[deliverable/linux.git] / arch / hexagon / kernel / signal.c

/*
 * Signal support for Hexagon processor
 *
 * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

#include <linux/linkage.h>
#include <linux/syscalls.h>
#include <linux/tracehook.h>
#include <asm/registers.h>
#include <asm/thread_info.h>
#include <asm/unistd.h>
#include <asm/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 k_sigaction *ka, struct pt_regs *regs,
			  size_t frame_size)
{
	unsigned long sp = regs->r29;

	/* check if we would overflow the alt stack */
	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
		return (void __user __force *)-1UL;

	/* Switch to signal stack if appropriate */
	if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
		sp = current->sas_ss_sp + current->sas_ss_size;

	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(int signr, struct k_sigaction *ka, siginfo_t *info,
			  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(ka, regs, sizeof(struct rt_sigframe));

	if (!access_ok(VERIFY_WRITE, frame, sizeof(struct rt_sigframe)))
		goto	sigsegv;

	if (copy_siginfo_to_user(&frame->info, info))
		goto	sigsegv;

	/* 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)
		goto sigsegv;

	/* Load r0/r1 pair with signumber/siginfo pointer... */
	regs->r0100 = ((unsigned long long)((unsigned long)&frame->info) << 32)
		| (unsigned long long)signr;
	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)ka->sa.sa_handler);

	return 0;

sigsegv:
	force_sigsegv(signr, current);
	return -EFAULT;
}

/*
 * Setup invocation of signal handler
 */
static void handle_signal(int sig, siginfo_t *info, struct k_sigaction *ka,
			 struct pt_regs *regs)
{
	/*
	 * 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 (!(ka->sa.sa_flags & SA_RESTART)) {
				regs->r00 = -EINTR;
				break;
			}
			/* Fall through */
		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. */
	if (setup_rt_frame(sig, ka, info, sigmask_to_save(), regs) < 0)
		return;

	signal_delivered(sig, info, ka, regs,
			test_thread_flag(TIF_SINGLESTEP));
}

/*
 * Called from return-from-event code.
 */
void do_signal(struct pt_regs *regs)
{
	struct k_sigaction sigact;
	siginfo_t info;
	int signo;

	if (!user_mode(regs))
		return;

	signo = get_signal_to_deliver(&info, &sigact, regs, NULL);

	if (signo > 0) {
		handle_signal(signo, &info, &sigact, 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_thread_info()->restart_block.fn = do_no_restart_syscall;

	frame = (struct rt_sigframe __user *)pt_psp(regs);
	if (!access_ok(VERIFY_READ, 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, current);
	return 0;
}
Commit	Line	Data
cd5b61d6 RK	1	/*
	2	* Signal support for Hexagon processor
	3	*
7c6a5df4	4	* Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
cd5b61d6 RK	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 and
	8	* only version 2 as published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	18	* 02110-1301, USA.
	19	*/
	20
	21	#include <linux/linkage.h>
	22	#include <linux/syscalls.h>
cd5b61d6 RK	23	#include <linux/tracehook.h>
	24	#include <asm/registers.h>
	25	#include <asm/thread_info.h>
	26	#include <asm/unistd.h>
	27	#include <asm/uaccess.h>
	28	#include <asm/ucontext.h>
	29	#include <asm/cacheflush.h>
	30	#include <asm/signal.h>
	31	#include <asm/vdso.h>
	32
cd5b61d6 RK	33	struct rt_sigframe {
	34	unsigned long tramp[2];
	35	struct siginfo info;
	36	struct ucontext uc;
	37	};
	38
	39	static void __user get_sigframe(struct k_sigaction ka, struct pt_regs *regs,
	40	size_t frame_size)
	41	{
	42	unsigned long sp = regs->r29;
	43
9cdae82d RK	44	/* check if we would overflow the alt stack */
	45	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
	46	return (void __user __force *)-1UL;
	47
cd5b61d6 RK	48	/* Switch to signal stack if appropriate */
	49	if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
	50	sp = current->sas_ss_sp + current->sas_ss_size;
	51
	52	return (void __user *)((sp - frame_size) & ~(sizeof(long long) - 1));
	53	}
	54
	55	static int setup_sigcontext(struct pt_regs regs, struct sigcontext __user sc)
	56	{
	57	unsigned long tmp;
	58	int err = 0;
	59
	60	err \|= copy_to_user(&sc->sc_regs.r0, &regs->r00,
	61	32*sizeof(unsigned long));
	62
	63	err \|= __put_user(regs->sa0, &sc->sc_regs.sa0);
	64	err \|= __put_user(regs->lc0, &sc->sc_regs.lc0);
	65	err \|= __put_user(regs->sa1, &sc->sc_regs.sa1);
	66	err \|= __put_user(regs->lc1, &sc->sc_regs.lc1);
	67	err \|= __put_user(regs->m0, &sc->sc_regs.m0);
	68	err \|= __put_user(regs->m1, &sc->sc_regs.m1);
	69	err \|= __put_user(regs->usr, &sc->sc_regs.usr);
	70	err \|= __put_user(regs->preds, &sc->sc_regs.p3_0);
	71	err \|= __put_user(regs->gp, &sc->sc_regs.gp);
	72	err \|= __put_user(regs->ugp, &sc->sc_regs.ugp);
60c4ba99 RK	73	#if CONFIG_HEXAGON_ARCH_VERSION >= 4
	74	err \|= __put_user(regs->cs0, &sc->sc_regs.cs0);
	75	err \|= __put_user(regs->cs1, &sc->sc_regs.cs1);
	76	#endif
cd5b61d6 RK	77	tmp = pt_elr(regs); err \|= __put_user(tmp, &sc->sc_regs.pc);
	78	tmp = pt_cause(regs); err \|= __put_user(tmp, &sc->sc_regs.cause);
	79	tmp = pt_badva(regs); err \|= __put_user(tmp, &sc->sc_regs.badva);
	80
	81	return err;
	82	}
	83
	84	static int restore_sigcontext(struct pt_regs *regs,
	85	struct sigcontext __user *sc)
	86	{
	87	unsigned long tmp;
	88	int err = 0;
	89
	90	err \|= copy_from_user(&regs->r00, &sc->sc_regs.r0,
	91	32 * sizeof(unsigned long));
	92
	93	err \|= __get_user(regs->sa0, &sc->sc_regs.sa0);
	94	err \|= __get_user(regs->lc0, &sc->sc_regs.lc0);
	95	err \|= __get_user(regs->sa1, &sc->sc_regs.sa1);
	96	err \|= __get_user(regs->lc1, &sc->sc_regs.lc1);
	97	err \|= __get_user(regs->m0, &sc->sc_regs.m0);
	98	err \|= __get_user(regs->m1, &sc->sc_regs.m1);
	99	err \|= __get_user(regs->usr, &sc->sc_regs.usr);
	100	err \|= __get_user(regs->preds, &sc->sc_regs.p3_0);
	101	err \|= __get_user(regs->gp, &sc->sc_regs.gp);
	102	err \|= __get_user(regs->ugp, &sc->sc_regs.ugp);
60c4ba99 RK	103	#if CONFIG_HEXAGON_ARCH_VERSION >= 4
	104	err \|= __get_user(regs->cs0, &sc->sc_regs.cs0);
	105	err \|= __get_user(regs->cs1, &sc->sc_regs.cs1);
	106	#endif
cd5b61d6 RK	107	err \|= __get_user(tmp, &sc->sc_regs.pc); pt_set_elr(regs, tmp);
	108
	109	return err;
	110	}
	111
	112	/*
	113	* Setup signal stack frame with siginfo structure
	114	*/
	115	static int setup_rt_frame(int signr, struct k_sigaction ka, siginfo_t info,
	116	sigset_t set, struct pt_regs regs)
	117	{
	118	int err = 0;
	119	struct rt_sigframe __user *frame;
	120	struct hexagon_vdso *vdso = current->mm->context.vdso;
	121
	122	frame = get_sigframe(ka, regs, sizeof(struct rt_sigframe));
	123
	124	if (!access_ok(VERIFY_WRITE, frame, sizeof(struct rt_sigframe)))
	125	goto sigsegv;
	126
	127	if (copy_siginfo_to_user(&frame->info, info))
	128	goto sigsegv;
	129
	130	/* The on-stack signal trampoline is no longer executed;
	131	* however, the libgcc signal frame unwinding code checks for
	132	* the presence of these two numeric magic values.
	133	*/
	134	err \|= __put_user(0x7800d166, &frame->tramp[0]);
	135	err \|= __put_user(0x5400c004, &frame->tramp[1]);
	136	err \|= setup_sigcontext(regs, &frame->uc.uc_mcontext);
	137	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
da36f98a	138	err \|= __save_altstack(&frame->uc.uc_stack, user_stack_pointer(regs));
cd5b61d6 RK	139	if (err)
	140	goto sigsegv;
	141
	142	/* Load r0/r1 pair with signumber/siginfo pointer... */
	143	regs->r0100 = ((unsigned long long)((unsigned long)&frame->info) << 32)
	144	\| (unsigned long long)signr;
	145	regs->r02 = (unsigned long) &frame->uc;
	146	regs->r31 = (unsigned long) vdso->rt_signal_trampoline;
	147	pt_psp(regs) = (unsigned long) frame;
	148	pt_set_elr(regs, (unsigned long)ka->sa.sa_handler);
	149
	150	return 0;
	151
	152	sigsegv:
	153	force_sigsegv(signr, current);
	154	return -EFAULT;
	155	}
	156
	157	/*
	158	* Setup invocation of signal handler
	159	*/
a610d6e6	160	static void handle_signal(int sig, siginfo_t info, struct k_sigaction ka,
b7f9a11a	161	struct pt_regs *regs)
cd5b61d6	162	{
cd5b61d6 RK	163	/*
	164	* If we're handling a signal that aborted a system call,
	165	* set up the error return value before adding the signal
	166	* frame to the stack.
	167	*/
	168
	169	if (regs->syscall_nr >= 0) {
	170	switch (regs->r00) {
	171	case -ERESTART_RESTARTBLOCK:
	172	case -ERESTARTNOHAND:
	173	regs->r00 = -EINTR;
	174	break;
	175	case -ERESTARTSYS:
	176	if (!(ka->sa.sa_flags & SA_RESTART)) {
	177	regs->r00 = -EINTR;
	178	break;
	179	}
	180	/* Fall through */
	181	case -ERESTARTNOINTR:
	182	regs->r06 = regs->syscall_nr;
	183	pt_set_elr(regs, pt_elr(regs) - 4);
	184	regs->r00 = regs->restart_r0;
	185	break;
	186	default:
	187	break;
	188	}
	189	}
	190
	191	/*
	192	* Set up the stack frame; not doing the SA_SIGINFO thing. We
	193	* only set up the rt_frame flavor.
	194	*/
cd5b61d6	195	/* If there was an error on setup, no signal was delivered. */
a610d6e6 AV	196	if (setup_rt_frame(sig, ka, info, sigmask_to_save(), regs) < 0)
a610d6e6 AV	197	return;
cd5b61d6	198
efee984c	199	signal_delivered(sig, info, ka, regs,
a610d6e6	200	test_thread_flag(TIF_SINGLESTEP));
cd5b61d6 RK	201	}
	202
	203	/*
	204	* Called from return-from-event code.
	205	*/
a11e67c2	206	void do_signal(struct pt_regs *regs)
cd5b61d6 RK	207	{
	208	struct k_sigaction sigact;
	209	siginfo_t info;
	210	int signo;
	211
	212	if (!user_mode(regs))
	213	return;
	214
cd5b61d6 RK	215	signo = get_signal_to_deliver(&info, &sigact, regs, NULL);
	216
	217	if (signo > 0) {
a610d6e6	218	handle_signal(signo, &info, &sigact, regs);
cd5b61d6 RK	219	return;
	220	}
	221
cd5b61d6	222	/*
a11e67c2	223	* No (more) signals; if we came from a system call, handle the restart.
cd5b61d6	224	*/
a11e67c2	225
cd5b61d6 RK	226	if (regs->syscall_nr >= 0) {
	227	switch (regs->r00) {
	228	case -ERESTARTNOHAND:
	229	case -ERESTARTSYS:
	230	case -ERESTARTNOINTR:
	231	regs->r06 = regs->syscall_nr;
	232	break;
	233	case -ERESTART_RESTARTBLOCK:
	234	regs->r06 = __NR_restart_syscall;
	235	break;
	236	default:
	237	goto no_restart;
	238	}
	239	pt_set_elr(regs, pt_elr(regs) - 4);
	240	regs->r00 = regs->restart_r0;
	241	}
	242
	243	no_restart:
	244	/* If there's no signal to deliver, put the saved sigmask back */
51a7b448	245	restore_saved_sigmask();
cd5b61d6 RK	246	}
cd5b61d6 RK	247
cd5b61d6 RK	248	/*
	249	* Architecture-specific wrappers for signal-related system calls
	250	*/
cd5b61d6 RK	251
	252	asmlinkage int sys_rt_sigreturn(void)
	253	{
99521855	254	struct pt_regs *regs = current_pt_regs();
cd5b61d6 RK	255	struct rt_sigframe __user *frame;
	256	sigset_t blocked;
	257
ef9b122f AV	258	/* Always make any pending restarted system calls return -EINTR */
	259	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	260
cd5b61d6 RK	261	frame = (struct rt_sigframe __user *)pt_psp(regs);
	262	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	263	goto badframe;
	264	if (__copy_from_user(&blocked, &frame->uc.uc_sigmask, sizeof(blocked)))
	265	goto badframe;
	266
43aca324	267	set_current_blocked(&blocked);
cd5b61d6 RK	268
	269	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
	270	goto badframe;
	271
	272	/* Restore the user's stack as well */
	273	pt_psp(regs) = regs->r29;
	274
a11e67c2	275	regs->syscall_nr = -1;
cd5b61d6	276
1e974c21	277	if (restore_altstack(&frame->uc.uc_stack))
cd5b61d6 RK	278	goto badframe;
cd5b61d6 RK	279
a11e67c2	280	return regs->r00;
cd5b61d6 RK	281
	282	badframe:
	283	force_sig(SIGSEGV, current);
	284	return 0;
	285	}