[mirror_ubuntu-hirsute-kernel.git] / arch / hexagon / kernel / signal.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Signal support for Hexagon processor
 *
 * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
 */

#include <linux/linkage.h>
#include <linux/syscalls.h>
#include <linux/tracehook.h>
#include <linux/sched/task_stack.h>

#include <asm/registers.h>
#include <asm/thread_info.h>
#include <asm/unistd.h>
#include <linux/uaccess.h>
#include <asm/ucontext.h>
#include <asm/cacheflush.h>
#include <asm/signal.h>
#include <asm/vdso.h>

struct rt_sigframe {
	unsigned long tramp[2];
	struct siginfo info;
	struct ucontext uc;
};

static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
			  size_t frame_size)
{
	unsigned long sp = sigsp(regs->r29, ksig);

	return (void __user *)((sp - frame_size) & ~(sizeof(long long) - 1));
}

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

	err |= copy_to_user(&sc->sc_regs.r0, &regs->r00,
			    32*sizeof(unsigned long));

	err |= __put_user(regs->sa0, &sc->sc_regs.sa0);
	err |= __put_user(regs->lc0, &sc->sc_regs.lc0);
	err |= __put_user(regs->sa1, &sc->sc_regs.sa1);
	err |= __put_user(regs->lc1, &sc->sc_regs.lc1);
	err |= __put_user(regs->m0, &sc->sc_regs.m0);
	err |= __put_user(regs->m1, &sc->sc_regs.m1);
	err |= __put_user(regs->usr, &sc->sc_regs.usr);
	err |= __put_user(regs->preds, &sc->sc_regs.p3_0);
	err |= __put_user(regs->gp, &sc->sc_regs.gp);
	err |= __put_user(regs->ugp, &sc->sc_regs.ugp);
#if CONFIG_HEXAGON_ARCH_VERSION >= 4
	err |= __put_user(regs->cs0, &sc->sc_regs.cs0);
	err |= __put_user(regs->cs1, &sc->sc_regs.cs1);
#endif
	tmp = pt_elr(regs); err |= __put_user(tmp, &sc->sc_regs.pc);
	tmp = pt_cause(regs); err |= __put_user(tmp, &sc->sc_regs.cause);
	tmp = pt_badva(regs); err |= __put_user(tmp, &sc->sc_regs.badva);

	return err;
}

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

	err |= copy_from_user(&regs->r00, &sc->sc_regs.r0,
			      32 * sizeof(unsigned long));

	err |= __get_user(regs->sa0, &sc->sc_regs.sa0);
	err |= __get_user(regs->lc0, &sc->sc_regs.lc0);
	err |= __get_user(regs->sa1, &sc->sc_regs.sa1);
	err |= __get_user(regs->lc1, &sc->sc_regs.lc1);
	err |= __get_user(regs->m0, &sc->sc_regs.m0);
	err |= __get_user(regs->m1, &sc->sc_regs.m1);
	err |= __get_user(regs->usr, &sc->sc_regs.usr);
	err |= __get_user(regs->preds, &sc->sc_regs.p3_0);
	err |= __get_user(regs->gp, &sc->sc_regs.gp);
	err |= __get_user(regs->ugp, &sc->sc_regs.ugp);
#if CONFIG_HEXAGON_ARCH_VERSION >= 4
	err |= __get_user(regs->cs0, &sc->sc_regs.cs0);
	err |= __get_user(regs->cs1, &sc->sc_regs.cs1);
#endif
	err |= __get_user(tmp, &sc->sc_regs.pc); pt_set_elr(regs, tmp);

	return err;
}

/*
 * Setup signal stack frame with siginfo structure
 */
static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
			  struct pt_regs *regs)
{
	int err = 0;
	struct rt_sigframe __user *frame;
	struct hexagon_vdso *vdso = current->mm->context.vdso;

	frame = get_sigframe(ksig, regs, sizeof(struct rt_sigframe));

	if (!access_ok(frame, sizeof(struct rt_sigframe)))
		return -EFAULT;

	if (copy_siginfo_to_user(&frame->info, &ksig->info))
		return -EFAULT;

	/* The on-stack signal trampoline is no longer executed;
	 * however, the libgcc signal frame unwinding code checks for
	 * the presence of these two numeric magic values.
	 */
	err |= __put_user(0x7800d166, &frame->tramp[0]);
	err |= __put_user(0x5400c004, &frame->tramp[1]);
	err |= setup_sigcontext(regs, &frame->uc.uc_mcontext);
	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	err |= __save_altstack(&frame->uc.uc_stack, user_stack_pointer(regs));
	if (err)
		return -EFAULT;

	/* Load r0/r1 pair with signumber/siginfo pointer... */
	regs->r0100 = ((unsigned long long)((unsigned long)&frame->info) << 32)
		| (unsigned long long)ksig->sig;
	regs->r02 = (unsigned long) &frame->uc;
	regs->r31 = (unsigned long) vdso->rt_signal_trampoline;
	pt_psp(regs) = (unsigned long) frame;
	pt_set_elr(regs, (unsigned long)ksig->ka.sa.sa_handler);

	return 0;
}

/*
 * Setup invocation of signal handler
 */
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
{
	int ret;

	/*
	 * If we're handling a signal that aborted a system call,
	 * set up the error return value before adding the signal
	 * frame to the stack.
	 */

	if (regs->syscall_nr >= 0) {
		switch (regs->r00) {
		case -ERESTART_RESTARTBLOCK:
		case -ERESTARTNOHAND:
			regs->r00 = -EINTR;
			break;
		case -ERESTARTSYS:
			if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
				regs->r00 = -EINTR;
				break;
			}
			fallthrough;
		case -ERESTARTNOINTR:
			regs->r06 = regs->syscall_nr;
			pt_set_elr(regs, pt_elr(regs) - 4);
			regs->r00 = regs->restart_r0;
			break;
		default:
			break;
		}
	}

	/*
	 * Set up the stack frame; not doing the SA_SIGINFO thing.  We
	 * only set up the rt_frame flavor.
	 */
	/* If there was an error on setup, no signal was delivered. */
	ret = setup_rt_frame(ksig, sigmask_to_save(), regs);

	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
}

/*
 * Called from return-from-event code.
 */
void do_signal(struct pt_regs *regs)
{
	struct ksignal ksig;

	if (!user_mode(regs))
		return;

	if (get_signal(&ksig)) {
		handle_signal(&ksig, regs);
		return;
	}

	/*
	 * No (more) signals; if we came from a system call, handle the restart.
	 */

	if (regs->syscall_nr >= 0) {
		switch (regs->r00) {
		case -ERESTARTNOHAND:
		case -ERESTARTSYS:
		case -ERESTARTNOINTR:
			regs->r06 = regs->syscall_nr;
			break;
		case -ERESTART_RESTARTBLOCK:
			regs->r06 = __NR_restart_syscall;
			break;
		default:
			goto no_restart;
		}
		pt_set_elr(regs, pt_elr(regs) - 4);
		regs->r00 = regs->restart_r0;
	}

no_restart:
	/* If there's no signal to deliver, put the saved sigmask back */
	restore_saved_sigmask();
}

/*
 * Architecture-specific wrappers for signal-related system calls
 */

asmlinkage int sys_rt_sigreturn(void)
{
	struct pt_regs *regs = current_pt_regs();
	struct rt_sigframe __user *frame;
	sigset_t blocked;

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

	frame = (struct rt_sigframe __user *)pt_psp(regs);
	if (!access_ok(frame, sizeof(*frame)))
		goto badframe;
	if (__copy_from_user(&blocked, &frame->uc.uc_sigmask, sizeof(blocked)))
		goto badframe;

	set_current_blocked(&blocked);

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

	/* Restore the user's stack as well */
	pt_psp(regs) = regs->r29;

	regs->syscall_nr = -1;

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

	return regs->r00;

badframe:
	force_sig(SIGSEGV);
	return 0;
}
Commit	Line	Data
08dbd0f8	1	// SPDX-License-Identifier: GPL-2.0-only
cd5b61d6 RK	2	/*
	3	* Signal support for Hexagon processor
	4	*
7c6a5df4	5	* Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
cd5b61d6 RK	6	*/
	7
	8	#include <linux/linkage.h>
	9	#include <linux/syscalls.h>
cd5b61d6	10	#include <linux/tracehook.h>
68db0cf1 IM	11	#include <linux/sched/task_stack.h>
68db0cf1 IM	12
cd5b61d6 RK	13	#include <asm/registers.h>
	14	#include <asm/thread_info.h>
	15	#include <asm/unistd.h>
7c0f6ba6	16	#include <linux/uaccess.h>
cd5b61d6 RK	17	#include <asm/ucontext.h>
	18	#include <asm/cacheflush.h>
	19	#include <asm/signal.h>
	20	#include <asm/vdso.h>
	21
cd5b61d6 RK	22	struct rt_sigframe {
	23	unsigned long tramp[2];
	24	struct siginfo info;
	25	struct ucontext uc;
	26	};
	27
8bc77aa4	28	static void __user get_sigframe(struct ksignal ksig, struct pt_regs *regs,
cd5b61d6 RK	29	size_t frame_size)
cd5b61d6 RK	30	{
8bc77aa4	31	unsigned long sp = sigsp(regs->r29, ksig);
cd5b61d6 RK	32
	33	return (void __user *)((sp - frame_size) & ~(sizeof(long long) - 1));
	34	}
	35
	36	static int setup_sigcontext(struct pt_regs regs, struct sigcontext __user sc)
	37	{
	38	unsigned long tmp;
	39	int err = 0;
	40
	41	err \|= copy_to_user(&sc->sc_regs.r0, &regs->r00,
	42	32*sizeof(unsigned long));
	43
	44	err \|= __put_user(regs->sa0, &sc->sc_regs.sa0);
	45	err \|= __put_user(regs->lc0, &sc->sc_regs.lc0);
	46	err \|= __put_user(regs->sa1, &sc->sc_regs.sa1);
	47	err \|= __put_user(regs->lc1, &sc->sc_regs.lc1);
	48	err \|= __put_user(regs->m0, &sc->sc_regs.m0);
	49	err \|= __put_user(regs->m1, &sc->sc_regs.m1);
	50	err \|= __put_user(regs->usr, &sc->sc_regs.usr);
	51	err \|= __put_user(regs->preds, &sc->sc_regs.p3_0);
	52	err \|= __put_user(regs->gp, &sc->sc_regs.gp);
	53	err \|= __put_user(regs->ugp, &sc->sc_regs.ugp);
60c4ba99 RK	54	#if CONFIG_HEXAGON_ARCH_VERSION >= 4
	55	err \|= __put_user(regs->cs0, &sc->sc_regs.cs0);
	56	err \|= __put_user(regs->cs1, &sc->sc_regs.cs1);
	57	#endif
cd5b61d6 RK	58	tmp = pt_elr(regs); err \|= __put_user(tmp, &sc->sc_regs.pc);
	59	tmp = pt_cause(regs); err \|= __put_user(tmp, &sc->sc_regs.cause);
	60	tmp = pt_badva(regs); err \|= __put_user(tmp, &sc->sc_regs.badva);
	61
	62	return err;
	63	}
	64
	65	static int restore_sigcontext(struct pt_regs *regs,
	66	struct sigcontext __user *sc)
	67	{
	68	unsigned long tmp;
	69	int err = 0;
	70
	71	err \|= copy_from_user(&regs->r00, &sc->sc_regs.r0,
	72	32 * sizeof(unsigned long));
	73
	74	err \|= __get_user(regs->sa0, &sc->sc_regs.sa0);
	75	err \|= __get_user(regs->lc0, &sc->sc_regs.lc0);
	76	err \|= __get_user(regs->sa1, &sc->sc_regs.sa1);
	77	err \|= __get_user(regs->lc1, &sc->sc_regs.lc1);
	78	err \|= __get_user(regs->m0, &sc->sc_regs.m0);
	79	err \|= __get_user(regs->m1, &sc->sc_regs.m1);
	80	err \|= __get_user(regs->usr, &sc->sc_regs.usr);
	81	err \|= __get_user(regs->preds, &sc->sc_regs.p3_0);
	82	err \|= __get_user(regs->gp, &sc->sc_regs.gp);
	83	err \|= __get_user(regs->ugp, &sc->sc_regs.ugp);
60c4ba99 RK	84	#if CONFIG_HEXAGON_ARCH_VERSION >= 4
	85	err \|= __get_user(regs->cs0, &sc->sc_regs.cs0);
	86	err \|= __get_user(regs->cs1, &sc->sc_regs.cs1);
	87	#endif
cd5b61d6 RK	88	err \|= __get_user(tmp, &sc->sc_regs.pc); pt_set_elr(regs, tmp);
	89
	90	return err;
	91	}
	92
	93	/*
	94	* Setup signal stack frame with siginfo structure
	95	*/
ac443624 RW	96	static int setup_rt_frame(struct ksignal ksig, sigset_t set,
ac443624 RW	97	struct pt_regs *regs)
cd5b61d6 RK	98	{
	99	int err = 0;
	100	struct rt_sigframe __user *frame;
	101	struct hexagon_vdso *vdso = current->mm->context.vdso;
	102
8bc77aa4	103	frame = get_sigframe(ksig, regs, sizeof(struct rt_sigframe));
cd5b61d6	104
96d4f267	105	if (!access_ok(frame, sizeof(struct rt_sigframe)))
ac443624	106	return -EFAULT;
cd5b61d6	107
ac443624 RW	108	if (copy_siginfo_to_user(&frame->info, &ksig->info))
ac443624 RW	109	return -EFAULT;
cd5b61d6 RK	110
	111	/* The on-stack signal trampoline is no longer executed;
	112	* however, the libgcc signal frame unwinding code checks for
	113	* the presence of these two numeric magic values.
	114	*/
	115	err \|= __put_user(0x7800d166, &frame->tramp[0]);
	116	err \|= __put_user(0x5400c004, &frame->tramp[1]);
	117	err \|= setup_sigcontext(regs, &frame->uc.uc_mcontext);
	118	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
da36f98a	119	err \|= __save_altstack(&frame->uc.uc_stack, user_stack_pointer(regs));
cd5b61d6	120	if (err)
ac443624	121	return -EFAULT;
cd5b61d6 RK	122
	123	/* Load r0/r1 pair with signumber/siginfo pointer... */
	124	regs->r0100 = ((unsigned long long)((unsigned long)&frame->info) << 32)
ac443624	125	\| (unsigned long long)ksig->sig;
cd5b61d6 RK	126	regs->r02 = (unsigned long) &frame->uc;
	127	regs->r31 = (unsigned long) vdso->rt_signal_trampoline;
	128	pt_psp(regs) = (unsigned long) frame;
ac443624	129	pt_set_elr(regs, (unsigned long)ksig->ka.sa.sa_handler);
cd5b61d6 RK	130
cd5b61d6 RK	131	return 0;
cd5b61d6 RK	132	}
	133
	134	/*
	135	* Setup invocation of signal handler
	136	*/
ac443624	137	static void handle_signal(struct ksignal ksig, struct pt_regs regs)
cd5b61d6	138	{
ac443624 RW	139	int ret;
ac443624 RW	140
cd5b61d6 RK	141	/*
	142	* If we're handling a signal that aborted a system call,
	143	* set up the error return value before adding the signal
	144	* frame to the stack.
	145	*/
	146
	147	if (regs->syscall_nr >= 0) {
	148	switch (regs->r00) {
	149	case -ERESTART_RESTARTBLOCK:
	150	case -ERESTARTNOHAND:
	151	regs->r00 = -EINTR;
	152	break;
	153	case -ERESTARTSYS:
ac443624	154	if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
cd5b61d6 RK	155	regs->r00 = -EINTR;
	156	break;
	157	}
df561f66	158	fallthrough;
cd5b61d6 RK	159	case -ERESTARTNOINTR:
	160	regs->r06 = regs->syscall_nr;
	161	pt_set_elr(regs, pt_elr(regs) - 4);
	162	regs->r00 = regs->restart_r0;
	163	break;
	164	default:
	165	break;
	166	}
	167	}
	168
	169	/*
	170	* Set up the stack frame; not doing the SA_SIGINFO thing. We
	171	* only set up the rt_frame flavor.
	172	*/
cd5b61d6	173	/* If there was an error on setup, no signal was delivered. */
ac443624	174	ret = setup_rt_frame(ksig, sigmask_to_save(), regs);
cd5b61d6	175
ac443624	176	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
cd5b61d6 RK	177	}
	178
	179	/*
	180	* Called from return-from-event code.
	181	*/
a11e67c2	182	void do_signal(struct pt_regs *regs)
cd5b61d6	183	{
ac443624	184	struct ksignal ksig;
cd5b61d6 RK	185
	186	if (!user_mode(regs))
	187	return;
	188
ac443624 RW	189	if (get_signal(&ksig)) {
ac443624 RW	190	handle_signal(&ksig, regs);
cd5b61d6 RK	191	return;
	192	}
	193
cd5b61d6	194	/*
a11e67c2	195	* No (more) signals; if we came from a system call, handle the restart.
cd5b61d6	196	*/
a11e67c2	197
cd5b61d6 RK	198	if (regs->syscall_nr >= 0) {
	199	switch (regs->r00) {
	200	case -ERESTARTNOHAND:
	201	case -ERESTARTSYS:
	202	case -ERESTARTNOINTR:
	203	regs->r06 = regs->syscall_nr;
	204	break;
	205	case -ERESTART_RESTARTBLOCK:
	206	regs->r06 = __NR_restart_syscall;
	207	break;
	208	default:
	209	goto no_restart;
	210	}
	211	pt_set_elr(regs, pt_elr(regs) - 4);
	212	regs->r00 = regs->restart_r0;
	213	}
	214
	215	no_restart:
	216	/* If there's no signal to deliver, put the saved sigmask back */
51a7b448	217	restore_saved_sigmask();
cd5b61d6 RK	218	}
cd5b61d6 RK	219
cd5b61d6 RK	220	/*
	221	* Architecture-specific wrappers for signal-related system calls
	222	*/
cd5b61d6 RK	223
	224	asmlinkage int sys_rt_sigreturn(void)
	225	{
99521855	226	struct pt_regs *regs = current_pt_regs();
cd5b61d6 RK	227	struct rt_sigframe __user *frame;
	228	sigset_t blocked;
	229
ef9b122f	230	/* Always make any pending restarted system calls return -EINTR */
f56141e3	231	current->restart_block.fn = do_no_restart_syscall;
ef9b122f	232
cd5b61d6	233	frame = (struct rt_sigframe __user *)pt_psp(regs);
96d4f267	234	if (!access_ok(frame, sizeof(*frame)))
cd5b61d6 RK	235	goto badframe;
	236	if (__copy_from_user(&blocked, &frame->uc.uc_sigmask, sizeof(blocked)))
	237	goto badframe;
	238
43aca324	239	set_current_blocked(&blocked);
cd5b61d6 RK	240
	241	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
	242	goto badframe;
	243
	244	/* Restore the user's stack as well */
	245	pt_psp(regs) = regs->r29;
	246
a11e67c2	247	regs->syscall_nr = -1;
cd5b61d6	248
1e974c21	249	if (restore_altstack(&frame->uc.uc_stack))
cd5b61d6 RK	250	goto badframe;
cd5b61d6 RK	251
a11e67c2	252	return regs->r00;
cd5b61d6 RK	253
cd5b61d6 RK	254	badframe:
3cf5d076	255	force_sig(SIGSEGV);
cd5b61d6 RK	256	return 0;
cd5b61d6 RK	257	}