xref: /freebsd/sys/arm/arm/exec_machdep.c (revision d29771a722acf17b3d2693e237c0da7ce866997f)
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/param.h>
43 #include <sys/exec.h>
44 #include <sys/imgact.h>
45 #include <sys/kdb.h>
46 #include <sys/kernel.h>
47 #include <sys/ktr.h>
48 #include <sys/lock.h>
49 #include <sys/mutex.h>
50 #include <sys/proc.h>
51 #include <sys/rwlock.h>
52 #include <sys/syscallsubr.h>
53 #include <sys/sysent.h>
54 #include <sys/sysproto.h>
55 #include <sys/vmmeter.h>
56 
57 #include <machine/asm.h>
58 #include <machine/machdep.h>
59 #include <machine/pcb.h>
60 #include <machine/sysarch.h>
61 #include <machine/vfp.h>
62 #include <machine/vmparam.h>
63 
64 #include <vm/vm.h>
65 #include <vm/vm_param.h>
66 #include <vm/pmap.h>
67 #include <vm/vm_map.h>
68 
69 _Static_assert(sizeof(mcontext_t) == 208, "mcontext_t size incorrect");
70 _Static_assert(sizeof(ucontext_t) == 260, "ucontext_t size incorrect");
71 _Static_assert(sizeof(siginfo_t) == 64, "siginfo_t size incorrect");
72 
73 /*
74  * Clear registers on exec
75  */
76 void
exec_setregs(struct thread * td,struct image_params * imgp,uintptr_t stack)77 exec_setregs(struct thread *td, struct image_params *imgp, uintptr_t stack)
78 {
79 	struct trapframe *tf = td->td_frame;
80 
81 	memset(tf, 0, sizeof(*tf));
82 	tf->tf_usr_sp = stack;
83 	tf->tf_usr_lr = imgp->entry_addr;
84 	tf->tf_svc_lr = 0x77777777;
85 	tf->tf_pc = imgp->entry_addr;
86 	tf->tf_spsr = PSR_USR32_MODE;
87 	if ((register_t)imgp->entry_addr & 1)
88 		tf->tf_spsr |= PSR_T;
89 }
90 
91 #ifdef VFP
92 /*
93  * Get machine VFP context.
94  */
95 void
get_vfpcontext(struct thread * td,mcontext_vfp_t * vfp)96 get_vfpcontext(struct thread *td, mcontext_vfp_t *vfp)
97 {
98 	struct pcb *pcb;
99 
100 	MPASS(td == curthread || TD_IS_SUSPENDED(td) ||
101 	    P_SHOULDSTOP(td->td_proc));
102 
103 	pcb = td->td_pcb;
104 	if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0 && td == curthread) {
105 		critical_enter();
106 		vfp_store(&pcb->pcb_vfpstate, false);
107 		critical_exit();
108 	}
109 	KASSERT(pcb->pcb_vfpsaved == &pcb->pcb_vfpstate,
110 		("Called get_vfpcontext while the kernel is using the VFP"));
111 	memcpy(vfp, &pcb->pcb_vfpstate, sizeof(*vfp));
112 }
113 
114 /*
115  * Set machine VFP context.
116  */
117 void
set_vfpcontext(struct thread * td,mcontext_vfp_t * vfp)118 set_vfpcontext(struct thread *td, mcontext_vfp_t *vfp)
119 {
120 	struct pcb *pcb;
121 
122 	pcb = td->td_pcb;
123 	if (td == curthread) {
124 		critical_enter();
125 		vfp_discard(td);
126 		critical_exit();
127 	}
128 	KASSERT(pcb->pcb_vfpsaved == &pcb->pcb_vfpstate,
129 		("Called set_vfpcontext while the kernel is using the VFP"));
130 	memcpy(&pcb->pcb_vfpstate, vfp, sizeof(*vfp));
131 }
132 #endif
133 
134 int
arm_get_vfpstate(struct thread * td,void * args)135 arm_get_vfpstate(struct thread *td, void *args)
136 {
137 	int rv;
138 	struct arm_get_vfpstate_args ua;
139 	mcontext_vfp_t	mcontext_vfp;
140 
141 	rv = copyin(args, &ua, sizeof(ua));
142 	if (rv != 0)
143 		return (rv);
144 	if (ua.mc_vfp_size != sizeof(mcontext_vfp_t))
145 		return (EINVAL);
146 #ifdef VFP
147 	get_vfpcontext(td, &mcontext_vfp);
148 #else
149 	bzero(&mcontext_vfp, sizeof(mcontext_vfp));
150 #endif
151 
152 	rv = copyout(&mcontext_vfp, ua.mc_vfp,  sizeof(mcontext_vfp));
153 	if (rv != 0)
154 		return (rv);
155 	return (0);
156 }
157 
158 /*
159  * Get machine context.
160  */
161 int
get_mcontext(struct thread * td,mcontext_t * mcp,int clear_ret)162 get_mcontext(struct thread *td, mcontext_t *mcp, int clear_ret)
163 {
164 	struct trapframe *tf = td->td_frame;
165 	__greg_t *gr = mcp->__gregs;
166 	mcontext_vfp_t	mcontext_vfp;
167 	int rv;
168 
169 	if (clear_ret & GET_MC_CLEAR_RET) {
170 		gr[_REG_R0] = 0;
171 		gr[_REG_CPSR] = tf->tf_spsr & ~PSR_C;
172 	} else {
173 		gr[_REG_R0]   = tf->tf_r0;
174 		gr[_REG_CPSR] = tf->tf_spsr;
175 	}
176 	gr[_REG_R1]   = tf->tf_r1;
177 	gr[_REG_R2]   = tf->tf_r2;
178 	gr[_REG_R3]   = tf->tf_r3;
179 	gr[_REG_R4]   = tf->tf_r4;
180 	gr[_REG_R5]   = tf->tf_r5;
181 	gr[_REG_R6]   = tf->tf_r6;
182 	gr[_REG_R7]   = tf->tf_r7;
183 	gr[_REG_R8]   = tf->tf_r8;
184 	gr[_REG_R9]   = tf->tf_r9;
185 	gr[_REG_R10]  = tf->tf_r10;
186 	gr[_REG_R11]  = tf->tf_r11;
187 	gr[_REG_R12]  = tf->tf_r12;
188 	gr[_REG_SP]   = tf->tf_usr_sp;
189 	gr[_REG_LR]   = tf->tf_usr_lr;
190 	gr[_REG_PC]   = tf->tf_pc;
191 
192 #ifdef VFP
193 	if (mcp->mc_vfp_size != sizeof(mcontext_vfp_t))
194 		return (EINVAL);
195 	get_vfpcontext(td, &mcontext_vfp);
196 #else
197 	bzero(&mcontext_vfp, sizeof(mcontext_vfp));
198 #endif
199 
200 	if (mcp->mc_vfp_ptr != NULL) {
201 		rv = copyout(&mcontext_vfp, mcp->mc_vfp_ptr,  sizeof(mcontext_vfp));
202 		if (rv != 0)
203 			return (rv);
204 	}
205 
206 	return (0);
207 }
208 
209 /*
210  * Set machine context.
211  *
212  * However, we don't set any but the user modifiable flags, and we won't
213  * touch the cs selector.
214  */
215 int
set_mcontext(struct thread * td,mcontext_t * mcp)216 set_mcontext(struct thread *td, mcontext_t *mcp)
217 {
218 	mcontext_vfp_t mc_vfp, *vfp;
219 	struct trapframe *tf = td->td_frame;
220 	const __greg_t *gr = mcp->__gregs;
221 	int spsr;
222 
223 	/*
224 	 * Make sure the processor mode has not been tampered with and
225 	 * interrupts have not been disabled.
226 	 */
227 	spsr = gr[_REG_CPSR];
228 	if ((spsr & PSR_MODE) != PSR_USR32_MODE ||
229 	    (spsr & (PSR_I | PSR_F)) != 0)
230 		return (EINVAL);
231 
232 #ifdef WITNESS
233 	if (mcp->mc_vfp_size != 0 && mcp->mc_vfp_size != sizeof(mc_vfp)) {
234 		printf("%s: %s: Malformed mc_vfp_size: %d (0x%08X)\n",
235 		    td->td_proc->p_comm, __func__,
236 		    mcp->mc_vfp_size, mcp->mc_vfp_size);
237 	} else if (mcp->mc_vfp_size != 0 && mcp->mc_vfp_ptr == NULL) {
238 		printf("%s: %s: c_vfp_size != 0 but mc_vfp_ptr == NULL\n",
239 		    td->td_proc->p_comm, __func__);
240 	}
241 #endif
242 
243 	if (mcp->mc_vfp_size == sizeof(mc_vfp) && mcp->mc_vfp_ptr != NULL) {
244 		if (copyin(mcp->mc_vfp_ptr, &mc_vfp, sizeof(mc_vfp)) != 0)
245 			return (EFAULT);
246 		vfp = &mc_vfp;
247 	} else {
248 		vfp = NULL;
249 	}
250 
251 	tf->tf_r0 = gr[_REG_R0];
252 	tf->tf_r1 = gr[_REG_R1];
253 	tf->tf_r2 = gr[_REG_R2];
254 	tf->tf_r3 = gr[_REG_R3];
255 	tf->tf_r4 = gr[_REG_R4];
256 	tf->tf_r5 = gr[_REG_R5];
257 	tf->tf_r6 = gr[_REG_R6];
258 	tf->tf_r7 = gr[_REG_R7];
259 	tf->tf_r8 = gr[_REG_R8];
260 	tf->tf_r9 = gr[_REG_R9];
261 	tf->tf_r10 = gr[_REG_R10];
262 	tf->tf_r11 = gr[_REG_R11];
263 	tf->tf_r12 = gr[_REG_R12];
264 	tf->tf_usr_sp = gr[_REG_SP];
265 	tf->tf_usr_lr = gr[_REG_LR];
266 	tf->tf_pc = gr[_REG_PC];
267 	tf->tf_spsr = gr[_REG_CPSR];
268 #ifdef VFP
269 	if (vfp != NULL)
270 		set_vfpcontext(td, vfp);
271 #endif
272 	return (0);
273 }
274 
275 void
sendsig(sig_t catcher,ksiginfo_t * ksi,sigset_t * mask)276 sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
277 {
278 	struct thread *td;
279 	struct proc *p;
280 	struct trapframe *tf;
281 	struct sigframe *fp, frame;
282 	struct sigacts *psp;
283 	struct sysentvec *sysent;
284 	int onstack;
285 	int sig;
286 
287 	td = curthread;
288 	p = td->td_proc;
289 	PROC_LOCK_ASSERT(p, MA_OWNED);
290 	sig = ksi->ksi_signo;
291 	psp = p->p_sigacts;
292 	mtx_assert(&psp->ps_mtx, MA_OWNED);
293 	tf = td->td_frame;
294 	onstack = sigonstack(tf->tf_usr_sp);
295 
296 	CTR4(KTR_SIG, "sendsig: td=%p (%s) catcher=%p sig=%d", td, p->p_comm,
297 	    catcher, sig);
298 
299 	/* Allocate and validate space for the signal handler context. */
300 	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !(onstack) &&
301 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
302 		fp = (struct sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
303 		    td->td_sigstk.ss_size);
304 #if defined(COMPAT_43)
305 		td->td_sigstk.ss_flags |= SS_ONSTACK;
306 #endif
307 	} else
308 		fp = (struct sigframe *)td->td_frame->tf_usr_sp;
309 
310 	/* make room on the stack */
311 	fp--;
312 
313 	/* make the stack aligned */
314 	fp = (struct sigframe *)STACKALIGN(fp);
315 	/* Populate the siginfo frame. */
316 	bzero(&frame, sizeof(frame));
317 	get_mcontext(td, &frame.sf_uc.uc_mcontext, 0);
318 	frame.sf_si = ksi->ksi_info;
319 	frame.sf_uc.uc_sigmask = *mask;
320 	frame.sf_uc.uc_stack = td->td_sigstk;
321 	frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) != 0 ?
322 	    (onstack ? SS_ONSTACK : 0) : SS_DISABLE;
323 	mtx_unlock(&psp->ps_mtx);
324 	PROC_UNLOCK(td->td_proc);
325 
326 	/* Copy the sigframe out to the user's stack. */
327 	if (copyout(&frame, fp, sizeof(*fp)) != 0) {
328 		/* Process has trashed its stack. Kill it. */
329 		CTR2(KTR_SIG, "sendsig: sigexit td=%p fp=%p", td, fp);
330 		PROC_LOCK(p);
331 		sigexit(td, SIGILL);
332 	}
333 
334 	/*
335 	 * Build context to run handler in.  We invoke the handler
336 	 * directly, only returning via the trampoline.  Note the
337 	 * trampoline version numbers are coordinated with machine-
338 	 * dependent code in libc.
339 	 */
340 
341 	tf->tf_r0 = sig;
342 	tf->tf_r1 = (register_t)&fp->sf_si;
343 	tf->tf_r2 = (register_t)&fp->sf_uc;
344 
345 	/* the trampoline uses r5 as the uc address */
346 	tf->tf_r5 = (register_t)&fp->sf_uc;
347 	tf->tf_pc = (register_t)catcher;
348 	tf->tf_usr_sp = (register_t)fp;
349 	sysent = p->p_sysent;
350 	if (PROC_HAS_SHP(p))
351 		tf->tf_usr_lr = (register_t)PROC_SIGCODE(p);
352 	else
353 		tf->tf_usr_lr = (register_t)(PROC_PS_STRINGS(p) -
354 		    *(sysent->sv_szsigcode));
355 	/* Set the mode to enter in the signal handler */
356 	if ((register_t)catcher & 1)
357 		tf->tf_spsr |= PSR_T;
358 	else
359 		tf->tf_spsr &= ~PSR_T;
360 
361 	CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_usr_lr,
362 	    tf->tf_usr_sp);
363 
364 	PROC_LOCK(p);
365 	mtx_lock(&psp->ps_mtx);
366 }
367 
368 int
sys_sigreturn(struct thread * td,struct sigreturn_args * uap)369 sys_sigreturn(struct thread *td, struct sigreturn_args *uap)
370 {
371 	ucontext_t uc;
372 	int error;
373 
374 	if (uap == NULL)
375 		return (EFAULT);
376 	if (copyin(uap->sigcntxp, &uc, sizeof(uc)))
377 		return (EFAULT);
378 	/* Restore register context. */
379 	error = set_mcontext(td, &uc.uc_mcontext);
380 	if (error != 0)
381 		return (error);
382 
383 	/* Restore signal mask. */
384 	kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);
385 
386 	return (EJUSTRETURN);
387 }
388