[linux-2.6-block.git] / arch / microblaze / kernel / signal.c

/*
 * Signal handling
 *
 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
 * Copyright (C) 2008-2009 PetaLogix
 * Copyright (C) 2003,2004 John Williams <jwilliams@itee.uq.edu.au>
 * Copyright (C) 2001 NEC Corporation
 * Copyright (C) 2001 Miles Bader <miles@gnu.org>
 * Copyright (C) 1999,2000 Niibe Yutaka & Kaz Kojima
 * Copyright (C) 1991,1992 Linus Torvalds
 *
 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
 *
 * This file was was derived from the sh version, arch/sh/kernel/signal.c
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License. See the file COPYING in the main directory of this
 * archive for more details.
 */

#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/ptrace.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/percpu.h>
#include <linux/linkage.h>
#include <linux/tracehook.h>
#include <asm/entry.h>
#include <asm/ucontext.h>
#include <linux/uaccess.h>
#include <linux/syscalls.h>
#include <asm/cacheflush.h>
#include <asm/syscalls.h>

/*
 * Do a signal return; undo the signal stack.
 */
struct sigframe {
	struct sigcontext sc;
	unsigned long extramask[_NSIG_WORDS-1];
	unsigned long tramp[2];	/* signal trampoline */
};

struct rt_sigframe {
	struct siginfo info;
	struct ucontext uc;
	unsigned long tramp[2];	/* signal trampoline */
};

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

#define COPY(x)		{err |= __get_user(regs->x, &sc->regs.x); }
	COPY(r0);
	COPY(r1);
	COPY(r2);	COPY(r3);	COPY(r4);	COPY(r5);
	COPY(r6);	COPY(r7);	COPY(r8);	COPY(r9);
	COPY(r10);	COPY(r11);	COPY(r12);	COPY(r13);
	COPY(r14);	COPY(r15);	COPY(r16);	COPY(r17);
	COPY(r18);	COPY(r19);	COPY(r20);	COPY(r21);
	COPY(r22);	COPY(r23);	COPY(r24);	COPY(r25);
	COPY(r26);	COPY(r27);	COPY(r28);	COPY(r29);
	COPY(r30);	COPY(r31);
	COPY(pc);	COPY(ear);	COPY(esr);	COPY(fsr);
#undef COPY

	*rval_p = regs->r3;

	return err;
}

asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
{
	struct rt_sigframe __user *frame =
		(struct rt_sigframe __user *)(regs->r1);

	sigset_t set;
	int rval;

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

	if (!access_ok(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, &rval))
		goto badframe;

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

	return rval;

badframe:
	force_sig(SIGSEGV);
	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->regs.x); }
	COPY(r0);
	COPY(r1);
	COPY(r2);	COPY(r3);	COPY(r4);	COPY(r5);
	COPY(r6);	COPY(r7);	COPY(r8);	COPY(r9);
	COPY(r10);	COPY(r11);	COPY(r12);	COPY(r13);
	COPY(r14);	COPY(r15);	COPY(r16);	COPY(r17);
	COPY(r18);	COPY(r19);	COPY(r20);	COPY(r21);
	COPY(r22);	COPY(r23);	COPY(r24);	COPY(r25);
	COPY(r26);	COPY(r27);	COPY(r28);	COPY(r29);
	COPY(r30);	COPY(r31);
	COPY(pc);	COPY(ear);	COPY(esr);	COPY(fsr);
#undef COPY

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

	return err;
}

/*
 * Determine which stack to use..
 */
static inline void __user *
get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size)
{
	/* Default to using normal stack */
	unsigned long sp = sigsp(regs->r1, ksig);

	return (void __user *)((sp - 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, sig = ksig->sig;
	unsigned long address = 0;
	pmd_t *pmdp;
	pte_t *ptep;

	frame = get_sigframe(ksig, regs, sizeof(*frame));

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

	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
		err |= copy_siginfo_to_user(&frame->info, &ksig->info);

	/* Create the ucontext. */
	err |= __put_user(0, &frame->uc.uc_flags);
	err |= __put_user(NULL, &frame->uc.uc_link);
	err |= __save_altstack(&frame->uc.uc_stack, regs->r1);
	err |= setup_sigcontext(&frame->uc.uc_mcontext,
			regs, set->sig[0]);
	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));

	/* Set up to return from userspace. If provided, use a stub
	 already in userspace. */
	/* minus 8 is offset to cater for "rtsd r15,8" */
	/* addi r12, r0, __NR_sigreturn */
	err |= __put_user(0x31800000 | __NR_rt_sigreturn ,
			frame->tramp + 0);
	/* brki r14, 0x8 */
	err |= __put_user(0xb9cc0008, frame->tramp + 1);

	/* Return from sighandler will jump to the tramp.
	 Negative 8 offset because return is rtsd r15, 8 */
	regs->r15 = ((unsigned long)frame->tramp)-8;

	address = ((unsigned long)frame->tramp);
	pmdp = pmd_off(current->mm, address);

	preempt_disable();
	ptep = pte_offset_map(pmdp, address);
	if (pte_present(*ptep)) {
		address = (unsigned long) page_address(pte_page(*ptep));
		/* MS: I need add offset in page */
		address += ((unsigned long)frame->tramp) & ~PAGE_MASK;
		/* MS address is virtual */
		address = __virt_to_phys(address);
		invalidate_icache_range(address, address + 8);
		flush_dcache_range(address, address + 8);
	}
	pte_unmap(ptep);
	preempt_enable();
	if (err)
		return -EFAULT;

	/* Set up registers for signal handler */
	regs->r1 = (unsigned long) frame;

	/* Signal handler args: */
	regs->r5 = sig; /* arg 0: signum */
	regs->r6 = (unsigned long) &frame->info; /* arg 1: siginfo */
	regs->r7 = (unsigned long) &frame->uc; /* arg2: ucontext */
	/* Offset to handle microblaze rtid r14, 0 */
	regs->pc = (unsigned long)ksig->ka.sa.sa_handler;

#ifdef DEBUG_SIG
	pr_info("SIG deliver (%s:%d): sp=%p pc=%08lx\n",
		current->comm, current->pid, frame, regs->pc);
#endif

	return 0;
}

/* Handle restarting system calls */
static inline void
handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
{
	switch (regs->r3) {
	case -ERESTART_RESTARTBLOCK:
	case -ERESTARTNOHAND:
		if (!has_handler)
			goto do_restart;
		regs->r3 = -EINTR;
		break;
	case -ERESTARTSYS:
		if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
			regs->r3 = -EINTR;
			break;
	}
		fallthrough;
	case -ERESTARTNOINTR:
do_restart:
		/* offset of 4 bytes to re-execute trap (brki) instruction */
		regs->pc -= 4;
		break;
	}
}

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

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

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

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

/*
 * 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.
 *
 * Note that we go through the signals twice: once to check the signals that
 * the kernel can handle, and then we build all the user-level signal handling
 * stack-frames in one go after that.
 */
static void do_signal(struct pt_regs *regs, int in_syscall)
{
	struct ksignal ksig;

#ifdef DEBUG_SIG
	pr_info("do signal: %p %d\n", regs, in_syscall);
	pr_info("do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1,
			regs->r12, read_thread_flags());
#endif

	if (get_signal(&ksig)) {
		/* Whee! Actually deliver the signal. */
		if (in_syscall)
			handle_restart(regs, &ksig.ka, 1);
		handle_signal(&ksig, regs);
		return;
	}

	if (in_syscall)
		handle_restart(regs, NULL, 0);

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

asmlinkage void do_notify_resume(struct pt_regs *regs, int in_syscall)
{
	if (test_thread_flag(TIF_SIGPENDING) ||
	    test_thread_flag(TIF_NOTIFY_SIGNAL))
		do_signal(regs, in_syscall);

	if (test_thread_flag(TIF_NOTIFY_RESUME))
		tracehook_notify_resume(regs);
}
Commit	Line	Data
2148daa9 MS	1	/*
	2	* Signal handling
	3	*
	4	* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
	5	* Copyright (C) 2008-2009 PetaLogix
	6	* Copyright (C) 2003,2004 John Williams <jwilliams@itee.uq.edu.au>
	7	* Copyright (C) 2001 NEC Corporation
	8	* Copyright (C) 2001 Miles Bader <miles@gnu.org>
	9	* Copyright (C) 1999,2000 Niibe Yutaka & Kaz Kojima
	10	* Copyright (C) 1991,1992 Linus Torvalds
	11	*
	12	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	13	*
	14	* This file was was derived from the sh version, arch/sh/kernel/signal.c
	15	*
	16	* This file is subject to the terms and conditions of the GNU General
	17	* Public License. See the file COPYING in the main directory of this
	18	* archive for more details.
	19	*/
	20
	21	#include <linux/sched.h>
	22	#include <linux/mm.h>
	23	#include <linux/smp.h>
2148daa9 MS	24	#include <linux/kernel.h>
	25	#include <linux/signal.h>
	26	#include <linux/errno.h>
	27	#include <linux/wait.h>
	28	#include <linux/ptrace.h>
	29	#include <linux/unistd.h>
	30	#include <linux/stddef.h>
	31	#include <linux/personality.h>
	32	#include <linux/percpu.h>
	33	#include <linux/linkage.h>
969a9616	34	#include <linux/tracehook.h>
2148daa9 MS	35	#include <asm/entry.h>
	36	#include <asm/ucontext.h>
	37	#include <linux/uaccess.h>
2148daa9 MS	38	#include <linux/syscalls.h>
	39	#include <asm/cacheflush.h>
	40	#include <asm/syscalls.h>
	41
2148daa9 MS	42	/*
	43	* Do a signal return; undo the signal stack.
	44	*/
2148daa9 MS	45	struct sigframe {
	46	struct sigcontext sc;
	47	unsigned long extramask[_NSIG_WORDS-1];
	48	unsigned long tramp[2]; /* signal trampoline */
	49	};
	50
	51	struct rt_sigframe {
	52	struct siginfo info;
	53	struct ucontext uc;
	54	unsigned long tramp[2]; /* signal trampoline */
	55	};
	56
353b431b AB	57	static int restore_sigcontext(struct pt_regs *regs,
353b431b AB	58	struct sigcontext __user sc, int rval_p)
2148daa9 MS	59	{
	60	unsigned int err = 0;
	61
	62	#define COPY(x) {err \|= __get_user(regs->x, &sc->regs.x); }
	63	COPY(r0);
	64	COPY(r1);
	65	COPY(r2); COPY(r3); COPY(r4); COPY(r5);
	66	COPY(r6); COPY(r7); COPY(r8); COPY(r9);
	67	COPY(r10); COPY(r11); COPY(r12); COPY(r13);
	68	COPY(r14); COPY(r15); COPY(r16); COPY(r17);
	69	COPY(r18); COPY(r19); COPY(r20); COPY(r21);
	70	COPY(r22); COPY(r23); COPY(r24); COPY(r25);
	71	COPY(r26); COPY(r27); COPY(r28); COPY(r29);
	72	COPY(r30); COPY(r31);
	73	COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
	74	#undef COPY
	75
	76	*rval_p = regs->r3;
	77
	78	return err;
	79	}
	80
3183e068	81	asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
2148daa9	82	{
353b431b	83	struct rt_sigframe __user *frame =
6e83557c	84	(struct rt_sigframe __user *)(regs->r1);
2921e2bd	85
2148daa9	86	sigset_t set;
2148daa9 MS	87	int rval;
2148daa9 MS	88
58e4257b	89	/* Always make any pending restarted system calls return -EINTR */
f56141e3	90	current->restart_block.fn = do_no_restart_syscall;
58e4257b	91
96d4f267	92	if (!access_ok(frame, sizeof(*frame)))
2148daa9 MS	93	goto badframe;
	94
	95	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	96	goto badframe;
	97
60c59751	98	set_current_blocked(&set);
2148daa9 MS	99
	100	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval))
	101	goto badframe;
	102
4a9d32d3	103	if (restore_altstack(&frame->uc.uc_stack))
353b431b	104	goto badframe;
2148daa9 MS	105
	106	return rval;
	107
	108	badframe:
3cf5d076	109	force_sig(SIGSEGV);
2148daa9 MS	110	return 0;
	111	}
	112
	113	/*
	114	* Set up a signal frame.
	115	*/
	116
	117	static int
353b431b	118	setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs,
2148daa9 MS	119	unsigned long mask)
	120	{
	121	int err = 0;
	122
	123	#define COPY(x) {err \|= __put_user(regs->x, &sc->regs.x); }
	124	COPY(r0);
	125	COPY(r1);
	126	COPY(r2); COPY(r3); COPY(r4); COPY(r5);
	127	COPY(r6); COPY(r7); COPY(r8); COPY(r9);
	128	COPY(r10); COPY(r11); COPY(r12); COPY(r13);
	129	COPY(r14); COPY(r15); COPY(r16); COPY(r17);
	130	COPY(r18); COPY(r19); COPY(r20); COPY(r21);
	131	COPY(r22); COPY(r23); COPY(r24); COPY(r25);
	132	COPY(r26); COPY(r27); COPY(r28); COPY(r29);
	133	COPY(r30); COPY(r31);
	134	COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
	135	#undef COPY
	136
	137	err \|= __put_user(mask, &sc->oldmask);
	138
	139	return err;
	140	}
	141
	142	/*
	143	* Determine which stack to use..
	144	*/
353b431b	145	static inline void __user *
c001cd21	146	get_sigframe(struct ksignal ksig, struct pt_regs regs, size_t frame_size)
2148daa9 MS	147	{
2148daa9 MS	148	/* Default to using normal stack */
c001cd21	149	unsigned long sp = sigsp(regs->r1, ksig);
2148daa9	150
353b431b	151	return (void __user *)((sp - frame_size) & -8UL);
2148daa9 MS	152	}
2148daa9 MS	153
9c53c7ec RW	154	static int setup_rt_frame(struct ksignal ksig, sigset_t set,
9c53c7ec RW	155	struct pt_regs *regs)
2148daa9	156	{
353b431b	157	struct rt_sigframe __user *frame;
9c53c7ec	158	int err = 0, sig = ksig->sig;
2ee2ff87	159	unsigned long address = 0;
2ee2ff87 MS	160	pmd_t *pmdp;
2ee2ff87 MS	161	pte_t *ptep;
2148daa9	162
c001cd21	163	frame = get_sigframe(ksig, regs, sizeof(*frame));
2148daa9	164
96d4f267	165	if (!access_ok(frame, sizeof(*frame)))
9c53c7ec	166	return -EFAULT;
2148daa9	167
9c53c7ec RW	168	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
9c53c7ec RW	169	err \|= copy_siginfo_to_user(&frame->info, &ksig->info);
2148daa9 MS	170
	171	/* Create the ucontext. */
	172	err \|= __put_user(0, &frame->uc.uc_flags);
2cfedb97	173	err \|= __put_user(NULL, &frame->uc.uc_link);
4a9d32d3	174	err \|= __save_altstack(&frame->uc.uc_stack, regs->r1);
2148daa9 MS	175	err \|= setup_sigcontext(&frame->uc.uc_mcontext,
	176	regs, set->sig[0]);
	177	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	178
	179	/* Set up to return from userspace. If provided, use a stub
	180	already in userspace. */
	181	/* minus 8 is offset to cater for "rtsd r15,8" */
3183e068 AB	182	/* addi r12, r0, __NR_sigreturn */
	183	err \|= __put_user(0x31800000 \| __NR_rt_sigreturn ,
	184	frame->tramp + 0);
	185	/* brki r14, 0x8 */
	186	err \|= __put_user(0xb9cc0008, frame->tramp + 1);
	187
	188	/* Return from sighandler will jump to the tramp.
	189	Negative 8 offset because return is rtsd r15, 8 */
	190	regs->r15 = ((unsigned long)frame->tramp)-8;
	191
2ee2ff87	192	address = ((unsigned long)frame->tramp);
e05c7b1f	193	pmdp = pmd_off(current->mm, address);
2ee2ff87 MS	194
	195	preempt_disable();
	196	ptep = pte_offset_map(pmdp, address);
	197	if (pte_present(*ptep)) {
	198	address = (unsigned long) page_address(pte_page(*ptep));
	199	/* MS: I need add offset in page */
	200	address += ((unsigned long)frame->tramp) & ~PAGE_MASK;
	201	/* MS address is virtual */
a66a6265	202	address = __virt_to_phys(address);
2ee2ff87 MS	203	invalidate_icache_range(address, address + 8);
	204	flush_dcache_range(address, address + 8);
	205	}
	206	pte_unmap(ptep);
	207	preempt_enable();
2148daa9	208	if (err)
9c53c7ec	209	return -EFAULT;
2148daa9 MS	210
2148daa9 MS	211	/* Set up registers for signal handler */
6e83557c	212	regs->r1 = (unsigned long) frame;
2921e2bd	213
2148daa9	214	/* Signal handler args: */
6140de5a	215	regs->r5 = sig; /* arg 0: signum */
2148daa9 MS	216	regs->r6 = (unsigned long) &frame->info; /* arg 1: siginfo */
	217	regs->r7 = (unsigned long) &frame->uc; /* arg2: ucontext */
	218	/* Offset to handle microblaze rtid r14, 0 */
9c53c7ec	219	regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
2148daa9	220
2148daa9	221	#ifdef DEBUG_SIG
6bd55f0b	222	pr_info("SIG deliver (%s:%d): sp=%p pc=%08lx\n",
2148daa9 MS	223	current->comm, current->pid, frame, regs->pc);
	224	#endif
	225
bcb8c8d0	226	return 0;
2148daa9 MS	227	}
	228
	229	/* Handle restarting system calls */
	230	static inline void
	231	handle_restart(struct pt_regs regs, struct k_sigaction ka, int has_handler)
	232	{
	233	switch (regs->r3) {
	234	case -ERESTART_RESTARTBLOCK:
	235	case -ERESTARTNOHAND:
	236	if (!has_handler)
	237	goto do_restart;
	238	regs->r3 = -EINTR;
	239	break;
	240	case -ERESTARTSYS:
	241	if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
	242	regs->r3 = -EINTR;
	243	break;
	244	}
df561f66	245	fallthrough;
2148daa9 MS	246	case -ERESTARTNOINTR:
	247	do_restart:
	248	/* offset of 4 bytes to re-execute trap (brki) instruction */
	249	regs->pc -= 4;
	250	break;
	251	}
	252	}
	253
	254	/*
	255	* OK, we're invoking a handler
	256	*/
	257
a610d6e6	258	static void
9c53c7ec	259	handle_signal(struct ksignal ksig, struct pt_regs regs)
2148daa9	260	{
b7f9a11a	261	sigset_t *oldset = sigmask_to_save();
bcb8c8d0 MF	262	int ret;
bcb8c8d0 MF	263
2148daa9	264	/* Set up the stack frame */
9c53c7ec	265	ret = setup_rt_frame(ksig, oldset, regs);
bcb8c8d0	266
9c53c7ec	267	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
2148daa9 MS	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	*
	275	* Note that we go through the signals twice: once to check the signals that
	276	* the kernel can handle, and then we build all the user-level signal handling
	277	* stack-frames in one go after that.
	278	*/
83140191	279	static void do_signal(struct pt_regs *regs, int in_syscall)
2148daa9	280	{
9c53c7ec RW	281	struct ksignal ksig;
9c53c7ec RW	282
2148daa9	283	#ifdef DEBUG_SIG
6bd55f0b MS	284	pr_info("do signal: %p %d\n", regs, in_syscall);
6bd55f0b MS	285	pr_info("do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1,
e538c584	286	regs->r12, read_thread_flags());
2148daa9	287	#endif
2148daa9	288
9c53c7ec	289	if (get_signal(&ksig)) {
2148daa9 MS	290	/* Whee! Actually deliver the signal. */
2148daa9 MS	291	if (in_syscall)
9c53c7ec RW	292	handle_restart(regs, &ksig.ka, 1);
9c53c7ec RW	293	handle_signal(&ksig, regs);
83140191	294	return;
2148daa9 MS	295	}
	296
	297	if (in_syscall)
	298	handle_restart(regs, NULL, 0);
	299
3183e068 AB	300	/*
	301	* If there's no signal to deliver, we just put the saved sigmask
	302	* back.
	303	*/
51a7b448	304	restore_saved_sigmask();
2148daa9	305	}
969a9616	306
4378bb69	307	asmlinkage void do_notify_resume(struct pt_regs *regs, int in_syscall)
969a9616	308	{
ed2124c0 JA	309	if (test_thread_flag(TIF_SIGPENDING) \|\|
ed2124c0 JA	310	test_thread_flag(TIF_NOTIFY_SIGNAL))
83140191	311	do_signal(regs, in_syscall);
969a9616	312
3c532798	313	if (test_thread_flag(TIF_NOTIFY_RESUME))
969a9616	314	tracehook_notify_resume(regs);
969a9616	315	}