_t *);
56 #endif
57 
58 /*
59  * Stubs for machine dependent 32-bits system calls.
60  */
61 
62 int
63 freebsd32_sysarch(struct thread *td, struct freebsd32_sysarch_args *uap)
64 {
65 	int error;
66 
67 #define ARM_SYNC_ICACHE		0
68 #define ARM_DRAIN_WRITEBUF	1
69 #define ARM_SET_TP		2
70 #define ARM_GET_TP		3
71 #define ARM_GET_VFPSTATE	4
72 
73 	switch(uap->op) {
74 	case ARM_SET_TP:
75 		WRITE_SPECIALREG(tpidr_el0, uap->parms);
76 		WRITE_SPECIALREG(tpidrro_el0, uap->parms);
77 		return 0;
78 	case ARM_SYNC_ICACHE:
79 		{
80 			struct {
81 				uint32_t addr;
82 				uint32_t size;
83 			} args;
84 
85 			if ((error = copyin(uap->parms, &args, sizeof(args))) != 0)
86 				return (error);
87 			if ((uint64_t)args.addr + (uint64_t)args.size > 0xffffffff)
88 				return (EINVAL);
89 			cpu_icache_sync_range_checked(args.addr, args.size);
90 			return 0;
91 		}
92 	case ARM_GET_VFPSTATE:
93 		{
94 			mcontext32_vfp_t mcontext_vfp;
95 
96 			struct {
97 				uint32_t mc_vfp_size;
98 				uint32_t mc_vfp;
99 			} args;
100 			if ((error = copyin(uap->parms, &args, sizeof(args))) != 0)
101 				return (error);
102 			if (args.mc_vfp_size != sizeof(mcontext_vfp))
103 				return (EINVAL);
104 #ifdef VFP
105 			get_fpcontext32(td, &mcontext_vfp);
106 #else
107 			bzero(&mcontext_vfp, sizeof(mcontext_vfp));
108 #endif
109 			error = copyout(&mcontext_vfp,
110 				(void *)(uintptr_t)args.mc_vfp,
111 				sizeof(mcontext_vfp));
112 			return error;
113 		}
114 	}
115 
116 	return (EINVAL);
117 }
118 
119 #ifdef VFP
120 static void
121 get_fpcontext32(struct thread *td, mcontext32_vfp_t *mcp)
122 {
123 	struct pcb *curpcb;
124 	int i;
125 
126 	critical_enter();
127 	curpcb = curthread->td_pcb;
128 
129 	if ((curpcb->pcb_fpflags & PCB_FP_STARTED) != 0) {
130 		/*
131 		 * If we have just been running VFP instructions we will
132 		 * need to save the state to memcpy it below.
133 		 */
134 		vfp_save_state(td, curpcb);
135 
136 		KASSERT(curpcb->pcb_fpusaved == &curpcb->pcb_fpustate,
137 				("Called get_fpcontext while the kernel is using the VFP"));
138 		KASSERT((curpcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0,
139 				("Non-userspace FPU flags set in get_fpcontext"));
140 		for (i = 0; i < 32; i++)
141 			mcp->mcv_reg[i] = (uint64_t)curpcb->pcb_fpustate.vfp_regs[i];
142 		mcp->mcv_fpscr = VFP_FPSCR_FROM_SRCR(curpcb->pcb_fpustate.vfp_fpcr,
143 				curpcb->pcb_fpustate.vfp_fpsr);
144 	}
145  critical_exit();
146 }
147 
148 static void
149 set_fpcontext32(struct thread *td, mcontext32_vfp_t *mcp)
150 {
151 	struct pcb *pcb;
152 	int i;
153 
154 	critical_enter();
155 	pcb = td->td_pcb;
156 	if (td == curthread)
157 		vfp_discard(td);
158 	for (i = 0; i < 32; i++)
159 		pcb->pcb_fpustate.vfp_regs[i] = mcp->mcv_reg[i];
160 	pcb->pcb_fpustate.vfp_fpsr = VFP_FPSR_FROM_FPSCR(mcp->mcv_fpscr);
161 	pcb->pcb_fpustate.vfp_fpcr = VFP_FPSR_FROM_FPSCR(mcp->mcv_fpscr);
162 	critical_exit();
163 }
164 #endif
165 static void
166 get_mcontext32(struct thread *td, mcontext32_t *mcp, int flags)
167 {
168 	struct pcb *pcb;
169 	struct trapframe *tf;
170 	int i;
171 
172 	pcb = td->td_pcb;
173 	tf = td->td_frame;
174 
175 	if ((flags & GET_MC_CLEAR_RET) != 0) {
176 		mcp->mc_gregset[0] = 0;
177 		mcp->mc_gregset[16] = tf->tf_spsr & ~PSR_C;
178 	} else {
179 		mcp->mc_gregset[0] = tf->tf_x[0];
180 		mcp->mc_gregset[16] = tf->tf_spsr;
181 	}
182 	for (i = 1; i < 15; i++)
183 		mcp->mc_gregset[i] = tf->tf_x[i];
184 	mcp->mc_gregset[15] = tf->tf_elr;
185 
186 	mcp->mc_vfp_size = 0;
187 	mcp->mc_vfp_ptr = 0;
188 
189 	memset(mcp->mc_spare, 0, sizeof(mcp->mc_spare));
190 }
191 
192 static int
193 set_mcontext32(struct thread *td, mcontext32_t *mcp)
194 {
195 	struct trapframe *tf;
196 	mcontext32_vfp_t mc_vfp;
197 	int i;
198 
199 	tf = td->td_frame;
200 
201 	for (i = 0; i < 15; i++)
202 		tf->tf_x[i] = mcp->mc_gregset[i];
203 	tf->tf_elr = mcp->mc_gregset[15];
204 	tf->tf_spsr = mcp->mc_gregset[16];
205 #ifdef VFP
206 	if (mcp->mc_vfp_size == sizeof(mc_vfp) && mcp->mc_vfp_ptr != 0) {
207 		if (copyin((void *)(uintptr_t)mcp->mc_vfp_ptr, &mc_vfp,
208 					sizeof(mc_vfp)) != 0)
209 			return (EFAULT);
210 		set_fpcontext32(td, &mc_vfp);
211 	}
212 #endif
213 
214 	return (0);
215 }
216 
217 #define UC_COPY_SIZE	offsetof(ucontext32_t, uc_link)
218 
219 int
220 freebsd32_getcontext(struct thread *td, struct freebsd32_getcontext_args *uap)
221 {
222 	ucontext32_t uc;
223 	int ret;
224 
225 	if (uap->ucp == NULL)
226 		ret = EINVAL;
227 	else {
228 		memset(&uc, 0, sizeof(uc));
229 		get_mcontext32(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
230 		PROC_LOCK(td->td_proc);
231 		uc.uc_sigmask = td->td_sigmask;
232 		PROC_UNLOCK(td->td_proc);
233 		ret = copyout(&uc, uap->ucp, UC_COPY_SIZE);
234 	}
235 	return (ret);
236 }
237 
238 int
239 freebsd32_setcontext(struct thread *td, struct freebsd32_setcontext_args *uap)
240 {
241 	ucontext32_t uc;
242 	int ret;
243 
244 	if (uap->ucp == NULL)
245 		ret = EINVAL;
246 	else {
247 		ret = copyin(uap->ucp, &uc, UC_COPY_SIZE);
248 		if (ret == 0) {
249 			ret = set_mcontext32(td, &uc.uc_mcontext);
250 			if (ret == 0)
251 				kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask,
252 						NULL, 0);
253 		}
254 	}
255 	return (ret);
256 }
257 
258 int
259 freebsd32_sigreturn(struct thread *td, struct freebsd32_sigreturn_args *uap)
260 {
261 	ucontext32_t uc;
262 	int error;
263 
264 	if (uap == NULL)
265 		return (EFAULT);
266 	if (copyin(uap->sigcntxp, &uc, sizeof(uc)))
267 		return (EFAULT);
268 	error = set_mcontext32(td, &uc.uc_mcontext);
269 	if (error != 0)
270 		return (0);
271 
272 	/* Restore signal mask. */
273 	kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);
274 
275 	return (EJUSTRETURN);
276 
277 }
278 
279 int
280 freebsd32_swapcontext(struct thread *td, struct freebsd32_swapcontext_args *uap)
281 {
282 	ucontext32_t uc;
283 	int ret;
284 
285 	if (uap->oucp == NULL || uap->ucp == NULL)
286 		ret = EINVAL;
287 	else {
288 		bzero(&uc, sizeof(uc));
289 		get_mcontext32(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
290 		PROC_LOCK(td->td_proc);
291 		uc.uc_sigmask = td->td_sigmask;
292 		PROC_UNLOCK(td->td_proc);
293 		ret = copyout(&uc, uap->oucp, UC32_COPY_SIZE);
294 		if (ret == 0) {
295 			ret = copyin(uap->ucp, &uc, UC32_COPY_SIZE);
296 			if (ret == 0) {
297 				ret = set_mcontext32(td, &uc.uc_mcontext);
298 				kern_sigprocmask(td, SIG_SETMASK,
299 						&uc.uc_sigmask, NULL, 0);
300 			}
301 		}
302 	}
303 	return (ret);
304 }
305 
306 void
307 freebsd32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
308 {
309 	struct thread *td;
310 	struct proc *p;
311 	struct trapframe *tf;
312 	struct sigframe32 *fp, frame;
313 	struct sigacts *psp;
314 	struct siginfo32 siginfo;
315 	struct sysentvec *sysent;
316 	int onstack;
317 	int sig;
318 	int code;
319 
320 	siginfo_to_siginfo32(&ksi->ksi_info, &siginfo);
321 	td = curthread;
322 	p = td->td_proc;
323 	PROC_LOCK_ASSERT(p, MA_OWNED);
324 	sig = ksi->ksi_signo;
325 	code = ksi->ksi_code;
326 	psp = p->p_sigacts;
327 	mtx_assert(&psp->ps_mtx, MA_OWNED);
328 	tf = td->td_frame;
329 	onstack = sigonstack(tf->tf_x[13]);
330 
331 	CTR4(KTR_SIG, "sendsig: td=%p (%s) catcher=%p sig=%d", td, p->p_comm,
332 	    catcher, sig);
333 
334 	/* Allocate and validate space for the signal handler context. */
335 	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !(onstack) &&
336 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
337 		fp = (struct sigframe32 *)((uintptr_t)td->td_sigstk.ss_sp +
338 		    td->td_sigstk.ss_size);
339 #if defined(COMPAT_43)
340 		td->td_sigstk.ss_flags |= SS_ONSTACK;
341 #endif
342 	} else
343 		fp = (struct sigframe32 *)td->td_frame->tf_x[13];
344 
345 	/* make room on the stack */
346 	fp--;
347 
348 	/* make the stack aligned */
349 	fp = (struct sigframe32 *)((unsigned long)(fp) &~ (8 - 1));
350 	/* Populate the siginfo frame. */
351 	get_mcontext32(td, &frame.sf_uc.uc_mcontext, 0);
352 #ifdef VFP
353 	get_fpcontext32(td, &frame.sf_vfp);
354 	frame.sf_uc.uc_mcontext.mc_vfp_size = sizeof(fp->sf_vfp);
355 	frame.sf_uc.uc_mcontext.mc_vfp_ptr = (uint32_t)(uintptr_t)&fp->sf_vfp;
356 #else
357 	frame.sf_uc.uc_mcontext.mc_vfp_size = 0;
358 	frame.sf_uc.uc_mcontext.mc_vfp_ptr = (uint32_t)NULL;
359 #endif
360 	frame.sf_si = siginfo;
361 	frame.sf_uc.uc_sigmask = *mask;
362 	frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK )
363 	    ? ((onstack) ? SS_ONSTACK : 0) : SS_DISABLE;
364 	frame.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp;
365 	frame.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size;
366 
367 	mtx_unlock(&psp->ps_mtx);
368 	PROC_UNLOCK(td->td_proc);
369 
370 	/* Copy the sigframe out to the user's stack. */
371 	if (copyout(&frame, fp, sizeof(*fp)) != 0) {
372 		/* Process has trashed its stack. Kill it. */
373 		CTR2(KTR_SIG, "sendsig: sigexit td=%p fp=%p", td, fp);
374 		PROC_LOCK(p);
375 		sigexit(td, SIGILL);
376 	}
377 
378 	/*
379 	 * Build context to run handler in.  We invoke the handler
380 	 * directly, only returning via the trampoline.  Note the
381 	 * trampoline version numbers are coordinated with machine-
382 	 * dependent code in libc.
383 	 */
384 
385 	tf->tf_x[0] = sig;
386 	tf->tf_x[1] = (register_t)&fp->sf_si;
387 	tf->tf_x[2] = (register_t)&fp->sf_uc;
388 
389 	/* the trampoline uses r5 as the uc address */
390 	tf->tf_x[5] = (register_t)&fp->sf_uc;
391 	tf->tf_elr = (register_t)catcher;
392 	tf->tf_x[13] = (register_t)fp;
393 	sysent = p->p_sysent;
394 	if (sysent->sv_sigcode_base != 0)
395 		tf->tf_x[14] = (register_t)sysent->sv_sigcode_base;
396 	else
397 		tf->tf_x[14] = (register_t)(sysent->sv_psstrings -
398 		    *(sysent->sv_szsigcode));
399 	/* Set the mode to enter in the signal handler */
400 	if ((register_t)catcher & 1)
401 		tf->tf_spsr |= PSR_T;
402 	else
403 		tf->tf_spsr &= ~PSR_T;
404 
405 	CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_x[14],
406 	    tf->tf_x[13]);
407 
408 	PROC_LOCK(p);
409 	mtx_lock(&psp->ps_mtx);
410 
411 }
412 
413 #ifdef COMPAT_43
414 /*
415  * COMPAT_FREEBSD32 assumes we have this system call when COMPAT_43 is defined.
416  * FreeBSD/arm provies a similar getpagesize() syscall.
417  */
418 #define ARM32_PAGE_SIZE 4096
419 int
420 ofreebsd32_getpagesize(struct thread *td,
421     struct ofreebsd32_getpagesize_args *uap)
422 {
423 
424 	td->td_retval[0] = ARM32_PAGE_SIZE;
425 	return (0);
426 }
427 
428 /*
429  * Mirror the osigreturn definition in kern_sig.c for !i386 platforms. This
430  * mirrors what's connected to the FreeBSD/arm syscall.
431  */
432 int
433 ofreebsd32_sigreturn(struct thread *td, struct ofreebsd32_sigreturn_args *uap)
434 {
435 
436 	return (nosys(td, (struct nosys_args *)uap));
437 }
438 #endif
439