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v3.1
  1/*
  2 * This file is subject to the terms and conditions of the GNU General Public
  3 * License.  See the file "COPYING" in the main directory of this archive
  4 * for more details.
  5 *
  6 * Copyright (C) 1991, 1992  Linus Torvalds
  7 * Copyright (C) 1994 - 2000  Ralf Baechle
  8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 
  9 */
 10#include <linux/cache.h>
 
 11#include <linux/irqflags.h>
 12#include <linux/sched.h>
 13#include <linux/mm.h>
 14#include <linux/personality.h>
 15#include <linux/smp.h>
 16#include <linux/kernel.h>
 17#include <linux/signal.h>
 18#include <linux/errno.h>
 19#include <linux/wait.h>
 20#include <linux/ptrace.h>
 21#include <linux/unistd.h>
 
 22#include <linux/compiler.h>
 23#include <linux/syscalls.h>
 24#include <linux/uaccess.h>
 25#include <linux/tracehook.h>
 26
 27#include <asm/abi.h>
 28#include <asm/asm.h>
 29#include <linux/bitops.h>
 30#include <asm/cacheflush.h>
 31#include <asm/fpu.h>
 32#include <asm/sim.h>
 33#include <asm/ucontext.h>
 34#include <asm/cpu-features.h>
 35#include <asm/war.h>
 36#include <asm/vdso.h>
 
 
 37
 38#include "signal-common.h"
 39
 40static int (*save_fp_context)(struct sigcontext __user *sc);
 41static int (*restore_fp_context)(struct sigcontext __user *sc);
 42
 43extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
 44extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
 45
 46extern asmlinkage int fpu_emulator_save_context(struct sigcontext __user *sc);
 47extern asmlinkage int fpu_emulator_restore_context(struct sigcontext __user *sc);
 48
 49struct sigframe {
 50	u32 sf_ass[4];		/* argument save space for o32 */
 51	u32 sf_pad[2];		/* Was: signal trampoline */
 
 
 52	struct sigcontext sf_sc;
 53	sigset_t sf_mask;
 
 54};
 55
 56struct rt_sigframe {
 57	u32 rs_ass[4];		/* argument save space for o32 */
 58	u32 rs_pad[2];		/* Was: signal trampoline */
 59	struct siginfo rs_info;
 60	struct ucontext rs_uc;
 61};
 62
 63/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 64 * Helper routines
 65 */
 66static int protected_save_fp_context(struct sigcontext __user *sc)
 67{
 
 
 
 
 
 68	int err;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 69	while (1) {
 70		lock_fpu_owner();
 71		own_fpu_inatomic(1);
 72		err = save_fp_context(sc); /* this might fail */
 73		unlock_fpu_owner();
 
 
 
 
 74		if (likely(!err))
 75			break;
 76		/* touch the sigcontext and try again */
 77		err = __put_user(0, &sc->sc_fpregs[0]) |
 78			__put_user(0, &sc->sc_fpregs[31]) |
 79			__put_user(0, &sc->sc_fpc_csr);
 80		if (err)
 81			break;	/* really bad sigcontext */
 82	}
 83	return err;
 
 
 
 
 
 
 
 84}
 85
 86static int protected_restore_fp_context(struct sigcontext __user *sc)
 87{
 88	int err, tmp __maybe_unused;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 89	while (1) {
 90		lock_fpu_owner();
 91		own_fpu_inatomic(0);
 92		err = restore_fp_context(sc); /* this might fail */
 93		unlock_fpu_owner();
 
 
 
 
 94		if (likely(!err))
 95			break;
 96		/* touch the sigcontext and try again */
 97		err = __get_user(tmp, &sc->sc_fpregs[0]) |
 98			__get_user(tmp, &sc->sc_fpregs[31]) |
 99			__get_user(tmp, &sc->sc_fpc_csr);
100		if (err)
101			break;	/* really bad sigcontext */
102	}
103	return err;
 
 
 
 
 
104}
105
106int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
107{
108	int err = 0;
109	int i;
110	unsigned int used_math;
111
112	err |= __put_user(regs->cp0_epc, &sc->sc_pc);
113
114	err |= __put_user(0, &sc->sc_regs[0]);
115	for (i = 1; i < 32; i++)
116		err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
117
118#ifdef CONFIG_CPU_HAS_SMARTMIPS
119	err |= __put_user(regs->acx, &sc->sc_acx);
120#endif
121	err |= __put_user(regs->hi, &sc->sc_mdhi);
122	err |= __put_user(regs->lo, &sc->sc_mdlo);
123	if (cpu_has_dsp) {
124		err |= __put_user(mfhi1(), &sc->sc_hi1);
125		err |= __put_user(mflo1(), &sc->sc_lo1);
126		err |= __put_user(mfhi2(), &sc->sc_hi2);
127		err |= __put_user(mflo2(), &sc->sc_lo2);
128		err |= __put_user(mfhi3(), &sc->sc_hi3);
129		err |= __put_user(mflo3(), &sc->sc_lo3);
130		err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
131	}
132
133	used_math = !!used_math();
134	err |= __put_user(used_math, &sc->sc_used_math);
135
136	if (used_math) {
137		/*
138		 * Save FPU state to signal context. Signal handler
139		 * will "inherit" current FPU state.
140		 */
141		err |= protected_save_fp_context(sc);
142	}
143	return err;
144}
145
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
146int fpcsr_pending(unsigned int __user *fpcsr)
147{
148	int err, sig = 0;
149	unsigned int csr, enabled;
150
151	err = __get_user(csr, fpcsr);
152	enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
153	/*
154	 * If the signal handler set some FPU exceptions, clear it and
155	 * send SIGFPE.
156	 */
157	if (csr & enabled) {
158		csr &= ~enabled;
159		err |= __put_user(csr, fpcsr);
160		sig = SIGFPE;
161	}
162	return err ?: sig;
163}
164
165static int
166check_and_restore_fp_context(struct sigcontext __user *sc)
167{
168	int err, sig;
169
170	err = sig = fpcsr_pending(&sc->sc_fpc_csr);
171	if (err > 0)
172		err = 0;
173	err |= protected_restore_fp_context(sc);
174	return err ?: sig;
175}
176
177int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
178{
179	unsigned int used_math;
180	unsigned long treg;
181	int err = 0;
182	int i;
183
184	/* Always make any pending restarted system calls return -EINTR */
185	current_thread_info()->restart_block.fn = do_no_restart_syscall;
186
187	err |= __get_user(regs->cp0_epc, &sc->sc_pc);
188
189#ifdef CONFIG_CPU_HAS_SMARTMIPS
190	err |= __get_user(regs->acx, &sc->sc_acx);
191#endif
192	err |= __get_user(regs->hi, &sc->sc_mdhi);
193	err |= __get_user(regs->lo, &sc->sc_mdlo);
194	if (cpu_has_dsp) {
195		err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
196		err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
197		err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
198		err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
199		err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
200		err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
201		err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
202	}
203
204	for (i = 1; i < 32; i++)
205		err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
206
207	err |= __get_user(used_math, &sc->sc_used_math);
208	conditional_used_math(used_math);
209
210	if (used_math) {
211		/* restore fpu context if we have used it before */
212		if (!err)
213			err = check_and_restore_fp_context(sc);
214	} else {
215		/* signal handler may have used FPU.  Give it up. */
216		lose_fpu(0);
217	}
218
219	return err;
220}
221
222void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
223			  size_t frame_size)
224{
225	unsigned long sp;
226
 
 
 
227	/* Default to using normal stack */
228	sp = regs->regs[29];
229
230	/*
231	 * FPU emulator may have it's own trampoline active just
232	 * above the user stack, 16-bytes before the next lowest
233	 * 16 byte boundary.  Try to avoid trashing it.
234	 */
235	sp -= 32;
236
237	/* This is the X/Open sanctioned signal stack switching.  */
238	if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags (sp) == 0))
239		sp = current->sas_ss_sp + current->sas_ss_size;
240
241	return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
242}
243
244/*
245 * Atomically swap in the new signal mask, and wait for a signal.
246 */
247
248#ifdef CONFIG_TRAD_SIGNALS
249asmlinkage int sys_sigsuspend(nabi_no_regargs struct pt_regs regs)
250{
251	sigset_t newset;
252	sigset_t __user *uset;
253
254	uset = (sigset_t __user *) regs.regs[4];
255	if (copy_from_user(&newset, uset, sizeof(sigset_t)))
256		return -EFAULT;
257	sigdelsetmask(&newset, ~_BLOCKABLE);
258
259	spin_lock_irq(&current->sighand->siglock);
260	current->saved_sigmask = current->blocked;
261	current->blocked = newset;
262	recalc_sigpending();
263	spin_unlock_irq(&current->sighand->siglock);
264
265	current->state = TASK_INTERRUPTIBLE;
266	schedule();
267	set_thread_flag(TIF_RESTORE_SIGMASK);
268	return -ERESTARTNOHAND;
269}
270#endif
271
272asmlinkage int sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
273{
274	sigset_t newset;
275	sigset_t __user *unewset;
276	size_t sigsetsize;
277
278	/* XXX Don't preclude handling different sized sigset_t's.  */
279	sigsetsize = regs.regs[5];
280	if (sigsetsize != sizeof(sigset_t))
281		return -EINVAL;
282
283	unewset = (sigset_t __user *) regs.regs[4];
284	if (copy_from_user(&newset, unewset, sizeof(newset)))
285		return -EFAULT;
286	sigdelsetmask(&newset, ~_BLOCKABLE);
287
288	spin_lock_irq(&current->sighand->siglock);
289	current->saved_sigmask = current->blocked;
290	current->blocked = newset;
291	recalc_sigpending();
292	spin_unlock_irq(&current->sighand->siglock);
293
294	current->state = TASK_INTERRUPTIBLE;
295	schedule();
296	set_thread_flag(TIF_RESTORE_SIGMASK);
297	return -ERESTARTNOHAND;
298}
299
300#ifdef CONFIG_TRAD_SIGNALS
301SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
302	struct sigaction __user *, oact)
303{
304	struct k_sigaction new_ka, old_ka;
305	int ret;
306	int err = 0;
307
308	if (act) {
309		old_sigset_t mask;
310
311		if (!access_ok(VERIFY_READ, act, sizeof(*act)))
312			return -EFAULT;
313		err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
314		err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
315		err |= __get_user(mask, &act->sa_mask.sig[0]);
316		if (err)
317			return -EFAULT;
318
319		siginitset(&new_ka.sa.sa_mask, mask);
320	}
321
322	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
323
324	if (!ret && oact) {
325		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
326			return -EFAULT;
327		err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
328		err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
329		err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
330		err |= __put_user(0, &oact->sa_mask.sig[1]);
331		err |= __put_user(0, &oact->sa_mask.sig[2]);
332		err |= __put_user(0, &oact->sa_mask.sig[3]);
333		if (err)
334			return -EFAULT;
335	}
336
337	return ret;
338}
339#endif
340
341asmlinkage int sys_sigaltstack(nabi_no_regargs struct pt_regs regs)
342{
343	const stack_t __user *uss = (const stack_t __user *) regs.regs[4];
344	stack_t __user *uoss = (stack_t __user *) regs.regs[5];
345	unsigned long usp = regs.regs[29];
346
347	return do_sigaltstack(uss, uoss, usp);
348}
349
350#ifdef CONFIG_TRAD_SIGNALS
351asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
352{
353	struct sigframe __user *frame;
354	sigset_t blocked;
355	int sig;
356
357	frame = (struct sigframe __user *) regs.regs[29];
358	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
359		goto badframe;
360	if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
361		goto badframe;
362
363	sigdelsetmask(&blocked, ~_BLOCKABLE);
364	spin_lock_irq(&current->sighand->siglock);
365	current->blocked = blocked;
366	recalc_sigpending();
367	spin_unlock_irq(&current->sighand->siglock);
368
369	sig = restore_sigcontext(&regs, &frame->sf_sc);
370	if (sig < 0)
371		goto badframe;
372	else if (sig)
373		force_sig(sig, current);
374
375	/*
376	 * Don't let your children do this ...
377	 */
378	__asm__ __volatile__(
379		"move\t$29, %0\n\t"
380		"j\tsyscall_exit"
381		:/* no outputs */
382		:"r" (&regs));
383	/* Unreached */
384
385badframe:
386	force_sig(SIGSEGV, current);
387}
388#endif /* CONFIG_TRAD_SIGNALS */
389
390asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
391{
392	struct rt_sigframe __user *frame;
393	sigset_t set;
394	int sig;
395
396	frame = (struct rt_sigframe __user *) regs.regs[29];
397	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
398		goto badframe;
399	if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
400		goto badframe;
401
402	sigdelsetmask(&set, ~_BLOCKABLE);
403	spin_lock_irq(&current->sighand->siglock);
404	current->blocked = set;
405	recalc_sigpending();
406	spin_unlock_irq(&current->sighand->siglock);
407
408	sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
409	if (sig < 0)
410		goto badframe;
411	else if (sig)
412		force_sig(sig, current);
413
414	/* It is more difficult to avoid calling this function than to
415	   call it and ignore errors.  */
416	do_sigaltstack(&frame->rs_uc.uc_stack, NULL, regs.regs[29]);
417
418	/*
419	 * Don't let your children do this ...
420	 */
421	__asm__ __volatile__(
422		"move\t$29, %0\n\t"
423		"j\tsyscall_exit"
424		:/* no outputs */
425		:"r" (&regs));
426	/* Unreached */
427
428badframe:
429	force_sig(SIGSEGV, current);
430}
431
432#ifdef CONFIG_TRAD_SIGNALS
433static int setup_frame(void *sig_return, struct k_sigaction *ka,
434		       struct pt_regs *regs, int signr, sigset_t *set)
435{
436	struct sigframe __user *frame;
437	int err = 0;
438
439	frame = get_sigframe(ka, regs, sizeof(*frame));
440	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
441		goto give_sigsegv;
442
443	err |= setup_sigcontext(regs, &frame->sf_sc);
444	err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
445	if (err)
446		goto give_sigsegv;
447
448	/*
449	 * Arguments to signal handler:
450	 *
451	 *   a0 = signal number
452	 *   a1 = 0 (should be cause)
453	 *   a2 = pointer to struct sigcontext
454	 *
455	 * $25 and c0_epc point to the signal handler, $29 points to the
456	 * struct sigframe.
457	 */
458	regs->regs[ 4] = signr;
459	regs->regs[ 5] = 0;
460	regs->regs[ 6] = (unsigned long) &frame->sf_sc;
461	regs->regs[29] = (unsigned long) frame;
462	regs->regs[31] = (unsigned long) sig_return;
463	regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
464
465	DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
466	       current->comm, current->pid,
467	       frame, regs->cp0_epc, regs->regs[31]);
468	return 0;
469
470give_sigsegv:
471	force_sigsegv(signr, current);
472	return -EFAULT;
473}
474#endif
475
476static int setup_rt_frame(void *sig_return, struct k_sigaction *ka,
477			  struct pt_regs *regs,	int signr, sigset_t *set,
478			  siginfo_t *info)
479{
480	struct rt_sigframe __user *frame;
481	int err = 0;
482
483	frame = get_sigframe(ka, regs, sizeof(*frame));
484	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
485		goto give_sigsegv;
486
487	/* Create siginfo.  */
488	err |= copy_siginfo_to_user(&frame->rs_info, info);
489
490	/* Create the ucontext.  */
491	err |= __put_user(0, &frame->rs_uc.uc_flags);
492	err |= __put_user(NULL, &frame->rs_uc.uc_link);
493	err |= __put_user((void __user *)current->sas_ss_sp,
494	                  &frame->rs_uc.uc_stack.ss_sp);
495	err |= __put_user(sas_ss_flags(regs->regs[29]),
496	                  &frame->rs_uc.uc_stack.ss_flags);
497	err |= __put_user(current->sas_ss_size,
498	                  &frame->rs_uc.uc_stack.ss_size);
499	err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
500	err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
501
502	if (err)
503		goto give_sigsegv;
504
505	/*
506	 * Arguments to signal handler:
507	 *
508	 *   a0 = signal number
509	 *   a1 = 0 (should be cause)
510	 *   a2 = pointer to ucontext
511	 *
512	 * $25 and c0_epc point to the signal handler, $29 points to
513	 * the struct rt_sigframe.
514	 */
515	regs->regs[ 4] = signr;
516	regs->regs[ 5] = (unsigned long) &frame->rs_info;
517	regs->regs[ 6] = (unsigned long) &frame->rs_uc;
518	regs->regs[29] = (unsigned long) frame;
519	regs->regs[31] = (unsigned long) sig_return;
520	regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
521
522	DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
523	       current->comm, current->pid,
524	       frame, regs->cp0_epc, regs->regs[31]);
525
526	return 0;
527
528give_sigsegv:
529	force_sigsegv(signr, current);
530	return -EFAULT;
531}
532
533struct mips_abi mips_abi = {
534#ifdef CONFIG_TRAD_SIGNALS
535	.setup_frame	= setup_frame,
536	.signal_return_offset = offsetof(struct mips_vdso, signal_trampoline),
537#endif
538	.setup_rt_frame	= setup_rt_frame,
539	.rt_signal_return_offset =
540		offsetof(struct mips_vdso, rt_signal_trampoline),
541	.restart	= __NR_restart_syscall
 
 
 
 
542};
543
544static int handle_signal(unsigned long sig, siginfo_t *info,
545	struct k_sigaction *ka, sigset_t *oldset, struct pt_regs *regs)
546{
 
547	int ret;
548	struct mips_abi *abi = current->thread.abi;
 
 
 
 
 
 
 
549	void *vdso = current->mm->context.vdso;
 
550
551	if (regs->regs[0]) {
552		switch(regs->regs[2]) {
553		case ERESTART_RESTARTBLOCK:
554		case ERESTARTNOHAND:
555			regs->regs[2] = EINTR;
556			break;
557		case ERESTARTSYS:
558			if (!(ka->sa.sa_flags & SA_RESTART)) {
559				regs->regs[2] = EINTR;
560				break;
561			}
562		/* fallthrough */
563		case ERESTARTNOINTR:
564			regs->regs[7] = regs->regs[26];
565			regs->regs[2] = regs->regs[0];
566			regs->cp0_epc -= 4;
567		}
568
569		regs->regs[0] = 0;		/* Don't deal with this again.  */
570	}
571
572	if (sig_uses_siginfo(ka))
573		ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset,
574					  ka, regs, sig, oldset, info);
575	else
576		ret = abi->setup_frame(vdso + abi->signal_return_offset,
577				       ka, regs, sig, oldset);
578
579	if (ret)
580		return ret;
581
582	spin_lock_irq(&current->sighand->siglock);
583	sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
584	if (!(ka->sa.sa_flags & SA_NODEFER))
585		sigaddset(&current->blocked, sig);
586	recalc_sigpending();
587	spin_unlock_irq(&current->sighand->siglock);
588
589	return ret;
590}
591
592static void do_signal(struct pt_regs *regs)
593{
594	struct k_sigaction ka;
595	sigset_t *oldset;
596	siginfo_t info;
597	int signr;
598
599	/*
600	 * We want the common case to go fast, which is why we may in certain
601	 * cases get here from kernel mode. Just return without doing anything
602	 * if so.
603	 */
604	if (!user_mode(regs))
605		return;
606
607	if (test_thread_flag(TIF_RESTORE_SIGMASK))
608		oldset = &current->saved_sigmask;
609	else
610		oldset = &current->blocked;
611
612	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
613	if (signr > 0) {
614		/* Whee!  Actually deliver the signal.  */
615		if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
616			/*
617			 * A signal was successfully delivered; the saved
618			 * sigmask will have been stored in the signal frame,
619			 * and will be restored by sigreturn, so we can simply
620			 * clear the TIF_RESTORE_SIGMASK flag.
621			 */
622			if (test_thread_flag(TIF_RESTORE_SIGMASK))
623				clear_thread_flag(TIF_RESTORE_SIGMASK);
624		}
625
 
 
 
626		return;
627	}
628
629	if (regs->regs[0]) {
630		if (regs->regs[2] == ERESTARTNOHAND ||
631		    regs->regs[2] == ERESTARTSYS ||
632		    regs->regs[2] == ERESTARTNOINTR) {
 
633			regs->regs[2] = regs->regs[0];
634			regs->regs[7] = regs->regs[26];
635			regs->cp0_epc -= 4;
636		}
637		if (regs->regs[2] == ERESTART_RESTARTBLOCK) {
 
638			regs->regs[2] = current->thread.abi->restart;
639			regs->regs[7] = regs->regs[26];
640			regs->cp0_epc -= 4;
 
641		}
642		regs->regs[0] = 0;	/* Don't deal with this again.  */
643	}
644
645	/*
646	 * If there's no signal to deliver, we just put the saved sigmask
647	 * back
648	 */
649	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
650		clear_thread_flag(TIF_RESTORE_SIGMASK);
651		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
652	}
653}
654
655/*
656 * notification of userspace execution resumption
657 * - triggered by the TIF_WORK_MASK flags
658 */
659asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
660	__u32 thread_info_flags)
661{
662	local_irq_enable();
663
 
 
 
 
 
664	/* deal with pending signal delivery */
665	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
666		do_signal(regs);
667
668	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
669		clear_thread_flag(TIF_NOTIFY_RESUME);
670		tracehook_notify_resume(regs);
671		if (current->replacement_session_keyring)
672			key_replace_session_keyring();
673	}
 
 
674}
675
676#ifdef CONFIG_SMP
677static int smp_save_fp_context(struct sigcontext __user *sc)
678{
679	return raw_cpu_has_fpu
680	       ? _save_fp_context(sc)
681	       : fpu_emulator_save_context(sc);
682}
683
684static int smp_restore_fp_context(struct sigcontext __user *sc)
685{
686	return raw_cpu_has_fpu
687	       ? _restore_fp_context(sc)
688	       : fpu_emulator_restore_context(sc);
689}
690#endif
691
692static int signal_setup(void)
693{
 
 
 
 
 
 
 
 
 
 
694#ifdef CONFIG_SMP
695	/* For now just do the cpu_has_fpu check when the functions are invoked */
696	save_fp_context = smp_save_fp_context;
697	restore_fp_context = smp_restore_fp_context;
698#else
699	if (cpu_has_fpu) {
700		save_fp_context = _save_fp_context;
701		restore_fp_context = _restore_fp_context;
702	} else {
703		save_fp_context = fpu_emulator_save_context;
704		restore_fp_context = fpu_emulator_restore_context;
705	}
706#endif
707
708	return 0;
709}
710
711arch_initcall(signal_setup);
v4.6
  1/*
  2 * This file is subject to the terms and conditions of the GNU General Public
  3 * License.  See the file "COPYING" in the main directory of this archive
  4 * for more details.
  5 *
  6 * Copyright (C) 1991, 1992  Linus Torvalds
  7 * Copyright (C) 1994 - 2000  Ralf Baechle
  8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
  9 * Copyright (C) 2014, Imagination Technologies Ltd.
 10 */
 11#include <linux/cache.h>
 12#include <linux/context_tracking.h>
 13#include <linux/irqflags.h>
 14#include <linux/sched.h>
 15#include <linux/mm.h>
 16#include <linux/personality.h>
 17#include <linux/smp.h>
 18#include <linux/kernel.h>
 19#include <linux/signal.h>
 20#include <linux/errno.h>
 21#include <linux/wait.h>
 22#include <linux/ptrace.h>
 23#include <linux/unistd.h>
 24#include <linux/uprobes.h>
 25#include <linux/compiler.h>
 26#include <linux/syscalls.h>
 27#include <linux/uaccess.h>
 28#include <linux/tracehook.h>
 29
 30#include <asm/abi.h>
 31#include <asm/asm.h>
 32#include <linux/bitops.h>
 33#include <asm/cacheflush.h>
 34#include <asm/fpu.h>
 35#include <asm/sim.h>
 36#include <asm/ucontext.h>
 37#include <asm/cpu-features.h>
 38#include <asm/war.h>
 39#include <asm/dsp.h>
 40#include <asm/inst.h>
 41#include <asm/msa.h>
 42
 43#include "signal-common.h"
 44
 45static int (*save_fp_context)(void __user *sc);
 46static int (*restore_fp_context)(void __user *sc);
 
 
 
 
 
 
 47
 48struct sigframe {
 49	u32 sf_ass[4];		/* argument save space for o32 */
 50	u32 sf_pad[2];		/* Was: signal trampoline */
 51
 52	/* Matches struct ucontext from its uc_mcontext field onwards */
 53	struct sigcontext sf_sc;
 54	sigset_t sf_mask;
 55	unsigned long long sf_extcontext[0];
 56};
 57
 58struct rt_sigframe {
 59	u32 rs_ass[4];		/* argument save space for o32 */
 60	u32 rs_pad[2];		/* Was: signal trampoline */
 61	struct siginfo rs_info;
 62	struct ucontext rs_uc;
 63};
 64
 65/*
 66 * Thread saved context copy to/from a signal context presumed to be on the
 67 * user stack, and therefore accessed with appropriate macros from uaccess.h.
 68 */
 69static int copy_fp_to_sigcontext(void __user *sc)
 70{
 71	struct mips_abi *abi = current->thread.abi;
 72	uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
 73	uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
 74	int i;
 75	int err = 0;
 76	int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
 77
 78	for (i = 0; i < NUM_FPU_REGS; i += inc) {
 79		err |=
 80		    __put_user(get_fpr64(&current->thread.fpu.fpr[i], 0),
 81			       &fpregs[i]);
 82	}
 83	err |= __put_user(current->thread.fpu.fcr31, csr);
 84
 85	return err;
 86}
 87
 88static int copy_fp_from_sigcontext(void __user *sc)
 89{
 90	struct mips_abi *abi = current->thread.abi;
 91	uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
 92	uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
 93	int i;
 94	int err = 0;
 95	int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
 96	u64 fpr_val;
 97
 98	for (i = 0; i < NUM_FPU_REGS; i += inc) {
 99		err |= __get_user(fpr_val, &fpregs[i]);
100		set_fpr64(&current->thread.fpu.fpr[i], 0, fpr_val);
101	}
102	err |= __get_user(current->thread.fpu.fcr31, csr);
103
104	return err;
105}
106
107/*
108 * Wrappers for the assembly _{save,restore}_fp_context functions.
109 */
110static int save_hw_fp_context(void __user *sc)
111{
112	struct mips_abi *abi = current->thread.abi;
113	uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
114	uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
115
116	return _save_fp_context(fpregs, csr);
117}
118
119static int restore_hw_fp_context(void __user *sc)
120{
121	struct mips_abi *abi = current->thread.abi;
122	uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
123	uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
124
125	return _restore_fp_context(fpregs, csr);
126}
127
128/*
129 * Extended context handling.
130 */
131
132static inline void __user *sc_to_extcontext(void __user *sc)
133{
134	struct ucontext __user *uc;
135
136	/*
137	 * We can just pretend the sigcontext is always embedded in a struct
138	 * ucontext here, because the offset from sigcontext to extended
139	 * context is the same in the struct sigframe case.
140	 */
141	uc = container_of(sc, struct ucontext, uc_mcontext);
142	return &uc->uc_extcontext;
143}
144
145static int save_msa_extcontext(void __user *buf)
146{
147	struct msa_extcontext __user *msa = buf;
148	uint64_t val;
149	int i, err;
150
151	if (!thread_msa_context_live())
152		return 0;
153
154	/*
155	 * Ensure that we can't lose the live MSA context between checking
156	 * for it & writing it to memory.
157	 */
158	preempt_disable();
159
160	if (is_msa_enabled()) {
161		/*
162		 * There are no EVA versions of the vector register load/store
163		 * instructions, so MSA context has to be saved to kernel memory
164		 * and then copied to user memory. The save to kernel memory
165		 * should already have been done when handling scalar FP
166		 * context.
167		 */
168		BUG_ON(config_enabled(CONFIG_EVA));
169
170		err = __put_user(read_msa_csr(), &msa->csr);
171		err |= _save_msa_all_upper(&msa->wr);
172
173		preempt_enable();
174	} else {
175		preempt_enable();
176
177		err = __put_user(current->thread.fpu.msacsr, &msa->csr);
178
179		for (i = 0; i < NUM_FPU_REGS; i++) {
180			val = get_fpr64(&current->thread.fpu.fpr[i], 1);
181			err |= __put_user(val, &msa->wr[i]);
182		}
183	}
184
185	err |= __put_user(MSA_EXTCONTEXT_MAGIC, &msa->ext.magic);
186	err |= __put_user(sizeof(*msa), &msa->ext.size);
187
188	return err ? -EFAULT : sizeof(*msa);
189}
190
191static int restore_msa_extcontext(void __user *buf, unsigned int size)
192{
193	struct msa_extcontext __user *msa = buf;
194	unsigned long long val;
195	unsigned int csr;
196	int i, err;
197
198	if (size != sizeof(*msa))
199		return -EINVAL;
200
201	err = get_user(csr, &msa->csr);
202	if (err)
203		return err;
204
205	preempt_disable();
206
207	if (is_msa_enabled()) {
208		/*
209		 * There are no EVA versions of the vector register load/store
210		 * instructions, so MSA context has to be copied to kernel
211		 * memory and later loaded to registers. The same is true of
212		 * scalar FP context, so FPU & MSA should have already been
213		 * disabled whilst handling scalar FP context.
214		 */
215		BUG_ON(config_enabled(CONFIG_EVA));
216
217		write_msa_csr(csr);
218		err |= _restore_msa_all_upper(&msa->wr);
219		preempt_enable();
220	} else {
221		preempt_enable();
222
223		current->thread.fpu.msacsr = csr;
224
225		for (i = 0; i < NUM_FPU_REGS; i++) {
226			err |= __get_user(val, &msa->wr[i]);
227			set_fpr64(&current->thread.fpu.fpr[i], 1, val);
228		}
229	}
230
231	return err;
232}
233
234static int save_extcontext(void __user *buf)
235{
236	int sz;
237
238	sz = save_msa_extcontext(buf);
239	if (sz < 0)
240		return sz;
241	buf += sz;
242
243	/* If no context was saved then trivially return */
244	if (!sz)
245		return 0;
246
247	/* Write the end marker */
248	if (__put_user(END_EXTCONTEXT_MAGIC, (u32 *)buf))
249		return -EFAULT;
250
251	sz += sizeof(((struct extcontext *)NULL)->magic);
252	return sz;
253}
254
255static int restore_extcontext(void __user *buf)
256{
257	struct extcontext ext;
258	int err;
259
260	while (1) {
261		err = __get_user(ext.magic, (unsigned int *)buf);
262		if (err)
263			return err;
264
265		if (ext.magic == END_EXTCONTEXT_MAGIC)
266			return 0;
267
268		err = __get_user(ext.size, (unsigned int *)(buf
269			+ offsetof(struct extcontext, size)));
270		if (err)
271			return err;
272
273		switch (ext.magic) {
274		case MSA_EXTCONTEXT_MAGIC:
275			err = restore_msa_extcontext(buf, ext.size);
276			break;
277
278		default:
279			err = -EINVAL;
280			break;
281		}
282
283		if (err)
284			return err;
285
286		buf += ext.size;
287	}
288}
289
290/*
291 * Helper routines
292 */
293int protected_save_fp_context(void __user *sc)
294{
295	struct mips_abi *abi = current->thread.abi;
296	uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
297	uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
298	uint32_t __user *used_math = sc + abi->off_sc_used_math;
299	unsigned int used, ext_sz;
300	int err;
301
302	used = used_math() ? USED_FP : 0;
303	if (!used)
304		goto fp_done;
305
306	if (!test_thread_flag(TIF_32BIT_FPREGS))
307		used |= USED_FR1;
308	if (test_thread_flag(TIF_HYBRID_FPREGS))
309		used |= USED_HYBRID_FPRS;
310
311	/*
312	 * EVA does not have userland equivalents of ldc1 or sdc1, so
313	 * save to the kernel FP context & copy that to userland below.
314	 */
315	if (config_enabled(CONFIG_EVA))
316		lose_fpu(1);
317
318	while (1) {
319		lock_fpu_owner();
320		if (is_fpu_owner()) {
321			err = save_fp_context(sc);
322			unlock_fpu_owner();
323		} else {
324			unlock_fpu_owner();
325			err = copy_fp_to_sigcontext(sc);
326		}
327		if (likely(!err))
328			break;
329		/* touch the sigcontext and try again */
330		err = __put_user(0, &fpregs[0]) |
331			__put_user(0, &fpregs[31]) |
332			__put_user(0, csr);
333		if (err)
334			return err;	/* really bad sigcontext */
335	}
336
337fp_done:
338	ext_sz = err = save_extcontext(sc_to_extcontext(sc));
339	if (err < 0)
340		return err;
341	used |= ext_sz ? USED_EXTCONTEXT : 0;
342
343	return __put_user(used, used_math);
344}
345
346int protected_restore_fp_context(void __user *sc)
347{
348	struct mips_abi *abi = current->thread.abi;
349	uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
350	uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
351	uint32_t __user *used_math = sc + abi->off_sc_used_math;
352	unsigned int used;
353	int err, sig = 0, tmp __maybe_unused;
354
355	err = __get_user(used, used_math);
356	conditional_used_math(used & USED_FP);
357
358	/*
359	 * The signal handler may have used FPU; give it up if the program
360	 * doesn't want it following sigreturn.
361	 */
362	if (err || !(used & USED_FP))
363		lose_fpu(0);
364	if (err)
365		return err;
366	if (!(used & USED_FP))
367		goto fp_done;
368
369	err = sig = fpcsr_pending(csr);
370	if (err < 0)
371		return err;
372
373	/*
374	 * EVA does not have userland equivalents of ldc1 or sdc1, so we
375	 * disable the FPU here such that the code below simply copies to
376	 * the kernel FP context.
377	 */
378	if (config_enabled(CONFIG_EVA))
379		lose_fpu(0);
380
381	while (1) {
382		lock_fpu_owner();
383		if (is_fpu_owner()) {
384			err = restore_fp_context(sc);
385			unlock_fpu_owner();
386		} else {
387			unlock_fpu_owner();
388			err = copy_fp_from_sigcontext(sc);
389		}
390		if (likely(!err))
391			break;
392		/* touch the sigcontext and try again */
393		err = __get_user(tmp, &fpregs[0]) |
394			__get_user(tmp, &fpregs[31]) |
395			__get_user(tmp, csr);
396		if (err)
397			break;	/* really bad sigcontext */
398	}
399
400fp_done:
401	if (used & USED_EXTCONTEXT)
402		err |= restore_extcontext(sc_to_extcontext(sc));
403
404	return err ?: sig;
405}
406
407int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
408{
409	int err = 0;
410	int i;
 
411
412	err |= __put_user(regs->cp0_epc, &sc->sc_pc);
413
414	err |= __put_user(0, &sc->sc_regs[0]);
415	for (i = 1; i < 32; i++)
416		err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
417
418#ifdef CONFIG_CPU_HAS_SMARTMIPS
419	err |= __put_user(regs->acx, &sc->sc_acx);
420#endif
421	err |= __put_user(regs->hi, &sc->sc_mdhi);
422	err |= __put_user(regs->lo, &sc->sc_mdlo);
423	if (cpu_has_dsp) {
424		err |= __put_user(mfhi1(), &sc->sc_hi1);
425		err |= __put_user(mflo1(), &sc->sc_lo1);
426		err |= __put_user(mfhi2(), &sc->sc_hi2);
427		err |= __put_user(mflo2(), &sc->sc_lo2);
428		err |= __put_user(mfhi3(), &sc->sc_hi3);
429		err |= __put_user(mflo3(), &sc->sc_lo3);
430		err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
431	}
432
 
 
433
434	/*
435	 * Save FPU state to signal context. Signal handler
436	 * will "inherit" current FPU state.
437	 */
438	err |= protected_save_fp_context(sc);
439
 
440	return err;
441}
442
443static size_t extcontext_max_size(void)
444{
445	size_t sz = 0;
446
447	/*
448	 * The assumption here is that between this point & the point at which
449	 * the extended context is saved the size of the context should only
450	 * ever be able to shrink (if the task is preempted), but never grow.
451	 * That is, what this function returns is an upper bound on the size of
452	 * the extended context for the current task at the current time.
453	 */
454
455	if (thread_msa_context_live())
456		sz += sizeof(struct msa_extcontext);
457
458	/* If any context is saved then we'll append the end marker */
459	if (sz)
460		sz += sizeof(((struct extcontext *)NULL)->magic);
461
462	return sz;
463}
464
465int fpcsr_pending(unsigned int __user *fpcsr)
466{
467	int err, sig = 0;
468	unsigned int csr, enabled;
469
470	err = __get_user(csr, fpcsr);
471	enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
472	/*
473	 * If the signal handler set some FPU exceptions, clear it and
474	 * send SIGFPE.
475	 */
476	if (csr & enabled) {
477		csr &= ~enabled;
478		err |= __put_user(csr, fpcsr);
479		sig = SIGFPE;
480	}
481	return err ?: sig;
482}
483
 
 
 
 
 
 
 
 
 
 
 
 
484int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
485{
 
486	unsigned long treg;
487	int err = 0;
488	int i;
489
490	/* Always make any pending restarted system calls return -EINTR */
491	current->restart_block.fn = do_no_restart_syscall;
492
493	err |= __get_user(regs->cp0_epc, &sc->sc_pc);
494
495#ifdef CONFIG_CPU_HAS_SMARTMIPS
496	err |= __get_user(regs->acx, &sc->sc_acx);
497#endif
498	err |= __get_user(regs->hi, &sc->sc_mdhi);
499	err |= __get_user(regs->lo, &sc->sc_mdlo);
500	if (cpu_has_dsp) {
501		err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
502		err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
503		err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
504		err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
505		err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
506		err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
507		err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
508	}
509
510	for (i = 1; i < 32; i++)
511		err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
512
513	return err ?: protected_restore_fp_context(sc);
 
 
 
 
 
 
 
 
 
 
 
 
514}
515
516void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
517			  size_t frame_size)
518{
519	unsigned long sp;
520
521	/* Leave space for potential extended context */
522	frame_size += extcontext_max_size();
523
524	/* Default to using normal stack */
525	sp = regs->regs[29];
526
527	/*
528	 * FPU emulator may have it's own trampoline active just
529	 * above the user stack, 16-bytes before the next lowest
530	 * 16 byte boundary.  Try to avoid trashing it.
531	 */
532	sp -= 32;
533
534	sp = sigsp(sp, ksig);
 
 
535
536	return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
537}
538
539/*
540 * Atomically swap in the new signal mask, and wait for a signal.
541 */
542
543#ifdef CONFIG_TRAD_SIGNALS
544SYSCALL_DEFINE1(sigsuspend, sigset_t __user *, uset)
545{
546	return sys_rt_sigsuspend(uset, sizeof(sigset_t));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
547}
548#endif
549
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
550#ifdef CONFIG_TRAD_SIGNALS
551SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
552	struct sigaction __user *, oact)
553{
554	struct k_sigaction new_ka, old_ka;
555	int ret;
556	int err = 0;
557
558	if (act) {
559		old_sigset_t mask;
560
561		if (!access_ok(VERIFY_READ, act, sizeof(*act)))
562			return -EFAULT;
563		err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
564		err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
565		err |= __get_user(mask, &act->sa_mask.sig[0]);
566		if (err)
567			return -EFAULT;
568
569		siginitset(&new_ka.sa.sa_mask, mask);
570	}
571
572	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
573
574	if (!ret && oact) {
575		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
576			return -EFAULT;
577		err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
578		err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
579		err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
580		err |= __put_user(0, &oact->sa_mask.sig[1]);
581		err |= __put_user(0, &oact->sa_mask.sig[2]);
582		err |= __put_user(0, &oact->sa_mask.sig[3]);
583		if (err)
584			return -EFAULT;
585	}
586
587	return ret;
588}
589#endif
590
 
 
 
 
 
 
 
 
 
591#ifdef CONFIG_TRAD_SIGNALS
592asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
593{
594	struct sigframe __user *frame;
595	sigset_t blocked;
596	int sig;
597
598	frame = (struct sigframe __user *) regs.regs[29];
599	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
600		goto badframe;
601	if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
602		goto badframe;
603
604	set_current_blocked(&blocked);
 
 
 
 
605
606	sig = restore_sigcontext(&regs, &frame->sf_sc);
607	if (sig < 0)
608		goto badframe;
609	else if (sig)
610		force_sig(sig, current);
611
612	/*
613	 * Don't let your children do this ...
614	 */
615	__asm__ __volatile__(
616		"move\t$29, %0\n\t"
617		"j\tsyscall_exit"
618		:/* no outputs */
619		:"r" (&regs));
620	/* Unreached */
621
622badframe:
623	force_sig(SIGSEGV, current);
624}
625#endif /* CONFIG_TRAD_SIGNALS */
626
627asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
628{
629	struct rt_sigframe __user *frame;
630	sigset_t set;
631	int sig;
632
633	frame = (struct rt_sigframe __user *) regs.regs[29];
634	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
635		goto badframe;
636	if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
637		goto badframe;
638
639	set_current_blocked(&set);
 
 
 
 
640
641	sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
642	if (sig < 0)
643		goto badframe;
644	else if (sig)
645		force_sig(sig, current);
646
647	if (restore_altstack(&frame->rs_uc.uc_stack))
648		goto badframe;
 
649
650	/*
651	 * Don't let your children do this ...
652	 */
653	__asm__ __volatile__(
654		"move\t$29, %0\n\t"
655		"j\tsyscall_exit"
656		:/* no outputs */
657		:"r" (&regs));
658	/* Unreached */
659
660badframe:
661	force_sig(SIGSEGV, current);
662}
663
664#ifdef CONFIG_TRAD_SIGNALS
665static int setup_frame(void *sig_return, struct ksignal *ksig,
666		       struct pt_regs *regs, sigset_t *set)
667{
668	struct sigframe __user *frame;
669	int err = 0;
670
671	frame = get_sigframe(ksig, regs, sizeof(*frame));
672	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
673		return -EFAULT;
674
675	err |= setup_sigcontext(regs, &frame->sf_sc);
676	err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
677	if (err)
678		return -EFAULT;
679
680	/*
681	 * Arguments to signal handler:
682	 *
683	 *   a0 = signal number
684	 *   a1 = 0 (should be cause)
685	 *   a2 = pointer to struct sigcontext
686	 *
687	 * $25 and c0_epc point to the signal handler, $29 points to the
688	 * struct sigframe.
689	 */
690	regs->regs[ 4] = ksig->sig;
691	regs->regs[ 5] = 0;
692	regs->regs[ 6] = (unsigned long) &frame->sf_sc;
693	regs->regs[29] = (unsigned long) frame;
694	regs->regs[31] = (unsigned long) sig_return;
695	regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
696
697	DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
698	       current->comm, current->pid,
699	       frame, regs->cp0_epc, regs->regs[31]);
700	return 0;
 
 
 
 
701}
702#endif
703
704static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
705			  struct pt_regs *regs, sigset_t *set)
 
706{
707	struct rt_sigframe __user *frame;
708	int err = 0;
709
710	frame = get_sigframe(ksig, regs, sizeof(*frame));
711	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
712		return -EFAULT;
713
714	/* Create siginfo.  */
715	err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
716
717	/* Create the ucontext.	 */
718	err |= __put_user(0, &frame->rs_uc.uc_flags);
719	err |= __put_user(NULL, &frame->rs_uc.uc_link);
720	err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
 
 
 
 
 
721	err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
722	err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
723
724	if (err)
725		return -EFAULT;
726
727	/*
728	 * Arguments to signal handler:
729	 *
730	 *   a0 = signal number
731	 *   a1 = 0 (should be cause)
732	 *   a2 = pointer to ucontext
733	 *
734	 * $25 and c0_epc point to the signal handler, $29 points to
735	 * the struct rt_sigframe.
736	 */
737	regs->regs[ 4] = ksig->sig;
738	regs->regs[ 5] = (unsigned long) &frame->rs_info;
739	regs->regs[ 6] = (unsigned long) &frame->rs_uc;
740	regs->regs[29] = (unsigned long) frame;
741	regs->regs[31] = (unsigned long) sig_return;
742	regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
743
744	DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
745	       current->comm, current->pid,
746	       frame, regs->cp0_epc, regs->regs[31]);
747
748	return 0;
 
 
 
 
749}
750
751struct mips_abi mips_abi = {
752#ifdef CONFIG_TRAD_SIGNALS
753	.setup_frame	= setup_frame,
 
754#endif
755	.setup_rt_frame = setup_rt_frame,
756	.restart	= __NR_restart_syscall,
757
758	.off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
759	.off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
760	.off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
761
762	.vdso		= &vdso_image,
763};
764
765static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 
766{
767	sigset_t *oldset = sigmask_to_save();
768	int ret;
769	struct mips_abi *abi = current->thread.abi;
770#ifdef CONFIG_CPU_MICROMIPS
771	void *vdso;
772	unsigned long tmp = (unsigned long)current->mm->context.vdso;
773
774	set_isa16_mode(tmp);
775	vdso = (void *)tmp;
776#else
777	void *vdso = current->mm->context.vdso;
778#endif
779
780	if (regs->regs[0]) {
781		switch(regs->regs[2]) {
782		case ERESTART_RESTARTBLOCK:
783		case ERESTARTNOHAND:
784			regs->regs[2] = EINTR;
785			break;
786		case ERESTARTSYS:
787			if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
788				regs->regs[2] = EINTR;
789				break;
790			}
791		/* fallthrough */
792		case ERESTARTNOINTR:
793			regs->regs[7] = regs->regs[26];
794			regs->regs[2] = regs->regs[0];
795			regs->cp0_epc -= 4;
796		}
797
798		regs->regs[0] = 0;		/* Don't deal with this again.	*/
799	}
800
801	if (sig_uses_siginfo(&ksig->ka))
802		ret = abi->setup_rt_frame(vdso + abi->vdso->off_rt_sigreturn,
803					  ksig, regs, oldset);
804	else
805		ret = abi->setup_frame(vdso + abi->vdso->off_sigreturn,
806				       ksig, regs, oldset);
807
808	signal_setup_done(ret, ksig, 0);
 
 
 
 
 
 
 
 
 
 
809}
810
811static void do_signal(struct pt_regs *regs)
812{
813	struct ksignal ksig;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
814
815	if (get_signal(&ksig)) {
816		/* Whee!  Actually deliver the signal.	*/
817		handle_signal(&ksig, regs);
818		return;
819	}
820
821	if (regs->regs[0]) {
822		switch (regs->regs[2]) {
823		case ERESTARTNOHAND:
824		case ERESTARTSYS:
825		case ERESTARTNOINTR:
826			regs->regs[2] = regs->regs[0];
827			regs->regs[7] = regs->regs[26];
828			regs->cp0_epc -= 4;
829			break;
830
831		case ERESTART_RESTARTBLOCK:
832			regs->regs[2] = current->thread.abi->restart;
833			regs->regs[7] = regs->regs[26];
834			regs->cp0_epc -= 4;
835			break;
836		}
837		regs->regs[0] = 0;	/* Don't deal with this again.	*/
838	}
839
840	/*
841	 * If there's no signal to deliver, we just put the saved sigmask
842	 * back
843	 */
844	restore_saved_sigmask();
 
 
 
845}
846
847/*
848 * notification of userspace execution resumption
849 * - triggered by the TIF_WORK_MASK flags
850 */
851asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
852	__u32 thread_info_flags)
853{
854	local_irq_enable();
855
856	user_exit();
857
858	if (thread_info_flags & _TIF_UPROBE)
859		uprobe_notify_resume(regs);
860
861	/* deal with pending signal delivery */
862	if (thread_info_flags & _TIF_SIGPENDING)
863		do_signal(regs);
864
865	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
866		clear_thread_flag(TIF_NOTIFY_RESUME);
867		tracehook_notify_resume(regs);
 
 
868	}
869
870	user_enter();
871}
872
873#ifdef CONFIG_SMP
874static int smp_save_fp_context(void __user *sc)
875{
876	return raw_cpu_has_fpu
877	       ? save_hw_fp_context(sc)
878	       : copy_fp_to_sigcontext(sc);
879}
880
881static int smp_restore_fp_context(void __user *sc)
882{
883	return raw_cpu_has_fpu
884	       ? restore_hw_fp_context(sc)
885	       : copy_fp_from_sigcontext(sc);
886}
887#endif
888
889static int signal_setup(void)
890{
891	/*
892	 * The offset from sigcontext to extended context should be the same
893	 * regardless of the type of signal, such that userland can always know
894	 * where to look if it wishes to find the extended context structures.
895	 */
896	BUILD_BUG_ON((offsetof(struct sigframe, sf_extcontext) -
897		      offsetof(struct sigframe, sf_sc)) !=
898		     (offsetof(struct rt_sigframe, rs_uc.uc_extcontext) -
899		      offsetof(struct rt_sigframe, rs_uc.uc_mcontext)));
900
901#ifdef CONFIG_SMP
902	/* For now just do the cpu_has_fpu check when the functions are invoked */
903	save_fp_context = smp_save_fp_context;
904	restore_fp_context = smp_restore_fp_context;
905#else
906	if (cpu_has_fpu) {
907		save_fp_context = save_hw_fp_context;
908		restore_fp_context = restore_hw_fp_context;
909	} else {
910		save_fp_context = copy_fp_to_sigcontext;
911		restore_fp_context = copy_fp_from_sigcontext;
912	}
913#endif /* CONFIG_SMP */
914
915	return 0;
916}
917
918arch_initcall(signal_setup);