blob: 2f3cb573423564b52c9227663de5b479d924df9c [file] [log] [blame]
David Howellsb920de12008-02-08 04:19:31 -08001/* MN10300 Signal handling
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11
12#include <linux/sched.h>
13#include <linux/mm.h>
14#include <linux/smp.h>
David Howellsb920de12008-02-08 04:19:31 -080015#include <linux/kernel.h>
16#include <linux/signal.h>
17#include <linux/errno.h>
18#include <linux/wait.h>
19#include <linux/ptrace.h>
20#include <linux/unistd.h>
21#include <linux/stddef.h>
22#include <linux/tty.h>
23#include <linux/personality.h>
24#include <linux/suspend.h>
David Howells5d289962009-06-11 13:08:37 +010025#include <linux/tracehook.h>
David Howellsb920de12008-02-08 04:19:31 -080026#include <asm/cacheflush.h>
27#include <asm/ucontext.h>
Linus Torvalds7c0f6ba2016-12-24 11:46:01 -080028#include <linux/uaccess.h>
David Howellsb920de12008-02-08 04:19:31 -080029#include <asm/fpu.h>
30#include "sigframe.h"
31
32#define DEBUG_SIG 0
33
David Howellsb920de12008-02-08 04:19:31 -080034/*
David Howellsb920de12008-02-08 04:19:31 -080035 * do a signal return; undo the signal stack.
36 */
37static int restore_sigcontext(struct pt_regs *regs,
38 struct sigcontext __user *sc, long *_d0)
39{
40 unsigned int err = 0;
41
Al Viroc05628b2010-09-26 19:28:52 +010042 /* Always make any pending restarted system calls return -EINTR */
Andy Lutomirskif56141e2015-02-12 15:01:14 -080043 current->restart_block.fn = do_no_restart_syscall;
Al Viroc05628b2010-09-26 19:28:52 +010044
David Howellsb920de12008-02-08 04:19:31 -080045 if (is_using_fpu(current))
46 fpu_kill_state(current);
47
48#define COPY(x) err |= __get_user(regs->x, &sc->x)
49 COPY(d1); COPY(d2); COPY(d3);
50 COPY(a0); COPY(a1); COPY(a2); COPY(a3);
51 COPY(e0); COPY(e1); COPY(e2); COPY(e3);
52 COPY(e4); COPY(e5); COPY(e6); COPY(e7);
53 COPY(lar); COPY(lir);
54 COPY(mdr); COPY(mdrq);
55 COPY(mcvf); COPY(mcrl); COPY(mcrh);
56 COPY(sp); COPY(pc);
57#undef COPY
58
59 {
60 unsigned int tmpflags;
61#ifndef CONFIG_MN10300_USING_JTAG
62#define USER_EPSW (EPSW_FLAG_Z | EPSW_FLAG_N | EPSW_FLAG_C | EPSW_FLAG_V | \
63 EPSW_T | EPSW_nAR)
64#else
65#define USER_EPSW (EPSW_FLAG_Z | EPSW_FLAG_N | EPSW_FLAG_C | EPSW_FLAG_V | \
66 EPSW_nAR)
67#endif
68 err |= __get_user(tmpflags, &sc->epsw);
69 regs->epsw = (regs->epsw & ~USER_EPSW) |
70 (tmpflags & USER_EPSW);
71 regs->orig_d0 = -1; /* disable syscall checks */
72 }
73
74 {
75 struct fpucontext *buf;
76 err |= __get_user(buf, &sc->fpucontext);
77 if (buf) {
Al Viro81029b12016-09-03 18:05:00 -040078 if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
David Howellsb920de12008-02-08 04:19:31 -080079 goto badframe;
80 err |= fpu_restore_sigcontext(buf);
81 }
82 }
83
84 err |= __get_user(*_d0, &sc->d0);
85 return err;
86
87badframe:
88 return 1;
89}
90
91/*
92 * standard signal return syscall
93 */
94asmlinkage long sys_sigreturn(void)
95{
David Howells7c7fcf72010-10-27 17:29:01 +010096 struct sigframe __user *frame;
David Howellsb920de12008-02-08 04:19:31 -080097 sigset_t set;
98 long d0;
99
David Howells7c7fcf72010-10-27 17:29:01 +0100100 frame = (struct sigframe __user *) current_frame()->sp;
Al Viro81029b12016-09-03 18:05:00 -0400101 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
David Howellsb920de12008-02-08 04:19:31 -0800102 goto badframe;
103 if (__get_user(set.sig[0], &frame->sc.oldmask))
104 goto badframe;
105
106 if (_NSIG_WORDS > 1 &&
107 __copy_from_user(&set.sig[1], &frame->extramask,
108 sizeof(frame->extramask)))
109 goto badframe;
110
Matt Fleming00f35782012-05-11 10:57:59 +1000111 set_current_blocked(&set);
David Howellsb920de12008-02-08 04:19:31 -0800112
David Howells7c7fcf72010-10-27 17:29:01 +0100113 if (restore_sigcontext(current_frame(), &frame->sc, &d0))
David Howellsb920de12008-02-08 04:19:31 -0800114 goto badframe;
115
116 return d0;
117
118badframe:
119 force_sig(SIGSEGV, current);
120 return 0;
121}
122
123/*
124 * realtime signal return syscall
125 */
126asmlinkage long sys_rt_sigreturn(void)
127{
David Howells7c7fcf72010-10-27 17:29:01 +0100128 struct rt_sigframe __user *frame;
David Howellsb920de12008-02-08 04:19:31 -0800129 sigset_t set;
David Howells7c7fcf72010-10-27 17:29:01 +0100130 long d0;
David Howellsb920de12008-02-08 04:19:31 -0800131
David Howells7c7fcf72010-10-27 17:29:01 +0100132 frame = (struct rt_sigframe __user *) current_frame()->sp;
Al Viro81029b12016-09-03 18:05:00 -0400133 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
David Howellsb920de12008-02-08 04:19:31 -0800134 goto badframe;
135 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
136 goto badframe;
137
Matt Fleming00f35782012-05-11 10:57:59 +1000138 set_current_blocked(&set);
David Howellsb920de12008-02-08 04:19:31 -0800139
David Howells7c7fcf72010-10-27 17:29:01 +0100140 if (restore_sigcontext(current_frame(), &frame->uc.uc_mcontext, &d0))
David Howellsb920de12008-02-08 04:19:31 -0800141 goto badframe;
142
Al Virob30c7d52012-12-23 03:17:06 -0500143 if (restore_altstack(&frame->uc.uc_stack))
David Howellsb920de12008-02-08 04:19:31 -0800144 goto badframe;
145
146 return d0;
147
148badframe:
149 force_sig(SIGSEGV, current);
150 return 0;
151}
152
153/*
154 * store the userspace context into a signal frame
155 */
156static int setup_sigcontext(struct sigcontext __user *sc,
157 struct fpucontext *fpuctx,
158 struct pt_regs *regs,
159 unsigned long mask)
160{
161 int tmp, err = 0;
162
163#define COPY(x) err |= __put_user(regs->x, &sc->x)
164 COPY(d0); COPY(d1); COPY(d2); COPY(d3);
165 COPY(a0); COPY(a1); COPY(a2); COPY(a3);
166 COPY(e0); COPY(e1); COPY(e2); COPY(e3);
167 COPY(e4); COPY(e5); COPY(e6); COPY(e7);
168 COPY(lar); COPY(lir);
169 COPY(mdr); COPY(mdrq);
170 COPY(mcvf); COPY(mcrl); COPY(mcrh);
171 COPY(sp); COPY(epsw); COPY(pc);
172#undef COPY
173
174 tmp = fpu_setup_sigcontext(fpuctx);
175 if (tmp < 0)
176 err = 1;
177 else
178 err |= __put_user(tmp ? fpuctx : NULL, &sc->fpucontext);
179
180 /* non-iBCS2 extensions.. */
181 err |= __put_user(mask, &sc->oldmask);
182
183 return err;
184}
185
186/*
187 * determine which stack to use..
188 */
Richard Weinbergera8040ff2014-03-05 15:36:49 +0100189static inline void __user *get_sigframe(struct ksignal *ksig,
David Howellsb920de12008-02-08 04:19:31 -0800190 struct pt_regs *regs,
191 size_t frame_size)
192{
Richard Weinbergera8040ff2014-03-05 15:36:49 +0100193 unsigned long sp = sigsp(regs->sp, ksig);
David Howellsb920de12008-02-08 04:19:31 -0800194
195 return (void __user *) ((sp - frame_size) & ~7UL);
196}
197
198/*
199 * set up a normal signal frame
200 */
Richard Weinberger8b166552013-10-07 14:22:50 +0200201static int setup_frame(struct ksignal *ksig, sigset_t *set,
David Howellsb920de12008-02-08 04:19:31 -0800202 struct pt_regs *regs)
203{
204 struct sigframe __user *frame;
Richard Weinberger78d156b2014-07-13 17:28:15 +0200205 int sig = ksig->sig;
David Howellsb920de12008-02-08 04:19:31 -0800206
Richard Weinbergera8040ff2014-03-05 15:36:49 +0100207 frame = get_sigframe(ksig, regs, sizeof(*frame));
David Howellsb920de12008-02-08 04:19:31 -0800208
209 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
Richard Weinberger8b166552013-10-07 14:22:50 +0200210 return -EFAULT;
David Howellsb920de12008-02-08 04:19:31 -0800211
Richard Weinberger78d156b2014-07-13 17:28:15 +0200212 if (__put_user(sig, &frame->sig) < 0 ||
David Howellsb920de12008-02-08 04:19:31 -0800213 __put_user(&frame->sc, &frame->psc) < 0)
Richard Weinberger8b166552013-10-07 14:22:50 +0200214 return -EFAULT;
David Howellsb920de12008-02-08 04:19:31 -0800215
216 if (setup_sigcontext(&frame->sc, &frame->fpuctx, regs, set->sig[0]))
Richard Weinberger8b166552013-10-07 14:22:50 +0200217 return -EFAULT;
David Howellsb920de12008-02-08 04:19:31 -0800218
219 if (_NSIG_WORDS > 1) {
220 if (__copy_to_user(frame->extramask, &set->sig[1],
221 sizeof(frame->extramask)))
Richard Weinberger8b166552013-10-07 14:22:50 +0200222 return -EFAULT;
David Howellsb920de12008-02-08 04:19:31 -0800223 }
224
225 /* set up to return from userspace. If provided, use a stub already in
226 * userspace */
Richard Weinberger8b166552013-10-07 14:22:50 +0200227 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
228 if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode))
229 return -EFAULT;
David Howellsb920de12008-02-08 04:19:31 -0800230 } else {
231 if (__put_user((void (*)(void))frame->retcode,
232 &frame->pretcode))
Richard Weinberger8b166552013-10-07 14:22:50 +0200233 return -EFAULT;
David Howellsb920de12008-02-08 04:19:31 -0800234 /* this is mov $,d0; syscall 0 */
235 if (__put_user(0x2c, (char *)(frame->retcode + 0)) ||
236 __put_user(__NR_sigreturn, (char *)(frame->retcode + 1)) ||
237 __put_user(0x00, (char *)(frame->retcode + 2)) ||
238 __put_user(0xf0, (char *)(frame->retcode + 3)) ||
239 __put_user(0xe0, (char *)(frame->retcode + 4)))
Richard Weinberger8b166552013-10-07 14:22:50 +0200240 return -EFAULT;
David Howellsb920de12008-02-08 04:19:31 -0800241 flush_icache_range((unsigned long) frame->retcode,
242 (unsigned long) frame->retcode + 5);
243 }
244
245 /* set up registers for signal handler */
246 regs->sp = (unsigned long) frame;
Richard Weinberger8b166552013-10-07 14:22:50 +0200247 regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
David Howellsb920de12008-02-08 04:19:31 -0800248 regs->d0 = sig;
249 regs->d1 = (unsigned long) &frame->sc;
250
David Howellsb920de12008-02-08 04:19:31 -0800251#if DEBUG_SIG
252 printk(KERN_DEBUG "SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
253 sig, current->comm, current->pid, frame, regs->pc,
254 frame->pretcode);
255#endif
256
257 return 0;
David Howellsb920de12008-02-08 04:19:31 -0800258}
259
260/*
261 * set up a realtime signal frame
262 */
Richard Weinberger8b166552013-10-07 14:22:50 +0200263static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
264 struct pt_regs *regs)
David Howellsb920de12008-02-08 04:19:31 -0800265{
266 struct rt_sigframe __user *frame;
Richard Weinberger78d156b2014-07-13 17:28:15 +0200267 int sig = ksig->sig;
David Howellsb920de12008-02-08 04:19:31 -0800268
Richard Weinbergera8040ff2014-03-05 15:36:49 +0100269 frame = get_sigframe(ksig, regs, sizeof(*frame));
David Howellsb920de12008-02-08 04:19:31 -0800270
271 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
Richard Weinberger8b166552013-10-07 14:22:50 +0200272 return -EFAULT;
David Howellsb920de12008-02-08 04:19:31 -0800273
Richard Weinberger78d156b2014-07-13 17:28:15 +0200274 if (__put_user(sig, &frame->sig) ||
David Howellsb920de12008-02-08 04:19:31 -0800275 __put_user(&frame->info, &frame->pinfo) ||
276 __put_user(&frame->uc, &frame->puc) ||
Richard Weinberger8b166552013-10-07 14:22:50 +0200277 copy_siginfo_to_user(&frame->info, &ksig->info))
278 return -EFAULT;
David Howellsb920de12008-02-08 04:19:31 -0800279
280 /* create the ucontext. */
281 if (__put_user(0, &frame->uc.uc_flags) ||
282 __put_user(0, &frame->uc.uc_link) ||
Al Virob30c7d52012-12-23 03:17:06 -0500283 __save_altstack(&frame->uc.uc_stack, regs->sp) ||
David Howellsb920de12008-02-08 04:19:31 -0800284 setup_sigcontext(&frame->uc.uc_mcontext,
285 &frame->fpuctx, regs, set->sig[0]) ||
286 __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)))
Richard Weinberger8b166552013-10-07 14:22:50 +0200287 return -EFAULT;
David Howellsb920de12008-02-08 04:19:31 -0800288
289 /* set up to return from userspace. If provided, use a stub already in
290 * userspace */
Richard Weinberger8b166552013-10-07 14:22:50 +0200291 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
292 if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode))
293 return -EFAULT;
294
David Howellsb920de12008-02-08 04:19:31 -0800295 } else {
296 if (__put_user((void(*)(void))frame->retcode,
297 &frame->pretcode) ||
298 /* This is mov $,d0; syscall 0 */
299 __put_user(0x2c, (char *)(frame->retcode + 0)) ||
300 __put_user(__NR_rt_sigreturn,
301 (char *)(frame->retcode + 1)) ||
302 __put_user(0x00, (char *)(frame->retcode + 2)) ||
303 __put_user(0xf0, (char *)(frame->retcode + 3)) ||
304 __put_user(0xe0, (char *)(frame->retcode + 4)))
Richard Weinberger8b166552013-10-07 14:22:50 +0200305 return -EFAULT;
David Howellsb920de12008-02-08 04:19:31 -0800306
307 flush_icache_range((u_long) frame->retcode,
308 (u_long) frame->retcode + 5);
309 }
310
311 /* Set up registers for signal handler */
312 regs->sp = (unsigned long) frame;
Richard Weinberger8b166552013-10-07 14:22:50 +0200313 regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
David Howellsb920de12008-02-08 04:19:31 -0800314 regs->d0 = sig;
315 regs->d1 = (long) &frame->info;
316
David Howellsb920de12008-02-08 04:19:31 -0800317#if DEBUG_SIG
318 printk(KERN_DEBUG "SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
319 sig, current->comm, current->pid, frame, regs->pc,
320 frame->pretcode);
321#endif
322
323 return 0;
David Howellsb920de12008-02-08 04:19:31 -0800324}
325
Al Viro00cbf602010-09-26 19:28:42 +0100326static inline void stepback(struct pt_regs *regs)
327{
328 regs->pc -= 2;
329 regs->orig_d0 = -1;
330}
331
David Howellsb920de12008-02-08 04:19:31 -0800332/*
333 * handle the actual delivery of a signal to userspace
334 */
Richard Weinberger8b166552013-10-07 14:22:50 +0200335static int handle_signal(struct ksignal *ksig, struct pt_regs *regs)
David Howellsb920de12008-02-08 04:19:31 -0800336{
Al Virob7f9a112012-05-02 09:59:21 -0400337 sigset_t *oldset = sigmask_to_save();
David Howellsb920de12008-02-08 04:19:31 -0800338 int ret;
339
340 /* Are we from a system call? */
341 if (regs->orig_d0 >= 0) {
342 /* If so, check system call restarting.. */
343 switch (regs->d0) {
344 case -ERESTART_RESTARTBLOCK:
345 case -ERESTARTNOHAND:
346 regs->d0 = -EINTR;
347 break;
348
349 case -ERESTARTSYS:
Richard Weinberger8b166552013-10-07 14:22:50 +0200350 if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
David Howellsb920de12008-02-08 04:19:31 -0800351 regs->d0 = -EINTR;
352 break;
353 }
354
355 /* fallthrough */
356 case -ERESTARTNOINTR:
357 regs->d0 = regs->orig_d0;
Al Viro00cbf602010-09-26 19:28:42 +0100358 stepback(regs);
David Howellsb920de12008-02-08 04:19:31 -0800359 }
360 }
361
362 /* Set up the stack frame */
Richard Weinberger8b166552013-10-07 14:22:50 +0200363 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
364 ret = setup_rt_frame(ksig, oldset, regs);
David Howellsb920de12008-02-08 04:19:31 -0800365 else
Richard Weinberger8b166552013-10-07 14:22:50 +0200366 ret = setup_frame(ksig, oldset, regs);
David Howellsb920de12008-02-08 04:19:31 -0800367
Richard Weinberger8b166552013-10-07 14:22:50 +0200368 signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
Geert Uytterhoevenb45f9332012-07-17 15:47:54 -0700369 return 0;
David Howellsb920de12008-02-08 04:19:31 -0800370}
371
372/*
373 * handle a potential signal
374 */
375static void do_signal(struct pt_regs *regs)
376{
Richard Weinberger8b166552013-10-07 14:22:50 +0200377 struct ksignal ksig;
David Howellsb920de12008-02-08 04:19:31 -0800378
Richard Weinberger8b166552013-10-07 14:22:50 +0200379 if (get_signal(&ksig)) {
380 handle_signal(&ksig, regs);
David Howellsb920de12008-02-08 04:19:31 -0800381 return;
382 }
383
384 /* did we come from a system call? */
385 if (regs->orig_d0 >= 0) {
386 /* restart the system call - no handlers present */
387 switch (regs->d0) {
388 case -ERESTARTNOHAND:
389 case -ERESTARTSYS:
390 case -ERESTARTNOINTR:
391 regs->d0 = regs->orig_d0;
Al Viro00cbf602010-09-26 19:28:42 +0100392 stepback(regs);
David Howellsb920de12008-02-08 04:19:31 -0800393 break;
394
395 case -ERESTART_RESTARTBLOCK:
396 regs->d0 = __NR_restart_syscall;
Al Viro00cbf602010-09-26 19:28:42 +0100397 stepback(regs);
David Howellsb920de12008-02-08 04:19:31 -0800398 break;
399 }
400 }
401
402 /* if there's no signal to deliver, we just put the saved sigmask
403 * back */
Al Viro51a7b442012-05-21 23:33:55 -0400404 restore_saved_sigmask();
David Howellsb920de12008-02-08 04:19:31 -0800405}
406
407/*
408 * notification of userspace execution resumption
409 * - triggered by current->work.notify_resume
410 */
411asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags)
412{
413 /* Pending single-step? */
414 if (thread_info_flags & _TIF_SINGLESTEP) {
415#ifndef CONFIG_MN10300_USING_JTAG
416 regs->epsw |= EPSW_T;
417 clear_thread_flag(TIF_SINGLESTEP);
418#else
419 BUG(); /* no h/w single-step if using JTAG unit */
420#endif
421 }
422
423 /* deal with pending signal delivery */
Al Viro6fd84c02012-05-23 15:28:58 -0400424 if (thread_info_flags & _TIF_SIGPENDING)
David Howellsb920de12008-02-08 04:19:31 -0800425 do_signal(regs);
David Howells5d289962009-06-11 13:08:37 +0100426
427 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
428 clear_thread_flag(TIF_NOTIFY_RESUME);
David Howells7c7fcf72010-10-27 17:29:01 +0100429 tracehook_notify_resume(current_frame());
David Howells5d289962009-06-11 13:08:37 +0100430 }
David Howellsb920de12008-02-08 04:19:31 -0800431}