xref: /freebsd/sys/arm/arm/exec_machdep.c (revision 9768746b)
1 /*	$NetBSD: arm32_machdep.c,v 1.44 2004/03/24 15:34:47 atatat Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-4-Clause
5  *
6  * Copyright (c) 2004 Olivier Houchard
7  * Copyright (c) 1994-1998 Mark Brinicombe.
8  * Copyright (c) 1994 Brini.
9  * All rights reserved.
10  *
11  * This code is derived from software written for Brini by Mark Brinicombe
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. All advertising materials mentioning features or use of this software
22  *    must display the following acknowledgement:
23  *	This product includes software developed by Mark Brinicombe
24  *	for the NetBSD Project.
25  * 4. The name of the company nor the name of the author may be used to
26  *    endorse or promote products derived from this software without specific
27  *    prior written permission.
28  *
29  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
30  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
31  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
32  * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
33  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
34  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
35  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39  * SUCH DAMAGE.
40  */
41 
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44 
45 #include <sys/param.h>
46 #include <sys/exec.h>
47 #include <sys/imgact.h>
48 #include <sys/kdb.h>
49 #include <sys/kernel.h>
50 #include <sys/ktr.h>
51 #include <sys/lock.h>
52 #include <sys/mutex.h>
53 #include <sys/proc.h>
54 #include <sys/rwlock.h>
55 #include <sys/syscallsubr.h>
56 #include <sys/sysent.h>
57 #include <sys/sysproto.h>
58 #include <sys/vmmeter.h>
59 
60 #include <machine/asm.h>
61 #include <machine/machdep.h>
62 #include <machine/pcb.h>
63 #include <machine/sysarch.h>
64 #include <machine/vfp.h>
65 #include <machine/vmparam.h>
66 
67 #include <vm/vm.h>
68 #include <vm/vm_param.h>
69 #include <vm/pmap.h>
70 #include <vm/vm_map.h>
71 
72 _Static_assert(sizeof(mcontext_t) == 208, "mcontext_t size incorrect");
73 _Static_assert(sizeof(ucontext_t) == 260, "ucontext_t size incorrect");
74 _Static_assert(sizeof(siginfo_t) == 64, "siginfo_t size incorrect");
75 
76 /*
77  * Clear registers on exec
78  */
79 void
80 exec_setregs(struct thread *td, struct image_params *imgp, uintptr_t stack)
81 {
82 	struct trapframe *tf = td->td_frame;
83 
84 	memset(tf, 0, sizeof(*tf));
85 	tf->tf_usr_sp = stack;
86 	tf->tf_usr_lr = imgp->entry_addr;
87 	tf->tf_svc_lr = 0x77777777;
88 	tf->tf_pc = imgp->entry_addr;
89 	tf->tf_spsr = PSR_USR32_MODE;
90 	if ((register_t)imgp->entry_addr & 1)
91 		tf->tf_spsr |= PSR_T;
92 }
93 
94 #ifdef VFP
95 /*
96  * Get machine VFP context.
97  */
98 void
99 get_vfpcontext(struct thread *td, mcontext_vfp_t *vfp)
100 {
101 	struct pcb *pcb;
102 
103 	MPASS(td == curthread);
104 
105 	pcb = td->td_pcb;
106 	if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0) {
107 		critical_enter();
108 		vfp_store(&pcb->pcb_vfpstate, false);
109 		critical_exit();
110 	}
111 	KASSERT(pcb->pcb_vfpsaved == &pcb->pcb_vfpstate,
112 		("Called get_vfpcontext while the kernel is using the VFP"));
113 	memcpy(vfp->mcv_reg, pcb->pcb_vfpstate.reg,
114 		sizeof(vfp->mcv_reg));
115 	vfp->mcv_fpscr = pcb->pcb_vfpstate.fpscr;
116 }
117 
118 /*
119  * Set machine VFP context.
120  */
121 void
122 set_vfpcontext(struct thread *td, mcontext_vfp_t *vfp)
123 {
124 	struct pcb *pcb;
125 
126 	MPASS(td == curthread);
127 
128 	pcb = td->td_pcb;
129 	if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0) {
130 		critical_enter();
131 		vfp_discard(td);
132 		critical_exit();
133 	}
134 	KASSERT(pcb->pcb_vfpsaved == &pcb->pcb_vfpstate,
135 		("Called set_vfpcontext while the kernel is using the VFP"));
136 	memcpy(pcb->pcb_vfpstate.reg, vfp->mcv_reg,
137 		sizeof(pcb->pcb_vfpstate.reg));
138 	pcb->pcb_vfpstate.fpscr = vfp->mcv_fpscr;
139 }
140 #endif
141 
142 int
143 arm_get_vfpstate(struct thread *td, void *args)
144 {
145 	int rv;
146 	struct arm_get_vfpstate_args ua;
147 	mcontext_vfp_t	mcontext_vfp;
148 
149 	rv = copyin(args, &ua, sizeof(ua));
150 	if (rv != 0)
151 		return (rv);
152 	if (ua.mc_vfp_size != sizeof(mcontext_vfp_t))
153 		return (EINVAL);
154 #ifdef VFP
155 	get_vfpcontext(td, &mcontext_vfp);
156 #else
157 	bzero(&mcontext_vfp, sizeof(mcontext_vfp));
158 #endif
159 
160 	rv = copyout(&mcontext_vfp, ua.mc_vfp,  sizeof(mcontext_vfp));
161 	if (rv != 0)
162 		return (rv);
163 	return (0);
164 }
165 
166 /*
167  * Get machine context.
168  */
169 int
170 get_mcontext(struct thread *td, mcontext_t *mcp, int clear_ret)
171 {
172 	struct trapframe *tf = td->td_frame;
173 	__greg_t *gr = mcp->__gregs;
174 	mcontext_vfp_t	mcontext_vfp;
175 	int rv;
176 
177 	if (clear_ret & GET_MC_CLEAR_RET) {
178 		gr[_REG_R0] = 0;
179 		gr[_REG_CPSR] = tf->tf_spsr & ~PSR_C;
180 	} else {
181 		gr[_REG_R0]   = tf->tf_r0;
182 		gr[_REG_CPSR] = tf->tf_spsr;
183 	}
184 	gr[_REG_R1]   = tf->tf_r1;
185 	gr[_REG_R2]   = tf->tf_r2;
186 	gr[_REG_R3]   = tf->tf_r3;
187 	gr[_REG_R4]   = tf->tf_r4;
188 	gr[_REG_R5]   = tf->tf_r5;
189 	gr[_REG_R6]   = tf->tf_r6;
190 	gr[_REG_R7]   = tf->tf_r7;
191 	gr[_REG_R8]   = tf->tf_r8;
192 	gr[_REG_R9]   = tf->tf_r9;
193 	gr[_REG_R10]  = tf->tf_r10;
194 	gr[_REG_R11]  = tf->tf_r11;
195 	gr[_REG_R12]  = tf->tf_r12;
196 	gr[_REG_SP]   = tf->tf_usr_sp;
197 	gr[_REG_LR]   = tf->tf_usr_lr;
198 	gr[_REG_PC]   = tf->tf_pc;
199 
200 #ifdef VFP
201 	if (mcp->mc_vfp_size != sizeof(mcontext_vfp_t))
202 		return (EINVAL);
203 	get_vfpcontext(td, &mcontext_vfp);
204 #else
205 	bzero(&mcontext_vfp, sizeof(mcontext_vfp));
206 #endif
207 
208 	if (mcp->mc_vfp_ptr != NULL) {
209 		rv = copyout(&mcontext_vfp, mcp->mc_vfp_ptr,  sizeof(mcontext_vfp));
210 		if (rv != 0)
211 			return (rv);
212 	}
213 
214 	return (0);
215 }
216 
217 /*
218  * Set machine context.
219  *
220  * However, we don't set any but the user modifiable flags, and we won't
221  * touch the cs selector.
222  */
223 int
224 set_mcontext(struct thread *td, mcontext_t *mcp)
225 {
226 	mcontext_vfp_t mc_vfp, *vfp;
227 	struct trapframe *tf = td->td_frame;
228 	const __greg_t *gr = mcp->__gregs;
229 	int spsr;
230 
231 	/*
232 	 * Make sure the processor mode has not been tampered with and
233 	 * interrupts have not been disabled.
234 	 */
235 	spsr = gr[_REG_CPSR];
236 	if ((spsr & PSR_MODE) != PSR_USR32_MODE ||
237 	    (spsr & (PSR_I | PSR_F)) != 0)
238 		return (EINVAL);
239 
240 #ifdef WITNESS
241 	if (mcp->mc_vfp_size != 0 && mcp->mc_vfp_size != sizeof(mc_vfp)) {
242 		printf("%s: %s: Malformed mc_vfp_size: %d (0x%08X)\n",
243 		    td->td_proc->p_comm, __func__,
244 		    mcp->mc_vfp_size, mcp->mc_vfp_size);
245 	} else if (mcp->mc_vfp_size != 0 && mcp->mc_vfp_ptr == NULL) {
246 		printf("%s: %s: c_vfp_size != 0 but mc_vfp_ptr == NULL\n",
247 		    td->td_proc->p_comm, __func__);
248 	}
249 #endif
250 
251 	if (mcp->mc_vfp_size == sizeof(mc_vfp) && mcp->mc_vfp_ptr != NULL) {
252 		if (copyin(mcp->mc_vfp_ptr, &mc_vfp, sizeof(mc_vfp)) != 0)
253 			return (EFAULT);
254 		vfp = &mc_vfp;
255 	} else {
256 		vfp = NULL;
257 	}
258 
259 	tf->tf_r0 = gr[_REG_R0];
260 	tf->tf_r1 = gr[_REG_R1];
261 	tf->tf_r2 = gr[_REG_R2];
262 	tf->tf_r3 = gr[_REG_R3];
263 	tf->tf_r4 = gr[_REG_R4];
264 	tf->tf_r5 = gr[_REG_R5];
265 	tf->tf_r6 = gr[_REG_R6];
266 	tf->tf_r7 = gr[_REG_R7];
267 	tf->tf_r8 = gr[_REG_R8];
268 	tf->tf_r9 = gr[_REG_R9];
269 	tf->tf_r10 = gr[_REG_R10];
270 	tf->tf_r11 = gr[_REG_R11];
271 	tf->tf_r12 = gr[_REG_R12];
272 	tf->tf_usr_sp = gr[_REG_SP];
273 	tf->tf_usr_lr = gr[_REG_LR];
274 	tf->tf_pc = gr[_REG_PC];
275 	tf->tf_spsr = gr[_REG_CPSR];
276 #ifdef VFP
277 	if (vfp != NULL)
278 		set_vfpcontext(td, vfp);
279 #endif
280 	return (0);
281 }
282 
283 void
284 sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
285 {
286 	struct thread *td;
287 	struct proc *p;
288 	struct trapframe *tf;
289 	struct sigframe *fp, frame;
290 	struct sigacts *psp;
291 	struct sysentvec *sysent;
292 	int onstack;
293 	int sig;
294 
295 	td = curthread;
296 	p = td->td_proc;
297 	PROC_LOCK_ASSERT(p, MA_OWNED);
298 	sig = ksi->ksi_signo;
299 	psp = p->p_sigacts;
300 	mtx_assert(&psp->ps_mtx, MA_OWNED);
301 	tf = td->td_frame;
302 	onstack = sigonstack(tf->tf_usr_sp);
303 
304 	CTR4(KTR_SIG, "sendsig: td=%p (%s) catcher=%p sig=%d", td, p->p_comm,
305 	    catcher, sig);
306 
307 	/* Allocate and validate space for the signal handler context. */
308 	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !(onstack) &&
309 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
310 		fp = (struct sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
311 		    td->td_sigstk.ss_size);
312 #if defined(COMPAT_43)
313 		td->td_sigstk.ss_flags |= SS_ONSTACK;
314 #endif
315 	} else
316 		fp = (struct sigframe *)td->td_frame->tf_usr_sp;
317 
318 	/* make room on the stack */
319 	fp--;
320 
321 	/* make the stack aligned */
322 	fp = (struct sigframe *)STACKALIGN(fp);
323 	/* Populate the siginfo frame. */
324 	bzero(&frame, sizeof(frame));
325 	get_mcontext(td, &frame.sf_uc.uc_mcontext, 0);
326 	frame.sf_si = ksi->ksi_info;
327 	frame.sf_uc.uc_sigmask = *mask;
328 	frame.sf_uc.uc_stack = td->td_sigstk;
329 	frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) != 0 ?
330 	    (onstack ? SS_ONSTACK : 0) : SS_DISABLE;
331 	mtx_unlock(&psp->ps_mtx);
332 	PROC_UNLOCK(td->td_proc);
333 
334 	/* Copy the sigframe out to the user's stack. */
335 	if (copyout(&frame, fp, sizeof(*fp)) != 0) {
336 		/* Process has trashed its stack. Kill it. */
337 		CTR2(KTR_SIG, "sendsig: sigexit td=%p fp=%p", td, fp);
338 		PROC_LOCK(p);
339 		sigexit(td, SIGILL);
340 	}
341 
342 	/*
343 	 * Build context to run handler in.  We invoke the handler
344 	 * directly, only returning via the trampoline.  Note the
345 	 * trampoline version numbers are coordinated with machine-
346 	 * dependent code in libc.
347 	 */
348 
349 	tf->tf_r0 = sig;
350 	tf->tf_r1 = (register_t)&fp->sf_si;
351 	tf->tf_r2 = (register_t)&fp->sf_uc;
352 
353 	/* the trampoline uses r5 as the uc address */
354 	tf->tf_r5 = (register_t)&fp->sf_uc;
355 	tf->tf_pc = (register_t)catcher;
356 	tf->tf_usr_sp = (register_t)fp;
357 	sysent = p->p_sysent;
358 	if (PROC_HAS_SHP(p))
359 		tf->tf_usr_lr = (register_t)PROC_SIGCODE(p);
360 	else
361 		tf->tf_usr_lr = (register_t)(PROC_PS_STRINGS(p) -
362 		    *(sysent->sv_szsigcode));
363 	/* Set the mode to enter in the signal handler */
364 #if __ARM_ARCH >= 7
365 	if ((register_t)catcher & 1)
366 		tf->tf_spsr |= PSR_T;
367 	else
368 		tf->tf_spsr &= ~PSR_T;
369 #endif
370 
371 	CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_usr_lr,
372 	    tf->tf_usr_sp);
373 
374 	PROC_LOCK(p);
375 	mtx_lock(&psp->ps_mtx);
376 }
377 
378 int
379 sys_sigreturn(struct thread *td, struct sigreturn_args *uap)
380 {
381 	ucontext_t uc;
382 	int error;
383 
384 	if (uap == NULL)
385 		return (EFAULT);
386 	if (copyin(uap->sigcntxp, &uc, sizeof(uc)))
387 		return (EFAULT);
388 	/* Restore register context. */
389 	error = set_mcontext(td, &uc.uc_mcontext);
390 	if (error != 0)
391 		return (error);
392 
393 	/* Restore signal mask. */
394 	kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);
395 
396 	return (EJUSTRETURN);
397 }
398