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