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 */
76void
77exec_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 */
95void
96get_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 */
117void
118set_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
134int
135arm_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 */
161int
162get_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 */
215int
216set_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
275void
276sendsig(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 __ARM_ARCH >= 7
357	if ((register_t)catcher & 1)
358		tf->tf_spsr |= PSR_T;
359	else
360		tf->tf_spsr &= ~PSR_T;
361#endif
362
363	CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_usr_lr,
364	    tf->tf_usr_sp);
365
366	PROC_LOCK(p);
367	mtx_lock(&psp->ps_mtx);
368}
369
370int
371sys_sigreturn(struct thread *td, struct sigreturn_args *uap)
372{
373	ucontext_t uc;
374	int error;
375
376	if (uap == NULL)
377		return (EFAULT);
378	if (copyin(uap->sigcntxp, &uc, sizeof(uc)))
379		return (EFAULT);
380	/* Restore register context. */
381	error = set_mcontext(td, &uc.uc_mcontext);
382	if (error != 0)
383		return (error);
384
385	/* Restore signal mask. */
386	kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);
387
388	return (EJUSTRETURN);
389}
390