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v4.6
  1/*
  2 *  linux/arch/sh/kernel/signal.c
  3 *
  4 *  Copyright (C) 1991, 1992  Linus Torvalds
  5 *
  6 *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
  7 *
  8 *  SuperH version:  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
  9 *
 10 */
 11#include <linux/sched.h>
 12#include <linux/mm.h>
 13#include <linux/smp.h>
 14#include <linux/kernel.h>
 15#include <linux/signal.h>
 16#include <linux/errno.h>
 17#include <linux/wait.h>
 18#include <linux/ptrace.h>
 19#include <linux/unistd.h>
 20#include <linux/stddef.h>
 21#include <linux/tty.h>
 22#include <linux/elf.h>
 23#include <linux/personality.h>
 24#include <linux/binfmts.h>
 
 25#include <linux/io.h>
 26#include <linux/tracehook.h>
 
 27#include <asm/ucontext.h>
 28#include <asm/uaccess.h>
 29#include <asm/pgtable.h>
 30#include <asm/cacheflush.h>
 31#include <asm/syscalls.h>
 32#include <asm/fpu.h>
 33
 
 
 34struct fdpic_func_descriptor {
 35	unsigned long	text;
 36	unsigned long	GOT;
 37};
 38
 39/*
 40 * The following define adds a 64 byte gap between the signal
 41 * stack frame and previous contents of the stack.  This allows
 42 * frame unwinding in a function epilogue but only if a frame
 43 * pointer is used in the function.  This is necessary because
 44 * current gcc compilers (<4.3) do not generate unwind info on
 45 * SH for function epilogues.
 46 */
 47#define UNWINDGUARD 64
 48
 49/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 50 * Do a signal return; undo the signal stack.
 51 */
 52
 53#define MOVW(n)	 (0x9300|((n)-2))	/* Move mem word at PC+n to R3 */
 54#if defined(CONFIG_CPU_SH2)
 55#define TRAP_NOARG 0xc320		/* Syscall w/no args (NR in R3) */
 56#else
 57#define TRAP_NOARG 0xc310		/* Syscall w/no args (NR in R3) */
 58#endif
 59#define OR_R0_R0 0x200b			/* or r0,r0 (insert to avoid hardware bug) */
 60
 61struct sigframe
 62{
 63	struct sigcontext sc;
 64	unsigned long extramask[_NSIG_WORDS-1];
 65	u16 retcode[8];
 66};
 67
 68struct rt_sigframe
 69{
 70	struct siginfo info;
 71	struct ucontext uc;
 72	u16 retcode[8];
 73};
 74
 75#ifdef CONFIG_SH_FPU
 76static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
 77{
 78	struct task_struct *tsk = current;
 79
 80	if (!(boot_cpu_data.flags & CPU_HAS_FPU))
 81		return 0;
 82
 83	set_used_math();
 84	return __copy_from_user(&tsk->thread.xstate->hardfpu, &sc->sc_fpregs[0],
 85				sizeof(long)*(16*2+2));
 86}
 87
 88static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
 89				      struct pt_regs *regs)
 90{
 91	struct task_struct *tsk = current;
 92
 93	if (!(boot_cpu_data.flags & CPU_HAS_FPU))
 94		return 0;
 95
 96	if (!used_math())
 97		return __put_user(0, &sc->sc_ownedfp);
 
 
 98
 99	if (__put_user(1, &sc->sc_ownedfp))
100		return -EFAULT;
101
102	/* This will cause a "finit" to be triggered by the next
103	   attempted FPU operation by the 'current' process.
104	   */
105	clear_used_math();
106
107	unlazy_fpu(tsk, regs);
108	return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.xstate->hardfpu,
109			      sizeof(long)*(16*2+2));
110}
111#endif /* CONFIG_SH_FPU */
112
113static int
114restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p)
115{
116	unsigned int err = 0;
117
118#define COPY(x)		err |= __get_user(regs->x, &sc->sc_##x)
119			COPY(regs[1]);
120	COPY(regs[2]);	COPY(regs[3]);
121	COPY(regs[4]);	COPY(regs[5]);
122	COPY(regs[6]);	COPY(regs[7]);
123	COPY(regs[8]);	COPY(regs[9]);
124	COPY(regs[10]);	COPY(regs[11]);
125	COPY(regs[12]);	COPY(regs[13]);
126	COPY(regs[14]);	COPY(regs[15]);
127	COPY(gbr);	COPY(mach);
128	COPY(macl);	COPY(pr);
129	COPY(sr);	COPY(pc);
130#undef COPY
131
132#ifdef CONFIG_SH_FPU
133	if (boot_cpu_data.flags & CPU_HAS_FPU) {
134		int owned_fp;
135		struct task_struct *tsk = current;
136
137		regs->sr |= SR_FD; /* Release FPU */
138		clear_fpu(tsk, regs);
139		clear_used_math();
140		err |= __get_user (owned_fp, &sc->sc_ownedfp);
141		if (owned_fp)
142			err |= restore_sigcontext_fpu(sc);
143	}
144#endif
145
146	regs->tra = -1;		/* disable syscall checks */
147	err |= __get_user(*r0_p, &sc->sc_regs[0]);
148	return err;
149}
150
151asmlinkage int sys_sigreturn(void)
 
 
152{
153	struct pt_regs *regs = current_pt_regs();
154	struct sigframe __user *frame = (struct sigframe __user *)regs->regs[15];
155	sigset_t set;
156	int r0;
157
158        /* Always make any pending restarted system calls return -EINTR */
159	current->restart_block.fn = do_no_restart_syscall;
160
161	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
162		goto badframe;
163
164	if (__get_user(set.sig[0], &frame->sc.oldmask)
165	    || (_NSIG_WORDS > 1
166		&& __copy_from_user(&set.sig[1], &frame->extramask,
167				    sizeof(frame->extramask))))
168		goto badframe;
169
170	set_current_blocked(&set);
 
 
 
 
 
171
172	if (restore_sigcontext(regs, &frame->sc, &r0))
173		goto badframe;
174	return r0;
175
176badframe:
177	force_sig(SIGSEGV, current);
178	return 0;
179}
180
181asmlinkage int sys_rt_sigreturn(void)
 
 
182{
183	struct pt_regs *regs = current_pt_regs();
184	struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->regs[15];
185	sigset_t set;
186	int r0;
187
188	/* Always make any pending restarted system calls return -EINTR */
189	current->restart_block.fn = do_no_restart_syscall;
190
191	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
192		goto badframe;
193
194	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
195		goto badframe;
196
197	set_current_blocked(&set);
 
 
 
 
198
199	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
200		goto badframe;
201
202	if (restore_altstack(&frame->uc.uc_stack))
 
203		goto badframe;
204
205	return r0;
206
207badframe:
208	force_sig(SIGSEGV, current);
209	return 0;
210}
211
212/*
213 * Set up a signal frame.
214 */
215
216static int
217setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
218		 unsigned long mask)
219{
220	int err = 0;
221
222#define COPY(x)		err |= __put_user(regs->x, &sc->sc_##x)
223	COPY(regs[0]);	COPY(regs[1]);
224	COPY(regs[2]);	COPY(regs[3]);
225	COPY(regs[4]);	COPY(regs[5]);
226	COPY(regs[6]);	COPY(regs[7]);
227	COPY(regs[8]);	COPY(regs[9]);
228	COPY(regs[10]);	COPY(regs[11]);
229	COPY(regs[12]);	COPY(regs[13]);
230	COPY(regs[14]);	COPY(regs[15]);
231	COPY(gbr);	COPY(mach);
232	COPY(macl);	COPY(pr);
233	COPY(sr);	COPY(pc);
234#undef COPY
235
236#ifdef CONFIG_SH_FPU
237	err |= save_sigcontext_fpu(sc, regs);
238#endif
239
240	/* non-iBCS2 extensions.. */
241	err |= __put_user(mask, &sc->oldmask);
242
243	return err;
244}
245
246/*
247 * Determine which stack to use..
248 */
249static inline void __user *
250get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
251{
252	if (ka->sa.sa_flags & SA_ONSTACK) {
253		if (sas_ss_flags(sp) == 0)
254			sp = current->sas_ss_sp + current->sas_ss_size;
255	}
256
257	return (void __user *)((sp - (frame_size+UNWINDGUARD)) & -8ul);
258}
259
260/* These symbols are defined with the addresses in the vsyscall page.
261   See vsyscall-trapa.S.  */
262extern void __kernel_sigreturn(void);
263extern void __kernel_rt_sigreturn(void);
264
265static int setup_frame(struct ksignal *ksig, sigset_t *set,
266		       struct pt_regs *regs)
267{
268	struct sigframe __user *frame;
269	int err = 0, sig = ksig->sig;
 
270
271	frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));
272
273	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
274		return -EFAULT;
 
 
 
 
 
 
275
276	err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
277
278	if (_NSIG_WORDS > 1)
279		err |= __copy_to_user(frame->extramask, &set->sig[1],
280				      sizeof(frame->extramask));
281
282	/* Set up to return from userspace.  If provided, use a stub
283	   already in userspace.  */
284	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
285		regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
286#ifdef CONFIG_VSYSCALL
287	} else if (likely(current->mm->context.vdso)) {
288		regs->pr = VDSO_SYM(&__kernel_sigreturn);
289#endif
290	} else {
291		/* Generate return code (system call to sigreturn) */
292		err |= __put_user(MOVW(7), &frame->retcode[0]);
293		err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
294		err |= __put_user(OR_R0_R0, &frame->retcode[2]);
295		err |= __put_user(OR_R0_R0, &frame->retcode[3]);
296		err |= __put_user(OR_R0_R0, &frame->retcode[4]);
297		err |= __put_user(OR_R0_R0, &frame->retcode[5]);
298		err |= __put_user(OR_R0_R0, &frame->retcode[6]);
299		err |= __put_user((__NR_sigreturn), &frame->retcode[7]);
300		regs->pr = (unsigned long) frame->retcode;
301		flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
302	}
303
304	if (err)
305		return -EFAULT;
306
307	/* Set up registers for signal handler */
308	regs->regs[15] = (unsigned long) frame;
309	regs->regs[4] = sig; /* Arg for signal handler */
310	regs->regs[5] = 0;
311	regs->regs[6] = (unsigned long) &frame->sc;
312
313	if (current->personality & FDPIC_FUNCPTRS) {
314		struct fdpic_func_descriptor __user *funcptr =
315			(struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;
316
317		err |= __get_user(regs->pc, &funcptr->text);
318		err |= __get_user(regs->regs[12], &funcptr->GOT);
319	} else
320		regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
321
322	if (err)
323		return -EFAULT;
324
325	pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
326		 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
327
328	return 0;
 
 
 
 
329}
330
331static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
332			  struct pt_regs *regs)
333{
334	struct rt_sigframe __user *frame;
335	int err = 0, sig = ksig->sig;
 
336
337	frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));
338
339	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
340		return -EFAULT;
 
 
 
 
 
 
341
342	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
343
344	/* Create the ucontext.  */
345	err |= __put_user(0, &frame->uc.uc_flags);
346	err |= __put_user(NULL, &frame->uc.uc_link);
347	err |= __save_altstack(&frame->uc.uc_stack, regs->regs[15]);
 
 
 
 
348	err |= setup_sigcontext(&frame->uc.uc_mcontext,
349			        regs, set->sig[0]);
350	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
351
352	/* Set up to return from userspace.  If provided, use a stub
353	   already in userspace.  */
354	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
355		regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
356#ifdef CONFIG_VSYSCALL
357	} else if (likely(current->mm->context.vdso)) {
358		regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
359#endif
360	} else {
361		/* Generate return code (system call to rt_sigreturn) */
362		err |= __put_user(MOVW(7), &frame->retcode[0]);
363		err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
364		err |= __put_user(OR_R0_R0, &frame->retcode[2]);
365		err |= __put_user(OR_R0_R0, &frame->retcode[3]);
366		err |= __put_user(OR_R0_R0, &frame->retcode[4]);
367		err |= __put_user(OR_R0_R0, &frame->retcode[5]);
368		err |= __put_user(OR_R0_R0, &frame->retcode[6]);
369		err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
370		regs->pr = (unsigned long) frame->retcode;
371		flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
372	}
373
374	if (err)
375		return -EFAULT;
376
377	/* Set up registers for signal handler */
378	regs->regs[15] = (unsigned long) frame;
379	regs->regs[4] = sig; /* Arg for signal handler */
380	regs->regs[5] = (unsigned long) &frame->info;
381	regs->regs[6] = (unsigned long) &frame->uc;
382
383	if (current->personality & FDPIC_FUNCPTRS) {
384		struct fdpic_func_descriptor __user *funcptr =
385			(struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;
386
387		err |= __get_user(regs->pc, &funcptr->text);
388		err |= __get_user(regs->regs[12], &funcptr->GOT);
389	} else
390		regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
391
392	if (err)
393		return -EFAULT;
394
395	pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
396		 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
397
398	return 0;
 
 
 
 
399}
400
401static inline void
402handle_syscall_restart(unsigned long save_r0, struct pt_regs *regs,
403		       struct sigaction *sa)
404{
405	/* If we're not from a syscall, bail out */
406	if (regs->tra < 0)
407		return;
408
409	/* check for system call restart.. */
410	switch (regs->regs[0]) {
411		case -ERESTART_RESTARTBLOCK:
412		case -ERESTARTNOHAND:
413		no_system_call_restart:
414			regs->regs[0] = -EINTR;
415			break;
416
417		case -ERESTARTSYS:
418			if (!(sa->sa_flags & SA_RESTART))
419				goto no_system_call_restart;
420		/* fallthrough */
421		case -ERESTARTNOINTR:
422			regs->regs[0] = save_r0;
423			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
424			break;
425	}
426}
427
428/*
429 * OK, we're invoking a handler
430 */
431static void
432handle_signal(struct ksignal *ksig, struct pt_regs *regs, unsigned int save_r0)
 
433{
434	sigset_t *oldset = sigmask_to_save();
435	int ret;
436
437	/* Set up the stack frame */
438	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
439		ret = setup_rt_frame(ksig, oldset, regs);
440	else
441		ret = setup_frame(ksig, oldset, regs);
442
443	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
 
 
 
 
 
 
 
 
 
 
 
 
444}
445
446/*
447 * Note that 'init' is a special process: it doesn't get signals it doesn't
448 * want to handle. Thus you cannot kill init even with a SIGKILL even by
449 * mistake.
450 *
451 * Note that we go through the signals twice: once to check the signals that
452 * the kernel can handle, and then we build all the user-level signal handling
453 * stack-frames in one go after that.
454 */
455static void do_signal(struct pt_regs *regs, unsigned int save_r0)
456{
457	struct ksignal ksig;
 
 
 
458
459	/*
460	 * We want the common case to go fast, which
461	 * is why we may in certain cases get here from
462	 * kernel mode. Just return without doing anything
463	 * if so.
464	 */
465	if (!user_mode(regs))
466		return;
467
468	if (get_signal(&ksig)) {
469		handle_syscall_restart(save_r0, regs, &ksig.ka.sa);
 
 
 
 
 
 
 
 
 
470
471		/* Whee!  Actually deliver the signal.  */
472		handle_signal(&ksig, regs, save_r0);
 
 
 
 
 
 
 
 
 
 
 
 
 
473		return;
474	}
475
 
476	/* Did we come from a system call? */
477	if (regs->tra >= 0) {
478		/* Restart the system call - no handlers present */
479		if (regs->regs[0] == -ERESTARTNOHAND ||
480		    regs->regs[0] == -ERESTARTSYS ||
481		    regs->regs[0] == -ERESTARTNOINTR) {
482			regs->regs[0] = save_r0;
483			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
484		} else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
485			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
486			regs->regs[3] = __NR_restart_syscall;
487		}
488	}
489
490	/*
491	 * If there's no signal to deliver, we just put the saved sigmask
492	 * back.
493	 */
494	restore_saved_sigmask();
 
 
 
495}
496
497asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
498				 unsigned long thread_info_flags)
499{
500	/* deal with pending signal delivery */
501	if (thread_info_flags & _TIF_SIGPENDING)
502		do_signal(regs, save_r0);
503
504	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
505		clear_thread_flag(TIF_NOTIFY_RESUME);
506		tracehook_notify_resume(regs);
 
 
507	}
508}
v3.1
  1/*
  2 *  linux/arch/sh/kernel/signal.c
  3 *
  4 *  Copyright (C) 1991, 1992  Linus Torvalds
  5 *
  6 *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
  7 *
  8 *  SuperH version:  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
  9 *
 10 */
 11#include <linux/sched.h>
 12#include <linux/mm.h>
 13#include <linux/smp.h>
 14#include <linux/kernel.h>
 15#include <linux/signal.h>
 16#include <linux/errno.h>
 17#include <linux/wait.h>
 18#include <linux/ptrace.h>
 19#include <linux/unistd.h>
 20#include <linux/stddef.h>
 21#include <linux/tty.h>
 22#include <linux/elf.h>
 23#include <linux/personality.h>
 24#include <linux/binfmts.h>
 25#include <linux/freezer.h>
 26#include <linux/io.h>
 27#include <linux/tracehook.h>
 28#include <asm/system.h>
 29#include <asm/ucontext.h>
 30#include <asm/uaccess.h>
 31#include <asm/pgtable.h>
 32#include <asm/cacheflush.h>
 33#include <asm/syscalls.h>
 34#include <asm/fpu.h>
 35
 36#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 37
 38struct fdpic_func_descriptor {
 39	unsigned long	text;
 40	unsigned long	GOT;
 41};
 42
 43/*
 44 * The following define adds a 64 byte gap between the signal
 45 * stack frame and previous contents of the stack.  This allows
 46 * frame unwinding in a function epilogue but only if a frame
 47 * pointer is used in the function.  This is necessary because
 48 * current gcc compilers (<4.3) do not generate unwind info on
 49 * SH for function epilogues.
 50 */
 51#define UNWINDGUARD 64
 52
 53/*
 54 * Atomically swap in the new signal mask, and wait for a signal.
 55 */
 56asmlinkage int
 57sys_sigsuspend(old_sigset_t mask,
 58	       unsigned long r5, unsigned long r6, unsigned long r7,
 59	       struct pt_regs __regs)
 60{
 61	mask &= _BLOCKABLE;
 62	spin_lock_irq(&current->sighand->siglock);
 63	current->saved_sigmask = current->blocked;
 64	siginitset(&current->blocked, mask);
 65	recalc_sigpending();
 66	spin_unlock_irq(&current->sighand->siglock);
 67
 68	current->state = TASK_INTERRUPTIBLE;
 69	schedule();
 70	set_restore_sigmask();
 71
 72	return -ERESTARTNOHAND;
 73}
 74
 75asmlinkage int
 76sys_sigaction(int sig, const struct old_sigaction __user *act,
 77	      struct old_sigaction __user *oact)
 78{
 79	struct k_sigaction new_ka, old_ka;
 80	int ret;
 81
 82	if (act) {
 83		old_sigset_t mask;
 84		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
 85		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
 86		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
 87			return -EFAULT;
 88		__get_user(new_ka.sa.sa_flags, &act->sa_flags);
 89		__get_user(mask, &act->sa_mask);
 90		siginitset(&new_ka.sa.sa_mask, mask);
 91	}
 92
 93	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 94
 95	if (!ret && oact) {
 96		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
 97		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
 98		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
 99			return -EFAULT;
100		__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
101		__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
102	}
103
104	return ret;
105}
106
107asmlinkage int
108sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
109		unsigned long r6, unsigned long r7,
110		struct pt_regs __regs)
111{
112	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
113
114	return do_sigaltstack(uss, uoss, regs->regs[15]);
115}
116
117
118/*
119 * Do a signal return; undo the signal stack.
120 */
121
122#define MOVW(n)	 (0x9300|((n)-2))	/* Move mem word at PC+n to R3 */
123#if defined(CONFIG_CPU_SH2)
124#define TRAP_NOARG 0xc320		/* Syscall w/no args (NR in R3) */
125#else
126#define TRAP_NOARG 0xc310		/* Syscall w/no args (NR in R3) */
127#endif
128#define OR_R0_R0 0x200b			/* or r0,r0 (insert to avoid hardware bug) */
129
130struct sigframe
131{
132	struct sigcontext sc;
133	unsigned long extramask[_NSIG_WORDS-1];
134	u16 retcode[8];
135};
136
137struct rt_sigframe
138{
139	struct siginfo info;
140	struct ucontext uc;
141	u16 retcode[8];
142};
143
144#ifdef CONFIG_SH_FPU
145static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
146{
147	struct task_struct *tsk = current;
148
149	if (!(boot_cpu_data.flags & CPU_HAS_FPU))
150		return 0;
151
152	set_used_math();
153	return __copy_from_user(&tsk->thread.xstate->hardfpu, &sc->sc_fpregs[0],
154				sizeof(long)*(16*2+2));
155}
156
157static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
158				      struct pt_regs *regs)
159{
160	struct task_struct *tsk = current;
161
162	if (!(boot_cpu_data.flags & CPU_HAS_FPU))
163		return 0;
164
165	if (!used_math()) {
166		__put_user(0, &sc->sc_ownedfp);
167		return 0;
168	}
169
170	__put_user(1, &sc->sc_ownedfp);
 
171
172	/* This will cause a "finit" to be triggered by the next
173	   attempted FPU operation by the 'current' process.
174	   */
175	clear_used_math();
176
177	unlazy_fpu(tsk, regs);
178	return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.xstate->hardfpu,
179			      sizeof(long)*(16*2+2));
180}
181#endif /* CONFIG_SH_FPU */
182
183static int
184restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p)
185{
186	unsigned int err = 0;
187
188#define COPY(x)		err |= __get_user(regs->x, &sc->sc_##x)
189			COPY(regs[1]);
190	COPY(regs[2]);	COPY(regs[3]);
191	COPY(regs[4]);	COPY(regs[5]);
192	COPY(regs[6]);	COPY(regs[7]);
193	COPY(regs[8]);	COPY(regs[9]);
194	COPY(regs[10]);	COPY(regs[11]);
195	COPY(regs[12]);	COPY(regs[13]);
196	COPY(regs[14]);	COPY(regs[15]);
197	COPY(gbr);	COPY(mach);
198	COPY(macl);	COPY(pr);
199	COPY(sr);	COPY(pc);
200#undef COPY
201
202#ifdef CONFIG_SH_FPU
203	if (boot_cpu_data.flags & CPU_HAS_FPU) {
204		int owned_fp;
205		struct task_struct *tsk = current;
206
207		regs->sr |= SR_FD; /* Release FPU */
208		clear_fpu(tsk, regs);
209		clear_used_math();
210		__get_user (owned_fp, &sc->sc_ownedfp);
211		if (owned_fp)
212			err |= restore_sigcontext_fpu(sc);
213	}
214#endif
215
216	regs->tra = -1;		/* disable syscall checks */
217	err |= __get_user(*r0_p, &sc->sc_regs[0]);
218	return err;
219}
220
221asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5,
222			     unsigned long r6, unsigned long r7,
223			     struct pt_regs __regs)
224{
225	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
226	struct sigframe __user *frame = (struct sigframe __user *)regs->regs[15];
227	sigset_t set;
228	int r0;
229
230        /* Always make any pending restarted system calls return -EINTR */
231	current_thread_info()->restart_block.fn = do_no_restart_syscall;
232
233	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
234		goto badframe;
235
236	if (__get_user(set.sig[0], &frame->sc.oldmask)
237	    || (_NSIG_WORDS > 1
238		&& __copy_from_user(&set.sig[1], &frame->extramask,
239				    sizeof(frame->extramask))))
240		goto badframe;
241
242	sigdelsetmask(&set, ~_BLOCKABLE);
243
244	spin_lock_irq(&current->sighand->siglock);
245	current->blocked = set;
246	recalc_sigpending();
247	spin_unlock_irq(&current->sighand->siglock);
248
249	if (restore_sigcontext(regs, &frame->sc, &r0))
250		goto badframe;
251	return r0;
252
253badframe:
254	force_sig(SIGSEGV, current);
255	return 0;
256}
257
258asmlinkage int sys_rt_sigreturn(unsigned long r4, unsigned long r5,
259				unsigned long r6, unsigned long r7,
260				struct pt_regs __regs)
261{
262	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
263	struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->regs[15];
264	sigset_t set;
265	int r0;
266
267	/* Always make any pending restarted system calls return -EINTR */
268	current_thread_info()->restart_block.fn = do_no_restart_syscall;
269
270	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
271		goto badframe;
272
273	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
274		goto badframe;
275
276	sigdelsetmask(&set, ~_BLOCKABLE);
277	spin_lock_irq(&current->sighand->siglock);
278	current->blocked = set;
279	recalc_sigpending();
280	spin_unlock_irq(&current->sighand->siglock);
281
282	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
283		goto badframe;
284
285	if (do_sigaltstack(&frame->uc.uc_stack, NULL,
286			   regs->regs[15]) == -EFAULT)
287		goto badframe;
288
289	return r0;
290
291badframe:
292	force_sig(SIGSEGV, current);
293	return 0;
294}
295
296/*
297 * Set up a signal frame.
298 */
299
300static int
301setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
302		 unsigned long mask)
303{
304	int err = 0;
305
306#define COPY(x)		err |= __put_user(regs->x, &sc->sc_##x)
307	COPY(regs[0]);	COPY(regs[1]);
308	COPY(regs[2]);	COPY(regs[3]);
309	COPY(regs[4]);	COPY(regs[5]);
310	COPY(regs[6]);	COPY(regs[7]);
311	COPY(regs[8]);	COPY(regs[9]);
312	COPY(regs[10]);	COPY(regs[11]);
313	COPY(regs[12]);	COPY(regs[13]);
314	COPY(regs[14]);	COPY(regs[15]);
315	COPY(gbr);	COPY(mach);
316	COPY(macl);	COPY(pr);
317	COPY(sr);	COPY(pc);
318#undef COPY
319
320#ifdef CONFIG_SH_FPU
321	err |= save_sigcontext_fpu(sc, regs);
322#endif
323
324	/* non-iBCS2 extensions.. */
325	err |= __put_user(mask, &sc->oldmask);
326
327	return err;
328}
329
330/*
331 * Determine which stack to use..
332 */
333static inline void __user *
334get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
335{
336	if (ka->sa.sa_flags & SA_ONSTACK) {
337		if (sas_ss_flags(sp) == 0)
338			sp = current->sas_ss_sp + current->sas_ss_size;
339	}
340
341	return (void __user *)((sp - (frame_size+UNWINDGUARD)) & -8ul);
342}
343
344/* These symbols are defined with the addresses in the vsyscall page.
345   See vsyscall-trapa.S.  */
346extern void __kernel_sigreturn(void);
347extern void __kernel_rt_sigreturn(void);
348
349static int setup_frame(int sig, struct k_sigaction *ka,
350			sigset_t *set, struct pt_regs *regs)
351{
352	struct sigframe __user *frame;
353	int err = 0;
354	int signal;
355
356	frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
357
358	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
359		goto give_sigsegv;
360
361	signal = current_thread_info()->exec_domain
362		&& current_thread_info()->exec_domain->signal_invmap
363		&& sig < 32
364		? current_thread_info()->exec_domain->signal_invmap[sig]
365		: sig;
366
367	err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
368
369	if (_NSIG_WORDS > 1)
370		err |= __copy_to_user(frame->extramask, &set->sig[1],
371				      sizeof(frame->extramask));
372
373	/* Set up to return from userspace.  If provided, use a stub
374	   already in userspace.  */
375	if (ka->sa.sa_flags & SA_RESTORER) {
376		regs->pr = (unsigned long) ka->sa.sa_restorer;
377#ifdef CONFIG_VSYSCALL
378	} else if (likely(current->mm->context.vdso)) {
379		regs->pr = VDSO_SYM(&__kernel_sigreturn);
380#endif
381	} else {
382		/* Generate return code (system call to sigreturn) */
383		err |= __put_user(MOVW(7), &frame->retcode[0]);
384		err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
385		err |= __put_user(OR_R0_R0, &frame->retcode[2]);
386		err |= __put_user(OR_R0_R0, &frame->retcode[3]);
387		err |= __put_user(OR_R0_R0, &frame->retcode[4]);
388		err |= __put_user(OR_R0_R0, &frame->retcode[5]);
389		err |= __put_user(OR_R0_R0, &frame->retcode[6]);
390		err |= __put_user((__NR_sigreturn), &frame->retcode[7]);
391		regs->pr = (unsigned long) frame->retcode;
392		flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
393	}
394
395	if (err)
396		goto give_sigsegv;
397
398	/* Set up registers for signal handler */
399	regs->regs[15] = (unsigned long) frame;
400	regs->regs[4] = signal; /* Arg for signal handler */
401	regs->regs[5] = 0;
402	regs->regs[6] = (unsigned long) &frame->sc;
403
404	if (current->personality & FDPIC_FUNCPTRS) {
405		struct fdpic_func_descriptor __user *funcptr =
406			(struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
407
408		__get_user(regs->pc, &funcptr->text);
409		__get_user(regs->regs[12], &funcptr->GOT);
410	} else
411		regs->pc = (unsigned long)ka->sa.sa_handler;
412
413	set_fs(USER_DS);
 
414
415	pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
416		 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
417
418	return 0;
419
420give_sigsegv:
421	force_sigsegv(sig, current);
422	return -EFAULT;
423}
424
425static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
426			   sigset_t *set, struct pt_regs *regs)
427{
428	struct rt_sigframe __user *frame;
429	int err = 0;
430	int signal;
431
432	frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
433
434	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
435		goto give_sigsegv;
436
437	signal = current_thread_info()->exec_domain
438		&& current_thread_info()->exec_domain->signal_invmap
439		&& sig < 32
440		? current_thread_info()->exec_domain->signal_invmap[sig]
441		: sig;
442
443	err |= copy_siginfo_to_user(&frame->info, info);
444
445	/* Create the ucontext.  */
446	err |= __put_user(0, &frame->uc.uc_flags);
447	err |= __put_user(NULL, &frame->uc.uc_link);
448	err |= __put_user((void *)current->sas_ss_sp,
449			  &frame->uc.uc_stack.ss_sp);
450	err |= __put_user(sas_ss_flags(regs->regs[15]),
451			  &frame->uc.uc_stack.ss_flags);
452	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
453	err |= setup_sigcontext(&frame->uc.uc_mcontext,
454			        regs, set->sig[0]);
455	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
456
457	/* Set up to return from userspace.  If provided, use a stub
458	   already in userspace.  */
459	if (ka->sa.sa_flags & SA_RESTORER) {
460		regs->pr = (unsigned long) ka->sa.sa_restorer;
461#ifdef CONFIG_VSYSCALL
462	} else if (likely(current->mm->context.vdso)) {
463		regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
464#endif
465	} else {
466		/* Generate return code (system call to rt_sigreturn) */
467		err |= __put_user(MOVW(7), &frame->retcode[0]);
468		err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
469		err |= __put_user(OR_R0_R0, &frame->retcode[2]);
470		err |= __put_user(OR_R0_R0, &frame->retcode[3]);
471		err |= __put_user(OR_R0_R0, &frame->retcode[4]);
472		err |= __put_user(OR_R0_R0, &frame->retcode[5]);
473		err |= __put_user(OR_R0_R0, &frame->retcode[6]);
474		err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
475		regs->pr = (unsigned long) frame->retcode;
476		flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
477	}
478
479	if (err)
480		goto give_sigsegv;
481
482	/* Set up registers for signal handler */
483	regs->regs[15] = (unsigned long) frame;
484	regs->regs[4] = signal; /* Arg for signal handler */
485	regs->regs[5] = (unsigned long) &frame->info;
486	regs->regs[6] = (unsigned long) &frame->uc;
487
488	if (current->personality & FDPIC_FUNCPTRS) {
489		struct fdpic_func_descriptor __user *funcptr =
490			(struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
491
492		__get_user(regs->pc, &funcptr->text);
493		__get_user(regs->regs[12], &funcptr->GOT);
494	} else
495		regs->pc = (unsigned long)ka->sa.sa_handler;
496
497	set_fs(USER_DS);
 
498
499	pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
500		 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
501
502	return 0;
503
504give_sigsegv:
505	force_sigsegv(sig, current);
506	return -EFAULT;
507}
508
509static inline void
510handle_syscall_restart(unsigned long save_r0, struct pt_regs *regs,
511		       struct sigaction *sa)
512{
513	/* If we're not from a syscall, bail out */
514	if (regs->tra < 0)
515		return;
516
517	/* check for system call restart.. */
518	switch (regs->regs[0]) {
519		case -ERESTART_RESTARTBLOCK:
520		case -ERESTARTNOHAND:
521		no_system_call_restart:
522			regs->regs[0] = -EINTR;
523			break;
524
525		case -ERESTARTSYS:
526			if (!(sa->sa_flags & SA_RESTART))
527				goto no_system_call_restart;
528		/* fallthrough */
529		case -ERESTARTNOINTR:
530			regs->regs[0] = save_r0;
531			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
532			break;
533	}
534}
535
536/*
537 * OK, we're invoking a handler
538 */
539static int
540handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
541	      sigset_t *oldset, struct pt_regs *regs, unsigned int save_r0)
542{
 
543	int ret;
544
545	/* Set up the stack frame */
546	if (ka->sa.sa_flags & SA_SIGINFO)
547		ret = setup_rt_frame(sig, ka, info, oldset, regs);
548	else
549		ret = setup_frame(sig, ka, oldset, regs);
550
551	if (ka->sa.sa_flags & SA_ONESHOT)
552		ka->sa.sa_handler = SIG_DFL;
553
554	if (ret == 0) {
555		spin_lock_irq(&current->sighand->siglock);
556		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
557		if (!(ka->sa.sa_flags & SA_NODEFER))
558			sigaddset(&current->blocked,sig);
559		recalc_sigpending();
560		spin_unlock_irq(&current->sighand->siglock);
561	}
562
563	return ret;
564}
565
566/*
567 * Note that 'init' is a special process: it doesn't get signals it doesn't
568 * want to handle. Thus you cannot kill init even with a SIGKILL even by
569 * mistake.
570 *
571 * Note that we go through the signals twice: once to check the signals that
572 * the kernel can handle, and then we build all the user-level signal handling
573 * stack-frames in one go after that.
574 */
575static void do_signal(struct pt_regs *regs, unsigned int save_r0)
576{
577	siginfo_t info;
578	int signr;
579	struct k_sigaction ka;
580	sigset_t *oldset;
581
582	/*
583	 * We want the common case to go fast, which
584	 * is why we may in certain cases get here from
585	 * kernel mode. Just return without doing anything
586	 * if so.
587	 */
588	if (!user_mode(regs))
589		return;
590
591	if (try_to_freeze())
592		goto no_signal;
593
594	if (current_thread_info()->status & TS_RESTORE_SIGMASK)
595		oldset = &current->saved_sigmask;
596	else
597		oldset = &current->blocked;
598
599	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
600	if (signr > 0) {
601		handle_syscall_restart(save_r0, regs, &ka.sa);
602
603		/* Whee!  Actually deliver the signal.  */
604		if (handle_signal(signr, &ka, &info, oldset,
605				  regs, save_r0) == 0) {
606			/*
607			 * A signal was successfully delivered; the saved
608			 * sigmask will have been stored in the signal frame,
609			 * and will be restored by sigreturn, so we can simply
610			 * clear the TS_RESTORE_SIGMASK flag
611			 */
612			current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
613
614			tracehook_signal_handler(signr, &info, &ka, regs,
615					test_thread_flag(TIF_SINGLESTEP));
616		}
617
618		return;
619	}
620
621no_signal:
622	/* Did we come from a system call? */
623	if (regs->tra >= 0) {
624		/* Restart the system call - no handlers present */
625		if (regs->regs[0] == -ERESTARTNOHAND ||
626		    regs->regs[0] == -ERESTARTSYS ||
627		    regs->regs[0] == -ERESTARTNOINTR) {
628			regs->regs[0] = save_r0;
629			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
630		} else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
631			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
632			regs->regs[3] = __NR_restart_syscall;
633		}
634	}
635
636	/*
637	 * If there's no signal to deliver, we just put the saved sigmask
638	 * back.
639	 */
640	if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
641		current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
642		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
643	}
644}
645
646asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
647				 unsigned long thread_info_flags)
648{
649	/* deal with pending signal delivery */
650	if (thread_info_flags & _TIF_SIGPENDING)
651		do_signal(regs, save_r0);
652
653	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
654		clear_thread_flag(TIF_NOTIFY_RESUME);
655		tracehook_notify_resume(regs);
656		if (current->replacement_session_keyring)
657			key_replace_session_keyring();
658	}
659}