signal32.c

microwindows移植到S3C44B0的源码

	switch (_NSIG_WORDS) {
	case 4: seta.sig[7] = (oldset->sig[3] >> 32);
		seta.sig[6] = oldset->sig[3];
	case 3: seta.sig[5] = (oldset->sig[2] >> 32);
		seta.sig[4] = oldset->sig[2];
	case 2: seta.sig[3] = (oldset->sig[1] >> 32);
		seta.sig[2] = oldset->sig[1];
	case 1: seta.sig[1] = (oldset->sig[0] >> 32);
		seta.sig[0] = oldset->sig[0];
	}
	err |= __copy_to_user(&sf->mask, &seta, sizeof(sigset_t32));

	err |= copy_in_user((u32 *)sf,
			    (u32 *)(regs->u_regs[UREG_FP]),
			    sizeof(struct reg_window32));
	if (err)
		goto sigsegv;
	
	/* 3. signal handler back-trampoline and parameters */
	regs->u_regs[UREG_FP] = (unsigned long) sf;
	regs->u_regs[UREG_I0] = signr;
	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;

	/* 4. signal handler */
	regs->tpc = (unsigned long) ka->sa.sa_handler;
	regs->tnpc = (regs->tpc + 4);
	if ((current->thread.flags & SPARC_FLAG_32BIT) != 0) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}

	/* 5. return to kernel instructions */
	if (ka->ka_restorer)
		regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
	else {
		/* Flush instruction space. */
		unsigned long address = ((unsigned long)&(sf->insns[0]));
		pgd_t *pgdp = pgd_offset(current->mm, address);
		pmd_t *pmdp = pmd_offset(pgdp, address);
		pte_t *ptep = pte_offset(pmdp, address);

		regs->u_regs[UREG_I7] = (unsigned long) (&(sf->insns[0]) - 2);
	
		/* mov __NR_rt_sigreturn, %g1 */
		err |= __put_user(0x82102065, &sf->insns[0]);

		/* t 0x10 */
		err |= __put_user(0x91d02010, &sf->insns[1]);
		if (err)
			goto sigsegv;

		if(pte_present(*ptep)) {
			unsigned long page = (unsigned long) page_address(pte_page(*ptep));

			__asm__ __volatile__(
			"	membar	#StoreStore\n"
			"	flush	%0 + %1"
			: : "r" (page), "r" (address & (PAGE_SIZE - 1))
			: "memory");
		}
	}
	return;

sigill:
	do_exit(SIGILL);
sigsegv:
	do_exit(SIGSEGV);
}

static inline void handle_signal32(unsigned long signr, struct k_sigaction *ka,
				   siginfo_t *info,
				   sigset_t *oldset, struct pt_regs *regs,
				   int svr4_signal)
{
	if(svr4_signal)
		setup_svr4_frame32(&ka->sa, regs->tpc, regs->tnpc, regs, signr, oldset);
	else {
		if (ka->sa.sa_flags & SA_SIGINFO)
			setup_rt_frame32(ka, regs, signr, oldset, info);
		else if (current->thread.flags & SPARC_FLAG_NEWSIGNALS)
			new_setup_frame32(ka, regs, signr, oldset);
		else
			setup_frame32(&ka->sa, regs, signr, oldset, info);
	}
	if(ka->sa.sa_flags & SA_ONESHOT)
		ka->sa.sa_handler = SIG_DFL;
	if(!(ka->sa.sa_flags & SA_NOMASK)) {
		spin_lock_irq(&current->sigmask_lock);
		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
		sigaddset(&current->blocked,signr);
		recalc_sigpending(current);
		spin_unlock_irq(&current->sigmask_lock);
	}
}

static inline void syscall_restart32(unsigned long orig_i0, struct pt_regs *regs,
				     struct sigaction *sa)
{
	switch(regs->u_regs[UREG_I0]) {
		case ERESTARTNOHAND:
		no_system_call_restart:
			regs->u_regs[UREG_I0] = EINTR;
			regs->tstate |= TSTATE_ICARRY;
			break;
		case ERESTARTSYS:
			if(!(sa->sa_flags & SA_RESTART))
				goto no_system_call_restart;
		/* fallthrough */
		case ERESTARTNOINTR:
			regs->u_regs[UREG_I0] = orig_i0;
			regs->tpc -= 4;
			regs->tnpc -= 4;
	}
}

#ifdef DEBUG_SIGNALS_MAPS

#define MAPS_LINE_FORMAT	  "%016lx-%016lx %s %016lx %s %lu "

static inline void read_maps (void)
{
	struct vm_area_struct * map, * next;
	char * buffer;
	ssize_t i;

	buffer = (char*)__get_free_page(GFP_KERNEL);
	if (!buffer)
		return;

	for (map = current->mm->mmap ; map ; map = next ) {
		/* produce the next line */
		char *line;
		char str[5], *cp = str;
		int flags;
		kdev_t dev;
		unsigned long ino;

		/*
		 * Get the next vma now (but it won't be used if we sleep).
		 */
		next = map->vm_next;
		flags = map->vm_flags;

		*cp++ = flags & VM_READ ? 'r' : '-';
		*cp++ = flags & VM_WRITE ? 'w' : '-';
		*cp++ = flags & VM_EXEC ? 'x' : '-';
		*cp++ = flags & VM_MAYSHARE ? 's' : 'p';
		*cp++ = 0;

		dev = 0;
		ino = 0;
		if (map->vm_file != NULL) {
			dev = map->vm_file->f_dentry->d_inode->i_dev;
			ino = map->vm_file->f_dentry->d_inode->i_ino;
			line = d_path(map->vm_file->f_dentry,
				      map->vm_file->f_vfsmnt,
				      buffer, PAGE_SIZE);
		}
		printk(MAPS_LINE_FORMAT, map->vm_start, map->vm_end, str, map->vm_pgoff << PAGE_SHIFT,
			      kdevname(dev), ino);
		if (map->vm_file != NULL)
			printk("%s\n", line);
		else
			printk("\n");
	}
	free_page((unsigned long)buffer);
	return;
}

#endif

/* 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.
 */
asmlinkage int do_signal32(sigset_t *oldset, struct pt_regs * regs,
			   unsigned long orig_i0, int restart_syscall)
{
	unsigned long signr;
	struct k_sigaction *ka;
	siginfo_t info;
	
	int svr4_signal = current->personality == PER_SVR4;
	
	for (;;) {
		spin_lock_irq(&current->sigmask_lock);
		signr = dequeue_signal(&current->blocked, &info);
		spin_unlock_irq(&current->sigmask_lock);
		
		if (!signr)
			break;

		if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) {
			/* Do the syscall restart before we let the debugger
			 * look at the child registers.
			 */
			if (restart_syscall &&
			    (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
			     regs->u_regs[UREG_I0] == ERESTARTSYS ||
			     regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
				regs->u_regs[UREG_I0] = orig_i0;
				regs->tpc -= 4;
				regs->tnpc -= 4;
				restart_syscall = 0;
			}

			current->exit_code = signr;
			current->state = TASK_STOPPED;
			notify_parent(current, SIGCHLD);
			schedule();
			if (!(signr = current->exit_code))
				continue;
			current->exit_code = 0;
			if (signr == SIGSTOP)
				continue;

			/* Update the siginfo structure.  Is this good?  */
			if (signr != info.si_signo) {
				info.si_signo = signr;
				info.si_errno = 0;
				info.si_code = SI_USER;
				info.si_pid = current->p_pptr->pid;
				info.si_uid = current->p_pptr->uid;
			}

			/* If the (new) signal is now blocked, requeue it.  */
			if (sigismember(&current->blocked, signr)) {
				send_sig_info(signr, &info, current);
				continue;
			}
		}
		
		ka = &current->sig->action[signr-1];
		
		if (ka->sa.sa_handler == SIG_IGN) {
			if (signr != SIGCHLD)
				continue;

			/* sys_wait4() grabs the master kernel lock, so
			 * we need not do so, that sucker should be
			 * threaded and would not be that difficult to
			 * do anyways.
			 */
			while (sys_wait4(-1, NULL, WNOHANG, NULL) > 0)
				;
			continue;
		}
		if (ka->sa.sa_handler == SIG_DFL) {
			unsigned long exit_code = signr;
			
			if (current->pid == 1)
				continue;
			switch (signr) {
			case SIGCONT: case SIGCHLD: case SIGWINCH:
				continue;

			case SIGTSTP: case SIGTTIN: case SIGTTOU:
				if (is_orphaned_pgrp(current->pgrp))
					continue;

			case SIGSTOP:
				if (current->ptrace & PT_PTRACED)
					continue;
				current->state = TASK_STOPPED;
				current->exit_code = signr;
				if (!(current->p_pptr->sig->action[SIGCHLD-1].sa.sa_flags &
				      SA_NOCLDSTOP))
					notify_parent(current, SIGCHLD);
				schedule();
				continue;

			case SIGQUIT: case SIGILL: case SIGTRAP:
			case SIGABRT: case SIGFPE: case SIGSEGV:
			case SIGBUS: case SIGSYS: case SIGXCPU: case SIGXFSZ:
				if (do_coredump(signr, regs))
					exit_code |= 0x80;
#ifdef DEBUG_SIGNALS
				/* Very useful to debug dynamic linker problems */
				printk ("Sig %ld going for %s[%d]...\n", signr, current->comm, current->pid);
				/* On SMP we are only interested in the current
				 * CPU's registers.
				 */
				__show_regs (regs);
#ifdef DEBUG_SIGNALS_TLB
				do {
					extern void sparc_ultra_dump_itlb(void);
					extern void sparc_ultra_dump_dtlb(void);
					sparc_ultra_dump_dtlb();
					sparc_ultra_dump_itlb();
				} while(0);
#endif
#ifdef DEBUG_SIGNALS_TRACE
				{
					struct reg_window32 *rw = (struct reg_window32 *)(regs->u_regs[UREG_FP] & 0xffffffff);
					unsigned int ins[8];

					while (rw &&
					       !(((unsigned long) rw) & 0x3)) {
						copy_from_user(ins, &rw->ins[0], sizeof(ins));
						printk("Caller[%08x](%08x,%08x,%08x,%08x,%08x,%08x)\n", ins[7], ins[0], ins[1], ins[2], ins[3], ins[4], ins[5]);
						rw = (struct reg_window32 *)(unsigned long)ins[6];
					}
				}
#endif			
#ifdef DEBUG_SIGNALS_MAPS	
				printk("Maps:\n");
				read_maps();
#endif
#endif
				/* fall through */
			default:
				sig_exit(signr, exit_code, &info);
				/* NOT REACHED */
			}
		}
		if (restart_syscall)
			syscall_restart32(orig_i0, regs, &ka->sa);
		handle_signal32(signr, ka, &info, oldset, regs, svr4_signal);
		return 1;
	}
	if (restart_syscall &&
	    (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
	     regs->u_regs[UREG_I0] == ERESTARTSYS ||
	     regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
		/* replay the system call when we are done */
		regs->u_regs[UREG_I0] = orig_i0;
		regs->tpc -= 4;
		regs->tnpc -= 4;
	}
	return 0;
}

struct sigstack32 {
	u32 the_stack;
	int cur_status;
};

asmlinkage int do_sys32_sigstack(u32 u_ssptr, u32 u_ossptr, unsigned long sp)
{
	struct sigstack32 *ssptr = (struct sigstack32 *)((unsigned long)(u_ssptr));
	struct sigstack32 *ossptr = (struct sigstack32 *)((unsigned long)(u_ossptr));
	int ret = -EFAULT;

	/* First see if old state is wanted. */
	if (ossptr) {
		if (put_user(current->sas_ss_sp + current->sas_ss_size, &ossptr->the_stack) ||
		    __put_user(on_sig_stack(sp), &ossptr->cur_status))
			goto out;
	}
	
	/* Now see if we want to update the new state. */
	if (ssptr) {
		void *ss_sp;

		if (get_user((long)ss_sp, &ssptr->the_stack))
			goto out;
		/* If the current stack was set with sigaltstack, don't
		   swap stacks while we are on it.  */
		ret = -EPERM;
		if (current->sas_ss_sp && on_sig_stack(sp))
			goto out;
			
		/* Since we don't know the extent of the stack, and we don't
		   track onstack-ness, but rather calculate it, we must
		   presume a size.  Ho hum this interface is lossy.  */
		current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
		current->sas_ss_size = SIGSTKSZ;
	}
	
	ret = 0;
out:
	return ret;
}

asmlinkage int do_sys32_sigaltstack(u32 ussa, u32 uossa, unsigned long sp)
{
	stack_t uss, uoss;
	int ret;
	mm_segment_t old_fs;
	
	if (ussa && (get_user((long)uss.ss_sp, &((stack_t32 *)(long)ussa)->ss_sp) ||
		    __get_user(uss.ss_flags, &((stack_t32 *)(long)ussa)->ss_flags) ||
		    __get_user(uss.ss_size, &((stack_t32 *)(long)ussa)->ss_size)))
		return -EFAULT;
	old_fs = get_fs();
	set_fs(KERNEL_DS);
	ret = do_sigaltstack(ussa ? &uss : NULL, uossa ? &uoss : NULL, sp);
	set_fs(old_fs);
	if (!ret && uossa && (put_user((long)uoss.ss_sp, &((stack_t32 *)(long)uossa)->ss_sp) ||
		    __put_user(uoss.ss_flags, &((stack_t32 *)(long)uossa)->ss_flags) ||
		    __put_user(uoss.ss_size, &((stack_t32 *)(long)uossa)->ss_size)))
		return -EFAULT;
	return ret;
}