[mirror_ubuntu-artful-kernel.git] / arch / sh / kernel / signal_32.c

/*
 *  linux/arch/sh/kernel/signal.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
 *
 *  SuperH version:  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
 *
 */
#include <linux/sched.h>
#include <linux/sched/task_stack.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/tty.h>
#include <linux/elf.h>
#include <linux/personality.h>
#include <linux/binfmts.h>
#include <linux/io.h>
#include <linux/tracehook.h>
#include <asm/ucontext.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
#include <asm/syscalls.h>
#include <asm/fpu.h>

struct fdpic_func_descriptor {
	unsigned long	text;
	unsigned long	GOT;
};

/*
 * The following define adds a 64 byte gap between the signal
 * stack frame and previous contents of the stack.  This allows
 * frame unwinding in a function epilogue but only if a frame
 * pointer is used in the function.  This is necessary because
 * current gcc compilers (<4.3) do not generate unwind info on
 * SH for function epilogues.
 */
#define UNWINDGUARD 64

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

#define MOVW(n)	 (0x9300|((n)-2))	/* Move mem word at PC+n to R3 */
#if defined(CONFIG_CPU_SH2)
#define TRAP_NOARG 0xc320		/* Syscall w/no args (NR in R3) */
#else
#define TRAP_NOARG 0xc310		/* Syscall w/no args (NR in R3) */
#endif
#define OR_R0_R0 0x200b			/* or r0,r0 (insert to avoid hardware bug) */

struct sigframe
{
	struct sigcontext sc;
	unsigned long extramask[_NSIG_WORDS-1];
	u16 retcode[8];
};

struct rt_sigframe
{
	struct siginfo info;
	struct ucontext uc;
	u16 retcode[8];
};

#ifdef CONFIG_SH_FPU
static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
{
	struct task_struct *tsk = current;

	if (!(boot_cpu_data.flags & CPU_HAS_FPU))
		return 0;

	set_used_math();
	return __copy_from_user(&tsk->thread.xstate->hardfpu, &sc->sc_fpregs[0],
				sizeof(long)*(16*2+2));
}

static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
				      struct pt_regs *regs)
{
	struct task_struct *tsk = current;

	if (!(boot_cpu_data.flags & CPU_HAS_FPU))
		return 0;

	if (!used_math())
		return __put_user(0, &sc->sc_ownedfp);

	if (__put_user(1, &sc->sc_ownedfp))
		return -EFAULT;

	/* This will cause a "finit" to be triggered by the next
	   attempted FPU operation by the 'current' process.
	   */
	clear_used_math();

	unlazy_fpu(tsk, regs);
	return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.xstate->hardfpu,
			      sizeof(long)*(16*2+2));
}
#endif /* CONFIG_SH_FPU */

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

#define COPY(x)		err |= __get_user(regs->x, &sc->sc_##x)
			COPY(regs[1]);
	COPY(regs[2]);	COPY(regs[3]);
	COPY(regs[4]);	COPY(regs[5]);
	COPY(regs[6]);	COPY(regs[7]);
	COPY(regs[8]);	COPY(regs[9]);
	COPY(regs[10]);	COPY(regs[11]);
	COPY(regs[12]);	COPY(regs[13]);
	COPY(regs[14]);	COPY(regs[15]);
	COPY(gbr);	COPY(mach);
	COPY(macl);	COPY(pr);
	COPY(sr);	COPY(pc);
#undef COPY

#ifdef CONFIG_SH_FPU
	if (boot_cpu_data.flags & CPU_HAS_FPU) {
		int owned_fp;
		struct task_struct *tsk = current;

		regs->sr |= SR_FD; /* Release FPU */
		clear_fpu(tsk, regs);
		clear_used_math();
		err |= __get_user (owned_fp, &sc->sc_ownedfp);
		if (owned_fp)
			err |= restore_sigcontext_fpu(sc);
	}
#endif

	regs->tra = -1;		/* disable syscall checks */
	err |= __get_user(*r0_p, &sc->sc_regs[0]);
	return err;
}

asmlinkage int sys_sigreturn(void)
{
	struct pt_regs *regs = current_pt_regs();
	struct sigframe __user *frame = (struct sigframe __user *)regs->regs[15];
	sigset_t set;
	int r0;

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

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;

	if (__get_user(set.sig[0], &frame->sc.oldmask)
	    || (_NSIG_WORDS > 1
		&& __copy_from_user(&set.sig[1], &frame->extramask,
				    sizeof(frame->extramask))))
		goto badframe;

	set_current_blocked(&set);

	if (restore_sigcontext(regs, &frame->sc, &r0))
		goto badframe;
	return r0;

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

asmlinkage int sys_rt_sigreturn(void)
{
	struct pt_regs *regs = current_pt_regs();
	struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->regs[15];
	sigset_t set;
	int r0;

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

	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, &r0))
		goto badframe;

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

	return r0;

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(regs[0]);	COPY(regs[1]);
	COPY(regs[2]);	COPY(regs[3]);
	COPY(regs[4]);	COPY(regs[5]);
	COPY(regs[6]);	COPY(regs[7]);
	COPY(regs[8]);	COPY(regs[9]);
	COPY(regs[10]);	COPY(regs[11]);
	COPY(regs[12]);	COPY(regs[13]);
	COPY(regs[14]);	COPY(regs[15]);
	COPY(gbr);	COPY(mach);
	COPY(macl);	COPY(pr);
	COPY(sr);	COPY(pc);
#undef COPY

#ifdef CONFIG_SH_FPU
	err |= save_sigcontext_fpu(sc, regs);
#endif

	/* non-iBCS2 extensions.. */
	err |= __put_user(mask, &sc->oldmask);

	return err;
}

/*
 * Determine which stack to use..
 */
static inline void __user *
get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
{
	if (ka->sa.sa_flags & SA_ONSTACK) {
		if (sas_ss_flags(sp) == 0)
			sp = current->sas_ss_sp + current->sas_ss_size;
	}

	return (void __user *)((sp - (frame_size+UNWINDGUARD)) & -8ul);
}

/* These symbols are defined with the addresses in the vsyscall page.
   See vsyscall-trapa.S.  */
extern void __kernel_sigreturn(void);
extern void __kernel_rt_sigreturn(void);

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

	frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));

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

	err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);

	if (_NSIG_WORDS > 1)
		err |= __copy_to_user(frame->extramask, &set->sig[1],
				      sizeof(frame->extramask));

	/* Set up to return from userspace.  If provided, use a stub
	   already in userspace.  */
	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
		regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
#ifdef CONFIG_VSYSCALL
	} else if (likely(current->mm->context.vdso)) {
		regs->pr = VDSO_SYM(&__kernel_sigreturn);
#endif
	} else {
		/* Generate return code (system call to sigreturn) */
		err |= __put_user(MOVW(7), &frame->retcode[0]);
		err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
		err |= __put_user(OR_R0_R0, &frame->retcode[2]);
		err |= __put_user(OR_R0_R0, &frame->retcode[3]);
		err |= __put_user(OR_R0_R0, &frame->retcode[4]);
		err |= __put_user(OR_R0_R0, &frame->retcode[5]);
		err |= __put_user(OR_R0_R0, &frame->retcode[6]);
		err |= __put_user((__NR_sigreturn), &frame->retcode[7]);
		regs->pr = (unsigned long) frame->retcode;
		flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
	}

	if (err)
		return -EFAULT;

	/* Set up registers for signal handler */
	regs->regs[15] = (unsigned long) frame;
	regs->regs[4] = sig; /* Arg for signal handler */
	regs->regs[5] = 0;
	regs->regs[6] = (unsigned long) &frame->sc;

	if (current->personality & FDPIC_FUNCPTRS) {
		struct fdpic_func_descriptor __user *funcptr =
			(struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;

		err |= __get_user(regs->pc, &funcptr->text);
		err |= __get_user(regs->regs[12], &funcptr->GOT);
	} else
		regs->pc = (unsigned long)ksig->ka.sa.sa_handler;

	if (err)
		return -EFAULT;

	pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
		 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);

	return 0;
}

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;

	frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));

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

	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->regs[15]);
	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.  */
	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
		regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
#ifdef CONFIG_VSYSCALL
	} else if (likely(current->mm->context.vdso)) {
		regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
#endif
	} else {
		/* Generate return code (system call to rt_sigreturn) */
		err |= __put_user(MOVW(7), &frame->retcode[0]);
		err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
		err |= __put_user(OR_R0_R0, &frame->retcode[2]);
		err |= __put_user(OR_R0_R0, &frame->retcode[3]);
		err |= __put_user(OR_R0_R0, &frame->retcode[4]);
		err |= __put_user(OR_R0_R0, &frame->retcode[5]);
		err |= __put_user(OR_R0_R0, &frame->retcode[6]);
		err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
		regs->pr = (unsigned long) frame->retcode;
		flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
	}

	if (err)
		return -EFAULT;

	/* Set up registers for signal handler */
	regs->regs[15] = (unsigned long) frame;
	regs->regs[4] = sig; /* Arg for signal handler */
	regs->regs[5] = (unsigned long) &frame->info;
	regs->regs[6] = (unsigned long) &frame->uc;

	if (current->personality & FDPIC_FUNCPTRS) {
		struct fdpic_func_descriptor __user *funcptr =
			(struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;

		err |= __get_user(regs->pc, &funcptr->text);
		err |= __get_user(regs->regs[12], &funcptr->GOT);
	} else
		regs->pc = (unsigned long)ksig->ka.sa.sa_handler;

	if (err)
		return -EFAULT;

	pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
		 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);

	return 0;
}

static inline void
handle_syscall_restart(unsigned long save_r0, struct pt_regs *regs,
		       struct sigaction *sa)
{
	/* If we're not from a syscall, bail out */
	if (regs->tra < 0)
		return;

	/* check for system call restart.. */
	switch (regs->regs[0]) {
		case -ERESTART_RESTARTBLOCK:
		case -ERESTARTNOHAND:
		no_system_call_restart:
			regs->regs[0] = -EINTR;
			break;

		case -ERESTARTSYS:
			if (!(sa->sa_flags & SA_RESTART))
				goto no_system_call_restart;
		/* fallthrough */
		case -ERESTARTNOINTR:
			regs->regs[0] = save_r0;
			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
			break;
	}
}

/*
 * OK, we're invoking a handler
 */
static void
handle_signal(struct ksignal *ksig, struct pt_regs *regs, unsigned int save_r0)
{
	sigset_t *oldset = sigmask_to_save();
	int ret;

	/* Set up the stack frame */
	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
		ret = setup_rt_frame(ksig, oldset, regs);
	else
		ret = setup_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, unsigned int save_r0)
{
	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)) {
		handle_syscall_restart(save_r0, regs, &ksig.ka.sa);

		/* Whee!  Actually deliver the signal.  */
		handle_signal(&ksig, regs, save_r0);
		return;
	}

	/* Did we come from a system call? */
	if (regs->tra >= 0) {
		/* Restart the system call - no handlers present */
		if (regs->regs[0] == -ERESTARTNOHAND ||
		    regs->regs[0] == -ERESTARTSYS ||
		    regs->regs[0] == -ERESTARTNOINTR) {
			regs->regs[0] = save_r0;
			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
		} else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
			regs->regs[3] = __NR_restart_syscall;
		}
	}

	/*
	 * 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, unsigned int save_r0,
				 unsigned long thread_info_flags)
{
	/* deal with pending signal delivery */
	if (thread_info_flags & _TIF_SIGPENDING)
		do_signal(regs, save_r0);

	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/sh/kernel/signal.c
	3	*
	4	* Copyright (C) 1991, 1992 Linus Torvalds
	5	*
	6	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	7	*
	8	* SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
	9	*
	10	*/
1da177e4	11	#include <linux/sched.h>
68db0cf1	12	#include <linux/sched/task_stack.h>
1da177e4 LT	13	#include <linux/mm.h>
1da177e4 LT	14	#include <linux/smp.h>
1da177e4 LT	15	#include <linux/kernel.h>
	16	#include <linux/signal.h>
	17	#include <linux/errno.h>
	18	#include <linux/wait.h>
	19	#include <linux/ptrace.h>
	20	#include <linux/unistd.h>
	21	#include <linux/stddef.h>
	22	#include <linux/tty.h>
19f9a34f	23	#include <linux/elf.h>
1da177e4 LT	24	#include <linux/personality.h>
1da177e4 LT	25	#include <linux/binfmts.h>
b66d51cb	26	#include <linux/io.h>
ab99c733	27	#include <linux/tracehook.h>
1da177e4	28	#include <asm/ucontext.h>
7c0f6ba6	29	#include <linux/uaccess.h>
1da177e4 LT	30	#include <asm/pgtable.h>
1da177e4 LT	31	#include <asm/cacheflush.h>
fa43972f	32	#include <asm/syscalls.h>
9bbafce2	33	#include <asm/fpu.h>
1da177e4	34
3bc24a1a PM	35	struct fdpic_func_descriptor {
	36	unsigned long text;
	37	unsigned long GOT;
	38	};
	39
2fc742f8 CS	40	/*
	41	* The following define adds a 64 byte gap between the signal
	42	* stack frame and previous contents of the stack. This allows
	43	* frame unwinding in a function epilogue but only if a frame
	44	* pointer is used in the function. This is necessary because
	45	* current gcc compilers (<4.3) do not generate unwind info on
	46	* SH for function epilogues.
	47	*/
	48	#define UNWINDGUARD 64
	49
1da177e4 LT	50	/*
	51	* Do a signal return; undo the signal stack.
	52	*/
	53
	54	#define MOVW(n) (0x9300\|((n)-2)) /* Move mem word at PC+n to R3 */
11cbb70e	55	#if defined(CONFIG_CPU_SH2)
9d4436a6 YS	56	#define TRAP_NOARG 0xc320 /* Syscall w/no args (NR in R3) */
	57	#else
	58	#define TRAP_NOARG 0xc310 /* Syscall w/no args (NR in R3) */
	59	#endif
1da177e4 LT	60	#define OR_R0_R0 0x200b /* or r0,r0 (insert to avoid hardware bug) */
	61
	62	struct sigframe
	63	{
	64	struct sigcontext sc;
	65	unsigned long extramask[_NSIG_WORDS-1];
	66	u16 retcode[8];
	67	};
	68
	69	struct rt_sigframe
	70	{
	71	struct siginfo info;
	72	struct ucontext uc;
	73	u16 retcode[8];
	74	};
	75
	76	#ifdef CONFIG_SH_FPU
	77	static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
	78	{
	79	struct task_struct *tsk = current;
	80
eaa47704	81	if (!(boot_cpu_data.flags & CPU_HAS_FPU))
1da177e4 LT	82	return 0;
	83
	84	set_used_math();
0ea820cf	85	return __copy_from_user(&tsk->thread.xstate->hardfpu, &sc->sc_fpregs[0],
1da177e4 LT	86	sizeof(long)(162+2));
	87	}
	88
	89	static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
	90	struct pt_regs *regs)
	91	{
	92	struct task_struct *tsk = current;
	93
eaa47704	94	if (!(boot_cpu_data.flags & CPU_HAS_FPU))
1da177e4 LT	95	return 0;
1da177e4 LT	96
a46808e1 AV	97	if (!used_math())
a46808e1 AV	98	return __put_user(0, &sc->sc_ownedfp);
1da177e4	99
a46808e1 AV	100	if (__put_user(1, &sc->sc_ownedfp))
a46808e1 AV	101	return -EFAULT;
1da177e4 LT	102
	103	/* This will cause a "finit" to be triggered by the next
	104	attempted FPU operation by the 'current' process.
	105	*/
	106	clear_used_math();
	107
	108	unlazy_fpu(tsk, regs);
0ea820cf	109	return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.xstate->hardfpu,
1da177e4 LT	110	sizeof(long)(162+2));
	111	}
	112	#endif /* CONFIG_SH_FPU */
	113
	114	static int
	115	restore_sigcontext(struct pt_regs regs, struct sigcontext __user sc, int *r0_p)
	116	{
	117	unsigned int err = 0;
	118
	119	#define COPY(x) err \|= __get_user(regs->x, &sc->sc_##x)
	120	COPY(regs[1]);
	121	COPY(regs[2]); COPY(regs[3]);
	122	COPY(regs[4]); COPY(regs[5]);
	123	COPY(regs[6]); COPY(regs[7]);
	124	COPY(regs[8]); COPY(regs[9]);
	125	COPY(regs[10]); COPY(regs[11]);
	126	COPY(regs[12]); COPY(regs[13]);
	127	COPY(regs[14]); COPY(regs[15]);
	128	COPY(gbr); COPY(mach);
	129	COPY(macl); COPY(pr);
	130	COPY(sr); COPY(pc);
	131	#undef COPY
	132
	133	#ifdef CONFIG_SH_FPU
eaa47704	134	if (boot_cpu_data.flags & CPU_HAS_FPU) {
1da177e4 LT	135	int owned_fp;
	136	struct task_struct *tsk = current;
	137
	138	regs->sr \|= SR_FD; /* Release FPU */
	139	clear_fpu(tsk, regs);
	140	clear_used_math();
a46808e1	141	err \|= __get_user (owned_fp, &sc->sc_ownedfp);
1da177e4 LT	142	if (owned_fp)
	143	err \|= restore_sigcontext_fpu(sc);
	144	}
	145	#endif
	146
	147	regs->tra = -1; /* disable syscall checks */
	148	err \|= __get_user(*r0_p, &sc->sc_regs[0]);
	149	return err;
	150	}
	151
abafe5d9	152	asmlinkage int sys_sigreturn(void)
1da177e4	153	{
abafe5d9	154	struct pt_regs *regs = current_pt_regs();
f0bc814c	155	struct sigframe __user frame = (struct sigframe __user )regs->regs[15];
1da177e4 LT	156	sigset_t set;
	157	int r0;
	158
1bec157a	159	/* Always make any pending restarted system calls return -EINTR */
f56141e3	160	current->restart_block.fn = do_no_restart_syscall;
1bec157a	161
1da177e4 LT	162	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	163	goto badframe;
	164
	165	if (__get_user(set.sig[0], &frame->sc.oldmask)
	166	\|\| (_NSIG_WORDS > 1
	167	&& __copy_from_user(&set.sig[1], &frame->extramask,
	168	sizeof(frame->extramask))))
	169	goto badframe;
	170
5e047fa1	171	set_current_blocked(&set);
1da177e4	172
f0bc814c	173	if (restore_sigcontext(regs, &frame->sc, &r0))
1da177e4 LT	174	goto badframe;
	175	return r0;
	176
	177	badframe:
	178	force_sig(SIGSEGV, current);
	179	return 0;
	180	}
	181
abafe5d9	182	asmlinkage int sys_rt_sigreturn(void)
1da177e4	183	{
abafe5d9	184	struct pt_regs *regs = current_pt_regs();
f0bc814c	185	struct rt_sigframe __user frame = (struct rt_sigframe __user )regs->regs[15];
1da177e4	186	sigset_t set;
1da177e4 LT	187	int r0;
1da177e4 LT	188
1bec157a	189	/* Always make any pending restarted system calls return -EINTR */
f56141e3	190	current->restart_block.fn = do_no_restart_syscall;
1bec157a	191
1da177e4 LT	192	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	193	goto badframe;
	194
	195	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	196	goto badframe;
	197
5e047fa1	198	set_current_blocked(&set);
1da177e4	199
f0bc814c	200	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
1da177e4 LT	201	goto badframe;
1da177e4 LT	202
7a879a94	203	if (restore_altstack(&frame->uc.uc_stack))
1da177e4	204	goto badframe;
1da177e4 LT	205
	206	return r0;
	207
	208	badframe:
	209	force_sig(SIGSEGV, current);
	210	return 0;
3aeb884b	211	}
1da177e4 LT	212
	213	/*
	214	* Set up a signal frame.
	215	*/
	216
	217	static int
	218	setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs,
	219	unsigned long mask)
	220	{
	221	int err = 0;
	222
	223	#define COPY(x) err \|= __put_user(regs->x, &sc->sc_##x)
	224	COPY(regs[0]); COPY(regs[1]);
	225	COPY(regs[2]); COPY(regs[3]);
	226	COPY(regs[4]); COPY(regs[5]);
	227	COPY(regs[6]); COPY(regs[7]);
	228	COPY(regs[8]); COPY(regs[9]);
	229	COPY(regs[10]); COPY(regs[11]);
	230	COPY(regs[12]); COPY(regs[13]);
	231	COPY(regs[14]); COPY(regs[15]);
	232	COPY(gbr); COPY(mach);
	233	COPY(macl); COPY(pr);
	234	COPY(sr); COPY(pc);
	235	#undef COPY
	236
	237	#ifdef CONFIG_SH_FPU
	238	err \|= save_sigcontext_fpu(sc, regs);
	239	#endif
	240
	241	/* non-iBCS2 extensions.. */
	242	err \|= __put_user(mask, &sc->oldmask);
	243
	244	return err;
	245	}
	246
	247	/*
	248	* Determine which stack to use..
	249	*/
	250	static inline void __user *
	251	get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
	252	{
	253	if (ka->sa.sa_flags & SA_ONSTACK) {
	254	if (sas_ss_flags(sp) == 0)
	255	sp = current->sas_ss_sp + current->sas_ss_size;
	256	}
	257
2fc742f8	258	return (void __user *)((sp - (frame_size+UNWINDGUARD)) & -8ul);
1da177e4 LT	259	}
1da177e4 LT	260
19f9a34f PM	261	/* These symbols are defined with the addresses in the vsyscall page.
19f9a34f PM	262	See vsyscall-trapa.S. */
94455711 MF	263	extern void __kernel_sigreturn(void);
94455711 MF	264	extern void __kernel_rt_sigreturn(void);
19f9a34f	265
b46e8487 RW	266	static int setup_frame(struct ksignal ksig, sigset_t set,
b46e8487 RW	267	struct pt_regs *regs)
1da177e4 LT	268	{
1da177e4 LT	269	struct sigframe __user *frame;
b46e8487	270	int err = 0, sig = ksig->sig;
1da177e4	271
b46e8487	272	frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));
1da177e4 LT	273
1da177e4 LT	274	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
b46e8487	275	return -EFAULT;
1da177e4	276
1da177e4 LT	277	err \|= setup_sigcontext(&frame->sc, regs, set->sig[0]);
1da177e4 LT	278
9f23e7e9	279	if (_NSIG_WORDS > 1)
1da177e4 LT	280	err \|= __copy_to_user(frame->extramask, &set->sig[1],
1da177e4 LT	281	sizeof(frame->extramask));
1da177e4 LT	282
	283	/* Set up to return from userspace. If provided, use a stub
	284	already in userspace. */
b46e8487 RW	285	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
b46e8487 RW	286	regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
19f9a34f PM	287	#ifdef CONFIG_VSYSCALL
	288	} else if (likely(current->mm->context.vdso)) {
	289	regs->pr = VDSO_SYM(&__kernel_sigreturn);
	290	#endif
1da177e4 LT	291	} else {
	292	/* Generate return code (system call to sigreturn) */
	293	err \|= __put_user(MOVW(7), &frame->retcode[0]);
9d4436a6	294	err \|= __put_user(TRAP_NOARG, &frame->retcode[1]);
1da177e4 LT	295	err \|= __put_user(OR_R0_R0, &frame->retcode[2]);
	296	err \|= __put_user(OR_R0_R0, &frame->retcode[3]);
	297	err \|= __put_user(OR_R0_R0, &frame->retcode[4]);
	298	err \|= __put_user(OR_R0_R0, &frame->retcode[5]);
	299	err \|= __put_user(OR_R0_R0, &frame->retcode[6]);
	300	err \|= __put_user((__NR_sigreturn), &frame->retcode[7]);
	301	regs->pr = (unsigned long) frame->retcode;
f2fb4e4f	302	flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
1da177e4 LT	303	}
	304
	305	if (err)
b46e8487	306	return -EFAULT;
1da177e4 LT	307
	308	/* Set up registers for signal handler */
	309	regs->regs[15] = (unsigned long) frame;
daea906d	310	regs->regs[4] = sig; /* Arg for signal handler */
1da177e4 LT	311	regs->regs[5] = 0;
1da177e4 LT	312	regs->regs[6] = (unsigned long) &frame->sc;
3bc24a1a PM	313
	314	if (current->personality & FDPIC_FUNCPTRS) {
	315	struct fdpic_func_descriptor __user *funcptr =
b46e8487	316	(struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;
3bc24a1a	317
a46808e1 AV	318	err \|= __get_user(regs->pc, &funcptr->text);
a46808e1 AV	319	err \|= __get_user(regs->regs[12], &funcptr->GOT);
3bc24a1a	320	} else
b46e8487	321	regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
1da177e4	322
a46808e1	323	if (err)
b46e8487	324	return -EFAULT;
a46808e1	325
9f23e7e9	326	pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
19c5870c	327	current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
1da177e4	328
9f23e7e9	329	return 0;
1da177e4 LT	330	}
1da177e4 LT	331
b46e8487 RW	332	static int setup_rt_frame(struct ksignal ksig, sigset_t set,
b46e8487 RW	333	struct pt_regs *regs)
1da177e4 LT	334	{
1da177e4 LT	335	struct rt_sigframe __user *frame;
b46e8487	336	int err = 0, sig = ksig->sig;
1da177e4	337
b46e8487	338	frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));
1da177e4 LT	339
1da177e4 LT	340	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
b46e8487	341	return -EFAULT;
1da177e4	342
b46e8487	343	err \|= copy_siginfo_to_user(&frame->info, &ksig->info);
1da177e4 LT	344
	345	/* Create the ucontext. */
	346	err \|= __put_user(0, &frame->uc.uc_flags);
fa43972f	347	err \|= __put_user(NULL, &frame->uc.uc_link);
7a879a94	348	err \|= __save_altstack(&frame->uc.uc_stack, regs->regs[15]);
1da177e4 LT	349	err \|= setup_sigcontext(&frame->uc.uc_mcontext,
	350	regs, set->sig[0]);
	351	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	352
	353	/* Set up to return from userspace. If provided, use a stub
	354	already in userspace. */
b46e8487 RW	355	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
b46e8487 RW	356	regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
19f9a34f PM	357	#ifdef CONFIG_VSYSCALL
	358	} else if (likely(current->mm->context.vdso)) {
	359	regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
	360	#endif
1da177e4 LT	361	} else {
	362	/* Generate return code (system call to rt_sigreturn) */
	363	err \|= __put_user(MOVW(7), &frame->retcode[0]);
9d4436a6	364	err \|= __put_user(TRAP_NOARG, &frame->retcode[1]);
1da177e4 LT	365	err \|= __put_user(OR_R0_R0, &frame->retcode[2]);
	366	err \|= __put_user(OR_R0_R0, &frame->retcode[3]);
	367	err \|= __put_user(OR_R0_R0, &frame->retcode[4]);
	368	err \|= __put_user(OR_R0_R0, &frame->retcode[5]);
	369	err \|= __put_user(OR_R0_R0, &frame->retcode[6]);
	370	err \|= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
	371	regs->pr = (unsigned long) frame->retcode;
4d2947f7	372	flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
1da177e4 LT	373	}
	374
	375	if (err)
b46e8487	376	return -EFAULT;
1da177e4 LT	377
	378	/* Set up registers for signal handler */
	379	regs->regs[15] = (unsigned long) frame;
daea906d	380	regs->regs[4] = sig; /* Arg for signal handler */
1da177e4 LT	381	regs->regs[5] = (unsigned long) &frame->info;
1da177e4 LT	382	regs->regs[6] = (unsigned long) &frame->uc;
3bc24a1a PM	383
	384	if (current->personality & FDPIC_FUNCPTRS) {
	385	struct fdpic_func_descriptor __user *funcptr =
b46e8487	386	(struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;
3bc24a1a	387
a46808e1 AV	388	err \|= __get_user(regs->pc, &funcptr->text);
a46808e1 AV	389	err \|= __get_user(regs->regs[12], &funcptr->GOT);
3bc24a1a	390	} else
b46e8487	391	regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
1da177e4	392
a46808e1	393	if (err)
b46e8487	394	return -EFAULT;
a46808e1	395
9f23e7e9	396	pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
19c5870c	397	current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
1da177e4	398
9f23e7e9	399	return 0;
1da177e4 LT	400	}
1da177e4 LT	401
f8b890ab PM	402	static inline void
	403	handle_syscall_restart(unsigned long save_r0, struct pt_regs *regs,
	404	struct sigaction *sa)
	405	{
	406	/* If we're not from a syscall, bail out */
	407	if (regs->tra < 0)
	408	return;
	409
	410	/* check for system call restart.. */
	411	switch (regs->regs[0]) {
	412	case -ERESTART_RESTARTBLOCK:
	413	case -ERESTARTNOHAND:
	414	no_system_call_restart:
	415	regs->regs[0] = -EINTR;
f8b890ab PM	416	break;
	417
	418	case -ERESTARTSYS:
	419	if (!(sa->sa_flags & SA_RESTART))
	420	goto no_system_call_restart;
	421	/* fallthrough */
	422	case -ERESTARTNOINTR:
	423	regs->regs[0] = save_r0;
9d56dd3b	424	regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
f8b890ab PM	425	break;
	426	}
	427	}
	428
1da177e4 LT	429	/*
	430	* OK, we're invoking a handler
	431	*/
a610d6e6	432	static void
b46e8487	433	handle_signal(struct ksignal ksig, struct pt_regs regs, unsigned int save_r0)
1da177e4	434	{
b7f9a11a	435	sigset_t *oldset = sigmask_to_save();
9f23e7e9 PM	436	int ret;
9f23e7e9 PM	437
1da177e4	438	/* Set up the stack frame */
b46e8487 RW	439	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
b46e8487 RW	440	ret = setup_rt_frame(ksig, oldset, regs);
1da177e4	441	else
b46e8487	442	ret = setup_frame(ksig, oldset, regs);
1da177e4	443
b46e8487	444	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
1da177e4 LT	445	}
	446
	447	/*
	448	* Note that 'init' is a special process: it doesn't get signals it doesn't
	449	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	450	* mistake.
	451	*
	452	* Note that we go through the signals twice: once to check the signals that
	453	* the kernel can handle, and then we build all the user-level signal handling
	454	* stack-frames in one go after that.
	455	*/
9f23e7e9	456	static void do_signal(struct pt_regs *regs, unsigned int save_r0)
1da177e4	457	{
b46e8487	458	struct ksignal ksig;
1da177e4 LT	459
	460	/*
	461	* We want the common case to go fast, which
	462	* is why we may in certain cases get here from
	463	* kernel mode. Just return without doing anything
	464	* if so.
	465	*/
	466	if (!user_mode(regs))
9f23e7e9	467	return;
1da177e4	468
b46e8487 RW	469	if (get_signal(&ksig)) {
b46e8487 RW	470	handle_syscall_restart(save_r0, regs, &ksig.ka.sa);
f8b890ab	471
1da177e4	472	/* Whee! Actually deliver the signal. */
b46e8487	473	handle_signal(&ksig, regs, save_r0);
c8bfa1fd	474	return;
1da177e4 LT	475	}
1da177e4 LT	476
1da177e4 LT	477	/* Did we come from a system call? */
	478	if (regs->tra >= 0) {
	479	/* Restart the system call - no handlers present */
	480	if (regs->regs[0] == -ERESTARTNOHAND \|\|
	481	regs->regs[0] == -ERESTARTSYS \|\|
0b892935	482	regs->regs[0] == -ERESTARTNOINTR) {
c8bfa1fd	483	regs->regs[0] = save_r0;
9d56dd3b	484	regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
0b892935	485	} else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
9d56dd3b	486	regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
0b892935	487	regs->regs[3] = __NR_restart_syscall;
1da177e4 LT	488	}
1da177e4 LT	489	}
9f23e7e9	490
56bfc42f PM	491	/*
	492	* If there's no signal to deliver, we just put the saved sigmask
	493	* back.
	494	*/
51a7b448	495	restore_saved_sigmask();
9f23e7e9 PM	496	}
	497
	498	asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
ab99c733	499	unsigned long thread_info_flags)
9f23e7e9 PM	500	{
9f23e7e9 PM	501	/* deal with pending signal delivery */
ab99c733	502	if (thread_info_flags & _TIF_SIGPENDING)
9f23e7e9	503	do_signal(regs, save_r0);
ab99c733 PM	504
	505	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
	506	clear_thread_flag(TIF_NOTIFY_RESUME);
	507	tracehook_notify_resume(regs);
	508	}
1da177e4	509	}