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

// SPDX-License-Identifier: GPL-2.0
/*
 *  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
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* linux/arch/m32r/kernel/signal.c
	4	*
	5	* Copyright (c) 2003 Hitoshi Yamamoto
	6	*
	7	* Taken from i386 version.
	8	* Copyright (C) 1991, 1992 Linus Torvalds
	9	*
	10	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	11	* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
	12	*/
	13
1da177e4 LT	14	#include <linux/sched.h>
	15	#include <linux/mm.h>
	16	#include <linux/smp.h>
1da177e4 LT	17	#include <linux/kernel.h>
	18	#include <linux/signal.h>
	19	#include <linux/errno.h>
	20	#include <linux/wait.h>
	21	#include <linux/unistd.h>
	22	#include <linux/stddef.h>
	23	#include <linux/personality.h>
733e5e4b	24	#include <linux/tracehook.h>
1da177e4 LT	25	#include <asm/cacheflush.h>
1da177e4 LT	26	#include <asm/ucontext.h>
7c0f6ba6	27	#include <linux/uaccess.h>
1da177e4 LT	28
	29	#define DEBUG_SIG 0
	30
1da177e4 LT	31	/*
	32	* Do a signal return; undo the signal stack.
	33	*/
	34
	35	struct rt_sigframe
	36	{
	37	int sig;
870e75a2 AV	38	struct siginfo __user *pinfo;
870e75a2 AV	39	void __user *puc;
1da177e4 LT	40	struct siginfo info;
	41	struct ucontext uc;
	42	// struct _fpstate fpstate;
	43	};
	44
	45	static int
	46	restore_sigcontext(struct pt_regs regs, struct sigcontext __user sc,
	47	int *r0_p)
	48	{
	49	unsigned int err = 0;
	50
	51	/* Always make any pending restarted system calls return -EINTR */
f56141e3	52	current->restart_block.fn = do_no_restart_syscall;
1da177e4 LT	53
	54	#define COPY(x) err \|= __get_user(regs->x, &sc->sc_##x)
	55	COPY(r4);
	56	COPY(r5);
	57	COPY(r6);
	58	COPY(pt_regs);
	59	/* COPY(r0); Skip r0 */
	60	COPY(r1);
	61	COPY(r2);
	62	COPY(r3);
	63	COPY(r7);
	64	COPY(r8);
	65	COPY(r9);
	66	COPY(r10);
	67	COPY(r11);
	68	COPY(r12);
1da177e4 LT	69	COPY(acc0h);
1da177e4 LT	70	COPY(acc0l);
9674dcf7 HT	71	COPY(acc1h); /* ISA_DSP_LEVEL2 only */
9674dcf7 HT	72	COPY(acc1l); /* ISA_DSP_LEVEL2 only */
1da177e4 LT	73	COPY(psw);
	74	COPY(bpc);
	75	COPY(bbpsw);
	76	COPY(bbpc);
	77	COPY(spu);
	78	COPY(fp);
	79	COPY(lr);
	80	COPY(spi);
	81	#undef COPY
	82
	83	regs->syscall_nr = -1; /* disable syscall checks */
	84	err \|= __get_user(*r0_p, &sc->sc_r0);
	85
	86	return err;
	87	}
	88
	89	asmlinkage int
	90	sys_rt_sigreturn(unsigned long r0, unsigned long r1,
	91	unsigned long r2, unsigned long r3, unsigned long r4,
6ced13cd	92	unsigned long r5, unsigned long r6, struct pt_regs *regs)
1da177e4	93	{
6ced13cd	94	struct rt_sigframe __user frame = (struct rt_sigframe __user )regs->spu;
1da177e4	95	sigset_t set;
1da177e4 LT	96	int result;
	97
	98	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	99	goto badframe;
	100	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	101	goto badframe;
	102
3883e301	103	set_current_blocked(&set);
1da177e4	104
6ced13cd	105	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
1da177e4 LT	106	goto badframe;
1da177e4 LT	107
1084f751	108	if (restore_altstack(&frame->uc.uc_stack))
1da177e4	109	goto badframe;
1da177e4 LT	110
	111	return result;
	112
	113	badframe:
	114	force_sig(SIGSEGV, current);
	115	return 0;
	116	}
	117
	118	/*
	119	* Set up a signal frame.
	120	*/
	121
	122	static int
	123	setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs,
	124	unsigned long mask)
	125	{
	126	int err = 0;
	127
	128	#define COPY(x) err \|= __put_user(regs->x, &sc->sc_##x)
	129	COPY(r4);
	130	COPY(r5);
	131	COPY(r6);
	132	COPY(pt_regs);
	133	COPY(r0);
	134	COPY(r1);
	135	COPY(r2);
	136	COPY(r3);
	137	COPY(r7);
	138	COPY(r8);
	139	COPY(r9);
	140	COPY(r10);
	141	COPY(r11);
	142	COPY(r12);
1da177e4 LT	143	COPY(acc0h);
1da177e4 LT	144	COPY(acc0l);
9674dcf7 HT	145	COPY(acc1h); /* ISA_DSP_LEVEL2 only */
9674dcf7 HT	146	COPY(acc1l); /* ISA_DSP_LEVEL2 only */
1da177e4 LT	147	COPY(psw);
	148	COPY(bpc);
	149	COPY(bbpsw);
	150	COPY(bbpc);
	151	COPY(spu);
	152	COPY(fp);
	153	COPY(lr);
	154	COPY(spi);
	155	#undef COPY
	156
	157	err \|= __put_user(mask, &sc->oldmask);
	158
	159	return err;
	160	}
	161
	162	/*
	163	* Determine which stack to use..
	164	*/
	165	static inline void __user *
5c0806fa	166	get_sigframe(struct ksignal *ksig, unsigned long sp, size_t frame_size)
1da177e4	167	{
5c0806fa	168	return (void __user *)((sigsp(sp, ksig) - frame_size) & -8ul);
1da177e4 LT	169	}
1da177e4 LT	170
0f5bef66 RW	171	static int setup_rt_frame(struct ksignal ksig, sigset_t set,
0f5bef66 RW	172	struct pt_regs *regs)
1da177e4 LT	173	{
	174	struct rt_sigframe __user *frame;
	175	int err = 0;
445a626a	176	int sig = ksig->sig;
1da177e4	177
5c0806fa	178	frame = get_sigframe(ksig, regs->spu, sizeof(*frame));
1da177e4 LT	179
1da177e4 LT	180	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
0f5bef66	181	return -EFAULT;
1da177e4	182
445a626a	183	err \|= __put_user(sig, &frame->sig);
1da177e4	184	if (err)
0f5bef66	185	return -EFAULT;
1da177e4 LT	186
	187	err \|= __put_user(&frame->info, &frame->pinfo);
	188	err \|= __put_user(&frame->uc, &frame->puc);
0f5bef66	189	err \|= copy_siginfo_to_user(&frame->info, &ksig->info);
1da177e4	190	if (err)
0f5bef66	191	return -EFAULT;
1da177e4 LT	192
	193	/* Create the ucontext. */
	194	err \|= __put_user(0, &frame->uc.uc_flags);
	195	err \|= __put_user(0, &frame->uc.uc_link);
1084f751	196	err \|= __save_altstack(&frame->uc.uc_stack, regs->spu);
1da177e4 LT	197	err \|= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
	198	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	199	if (err)
0f5bef66	200	return -EFAULT;
1da177e4 LT	201
1da177e4 LT	202	/* Set up to return from userspace. */
0f5bef66	203	regs->lr = (unsigned long)ksig->ka.sa.sa_restorer;
1da177e4 LT	204
	205	/* Set up registers for signal handler */
	206	regs->spu = (unsigned long)frame;
445a626a	207	regs->r0 = sig; /* Arg for signal handler */
1da177e4 LT	208	regs->r1 = (unsigned long)&frame->info;
1da177e4 LT	209	regs->r2 = (unsigned long)&frame->uc;
0f5bef66	210	regs->bpc = (unsigned long)ksig->ka.sa.sa_handler;
1da177e4	211
1da177e4 LT	212	#if DEBUG_SIG
	213	printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
	214	current->comm, current->pid, frame, regs->pc);
	215	#endif
	216
a05c4e1d	217	return 0;
1da177e4 LT	218	}
1da177e4 LT	219
bb9c861e AV	220	static int prev_insn(struct pt_regs *regs)
	221	{
	222	u16 inst;
388d148f	223	if (get_user(inst, (u16 __user *)(regs->bpc - 2)))
bb9c861e AV	224	return -EFAULT;
	225	if ((inst & 0xfff0) == 0x10f0) /* trap ? */
	226	regs->bpc -= 2;
	227	else
	228	regs->bpc -= 4;
	229	regs->syscall_nr = -1;
	230	return 0;
	231	}
	232
1da177e4 LT	233	/*
	234	* OK, we're invoking a handler
	235	*/
	236
a610d6e6	237	static void
0f5bef66	238	handle_signal(struct ksignal ksig, struct pt_regs regs)
1da177e4	239	{
0f5bef66 RW	240	int ret;
0f5bef66 RW	241
1da177e4 LT	242	/* Are we from a system call? */
	243	if (regs->syscall_nr >= 0) {
	244	/* If so, check system call restarting.. */
	245	switch (regs->r0) {
	246	case -ERESTART_RESTARTBLOCK:
	247	case -ERESTARTNOHAND:
	248	regs->r0 = -EINTR;
	249	break;
	250
	251	case -ERESTARTSYS:
0f5bef66	252	if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
1da177e4 LT	253	regs->r0 = -EINTR;
	254	break;
	255	}
	256	/* fallthrough */
	257	case -ERESTARTNOINTR:
	258	regs->r0 = regs->orig_r0;
bb9c861e	259	if (prev_insn(regs) < 0)
f9717f31	260	return;
1da177e4 LT	261	}
	262	}
	263
	264	/* Set up the stack frame */
0f5bef66	265	ret = setup_rt_frame(ksig, sigmask_to_save(), regs);
1da177e4	266
0f5bef66	267	signal_setup_done(ret, ksig, 0);
1da177e4 LT	268	}
	269
	270	/*
	271	* Note that 'init' is a special process: it doesn't get signals it doesn't
	272	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	273	* mistake.
	274	*/
a05c4e1d	275	static void do_signal(struct pt_regs *regs)
1da177e4	276	{
0f5bef66	277	struct ksignal ksig;
1da177e4 LT	278
	279	/*
	280	* We want the common case to go fast, which
	281	* is why we may in certain cases get here from
	282	* kernel mode. Just return without doing anything
	283	* if so.
	284	*/
	285	if (!user_mode(regs))
a05c4e1d	286	return;
1da177e4	287
0f5bef66	288	if (get_signal(&ksig)) {
5aa8b6c1	289	/* Re-enable any watchpoints before delivering the
1da177e4 LT	290	* signal to user space. The processor register will
	291	* have been cleared if the watchpoint triggered
	292	* inside the kernel.
	293	*/
	294
	295	/* Whee! Actually deliver the signal. */
0f5bef66	296	handle_signal(&ksig, regs);
a05c4e1d AV	297
a05c4e1d AV	298	return;
1da177e4 LT	299	}
1da177e4 LT	300
1da177e4 LT	301	/* Did we come from a system call? */
	302	if (regs->syscall_nr >= 0) {
	303	/* Restart the system call - no handlers present */
	304	if (regs->r0 == -ERESTARTNOHAND \|\|
	305	regs->r0 == -ERESTARTSYS \|\|
	306	regs->r0 == -ERESTARTNOINTR) {
	307	regs->r0 = regs->orig_r0;
bb9c861e	308	prev_insn(regs);
a7481024	309	} else if (regs->r0 == -ERESTART_RESTARTBLOCK){
1da177e4 LT	310	regs->r0 = regs->orig_r0;
1da177e4 LT	311	regs->r7 = __NR_restart_syscall;
bb9c861e	312	prev_insn(regs);
1da177e4 LT	313	}
1da177e4 LT	314	}
51a7b448	315	restore_saved_sigmask();
1da177e4 LT	316	}
	317
	318	/*
	319	* notification of userspace execution resumption
	320	* - triggered by current->work.notify_resume
	321	*/
a7f8388e	322	void do_notify_resume(struct pt_regs *regs, __u32 thread_info_flags)
1da177e4 LT	323	{
	324	/* Pending single-step? */
	325	if (thread_info_flags & _TIF_SINGLESTEP)
	326	clear_thread_flag(TIF_SINGLESTEP);
	327
	328	/* deal with pending signal delivery */
	329	if (thread_info_flags & _TIF_SIGPENDING)
a7f8388e	330	do_signal(regs);
1da177e4	331
d0420c83 DH	332	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
	333	clear_thread_flag(TIF_NOTIFY_RESUME);
	334	tracehook_notify_resume(regs);
	335	}
1da177e4	336	}