1 /* $OpenBSD: sig_machdep.c,v 1.21 2021/10/06 15:46:03 claudio Exp $ */
2 /* $NetBSD: sig_machdep.c,v 1.22 2003/10/08 00:28:41 thorpej Exp $ */
3
4 /*
5 * Copyright (c) 1994-1998 Mark Brinicombe.
6 * Copyright (c) 1994 Brini.
7 * All rights reserved.
8 *
9 * This code is derived from software written for Brini by Mark Brinicombe
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by Mark Brinicombe
22 * for the NetBSD Project.
23 * 4. The name of the company nor the name of the author may be used to
24 * endorse or promote products derived from this software without specific
25 * prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
28 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
29 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
30 * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
31 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
32 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
33 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 * Machine dependant functions for kernel setup
40 *
41 * Created : 17/09/94
42 */
43
44 #include <sys/param.h>
45
46 #include <sys/mount.h> /* XXX only needed by syscallargs.h */
47 #include <sys/proc.h>
48 #include <sys/signal.h>
49 #include <sys/signalvar.h>
50 #include <sys/syscallargs.h>
51 #include <sys/systm.h>
52 #include <sys/user.h>
53
54 #include <machine/cpu.h>
55 #include <machine/frame.h>
56 #include <machine/pcb.h>
57
58 #include <arm/armreg.h>
59
60 #include <uvm/uvm_extern.h>
61
62 static __inline struct trapframe *
process_frame(struct proc * p)63 process_frame(struct proc *p)
64 {
65 return p->p_addr->u_pcb.pcb_tf;
66 }
67
68 /*
69 * Send an interrupt to process.
70 *
71 * Stack is set up to allow sigcode to call routine, followed by
72 * syscall to sigreturn routine below. After sigreturn resets the
73 * signal mask, the stack, and the frame pointer, it returns to the
74 * user specified pc.
75 */
76 int
sendsig(sig_t catcher,int sig,sigset_t mask,const siginfo_t * ksip,int info,int onstack)77 sendsig(sig_t catcher, int sig, sigset_t mask, const siginfo_t *ksip,
78 int info, int onstack)
79 {
80 struct proc *p = curproc;
81 struct pcb *pcb = &p->p_addr->u_pcb;
82 struct trapframe *tf;
83 struct sigframe *fp, frame;
84
85 tf = process_frame(p);
86
87 /* Allocate space for the signal handler context. */
88 if ((p->p_sigstk.ss_flags & SS_DISABLE) == 0 &&
89 !sigonstack(tf->tf_usr_sp) && onstack)
90 fp = (struct sigframe *)
91 trunc_page((vaddr_t)p->p_sigstk.ss_sp + p->p_sigstk.ss_size);
92 else
93 fp = (struct sigframe *)tf->tf_usr_sp;
94
95 /* make room on the stack */
96 fp--;
97
98 /* make the stack aligned */
99 fp = (struct sigframe *)STACKALIGN(fp);
100
101 /* Build stack frame for signal trampoline. */
102 bzero(&frame, sizeof(frame));
103 frame.sf_signum = sig;
104 frame.sf_sip = NULL;
105 frame.sf_scp = &fp->sf_sc;
106 frame.sf_handler = catcher;
107
108 /* Save register context. */
109 frame.sf_sc.sc_r0 = tf->tf_r0;
110 frame.sf_sc.sc_r1 = tf->tf_r1;
111 frame.sf_sc.sc_r2 = tf->tf_r2;
112 frame.sf_sc.sc_r3 = tf->tf_r3;
113 frame.sf_sc.sc_r4 = tf->tf_r4;
114 frame.sf_sc.sc_r5 = tf->tf_r5;
115 frame.sf_sc.sc_r6 = tf->tf_r6;
116 frame.sf_sc.sc_r7 = tf->tf_r7;
117 frame.sf_sc.sc_r8 = tf->tf_r8;
118 frame.sf_sc.sc_r9 = tf->tf_r9;
119 frame.sf_sc.sc_r10 = tf->tf_r10;
120 frame.sf_sc.sc_r11 = tf->tf_r11;
121 frame.sf_sc.sc_r12 = tf->tf_r12;
122 frame.sf_sc.sc_usr_sp = tf->tf_usr_sp;
123 frame.sf_sc.sc_usr_lr = tf->tf_usr_lr;
124 frame.sf_sc.sc_svc_lr = tf->tf_svc_lr;
125 frame.sf_sc.sc_pc = tf->tf_pc;
126 frame.sf_sc.sc_spsr = tf->tf_spsr;
127
128 /* Save signal mask. */
129 frame.sf_sc.sc_mask = mask;
130
131 /* Save FPU registers. */
132 frame.sf_sc.sc_fpused = pcb->pcb_flags & PCB_FPU;
133 if (frame.sf_sc.sc_fpused) {
134 frame.sf_sc.sc_fpscr = pcb->pcb_fpstate.fp_scr;
135 memcpy(&frame.sf_sc.sc_fpreg, &pcb->pcb_fpstate.fp_reg,
136 sizeof(pcb->pcb_fpstate.fp_reg));
137 pcb->pcb_flags &= ~PCB_FPU;
138 pcb->pcb_fpcpu = NULL;
139 }
140
141 if (info) {
142 frame.sf_sip = &fp->sf_si;
143 frame.sf_si = *ksip;
144 }
145
146 frame.sf_sc.sc_cookie = (long)&fp->sf_sc ^ p->p_p->ps_sigcookie;
147 if (copyout(&frame, fp, sizeof(frame)) != 0)
148 return 1;
149
150 /*
151 * Build context to run handler in. We invoke the handler
152 * directly, only returning via the trampoline.
153 */
154 tf->tf_r0 = sig;
155 tf->tf_r1 = (register_t)frame.sf_sip;
156 tf->tf_r2 = (register_t)frame.sf_scp;
157 tf->tf_pc = (register_t)frame.sf_handler;
158 tf->tf_usr_sp = (register_t)fp;
159
160 tf->tf_usr_lr = p->p_p->ps_sigcode;
161
162 return 0;
163 }
164
165 /*
166 * System call to cleanup state after a signal
167 * has been taken. Reset signal mask and
168 * stack state from context left by sendsig (above).
169 * Return to previous pc and psl as specified by
170 * context left by sendsig. Check carefully to
171 * make sure that the user has not modified the
172 * psr to gain improper privileges or to cause
173 * a machine fault.
174 */
175
176 int
sys_sigreturn(struct proc * p,void * v,register_t * retval)177 sys_sigreturn(struct proc *p, void *v, register_t *retval)
178 {
179 struct sys_sigreturn_args /* {
180 syscallarg(struct sigcontext *) sigcntxp;
181 } */ *uap = v;
182 struct sigcontext ksc, *scp = SCARG(uap, sigcntxp);
183 struct pcb *pcb = &p->p_addr->u_pcb;
184 struct trapframe *tf;
185
186 if (PROC_PC(p) != p->p_p->ps_sigcoderet) {
187 sigexit(p, SIGILL);
188 return (EPERM);
189 }
190
191 if (copyin(scp, &ksc, sizeof(*scp)) != 0)
192 return (EFAULT);
193
194 if (ksc.sc_cookie != ((long)scp ^ p->p_p->ps_sigcookie)) {
195 sigexit(p, SIGILL);
196 return (EFAULT);
197 }
198
199 /* Prevent reuse of the sigcontext cookie */
200 ksc.sc_cookie = 0;
201 (void)copyout(&ksc.sc_cookie, (caddr_t)scp +
202 offsetof(struct sigcontext, sc_cookie), sizeof (ksc.sc_cookie));
203
204 /*
205 * Make sure the processor mode has not been tampered with and
206 * interrupts have not been disabled.
207 */
208 if ((ksc.sc_spsr & PSR_MODE) != PSR_USR32_MODE ||
209 (ksc.sc_spsr & (PSR_I | PSR_F)) != 0)
210 return (EINVAL);
211
212 /* Restore register context. */
213 tf = process_frame(p);
214 tf->tf_r0 = ksc.sc_r0;
215 tf->tf_r1 = ksc.sc_r1;
216 tf->tf_r2 = ksc.sc_r2;
217 tf->tf_r3 = ksc.sc_r3;
218 tf->tf_r4 = ksc.sc_r4;
219 tf->tf_r5 = ksc.sc_r5;
220 tf->tf_r6 = ksc.sc_r6;
221 tf->tf_r7 = ksc.sc_r7;
222 tf->tf_r8 = ksc.sc_r8;
223 tf->tf_r9 = ksc.sc_r9;
224 tf->tf_r10 = ksc.sc_r10;
225 tf->tf_r11 = ksc.sc_r11;
226 tf->tf_r12 = ksc.sc_r12;
227 tf->tf_usr_sp = ksc.sc_usr_sp;
228 tf->tf_usr_lr = ksc.sc_usr_lr;
229 tf->tf_svc_lr = ksc.sc_svc_lr;
230 tf->tf_pc = ksc.sc_pc;
231 tf->tf_spsr = ksc.sc_spsr;
232
233 /* Restore signal mask. */
234 p->p_sigmask = ksc.sc_mask & ~sigcantmask;
235
236 /* Restore FPU registers. */
237 if (ksc.sc_fpused) {
238 pcb->pcb_fpstate.fp_scr = ksc.sc_fpscr;
239 memcpy(&pcb->pcb_fpstate.fp_reg, &ksc.sc_fpreg,
240 sizeof(pcb->pcb_fpstate.fp_reg));
241 pcb->pcb_flags |= PCB_FPU;
242 pcb->pcb_fpcpu = NULL;
243 } else {
244 pcb->pcb_flags &= ~PCB_FPU;
245 pcb->pcb_fpcpu = NULL;
246 }
247
248 return (EJUSTRETURN);
249 }
250