signal32.c

linux-2.4.29操作系统的源码

 *       sigqueueinfo             sys32_rt_sigqueueinfo
 *       sigsuspend               sys32_rt_sigsuspend
 *
 *  Other routines
 *        setup_rt_frame32
 *        copy_siginfo_to_user32
 *        siginfo32to64
 */


/*
 * This code executes after the rt signal handler in 32 bit mode has
 * completed and returned  
 */
long sys32_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
			unsigned long r6, unsigned long r7, unsigned long r8,
			struct pt_regs * regs)
{
	struct rt_sigframe_32 *rt_stack_frame;
	struct sigcontext32 sigctx;
	struct sigregs32 *signalregs;
 
	int i;
	elf_gregset_t32 saved_regs;   /* an array of 32 bit register values */
	sigset_t signal_set; 
	stack_t stack;

	/* Adjust the inputted reg1 to point to the rt signal frame */
	rt_stack_frame = (struct rt_sigframe_32 *)(regs->gpr[1] + __SIGNAL_FRAMESIZE32);
	/* Copy the information from the user stack  */
	if (copy_from_user(&sigctx, &rt_stack_frame->uc.uc_mcontext,sizeof(sigctx))
	    || copy_from_user(&signal_set, &rt_stack_frame->uc.uc_sigmask,sizeof(signal_set))
	    || copy_from_user(&stack,&rt_stack_frame->uc.uc_stack,sizeof(stack)))
		/* unable to copy from user storage */
		goto badframe;

	/*
	 * Unblock the signal that was processed 
	 *   After a signal handler runs - 
	 *     if the signal is blockable - the signal will be unblocked  
	 *       ( sigkill and sigstop are not blockable)
	 */
	sigdelsetmask(&signal_set, ~_BLOCKABLE); 
	/* update the current based on the sigmask found in the rt_stackframe */
	spin_lock_irq(&current->sigmask_lock);
	current->blocked = signal_set;
	recalc_sigpending(current);
	spin_unlock_irq(&current->sigmask_lock);

	signalregs = (struct sigregs32 *) (u64)sigctx.regs;

	if (copy_from_user(saved_regs, &signalregs->gp_regs,
			   sizeof(signalregs->gp_regs))) 
		goto badframe;

	/*
	 * The saved reg structure in the frame is an elf_grepset_t32,
	 * it is a 32 bit register save of the registers in the
	 * pt_regs structure that was stored on the kernel stack
	 * during the system call when the system call was interrupted
	 * for the signal. Only 32 bits are saved because the
	 * sigcontext contains a pointer to the regs and the sig
	 * context address is passed as a pointer to the signal handler
	 *
	 * The entries in the elf_grepset have the same index as
	 * the elements in the pt_regs structure.
	 */
	for (i = 0; i < 32; i++)
		regs->gpr[i] = (u64)(saved_regs[i]) & 0xFFFFFFFF;
	/*
	 * restore the non gpr registers
	 */
	regs->nip = (u64)(saved_regs[PT_NIP]) & 0xFFFFFFFF;
	regs->orig_gpr3 = (u64)(saved_regs[PT_ORIG_R3]) & 0xFFFFFFFF; 
	regs->ctr = (u64)(saved_regs[PT_CTR]) & 0xFFFFFFFF; 
	regs->link = (u64)(saved_regs[PT_LNK]) & 0xFFFFFFFF; 
	regs->xer = (u64)(saved_regs[PT_XER]) & 0xFFFFFFFF; 
	regs->ccr = (u64)(saved_regs[PT_CCR]) & 0xFFFFFFFF;
	/* regs->softe is left unchanged (like MSR.EE) */
	regs->result = (u64)(saved_regs[PT_RESULT]) & 0xFFFFFFFF;

	/* force the process to reload the FP registers from
	   current->thread when it next does FP instructions */
	regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1);
#ifndef CONFIG_SMP
	if (last_task_used_math == current)
		last_task_used_math = NULL;
#endif
	if (copy_from_user(current->thread.fpr, &signalregs->fp_regs,
			   sizeof(signalregs->fp_regs))) 
		goto badframe;

	return regs->result;

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



asmlinkage long sys32_rt_sigaction(int sig, const struct sigaction32 *act, struct sigaction32 *oact, size_t sigsetsize)
{
	struct k_sigaction new_ka, old_ka;
	int ret;
	sigset32_t set32;
	u32 handler;

	/* XXX: Don't preclude handling different sized sigset_t's.  */
	if (sigsetsize != sizeof(sigset32_t))
		return -EINVAL;

	if (act) {
		ret = get_user(handler, &act->sa_handler);
		ret |= __copy_from_user(&set32, &act->sa_mask,
					sizeof(sigset32_t));
		switch (_NSIG_WORDS) {
		case 4: new_ka.sa.sa_mask.sig[3] = set32.sig[6]
				| (((long)set32.sig[7]) << 32);
		case 3: new_ka.sa.sa_mask.sig[2] = set32.sig[4]
				| (((long)set32.sig[5]) << 32);
		case 2: new_ka.sa.sa_mask.sig[1] = set32.sig[2]
				| (((long)set32.sig[3]) << 32);
		case 1: new_ka.sa.sa_mask.sig[0] = set32.sig[0]
				| (((long)set32.sig[1]) << 32);
		}

		ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
		
		if (ret)
			return -EFAULT;
		new_ka.sa.sa_handler = (__sighandler_t)(long) handler;
	}

	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

	if (!ret && oact) {
		switch (_NSIG_WORDS) {
		case 4:
			set32.sig[7] = (old_ka.sa.sa_mask.sig[3] >> 32);
			set32.sig[6] = old_ka.sa.sa_mask.sig[3];
		case 3:
			set32.sig[5] = (old_ka.sa.sa_mask.sig[2] >> 32);
			set32.sig[4] = old_ka.sa.sa_mask.sig[2];
		case 2:
			set32.sig[3] = (old_ka.sa.sa_mask.sig[1] >> 32);
			set32.sig[2] = old_ka.sa.sa_mask.sig[1];
		case 1:
			set32.sig[1] = (old_ka.sa.sa_mask.sig[0] >> 32);
			set32.sig[0] = old_ka.sa.sa_mask.sig[0];
		}
		ret = put_user((long)old_ka.sa.sa_handler, &oact->sa_handler);
		ret |= __copy_to_user(&oact->sa_mask, &set32,
				      sizeof(sigset32_t));
		ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
	}

  	return ret;
}


extern asmlinkage long sys_rt_sigprocmask(int how, sigset_t *set, sigset_t *oset,
					  size_t sigsetsize);

/*
 * Note: it is necessary to treat how as an unsigned int, with the
 * corresponding cast to a signed int to insure that the proper
 * conversion (sign extension) between the register representation
 * of a signed int (msr in 32-bit mode) and the register representation
 * of a signed int (msr in 64-bit mode) is performed.
 */
asmlinkage long sys32_rt_sigprocmask(u32 how, sigset32_t *set, sigset32_t *oset, size_t sigsetsize)
{
	sigset_t s;
	sigset32_t s32;
	int ret;
	mm_segment_t old_fs = get_fs();

	if (set) {
		if (copy_from_user (&s32, set, sizeof(sigset32_t)))
			return -EFAULT;
    
		switch (_NSIG_WORDS) {
		case 4: s.sig[3] = s32.sig[6] | (((long)s32.sig[7]) << 32);
		case 3: s.sig[2] = s32.sig[4] | (((long)s32.sig[5]) << 32);
		case 2: s.sig[1] = s32.sig[2] | (((long)s32.sig[3]) << 32);
		case 1: s.sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
		}
	}
	
	set_fs (KERNEL_DS);
	ret = sys_rt_sigprocmask((int)how, set ? &s : NULL, oset ? &s : NULL,
				 sigsetsize); 
	set_fs (old_fs);
	if (ret)
		return ret;
	if (oset) {
		switch (_NSIG_WORDS) {
		case 4: s32.sig[7] = (s.sig[3] >> 32); s32.sig[6] = s.sig[3];
		case 3: s32.sig[5] = (s.sig[2] >> 32); s32.sig[4] = s.sig[2];
		case 2: s32.sig[3] = (s.sig[1] >> 32); s32.sig[2] = s.sig[1];
		case 1: s32.sig[1] = (s.sig[0] >> 32); s32.sig[0] = s.sig[0];
		}
		if (copy_to_user (oset, &s32, sizeof(sigset32_t)))
			return -EFAULT;
	}
	return 0;
}


extern asmlinkage long sys_rt_sigpending(sigset_t *set, size_t sigsetsize);



asmlinkage long sys32_rt_sigpending(sigset32_t *set,   __kernel_size_t32 sigsetsize)
{

	sigset_t s;
	sigset32_t s32;
	int ret;
	mm_segment_t old_fs = get_fs();
		
	set_fs (KERNEL_DS);
	ret = sys_rt_sigpending(&s, sigsetsize);
	set_fs (old_fs);
	if (!ret) {
		switch (_NSIG_WORDS) {
		case 4: s32.sig[7] = (s.sig[3] >> 32); s32.sig[6] = s.sig[3];
		case 3: s32.sig[5] = (s.sig[2] >> 32); s32.sig[4] = s.sig[2];
		case 2: s32.sig[3] = (s.sig[1] >> 32); s32.sig[2] = s.sig[1];
		case 1: s32.sig[1] = (s.sig[0] >> 32); s32.sig[0] = s.sig[0];
		}
		if (copy_to_user (set, &s32, sizeof(sigset32_t)))
			return -EFAULT;
	}
	return ret;
}



siginfo_t32 *
siginfo64to32(siginfo_t32 *d, siginfo_t *s)
{
	memset (d, 0, sizeof(siginfo_t32));
	d->si_signo = s->si_signo;
	d->si_errno = s->si_errno;
	d->si_code = (short)s->si_code;
	if (s->si_signo >= SIGRTMIN) {
		d->si_pid = s->si_pid;
		d->si_uid = s->si_uid;
		
		d->si_int = s->si_int;
	} else switch (s->si_signo) {
	/* XXX: What about POSIX1.b timers */
	case SIGCHLD:
		d->si_pid = s->si_pid;
		d->si_status = s->si_status;
		d->si_utime = s->si_utime;
		d->si_stime = s->si_stime;
		break;
	case SIGSEGV:
	case SIGBUS:
	case SIGFPE:
	case SIGILL:
		d->si_addr = (unsigned int)(u64)(s->si_addr);
        break;
	case SIGPOLL:
		d->si_band = s->si_band;
		d->si_fd = s->si_fd;
		break;
	default:
		d->si_pid = s->si_pid;
		d->si_uid = s->si_uid;
		break;
	}
	return d;
}

extern asmlinkage long
sys_rt_sigtimedwait(const sigset_t *uthese, siginfo_t *uinfo,
		    const struct timespec *uts, size_t sigsetsize);

asmlinkage long
sys32_rt_sigtimedwait(sigset32_t *uthese, siginfo_t32 *uinfo,
		      struct timespec32 *uts, __kernel_size_t32 sigsetsize)
{
	sigset_t s;
	sigset32_t s32;
	struct timespec t;
	int ret;
	mm_segment_t old_fs = get_fs();
	siginfo_t info;
	siginfo_t32 info32;
		
	if (copy_from_user (&s32, uthese, sizeof(sigset32_t)))
		return -EFAULT;
	switch (_NSIG_WORDS) {
	case 4: s.sig[3] = s32.sig[6] | (((long)s32.sig[7]) << 32);
	case 3: s.sig[2] = s32.sig[4] | (((long)s32.sig[5]) << 32);
	case 2: s.sig[1] = s32.sig[2] | (((long)s32.sig[3]) << 32);
	case 1: s.sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
	}
	if (uts) {
		ret = get_user (t.tv_sec, &uts->tv_sec);
		ret |= __get_user (t.tv_nsec, &uts->tv_nsec);
		if (ret)
			return -EFAULT;
	}
	set_fs (KERNEL_DS);
	if (uts) 
		ret = sys_rt_sigtimedwait(&s, &info, &t, sigsetsize);
	else
		ret = sys_rt_sigtimedwait(&s, &info, (struct timespec *)uts,
				sigsetsize);
	set_fs (old_fs);
	if (ret >= 0 && uinfo) {
		if (copy_to_user (uinfo, siginfo64to32(&info32, &info),
				  sizeof(siginfo_t32)))
			return -EFAULT;
	}
	return ret;
}



siginfo_t *
siginfo32to64(siginfo_t *d, siginfo_t32 *s)
{
	d->si_signo = s->si_signo;
	d->si_errno = s->si_errno;
	d->si_code = s->si_code;
	if (s->si_signo >= SIGRTMIN) {
		d->si_pid = s->si_pid;
		d->si_uid = s->si_uid;
		d->si_int = s->si_int;
        
	} else switch (s->si_signo) {
	/* XXX: What about POSIX1.b timers */
	case SIGCHLD:
		d->si_pid = s->si_pid;
		d->si_status = s->si_status;
		d->si_utime = s->si_utime;
		d->si_stime = s->si_stime;
		break;
	case SIGSEGV:
	case SIGBUS:
	case SIGFPE:
	case SIGILL:
		d->si_addr = (void *)A(s->si_addr);
  		break;
	case SIGPOLL:
		d->si_band = s->si_band;
		d->si_fd = s->si_fd;
		break;
	default:
		d->si_pid = s->si_pid;
		d->si_uid = s->si_uid;
		break;
	}
	return d;
}


extern asmlinkage long sys_rt_sigqueueinfo(int pid, int sig, siginfo_t *uinfo);

/*
 * Note: it is necessary to treat pid and sig as unsigned ints, with the
 * corresponding cast to a signed int to insure that the proper conversion
 * (sign extension) between the register representation of a signed int
 * (msr in 32-bit mode) and the register representation of a signed int
 * (msr in 64-bit mode) is performed.
 */
asmlinkage long sys32_rt_sigqueueinfo(u32 pid, u32 sig, siginfo_t32 *uinfo)
{
	siginfo_t info;
	siginfo_t32 info32;
	int ret;
	mm_segment_t old_fs = get_fs();
	
	if (copy_from_user (&info32, uinfo, sizeof(siginfo_t32)))
		return -EFAULT;
    	/* XXX: Is this correct? */
	siginfo32to64(&info, &info32);

	set_fs (KERNEL_DS);
	ret = sys_rt_sigqueueinfo((int)pid, (int)sig, &info);
	set_fs (old_fs);
	return ret;
}


int do_signal(sigset_t *oldset, struct pt_regs *regs);
int sys32_rt_sigsuspend(sigset32_t* unewset, size_t sigsetsize, int p3, int p4, int p6, int p7, struct pt_regs *regs)
{
	sigset_t saveset, newset;
	
	sigset32_t s32;

	/* XXX: Don't preclude handling different sized sigset_t's.  */
	if (sigsetsize != sizeof(sigset_t))
		return -EINVAL;

	if (copy_from_user(&s32, unewset, sizeof(s32)))
		return -EFAULT;

	/*
	 * Swap the 2 words of the 64-bit sigset_t (they are stored
	 * in the "wrong" endian in 32-bit user storage).
	 */
	switch (_NSIG_WORDS) {