[mirror_ubuntu-zesty-kernel.git] / arch / m32r / kernel / signal.c

/*
 *  linux/arch/m32r/kernel/signal.c
 *
 *  Copyright (c) 2003  Hitoshi Yamamoto
 *
 *  Taken from i386 version.
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
 *  2000-06-20  Pentium III FXSR, SSE support by Gareth Hughes
 */

#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/tracehook.h>
#include <asm/cacheflush.h>
#include <asm/ucontext.h>
#include <linux/uaccess.h>

#define DEBUG_SIG 0

/*
 * Do a signal return; undo the signal stack.
 */

struct rt_sigframe
{
	int sig;
	struct siginfo __user *pinfo;
	void __user *puc;
	struct siginfo info;
	struct ucontext uc;
//	struct _fpstate fpstate;
};

static int
restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
		   int *r0_p)
{
	unsigned int err = 0;

	/* Always make any pending restarted system calls return -EINTR */
	current->restart_block.fn = do_no_restart_syscall;

#define COPY(x)		err |= __get_user(regs->x, &sc->sc_##x)
	COPY(r4);
	COPY(r5);
	COPY(r6);
	COPY(pt_regs);
	/* COPY(r0); Skip r0 */
	COPY(r1);
	COPY(r2);
	COPY(r3);
	COPY(r7);
	COPY(r8);
	COPY(r9);
	COPY(r10);
	COPY(r11);
	COPY(r12);
	COPY(acc0h);
	COPY(acc0l);
	COPY(acc1h);		/* ISA_DSP_LEVEL2 only */
	COPY(acc1l);		/* ISA_DSP_LEVEL2 only */
	COPY(psw);
	COPY(bpc);
	COPY(bbpsw);
	COPY(bbpc);
	COPY(spu);
	COPY(fp);
	COPY(lr);
	COPY(spi);
#undef COPY

	regs->syscall_nr = -1;	/* disable syscall checks */
	err |= __get_user(*r0_p, &sc->sc_r0);

	return err;
}

asmlinkage int
sys_rt_sigreturn(unsigned long r0, unsigned long r1,
		 unsigned long r2, unsigned long r3, unsigned long r4,
		 unsigned long r5, unsigned long r6, struct pt_regs *regs)
{
	struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
	sigset_t set;
	int result;

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
		goto badframe;

	set_current_blocked(&set);

	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
		goto badframe;

	if (restore_altstack(&frame->uc.uc_stack))
		goto badframe;

	return result;

badframe:
	force_sig(SIGSEGV, current);
	return 0;
}

/*
 * Set up a signal frame.
 */

static int
setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
	         unsigned long mask)
{
	int err = 0;

#define COPY(x)	err |= __put_user(regs->x, &sc->sc_##x)
	COPY(r4);
	COPY(r5);
	COPY(r6);
	COPY(pt_regs);
	COPY(r0);
	COPY(r1);
	COPY(r2);
	COPY(r3);
	COPY(r7);
	COPY(r8);
	COPY(r9);
	COPY(r10);
	COPY(r11);
	COPY(r12);
	COPY(acc0h);
	COPY(acc0l);
	COPY(acc1h);		/* ISA_DSP_LEVEL2 only */
	COPY(acc1l);		/* ISA_DSP_LEVEL2 only */
	COPY(psw);
	COPY(bpc);
	COPY(bbpsw);
	COPY(bbpc);
	COPY(spu);
	COPY(fp);
	COPY(lr);
	COPY(spi);
#undef COPY

	err |= __put_user(mask, &sc->oldmask);

	return err;
}

/*
 * Determine which stack to use..
 */
static inline void __user *
get_sigframe(struct ksignal *ksig, unsigned long sp, size_t frame_size)
{
	return (void __user *)((sigsp(sp, ksig) - frame_size) & -8ul);
}

static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
			  struct pt_regs *regs)
{
	struct rt_sigframe __user *frame;
	int err = 0;
	int sig = ksig->sig;

	frame = get_sigframe(ksig, regs->spu, sizeof(*frame));

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		return -EFAULT;

	err |= __put_user(sig, &frame->sig);
	if (err)
		return -EFAULT;

	err |= __put_user(&frame->info, &frame->pinfo);
	err |= __put_user(&frame->uc, &frame->puc);
	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
	if (err)
		return -EFAULT;

	/* Create the ucontext.  */
	err |= __put_user(0, &frame->uc.uc_flags);
	err |= __put_user(0, &frame->uc.uc_link);
	err |= __save_altstack(&frame->uc.uc_stack, regs->spu);
	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	if (err)
		return -EFAULT;

	/* Set up to return from userspace.  */
	regs->lr = (unsigned long)ksig->ka.sa.sa_restorer;

	/* Set up registers for signal handler */
	regs->spu = (unsigned long)frame;
	regs->r0 = sig;	/* Arg for signal handler */
	regs->r1 = (unsigned long)&frame->info;
	regs->r2 = (unsigned long)&frame->uc;
	regs->bpc = (unsigned long)ksig->ka.sa.sa_handler;

#if DEBUG_SIG
	printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
		current->comm, current->pid, frame, regs->pc);
#endif

	return 0;
}

static int prev_insn(struct pt_regs *regs)
{
	u16 inst;
	if (get_user(inst, (u16 __user *)(regs->bpc - 2)))
		return -EFAULT;
	if ((inst & 0xfff0) == 0x10f0)	/* trap ? */
		regs->bpc -= 2;
	else
		regs->bpc -= 4;
	regs->syscall_nr = -1;
	return 0;
}

/*
 * OK, we're invoking a handler
 */

static void
handle_signal(struct ksignal *ksig, struct pt_regs *regs)
{
	int ret;

	/* Are we from a system call? */
	if (regs->syscall_nr >= 0) {
		/* If so, check system call restarting.. */
		switch (regs->r0) {
		        case -ERESTART_RESTARTBLOCK:
			case -ERESTARTNOHAND:
				regs->r0 = -EINTR;
				break;

			case -ERESTARTSYS:
				if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
					regs->r0 = -EINTR;
					break;
				}
			/* fallthrough */
			case -ERESTARTNOINTR:
				regs->r0 = regs->orig_r0;
				if (prev_insn(regs) < 0)
					return;
		}
	}

	/* Set up the stack frame */
	ret = setup_rt_frame(ksig, sigmask_to_save(), regs);

	signal_setup_done(ret, ksig, 0);
}

/*
 * Note that 'init' is a special process: it doesn't get signals it doesn't
 * want to handle. Thus you cannot kill init even with a SIGKILL even by
 * mistake.
 */
static void do_signal(struct pt_regs *regs)
{
	struct ksignal ksig;

	/*
	 * We want the common case to go fast, which
	 * is why we may in certain cases get here from
	 * kernel mode. Just return without doing anything
	 * if so.
	 */
	if (!user_mode(regs))
		return;

	if (get_signal(&ksig)) {
		/* Re-enable any watchpoints before delivering the
		 * signal to user space. The processor register will
		 * have been cleared if the watchpoint triggered
		 * inside the kernel.
		 */

		/* Whee!  Actually deliver the signal.  */
		handle_signal(&ksig, regs);

		return;
	}

	/* Did we come from a system call? */
	if (regs->syscall_nr >= 0) {
		/* Restart the system call - no handlers present */
		if (regs->r0 == -ERESTARTNOHAND ||
		    regs->r0 == -ERESTARTSYS ||
		    regs->r0 == -ERESTARTNOINTR) {
			regs->r0 = regs->orig_r0;
			prev_insn(regs);
		} else if (regs->r0 == -ERESTART_RESTARTBLOCK){
			regs->r0 = regs->orig_r0;
			regs->r7 = __NR_restart_syscall;
			prev_insn(regs);
		}
	}
	restore_saved_sigmask();
}

/*
 * notification of userspace execution resumption
 * - triggered by current->work.notify_resume
 */
void do_notify_resume(struct pt_regs *regs, __u32 thread_info_flags)
{
	/* Pending single-step? */
	if (thread_info_flags & _TIF_SINGLESTEP)
		clear_thread_flag(TIF_SINGLESTEP);

	/* deal with pending signal delivery */
	if (thread_info_flags & _TIF_SIGPENDING)
		do_signal(regs);

	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
		clear_thread_flag(TIF_NOTIFY_RESUME);
		tracehook_notify_resume(regs);
	}
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/m32r/kernel/signal.c
	3	*
	4	* Copyright (c) 2003 Hitoshi Yamamoto
	5	*
	6	* Taken from i386 version.
	7	* Copyright (C) 1991, 1992 Linus Torvalds
	8	*
	9	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	10	* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
	11	*/
	12
1da177e4 LT	13	#include <linux/sched.h>
	14	#include <linux/mm.h>
	15	#include <linux/smp.h>
1da177e4 LT	16	#include <linux/kernel.h>
	17	#include <linux/signal.h>
	18	#include <linux/errno.h>
	19	#include <linux/wait.h>
	20	#include <linux/unistd.h>
	21	#include <linux/stddef.h>
	22	#include <linux/personality.h>
733e5e4b	23	#include <linux/tracehook.h>
1da177e4 LT	24	#include <asm/cacheflush.h>
1da177e4 LT	25	#include <asm/ucontext.h>
7c0f6ba6	26	#include <linux/uaccess.h>
1da177e4 LT	27
	28	#define DEBUG_SIG 0
	29
1da177e4 LT	30	/*
	31	* Do a signal return; undo the signal stack.
	32	*/
	33
	34	struct rt_sigframe
	35	{
	36	int sig;
870e75a2 AV	37	struct siginfo __user *pinfo;
870e75a2 AV	38	void __user *puc;
1da177e4 LT	39	struct siginfo info;
	40	struct ucontext uc;
	41	// struct _fpstate fpstate;
	42	};
	43
	44	static int
	45	restore_sigcontext(struct pt_regs regs, struct sigcontext __user sc,
	46	int *r0_p)
	47	{
	48	unsigned int err = 0;
	49
	50	/* Always make any pending restarted system calls return -EINTR */
f56141e3	51	current->restart_block.fn = do_no_restart_syscall;
1da177e4 LT	52
	53	#define COPY(x) err \|= __get_user(regs->x, &sc->sc_##x)
	54	COPY(r4);
	55	COPY(r5);
	56	COPY(r6);
	57	COPY(pt_regs);
	58	/* COPY(r0); Skip r0 */
	59	COPY(r1);
	60	COPY(r2);
	61	COPY(r3);
	62	COPY(r7);
	63	COPY(r8);
	64	COPY(r9);
	65	COPY(r10);
	66	COPY(r11);
	67	COPY(r12);
1da177e4 LT	68	COPY(acc0h);
1da177e4 LT	69	COPY(acc0l);
9674dcf7 HT	70	COPY(acc1h); /* ISA_DSP_LEVEL2 only */
9674dcf7 HT	71	COPY(acc1l); /* ISA_DSP_LEVEL2 only */
1da177e4 LT	72	COPY(psw);
	73	COPY(bpc);
	74	COPY(bbpsw);
	75	COPY(bbpc);
	76	COPY(spu);
	77	COPY(fp);
	78	COPY(lr);
	79	COPY(spi);
	80	#undef COPY
	81
	82	regs->syscall_nr = -1; /* disable syscall checks */
	83	err \|= __get_user(*r0_p, &sc->sc_r0);
	84
	85	return err;
	86	}
	87
	88	asmlinkage int
	89	sys_rt_sigreturn(unsigned long r0, unsigned long r1,
	90	unsigned long r2, unsigned long r3, unsigned long r4,
6ced13cd	91	unsigned long r5, unsigned long r6, struct pt_regs *regs)
1da177e4	92	{
6ced13cd	93	struct rt_sigframe __user frame = (struct rt_sigframe __user )regs->spu;
1da177e4	94	sigset_t set;
1da177e4 LT	95	int result;
	96
	97	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	98	goto badframe;
	99	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	100	goto badframe;
	101
3883e301	102	set_current_blocked(&set);
1da177e4	103
6ced13cd	104	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
1da177e4 LT	105	goto badframe;
1da177e4 LT	106
1084f751	107	if (restore_altstack(&frame->uc.uc_stack))
1da177e4	108	goto badframe;
1da177e4 LT	109
	110	return result;
	111
	112	badframe:
	113	force_sig(SIGSEGV, current);
	114	return 0;
	115	}
	116
	117	/*
	118	* Set up a signal frame.
	119	*/
	120
	121	static int
	122	setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs,
	123	unsigned long mask)
	124	{
	125	int err = 0;
	126
	127	#define COPY(x) err \|= __put_user(regs->x, &sc->sc_##x)
	128	COPY(r4);
	129	COPY(r5);
	130	COPY(r6);
	131	COPY(pt_regs);
	132	COPY(r0);
	133	COPY(r1);
	134	COPY(r2);
	135	COPY(r3);
	136	COPY(r7);
	137	COPY(r8);
	138	COPY(r9);
	139	COPY(r10);
	140	COPY(r11);
	141	COPY(r12);
1da177e4 LT	142	COPY(acc0h);
1da177e4 LT	143	COPY(acc0l);
9674dcf7 HT	144	COPY(acc1h); /* ISA_DSP_LEVEL2 only */
9674dcf7 HT	145	COPY(acc1l); /* ISA_DSP_LEVEL2 only */
1da177e4 LT	146	COPY(psw);
	147	COPY(bpc);
	148	COPY(bbpsw);
	149	COPY(bbpc);
	150	COPY(spu);
	151	COPY(fp);
	152	COPY(lr);
	153	COPY(spi);
	154	#undef COPY
	155
	156	err \|= __put_user(mask, &sc->oldmask);
	157
	158	return err;
	159	}
	160
	161	/*
	162	* Determine which stack to use..
	163	*/
	164	static inline void __user *
5c0806fa	165	get_sigframe(struct ksignal *ksig, unsigned long sp, size_t frame_size)
1da177e4	166	{
5c0806fa	167	return (void __user *)((sigsp(sp, ksig) - frame_size) & -8ul);
1da177e4 LT	168	}
1da177e4 LT	169
0f5bef66 RW	170	static int setup_rt_frame(struct ksignal ksig, sigset_t set,
0f5bef66 RW	171	struct pt_regs *regs)
1da177e4 LT	172	{
	173	struct rt_sigframe __user *frame;
	174	int err = 0;
445a626a	175	int sig = ksig->sig;
1da177e4	176
5c0806fa	177	frame = get_sigframe(ksig, regs->spu, sizeof(*frame));
1da177e4 LT	178
1da177e4 LT	179	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
0f5bef66	180	return -EFAULT;
1da177e4	181
445a626a	182	err \|= __put_user(sig, &frame->sig);
1da177e4	183	if (err)
0f5bef66	184	return -EFAULT;
1da177e4 LT	185
	186	err \|= __put_user(&frame->info, &frame->pinfo);
	187	err \|= __put_user(&frame->uc, &frame->puc);
0f5bef66	188	err \|= copy_siginfo_to_user(&frame->info, &ksig->info);
1da177e4	189	if (err)
0f5bef66	190	return -EFAULT;
1da177e4 LT	191
	192	/* Create the ucontext. */
	193	err \|= __put_user(0, &frame->uc.uc_flags);
	194	err \|= __put_user(0, &frame->uc.uc_link);
1084f751	195	err \|= __save_altstack(&frame->uc.uc_stack, regs->spu);
1da177e4 LT	196	err \|= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
	197	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	198	if (err)
0f5bef66	199	return -EFAULT;
1da177e4 LT	200
1da177e4 LT	201	/* Set up to return from userspace. */
0f5bef66	202	regs->lr = (unsigned long)ksig->ka.sa.sa_restorer;
1da177e4 LT	203
	204	/* Set up registers for signal handler */
	205	regs->spu = (unsigned long)frame;
445a626a	206	regs->r0 = sig; /* Arg for signal handler */
1da177e4 LT	207	regs->r1 = (unsigned long)&frame->info;
1da177e4 LT	208	regs->r2 = (unsigned long)&frame->uc;
0f5bef66	209	regs->bpc = (unsigned long)ksig->ka.sa.sa_handler;
1da177e4	210
1da177e4 LT	211	#if DEBUG_SIG
	212	printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
	213	current->comm, current->pid, frame, regs->pc);
	214	#endif
	215
a05c4e1d	216	return 0;
1da177e4 LT	217	}
1da177e4 LT	218
bb9c861e AV	219	static int prev_insn(struct pt_regs *regs)
	220	{
	221	u16 inst;
388d148f	222	if (get_user(inst, (u16 __user *)(regs->bpc - 2)))
bb9c861e AV	223	return -EFAULT;
	224	if ((inst & 0xfff0) == 0x10f0) /* trap ? */
	225	regs->bpc -= 2;
	226	else
	227	regs->bpc -= 4;
	228	regs->syscall_nr = -1;
	229	return 0;
	230	}
	231
1da177e4 LT	232	/*
	233	* OK, we're invoking a handler
	234	*/
	235
a610d6e6	236	static void
0f5bef66	237	handle_signal(struct ksignal ksig, struct pt_regs regs)
1da177e4	238	{
0f5bef66 RW	239	int ret;
0f5bef66 RW	240
1da177e4 LT	241	/* Are we from a system call? */
	242	if (regs->syscall_nr >= 0) {
	243	/* If so, check system call restarting.. */
	244	switch (regs->r0) {
	245	case -ERESTART_RESTARTBLOCK:
	246	case -ERESTARTNOHAND:
	247	regs->r0 = -EINTR;
	248	break;
	249
	250	case -ERESTARTSYS:
0f5bef66	251	if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
1da177e4 LT	252	regs->r0 = -EINTR;
	253	break;
	254	}
	255	/* fallthrough */
	256	case -ERESTARTNOINTR:
	257	regs->r0 = regs->orig_r0;
bb9c861e	258	if (prev_insn(regs) < 0)
f9717f31	259	return;
1da177e4 LT	260	}
	261	}
	262
	263	/* Set up the stack frame */
0f5bef66	264	ret = setup_rt_frame(ksig, sigmask_to_save(), regs);
1da177e4	265
0f5bef66	266	signal_setup_done(ret, ksig, 0);
1da177e4 LT	267	}
	268
	269	/*
	270	* Note that 'init' is a special process: it doesn't get signals it doesn't
	271	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	272	* mistake.
	273	*/
a05c4e1d	274	static void do_signal(struct pt_regs *regs)
1da177e4	275	{
0f5bef66	276	struct ksignal ksig;
1da177e4 LT	277
	278	/*
	279	* We want the common case to go fast, which
	280	* is why we may in certain cases get here from
	281	* kernel mode. Just return without doing anything
	282	* if so.
	283	*/
	284	if (!user_mode(regs))
a05c4e1d	285	return;
1da177e4	286
0f5bef66	287	if (get_signal(&ksig)) {
5aa8b6c1	288	/* Re-enable any watchpoints before delivering the
1da177e4 LT	289	* signal to user space. The processor register will
	290	* have been cleared if the watchpoint triggered
	291	* inside the kernel.
	292	*/
	293
	294	/* Whee! Actually deliver the signal. */
0f5bef66	295	handle_signal(&ksig, regs);
a05c4e1d AV	296
a05c4e1d AV	297	return;
1da177e4 LT	298	}
1da177e4 LT	299
1da177e4 LT	300	/* Did we come from a system call? */
	301	if (regs->syscall_nr >= 0) {
	302	/* Restart the system call - no handlers present */
	303	if (regs->r0 == -ERESTARTNOHAND \|\|
	304	regs->r0 == -ERESTARTSYS \|\|
	305	regs->r0 == -ERESTARTNOINTR) {
	306	regs->r0 = regs->orig_r0;
bb9c861e	307	prev_insn(regs);
a7481024	308	} else if (regs->r0 == -ERESTART_RESTARTBLOCK){
1da177e4 LT	309	regs->r0 = regs->orig_r0;
1da177e4 LT	310	regs->r7 = __NR_restart_syscall;
bb9c861e	311	prev_insn(regs);
1da177e4 LT	312	}
1da177e4 LT	313	}
51a7b448	314	restore_saved_sigmask();
1da177e4 LT	315	}
	316
	317	/*
	318	* notification of userspace execution resumption
	319	* - triggered by current->work.notify_resume
	320	*/
a7f8388e	321	void do_notify_resume(struct pt_regs *regs, __u32 thread_info_flags)
1da177e4 LT	322	{
	323	/* Pending single-step? */
	324	if (thread_info_flags & _TIF_SINGLESTEP)
	325	clear_thread_flag(TIF_SINGLESTEP);
	326
	327	/* deal with pending signal delivery */
	328	if (thread_info_flags & _TIF_SIGPENDING)
a7f8388e	329	do_signal(regs);
1da177e4	330
d0420c83 DH	331	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
	332	clear_thread_flag(TIF_NOTIFY_RESUME);
	333	tracehook_notify_resume(regs);
	334	}
1da177e4	335	}