C++ wrusp函数代码示例

/*
 * Re-start a thread when doing execve()
 */
void
start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
{
	regs->pc = pc;
	regs->ps = 8;
	wrusp(sp);
}

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

        
	current_thread_info()->restart_block.fn = do_no_restart_syscall;


	if (__copy_from_user(regs, sc, sizeof(struct pt_regs)))
                goto badframe;

	

	regs->dccr |= 1 << 8;


	err |= __get_user(old_usp, &sc->usp);

	wrusp(old_usp);


	return err;

badframe:
	return 1;
}

int vmadump_restore_cpu(struct vmadump_map_ctx *ctx, struct file *file,
			struct pt_regs *regs) {
    struct pt_regs regtmp;
    struct switch_stack *ss, sstmp;
    unsigned long usp;
    int r;

    r = read_kern(ctx, file, &regtmp, sizeof(regtmp));
    if (r != sizeof(regtmp)) goto bad_read;

    /* Read extra reg info for alpha */
    ss = ((struct switch_stack *)regs)-1;
    r = read_kern(ctx, file, &sstmp, sizeof(sstmp));
    if (r != sizeof(sstmp)) goto bad_read;
    r = read_kern(ctx, file, &usp, sizeof(usp));
    if (r != sizeof(usp)) goto bad_read;

    /* These are the tid-bits we don't want to restore */
    regtmp.ps  = 8;		/* Processor status 8 = user space */
    regtmp.hae = regs->hae;	/* XXX What is this reg? */
    sstmp.r26  = ss->r26;	/* Not actually the user r26(ra). That
				 * one is in struct pt_regs. */
    /* Ok, do restore */
    memcpy(regs, &regtmp, sizeof(regtmp));
    memcpy(ss, &sstmp, sizeof(sstmp)); /* Restores FP regs + saved regs */
    wrusp(usp);
    return 0;

 bad_read:
    if (r >= 0) r = -EIO;
    return r;
}

static inline int
restore_sigcontext(struct pt_regs *regs, struct sigcontext *usc,
		   int *pd0)
{
	int err = 0;
	unsigned int ccr;
	unsigned int usp;
	unsigned int er0;

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

#define COPY(r) err |= __get_user(regs->r, &usc->sc_##r)    /* restore passed registers */
	COPY(er1);
	COPY(er2);
	COPY(er3);
	COPY(er5);
	COPY(pc);
	ccr = regs->ccr & 0x10;
	COPY(ccr);
#undef COPY
	regs->ccr &= 0xef;
	regs->ccr |= ccr;
	regs->orig_er0 = -1;		/* disable syscall checks */
	err |= __get_user(usp, &usc->sc_usp);
	wrusp(usp);

	err |= __get_user(er0, &usc->sc_er0);
	*pd0 = er0;
	return err;
}

static inline int
rt_restore_ucontext(struct pt_regs *regs, struct ucontext *uc, int *pd0)
{
	int temp;
	greg_t *gregs = uc->uc_mcontext.gregs;
	unsigned long usp;
	int err;

	err = __get_user(temp, &uc->uc_mcontext.version);
	if (temp != MCONTEXT_VERSION)
		goto badframe;
	/* restore passed registers */
	err |= __get_user(regs->er0, &gregs[0]);
	err |= __get_user(regs->er1, &gregs[1]);
	err |= __get_user(regs->er2, &gregs[2]);
	err |= __get_user(regs->er3, &gregs[3]);
	err |= __get_user(regs->er4, &gregs[4]);
	err |= __get_user(regs->er5, &gregs[5]);
	err |= __get_user(regs->er6, &gregs[6]);
	err |= __get_user(usp, &gregs[7]);
	wrusp(usp);
	err |= __get_user(regs->pc, &gregs[8]);
	err |= __get_user(temp, &gregs[9]);
	regs->ccr = (regs->ccr & 0x10) | (temp & 0xef);
	regs->orig_er0 = -1;		/* disable syscall checks */

	if (do_sigaltstack(&uc->uc_stack, NULL, usp) == -EFAULT)
		goto badframe;

	*pd0 = regs->er0;
	return err;

badframe:
	return 1;
}

static inline int
restore_sigcontext(struct pt_regs *regs, struct sigcontext *usc, void *fp,
		   int *pd0)
{
	struct sigcontext context;
	int err = 0;

	/* get previous context */
	if (copy_from_user(&context, usc, sizeof(context)))
		goto badframe;
	
	/* restore passed registers */
	regs->er1 = context.sc_er1;
	regs->er2 = context.sc_er2;
	regs->er3 = context.sc_er3;
	regs->er5 = context.sc_er5;
	regs->ccr = (regs->ccr & 0x10)|(context.sc_ccr & 0xef);
	regs->pc = context.sc_pc;
	regs->orig_er0 = -1;		/* disable syscall checks */
	wrusp(context.sc_usp);

	*pd0 = context.sc_er0;
	return err;

badframe:
	return 1;
}

static void
setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
            struct pt_regs *regs, struct switch_stack * sw)
{
    unsigned long oldsp, r26, err = 0;
    struct sigframe *frame;

    oldsp = rdusp();
    frame = get_sigframe(ka, oldsp, sizeof(*frame));
    if (verify_area(VERIFY_WRITE, frame, sizeof(*frame)))
        goto give_sigsegv;

    err |= setup_sigcontext(&frame->sc, regs, sw, set->sig[0], oldsp);
    if (_NSIG_WORDS > 1) {
        err |= __copy_to_user(frame->extramask, &set->sig[1],
                              sizeof(frame->extramask));
    }
    if (err)
        goto give_sigsegv;

    /* Set up to return from userspace.  If provided, use a stub
       already in userspace.  */
    if (ka->ka_restorer) {
        r26 = (unsigned long) ka->ka_restorer;
    } else {
        err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0);
        err |= __put_user(INSN_LDI_R0+__NR_sigreturn, frame->retcode+1);
        err |= __put_user(INSN_CALLSYS, frame->retcode+2);
        imb();
        r26 = (unsigned long) frame->retcode;
    }

    /* Check that everything was written properly.  */
    if (err)
        goto give_sigsegv;

    /* "Return" to the handler */
    regs->r26 = r26;
    regs->r27 = regs->pc = (unsigned long) ka->sa.sa_handler;
    regs->r16 = sig;			/* a0: signal number */
    regs->r17 = 0;				/* a1: exception code */
    regs->r18 = (unsigned long) &frame->sc;	/* a2: sigcontext pointer */
    wrusp((unsigned long) frame);

#if DEBUG_SIG
    printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
           current->comm, current->pid, frame, regs->pc, regs->r26);
#endif

    return;

give_sigsegv:
    if (sig == SIGSEGV)
        ka->sa.sa_handler = SIG_DFL;
    force_sig(SIGSEGV, current);
}

static int
setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
	       sigset_t *set, struct pt_regs *regs)
{
	unsigned long oldsp, r26, err = 0;
	struct rt_sigframe __user *frame;

	oldsp = rdusp();
	frame = get_sigframe(ka, oldsp, sizeof(*frame));
	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		return -EFAULT;

	err |= copy_siginfo_to_user(&frame->info, info);

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

	/* Set up to return from userspace.  If provided, use a stub
	   already in userspace.  */
	if (ka->ka_restorer) {
		r26 = (unsigned long) ka->ka_restorer;
	} else {
		err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0);
		err |= __put_user(INSN_LDI_R0+__NR_rt_sigreturn,
				  frame->retcode+1);
		err |= __put_user(INSN_CALLSYS, frame->retcode+2);
		imb();
		r26 = (unsigned long) frame->retcode;
	}

	if (err)
		return -EFAULT;

	/* "Return" to the handler */
	regs->r26 = r26;
	regs->r27 = regs->pc = (unsigned long) ka->sa.sa_handler;
	regs->r16 = sig;			  /* a0: signal number */
	regs->r17 = (unsigned long) &frame->info; /* a1: siginfo pointer */
	regs->r18 = (unsigned long) &frame->uc;	  /* a2: ucontext pointer */
	wrusp((unsigned long) frame);

#if DEBUG_SIG
	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
		current->comm, current->pid, frame, regs->pc, regs->r26);
#endif

	return 0;
}

static int setup_frame(int sig, struct k_sigaction *ka,
		       sigset_t *set, struct pt_regs *regs)
{
	struct sigframe __user *frame;
	unsigned long return_ip;
	int err = 0;

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

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		goto give_sigsegv;

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

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

	/* Set up to return from userspace.  If provided, use a stub
	   already in userspace.  */
	if (ka->sa.sa_flags & SA_RESTORER) {
		return_ip = (unsigned long)ka->sa.sa_restorer;
	} else {
		/* trampoline - the desired return ip is the retcode itself */
		return_ip = (unsigned long)&frame->retcode;
		/* This is movu.w __NR_sigreturn, r9; break 13; */
		err |= __put_user(0x9c5f,         (short __user*)(frame->retcode+0));
		err |= __put_user(__NR_sigreturn, (short __user*)(frame->retcode+2));
		err |= __put_user(0xe93d,         (short __user*)(frame->retcode+4));
	}

	if (err)
		goto give_sigsegv;

	/* Set up registers for signal handler */

	regs->irp = (unsigned long) ka->sa.sa_handler;  /* what we enter NOW   */
	regs->srp = return_ip;                          /* what we enter LATER */
	regs->r10 = sig;                                /* first argument is signo */

	/* actually move the usp to reflect the stacked frame */

	wrusp((unsigned long)frame);

	return 0;

give_sigsegv:
	force_sigsegv(sig, current);
	return -EFAULT;
}

static int
setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t * info,
	       sigset_t * set, struct pt_regs *regs)
{
	struct rt_sigframe *frame;
	int err = 0;

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

	err |= __put_user((current_thread_info()->exec_domain
			   && current_thread_info()->exec_domain->signal_invmap
			   && sig < 32
			   ? current_thread_info()->exec_domain->
			   signal_invmap[sig] : sig), &frame->sig);

	err |= __put_user(&frame->info, &frame->pinfo);
	err |= __put_user(&frame->uc, &frame->puc);
	err |= copy_siginfo_to_user(&frame->info, info);

	/* Create the ucontext.  */
	err |= __put_user(0, &frame->uc.uc_flags);
	err |= __put_user(0, &frame->uc.uc_link);
	err |=
	    __put_user((void *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
	err |= __put_user(sas_ss_flags(rdusp()), &frame->uc.uc_stack.ss_flags);
	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	err |= rt_setup_sigcontext(&frame->uc.uc_mcontext, regs);
	err |= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));

	if (err)
		goto give_sigsegv;

	/* Set up registers for signal handler */
	wrusp((unsigned long)frame);
	if (current->personality & FDPIC_FUNCPTRS) {
		struct fdpic_func_descriptor __user *funcptr =
			(struct fdpic_func_descriptor *) ka->sa.sa_handler;
		__get_user(regs->pc, &funcptr->text);
		__get_user(regs->p3, &funcptr->GOT);
	} else
		regs->pc = (unsigned long)ka->sa.sa_handler;
	regs->rets = SIGRETURN_STUB;

	regs->r0 = frame->sig;
	regs->r1 = (unsigned long)(&frame->info);
	regs->r2 = (unsigned long)(&frame->uc);

	return 0;

 give_sigsegv:
	if (sig == SIGSEGV)
		ka->sa.sa_handler = SIG_DFL;
	force_sig(SIGSEGV, current);
	return -EFAULT;
}

static int setup_frame(int sig, struct k_sigaction *ka,
		       sigset_t *set, struct pt_regs *regs)
{
	struct sigframe __user *frame;
	unsigned long return_ip;
	int err = 0;

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

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		goto give_sigsegv;

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

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

	if (ka->sa.sa_flags & SA_RESTORER) {
		return_ip = (unsigned long)ka->sa.sa_restorer;
	} else {
		
		return_ip = (unsigned long)&frame->retcode;
		
		err |= __put_user(0x9c5f,         (short __user*)(frame->retcode+0));
		err |= __put_user(__NR_sigreturn, (short __user*)(frame->retcode+2));
		err |= __put_user(0xe93d,         (short __user*)(frame->retcode+4));
	}

	if (err)
		goto give_sigsegv;

	

	regs->irp = (unsigned long) ka->sa.sa_handler;  
	regs->srp = return_ip;                          
	regs->r10 = sig;                                

	

	wrusp((unsigned long)frame);

	return 0;

give_sigsegv:
	force_sigsegv(sig, current);
	return -EFAULT;
}

static long
restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
		   struct switch_stack *sw)
{
	unsigned long usp;
	long i, err = __get_user(regs->pc, &sc->sc_pc);

	current_thread_info()->restart_block.fn = do_no_restart_syscall;

	sw->r26 = (unsigned long) ret_from_sys_call;

	err |= __get_user(regs->r0, sc->sc_regs+0);
	err |= __get_user(regs->r1, sc->sc_regs+1);
	err |= __get_user(regs->r2, sc->sc_regs+2);
	err |= __get_user(regs->r3, sc->sc_regs+3);
	err |= __get_user(regs->r4, sc->sc_regs+4);
	err |= __get_user(regs->r5, sc->sc_regs+5);
	err |= __get_user(regs->r6, sc->sc_regs+6);
	err |= __get_user(regs->r7, sc->sc_regs+7);
	err |= __get_user(regs->r8, sc->sc_regs+8);
	err |= __get_user(sw->r9, sc->sc_regs+9);
	err |= __get_user(sw->r10, sc->sc_regs+10);
	err |= __get_user(sw->r11, sc->sc_regs+11);
	err |= __get_user(sw->r12, sc->sc_regs+12);
	err |= __get_user(sw->r13, sc->sc_regs+13);
	err |= __get_user(sw->r14, sc->sc_regs+14);
	err |= __get_user(sw->r15, sc->sc_regs+15);
	err |= __get_user(regs->r16, sc->sc_regs+16);
	err |= __get_user(regs->r17, sc->sc_regs+17);
	err |= __get_user(regs->r18, sc->sc_regs+18);
	err |= __get_user(regs->r19, sc->sc_regs+19);
	err |= __get_user(regs->r20, sc->sc_regs+20);
	err |= __get_user(regs->r21, sc->sc_regs+21);
	err |= __get_user(regs->r22, sc->sc_regs+22);
	err |= __get_user(regs->r23, sc->sc_regs+23);
	err |= __get_user(regs->r24, sc->sc_regs+24);
	err |= __get_user(regs->r25, sc->sc_regs+25);
	err |= __get_user(regs->r26, sc->sc_regs+26);
	err |= __get_user(regs->r27, sc->sc_regs+27);
	err |= __get_user(regs->r28, sc->sc_regs+28);
	err |= __get_user(regs->gp, sc->sc_regs+29);
	err |= __get_user(usp, sc->sc_regs+30);
	wrusp(usp);

	for (i = 0; i < 31; i++)
		err |= __get_user(sw->fp[i], sc->sc_fpregs+i);
	err |= __get_user(sw->fp[31], &sc->sc_fpcr);

	return err;
}

/*
 * Do necessary setup to start up a newly executed thread.
 *
 * pass the data segment into user programs if it exists,
 * it can't hurt anything as far as I can tell
 */
void start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
{
	regs->pc = new_ip;
	if (current->mm)
		regs->p5 = current->mm->start_data;
#ifndef CONFIG_SMP
	task_thread_info(current)->l1_task_info.stack_start =
		(void *)current->mm->context.stack_start;
	task_thread_info(current)->l1_task_info.lowest_sp = (void *)new_sp;
	memcpy(L1_SCRATCH_TASK_INFO, &task_thread_info(current)->l1_task_info,
	       sizeof(*L1_SCRATCH_TASK_INFO));
#endif
	wrusp(new_sp);
}

static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
			  struct pt_regs *regs)
{
	struct rt_sigframe *frame;
	int err = 0;
	unsigned char *ret;

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

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

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

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

	/* Set up to return from userspace.  */
	ret = frame->retcode;
	if (ksig->ka.sa.sa_flags & SA_RESTORER)
		ret = (unsigned char *)(ksig->ka.sa.sa_restorer);
	else {
		/* sub.l er0,er0; mov.b #__NR_rt_sigreturn,r0l; trapa #0 */
		err |= __put_user(0x1a80f800 + (__NR_rt_sigreturn & 0xff),
				  (unsigned long *)(frame->retcode + 0));
		err |= __put_user(0x5700,
				  (unsigned short *)(frame->retcode + 4));
	}
	err |= __put_user(ret, &frame->pretcode);

	if (err)
		return -EFAULT;

	/* Set up registers for signal handler */
	wrusp((unsigned long) frame);
	regs->pc  = (unsigned long) ksig->ka.sa.sa_handler;
	regs->er0 = ksig->sig;
	regs->er1 = (unsigned long)&(frame->info);
	regs->er2 = (unsigned long)&frame->uc;
	regs->er5 = current->mm->start_data;	/* GOT base */

	return 0;
}

static void setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
			    sigset_t *set, struct pt_regs *regs)
{
	struct rt_sigframe *frame;
	int err = 0;

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

	err |= copy_siginfo_to_user(&frame->info, info);

	/* Create the ucontext.  */
	err |= __put_user(0, &frame->uc.uc_flags);
	err |= __put_user(0, &frame->uc.uc_link);
	err |= __put_user((void *)current->sas_ss_sp,
			  &frame->uc.uc_stack.ss_sp);
	err |= __put_user(sas_ss_flags(rdusp()),
			  &frame->uc.uc_stack.ss_flags);
	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	err |= rt_setup_ucontext(&frame->uc, regs);
	err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));

	/* Set up to return from userspace.  */
	err |= __put_user(frame->retcode, &frame->pretcode);

	/* sub.l er0,er0; mov.b #__NR_rt_sigreturn,r0l; trapa #0 */
	err != __put_user(0x1a80f800 + (__NR_rt_sigreturn & 0xff),
			(long *)(frame->retcode + 0));
	err |= __put_user(0x5700, (short *)(frame->retcode + 4));

	if (err)
		goto give_sigsegv;

	/* Set up registers for signal handler */
	wrusp ((unsigned long) frame);
	regs->pc  = (unsigned long) ka->sa.sa_handler;
	regs->er0 = (current_thread_info()->exec_domain
		     && current_thread_info()->exec_domain->signal_invmap
		     && sig < 32
		     ? current_thread_info()->exec_domain->signal_invmap[sig]
		     : sig);
	regs->er1 = (unsigned long)&(frame->info);
	regs->er2 = (unsigned long)&frame->uc;
	regs->er5 = current->mm->start_data;	/* GOT base */

	return;

give_sigsegv:
	force_sigsegv(sig, current);
}