[linux-block.git] / arch / sh / kernel / signal_32.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  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
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* linux/arch/sh/kernel/signal.c
	4	*
	5	* Copyright (C) 1991, 1992 Linus Torvalds
	6	*
	7	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	8	*
	9	* SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
	10	*
	11	*/
1da177e4	12	#include <linux/sched.h>
68db0cf1	13	#include <linux/sched/task_stack.h>
1da177e4 LT	14	#include <linux/mm.h>
1da177e4 LT	15	#include <linux/smp.h>
1da177e4 LT	16	#include <linux/kernel.h>
	17	#include <linux/signal.h>
	18	#include <linux/errno.h>
	19	#include <linux/wait.h>
	20	#include <linux/ptrace.h>
	21	#include <linux/unistd.h>
	22	#include <linux/stddef.h>
	23	#include <linux/tty.h>
19f9a34f	24	#include <linux/elf.h>
1da177e4 LT	25	#include <linux/personality.h>
1da177e4 LT	26	#include <linux/binfmts.h>
b66d51cb	27	#include <linux/io.h>
ab99c733	28	#include <linux/tracehook.h>
1da177e4	29	#include <asm/ucontext.h>
7c0f6ba6	30	#include <linux/uaccess.h>
1da177e4 LT	31	#include <asm/pgtable.h>
1da177e4 LT	32	#include <asm/cacheflush.h>
fa43972f	33	#include <asm/syscalls.h>
9bbafce2	34	#include <asm/fpu.h>
1da177e4	35
3bc24a1a PM	36	struct fdpic_func_descriptor {
	37	unsigned long text;
	38	unsigned long GOT;
	39	};
	40
2fc742f8 CS	41	/*
	42	* The following define adds a 64 byte gap between the signal
	43	* stack frame and previous contents of the stack. This allows
	44	* frame unwinding in a function epilogue but only if a frame
	45	* pointer is used in the function. This is necessary because
	46	* current gcc compilers (<4.3) do not generate unwind info on
	47	* SH for function epilogues.
	48	*/
	49	#define UNWINDGUARD 64
	50
1da177e4 LT	51	/*
	52	* Do a signal return; undo the signal stack.
	53	*/
	54
	55	#define MOVW(n) (0x9300\|((n)-2)) /* Move mem word at PC+n to R3 */
11cbb70e	56	#if defined(CONFIG_CPU_SH2)
9d4436a6 YS	57	#define TRAP_NOARG 0xc320 /* Syscall w/no args (NR in R3) */
	58	#else
	59	#define TRAP_NOARG 0xc310 /* Syscall w/no args (NR in R3) */
	60	#endif
1da177e4 LT	61	#define OR_R0_R0 0x200b /* or r0,r0 (insert to avoid hardware bug) */
	62
	63	struct sigframe
	64	{
	65	struct sigcontext sc;
	66	unsigned long extramask[_NSIG_WORDS-1];
	67	u16 retcode[8];
	68	};
	69
	70	struct rt_sigframe
	71	{
	72	struct siginfo info;
	73	struct ucontext uc;
	74	u16 retcode[8];
	75	};
	76
	77	#ifdef CONFIG_SH_FPU
	78	static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
	79	{
	80	struct task_struct *tsk = current;
	81
eaa47704	82	if (!(boot_cpu_data.flags & CPU_HAS_FPU))
1da177e4 LT	83	return 0;
	84
	85	set_used_math();
0ea820cf	86	return __copy_from_user(&tsk->thread.xstate->hardfpu, &sc->sc_fpregs[0],
1da177e4 LT	87	sizeof(long)(162+2));
	88	}
	89
	90	static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
	91	struct pt_regs *regs)
	92	{
	93	struct task_struct *tsk = current;
	94
eaa47704	95	if (!(boot_cpu_data.flags & CPU_HAS_FPU))
1da177e4 LT	96	return 0;
1da177e4 LT	97
a46808e1 AV	98	if (!used_math())
a46808e1 AV	99	return __put_user(0, &sc->sc_ownedfp);
1da177e4	100
a46808e1 AV	101	if (__put_user(1, &sc->sc_ownedfp))
a46808e1 AV	102	return -EFAULT;
1da177e4 LT	103
	104	/* This will cause a "finit" to be triggered by the next
	105	attempted FPU operation by the 'current' process.
	106	*/
	107	clear_used_math();
	108
	109	unlazy_fpu(tsk, regs);
0ea820cf	110	return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.xstate->hardfpu,
1da177e4 LT	111	sizeof(long)(162+2));
	112	}
	113	#endif /* CONFIG_SH_FPU */
	114
	115	static int
	116	restore_sigcontext(struct pt_regs regs, struct sigcontext __user sc, int *r0_p)
	117	{
	118	unsigned int err = 0;
	119
	120	#define COPY(x) err \|= __get_user(regs->x, &sc->sc_##x)
	121	COPY(regs[1]);
	122	COPY(regs[2]); COPY(regs[3]);
	123	COPY(regs[4]); COPY(regs[5]);
	124	COPY(regs[6]); COPY(regs[7]);
	125	COPY(regs[8]); COPY(regs[9]);
	126	COPY(regs[10]); COPY(regs[11]);
	127	COPY(regs[12]); COPY(regs[13]);
	128	COPY(regs[14]); COPY(regs[15]);
	129	COPY(gbr); COPY(mach);
	130	COPY(macl); COPY(pr);
	131	COPY(sr); COPY(pc);
	132	#undef COPY
	133
	134	#ifdef CONFIG_SH_FPU
eaa47704	135	if (boot_cpu_data.flags & CPU_HAS_FPU) {
1da177e4 LT	136	int owned_fp;
	137	struct task_struct *tsk = current;
	138
	139	regs->sr \|= SR_FD; /* Release FPU */
	140	clear_fpu(tsk, regs);
	141	clear_used_math();
a46808e1	142	err \|= __get_user (owned_fp, &sc->sc_ownedfp);
1da177e4 LT	143	if (owned_fp)
	144	err \|= restore_sigcontext_fpu(sc);
	145	}
	146	#endif
	147
	148	regs->tra = -1; /* disable syscall checks */
	149	err \|= __get_user(*r0_p, &sc->sc_regs[0]);
	150	return err;
	151	}
	152
abafe5d9	153	asmlinkage int sys_sigreturn(void)
1da177e4	154	{
abafe5d9	155	struct pt_regs *regs = current_pt_regs();
f0bc814c	156	struct sigframe __user frame = (struct sigframe __user )regs->regs[15];
1da177e4 LT	157	sigset_t set;
	158	int r0;
	159
1bec157a	160	/* Always make any pending restarted system calls return -EINTR */
f56141e3	161	current->restart_block.fn = do_no_restart_syscall;
1bec157a	162
1da177e4 LT	163	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	164	goto badframe;
	165
	166	if (__get_user(set.sig[0], &frame->sc.oldmask)
	167	\|\| (_NSIG_WORDS > 1
	168	&& __copy_from_user(&set.sig[1], &frame->extramask,
	169	sizeof(frame->extramask))))
	170	goto badframe;
	171
5e047fa1	172	set_current_blocked(&set);
1da177e4	173
f0bc814c	174	if (restore_sigcontext(regs, &frame->sc, &r0))
1da177e4 LT	175	goto badframe;
	176	return r0;
	177
	178	badframe:
	179	force_sig(SIGSEGV, current);
	180	return 0;
	181	}
	182
abafe5d9	183	asmlinkage int sys_rt_sigreturn(void)
1da177e4	184	{
abafe5d9	185	struct pt_regs *regs = current_pt_regs();
f0bc814c	186	struct rt_sigframe __user frame = (struct rt_sigframe __user )regs->regs[15];
1da177e4	187	sigset_t set;
1da177e4 LT	188	int r0;
1da177e4 LT	189
1bec157a	190	/* Always make any pending restarted system calls return -EINTR */
f56141e3	191	current->restart_block.fn = do_no_restart_syscall;
1bec157a	192
1da177e4 LT	193	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	194	goto badframe;
	195
	196	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	197	goto badframe;
	198
5e047fa1	199	set_current_blocked(&set);
1da177e4	200
f0bc814c	201	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
1da177e4 LT	202	goto badframe;
1da177e4 LT	203
7a879a94	204	if (restore_altstack(&frame->uc.uc_stack))
1da177e4	205	goto badframe;
1da177e4 LT	206
	207	return r0;
	208
	209	badframe:
	210	force_sig(SIGSEGV, current);
	211	return 0;
3aeb884b	212	}
1da177e4 LT	213
	214	/*
	215	* Set up a signal frame.
	216	*/
	217
	218	static int
	219	setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs,
	220	unsigned long mask)
	221	{
	222	int err = 0;
	223
	224	#define COPY(x) err \|= __put_user(regs->x, &sc->sc_##x)
	225	COPY(regs[0]); COPY(regs[1]);
	226	COPY(regs[2]); COPY(regs[3]);
	227	COPY(regs[4]); COPY(regs[5]);
	228	COPY(regs[6]); COPY(regs[7]);
	229	COPY(regs[8]); COPY(regs[9]);
	230	COPY(regs[10]); COPY(regs[11]);
	231	COPY(regs[12]); COPY(regs[13]);
	232	COPY(regs[14]); COPY(regs[15]);
	233	COPY(gbr); COPY(mach);
	234	COPY(macl); COPY(pr);
	235	COPY(sr); COPY(pc);
	236	#undef COPY
	237
	238	#ifdef CONFIG_SH_FPU
	239	err \|= save_sigcontext_fpu(sc, regs);
	240	#endif
	241
	242	/* non-iBCS2 extensions.. */
	243	err \|= __put_user(mask, &sc->oldmask);
	244
	245	return err;
	246	}
	247
	248	/*
	249	* Determine which stack to use..
	250	*/
	251	static inline void __user *
	252	get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
	253	{
	254	if (ka->sa.sa_flags & SA_ONSTACK) {
	255	if (sas_ss_flags(sp) == 0)
	256	sp = current->sas_ss_sp + current->sas_ss_size;
	257	}
	258
2fc742f8	259	return (void __user *)((sp - (frame_size+UNWINDGUARD)) & -8ul);
1da177e4 LT	260	}
1da177e4 LT	261
19f9a34f PM	262	/* These symbols are defined with the addresses in the vsyscall page.
19f9a34f PM	263	See vsyscall-trapa.S. */
94455711 MF	264	extern void __kernel_sigreturn(void);
94455711 MF	265	extern void __kernel_rt_sigreturn(void);
19f9a34f	266
b46e8487 RW	267	static int setup_frame(struct ksignal ksig, sigset_t set,
b46e8487 RW	268	struct pt_regs *regs)
1da177e4 LT	269	{
1da177e4 LT	270	struct sigframe __user *frame;
b46e8487	271	int err = 0, sig = ksig->sig;
1da177e4	272
b46e8487	273	frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));
1da177e4 LT	274
1da177e4 LT	275	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
b46e8487	276	return -EFAULT;
1da177e4	277
1da177e4 LT	278	err \|= setup_sigcontext(&frame->sc, regs, set->sig[0]);
1da177e4 LT	279
9f23e7e9	280	if (_NSIG_WORDS > 1)
1da177e4 LT	281	err \|= __copy_to_user(frame->extramask, &set->sig[1],
1da177e4 LT	282	sizeof(frame->extramask));
1da177e4 LT	283
	284	/* Set up to return from userspace. If provided, use a stub
	285	already in userspace. */
b46e8487 RW	286	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
b46e8487 RW	287	regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
19f9a34f PM	288	#ifdef CONFIG_VSYSCALL
	289	} else if (likely(current->mm->context.vdso)) {
	290	regs->pr = VDSO_SYM(&__kernel_sigreturn);
	291	#endif
1da177e4 LT	292	} else {
	293	/* Generate return code (system call to sigreturn) */
	294	err \|= __put_user(MOVW(7), &frame->retcode[0]);
9d4436a6	295	err \|= __put_user(TRAP_NOARG, &frame->retcode[1]);
1da177e4 LT	296	err \|= __put_user(OR_R0_R0, &frame->retcode[2]);
	297	err \|= __put_user(OR_R0_R0, &frame->retcode[3]);
	298	err \|= __put_user(OR_R0_R0, &frame->retcode[4]);
	299	err \|= __put_user(OR_R0_R0, &frame->retcode[5]);
	300	err \|= __put_user(OR_R0_R0, &frame->retcode[6]);
	301	err \|= __put_user((__NR_sigreturn), &frame->retcode[7]);
	302	regs->pr = (unsigned long) frame->retcode;
f2fb4e4f	303	flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
1da177e4 LT	304	}
	305
	306	if (err)
b46e8487	307	return -EFAULT;
1da177e4 LT	308
	309	/* Set up registers for signal handler */
	310	regs->regs[15] = (unsigned long) frame;
daea906d	311	regs->regs[4] = sig; /* Arg for signal handler */
1da177e4 LT	312	regs->regs[5] = 0;
1da177e4 LT	313	regs->regs[6] = (unsigned long) &frame->sc;
3bc24a1a PM	314
	315	if (current->personality & FDPIC_FUNCPTRS) {
	316	struct fdpic_func_descriptor __user *funcptr =
b46e8487	317	(struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;
3bc24a1a	318
a46808e1 AV	319	err \|= __get_user(regs->pc, &funcptr->text);
a46808e1 AV	320	err \|= __get_user(regs->regs[12], &funcptr->GOT);
3bc24a1a	321	} else
b46e8487	322	regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
1da177e4	323
a46808e1	324	if (err)
b46e8487	325	return -EFAULT;
a46808e1	326
9f23e7e9	327	pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
19c5870c	328	current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
1da177e4	329
9f23e7e9	330	return 0;
1da177e4 LT	331	}
1da177e4 LT	332
b46e8487 RW	333	static int setup_rt_frame(struct ksignal ksig, sigset_t set,
b46e8487 RW	334	struct pt_regs *regs)
1da177e4 LT	335	{
1da177e4 LT	336	struct rt_sigframe __user *frame;
b46e8487	337	int err = 0, sig = ksig->sig;
1da177e4	338
b46e8487	339	frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));
1da177e4 LT	340
1da177e4 LT	341	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
b46e8487	342	return -EFAULT;
1da177e4	343
b46e8487	344	err \|= copy_siginfo_to_user(&frame->info, &ksig->info);
1da177e4 LT	345
	346	/* Create the ucontext. */
	347	err \|= __put_user(0, &frame->uc.uc_flags);
fa43972f	348	err \|= __put_user(NULL, &frame->uc.uc_link);
7a879a94	349	err \|= __save_altstack(&frame->uc.uc_stack, regs->regs[15]);
1da177e4 LT	350	err \|= setup_sigcontext(&frame->uc.uc_mcontext,
	351	regs, set->sig[0]);
	352	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	353
	354	/* Set up to return from userspace. If provided, use a stub
	355	already in userspace. */
b46e8487 RW	356	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
b46e8487 RW	357	regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
19f9a34f PM	358	#ifdef CONFIG_VSYSCALL
	359	} else if (likely(current->mm->context.vdso)) {
	360	regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
	361	#endif
1da177e4 LT	362	} else {
	363	/* Generate return code (system call to rt_sigreturn) */
	364	err \|= __put_user(MOVW(7), &frame->retcode[0]);
9d4436a6	365	err \|= __put_user(TRAP_NOARG, &frame->retcode[1]);
1da177e4 LT	366	err \|= __put_user(OR_R0_R0, &frame->retcode[2]);
	367	err \|= __put_user(OR_R0_R0, &frame->retcode[3]);
	368	err \|= __put_user(OR_R0_R0, &frame->retcode[4]);
	369	err \|= __put_user(OR_R0_R0, &frame->retcode[5]);
	370	err \|= __put_user(OR_R0_R0, &frame->retcode[6]);
	371	err \|= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
	372	regs->pr = (unsigned long) frame->retcode;
4d2947f7	373	flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
1da177e4 LT	374	}
	375
	376	if (err)
b46e8487	377	return -EFAULT;
1da177e4 LT	378
	379	/* Set up registers for signal handler */
	380	regs->regs[15] = (unsigned long) frame;
daea906d	381	regs->regs[4] = sig; /* Arg for signal handler */
1da177e4 LT	382	regs->regs[5] = (unsigned long) &frame->info;
1da177e4 LT	383	regs->regs[6] = (unsigned long) &frame->uc;
3bc24a1a PM	384
	385	if (current->personality & FDPIC_FUNCPTRS) {
	386	struct fdpic_func_descriptor __user *funcptr =
b46e8487	387	(struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;
3bc24a1a	388
a46808e1 AV	389	err \|= __get_user(regs->pc, &funcptr->text);
a46808e1 AV	390	err \|= __get_user(regs->regs[12], &funcptr->GOT);
3bc24a1a	391	} else
b46e8487	392	regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
1da177e4	393
a46808e1	394	if (err)
b46e8487	395	return -EFAULT;
a46808e1	396
9f23e7e9	397	pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
19c5870c	398	current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
1da177e4	399
9f23e7e9	400	return 0;
1da177e4 LT	401	}
1da177e4 LT	402
f8b890ab PM	403	static inline void
	404	handle_syscall_restart(unsigned long save_r0, struct pt_regs *regs,
	405	struct sigaction *sa)
	406	{
	407	/* If we're not from a syscall, bail out */
	408	if (regs->tra < 0)
	409	return;
	410
	411	/* check for system call restart.. */
	412	switch (regs->regs[0]) {
	413	case -ERESTART_RESTARTBLOCK:
	414	case -ERESTARTNOHAND:
	415	no_system_call_restart:
	416	regs->regs[0] = -EINTR;
f8b890ab PM	417	break;
	418
	419	case -ERESTARTSYS:
	420	if (!(sa->sa_flags & SA_RESTART))
	421	goto no_system_call_restart;
	422	/* fallthrough */
	423	case -ERESTARTNOINTR:
	424	regs->regs[0] = save_r0;
9d56dd3b	425	regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
f8b890ab PM	426	break;
	427	}
	428	}
	429
1da177e4 LT	430	/*
	431	* OK, we're invoking a handler
	432	*/
a610d6e6	433	static void
b46e8487	434	handle_signal(struct ksignal ksig, struct pt_regs regs, unsigned int save_r0)
1da177e4	435	{
b7f9a11a	436	sigset_t *oldset = sigmask_to_save();
9f23e7e9 PM	437	int ret;
9f23e7e9 PM	438
1da177e4	439	/* Set up the stack frame */
b46e8487 RW	440	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
b46e8487 RW	441	ret = setup_rt_frame(ksig, oldset, regs);
1da177e4	442	else
b46e8487	443	ret = setup_frame(ksig, oldset, regs);
1da177e4	444
b46e8487	445	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
1da177e4 LT	446	}
	447
	448	/*
	449	* Note that 'init' is a special process: it doesn't get signals it doesn't
	450	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	451	* mistake.
	452	*
	453	* Note that we go through the signals twice: once to check the signals that
	454	* the kernel can handle, and then we build all the user-level signal handling
	455	* stack-frames in one go after that.
	456	*/
9f23e7e9	457	static void do_signal(struct pt_regs *regs, unsigned int save_r0)
1da177e4	458	{
b46e8487	459	struct ksignal ksig;
1da177e4 LT	460
	461	/*
	462	* We want the common case to go fast, which
	463	* is why we may in certain cases get here from
	464	* kernel mode. Just return without doing anything
	465	* if so.
	466	*/
	467	if (!user_mode(regs))
9f23e7e9	468	return;
1da177e4	469
b46e8487 RW	470	if (get_signal(&ksig)) {
b46e8487 RW	471	handle_syscall_restart(save_r0, regs, &ksig.ka.sa);
f8b890ab	472
1da177e4	473	/* Whee! Actually deliver the signal. */
b46e8487	474	handle_signal(&ksig, regs, save_r0);
c8bfa1fd	475	return;
1da177e4 LT	476	}
1da177e4 LT	477
1da177e4 LT	478	/* Did we come from a system call? */
	479	if (regs->tra >= 0) {
	480	/* Restart the system call - no handlers present */
	481	if (regs->regs[0] == -ERESTARTNOHAND \|\|
	482	regs->regs[0] == -ERESTARTSYS \|\|
0b892935	483	regs->regs[0] == -ERESTARTNOINTR) {
c8bfa1fd	484	regs->regs[0] = save_r0;
9d56dd3b	485	regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
0b892935	486	} else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
9d56dd3b	487	regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
0b892935	488	regs->regs[3] = __NR_restart_syscall;
1da177e4 LT	489	}
1da177e4 LT	490	}
9f23e7e9	491
56bfc42f PM	492	/*
	493	* If there's no signal to deliver, we just put the saved sigmask
	494	* back.
	495	*/
51a7b448	496	restore_saved_sigmask();
9f23e7e9 PM	497	}
	498
	499	asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
ab99c733	500	unsigned long thread_info_flags)
9f23e7e9 PM	501	{
9f23e7e9 PM	502	/* deal with pending signal delivery */
ab99c733	503	if (thread_info_flags & _TIF_SIGPENDING)
9f23e7e9	504	do_signal(regs, save_r0);
ab99c733 PM	505
	506	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
	507	clear_thread_flag(TIF_NOTIFY_RESUME);
	508	tracehook_notify_resume(regs);
	509	}
1da177e4	510	}