compat_signal.c

LINUX 2.6.17.4的源码

/*
 *  arch/s390/kernel/compat_signal.c
 *
 *    Copyright (C) IBM Corp. 2000,2006
 *    Author(s): Denis Joseph Barrow ([e-mail],[e-mail])
 *               Gerhard Tonn ([e-mail])                  
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
 */

#include <linux/config.h>
#include <linux/compat.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.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/personality.h>
#include <linux/binfmts.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/lowcore.h>
#include "compat_linux.h"
#include "compat_ptrace.h"

#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))

typedef struct 
{
	__u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
	struct sigcontext32 sc;
	_sigregs32 sregs;
	int signo;
	__u8 retcode[S390_SYSCALL_SIZE];
} sigframe32;

typedef struct 
{
	__u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
	__u8 retcode[S390_SYSCALL_SIZE];
	compat_siginfo_t info;
	struct ucontext32 uc;
} rt_sigframe32;

int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
{
	int err;

	if (!access_ok (VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
		return -EFAULT;

	/* If you change siginfo_t structure, please be sure
	   this code is fixed accordingly.
	   It should never copy any pad contained in the structure
	   to avoid security leaks, but must copy the generic
	   3 ints plus the relevant union member.  
	   This routine must convert siginfo from 64bit to 32bit as well
	   at the same time.  */
	err = __put_user(from->si_signo, &to->si_signo);
	err |= __put_user(from->si_errno, &to->si_errno);
	err |= __put_user((short)from->si_code, &to->si_code);
	if (from->si_code < 0)
		err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
	else {
		switch (from->si_code >> 16) {
		case __SI_RT >> 16: /* This is not generated by the kernel as of now.  */
		case __SI_MESGQ >> 16:
			err |= __put_user(from->si_int, &to->si_int);
			/* fallthrough */
		case __SI_KILL >> 16:
			err |= __put_user(from->si_pid, &to->si_pid);
			err |= __put_user(from->si_uid, &to->si_uid);
			break;
		case __SI_CHLD >> 16:
			err |= __put_user(from->si_pid, &to->si_pid);
			err |= __put_user(from->si_uid, &to->si_uid);
			err |= __put_user(from->si_utime, &to->si_utime);
			err |= __put_user(from->si_stime, &to->si_stime);
			err |= __put_user(from->si_status, &to->si_status);
			break;
		case __SI_FAULT >> 16:
			err |= __put_user((unsigned long) from->si_addr,
					  &to->si_addr);
			break;
		case __SI_POLL >> 16:
			err |= __put_user(from->si_band, &to->si_band);
			err |= __put_user(from->si_fd, &to->si_fd);
			break;
		case __SI_TIMER >> 16:
			err |= __put_user(from->si_tid, &to->si_tid);
			err |= __put_user(from->si_overrun, &to->si_overrun);
			err |= __put_user(from->si_int, &to->si_int);
			break;
		default:
			break;
		}
	}
	return err;
}

int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
{
	int err;
	u32 tmp;

	if (!access_ok (VERIFY_READ, from, sizeof(compat_siginfo_t)))
		return -EFAULT;

	err = __get_user(to->si_signo, &from->si_signo);
	err |= __get_user(to->si_errno, &from->si_errno);
	err |= __get_user(to->si_code, &from->si_code);

	if (to->si_code < 0)
		err |= __copy_from_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
	else {
		switch (to->si_code >> 16) {
		case __SI_RT >> 16: /* This is not generated by the kernel as of now.  */
		case __SI_MESGQ >> 16:
			err |= __get_user(to->si_int, &from->si_int);
			/* fallthrough */
		case __SI_KILL >> 16:
			err |= __get_user(to->si_pid, &from->si_pid);
			err |= __get_user(to->si_uid, &from->si_uid);
			break;
		case __SI_CHLD >> 16:
			err |= __get_user(to->si_pid, &from->si_pid);
			err |= __get_user(to->si_uid, &from->si_uid);
			err |= __get_user(to->si_utime, &from->si_utime);
			err |= __get_user(to->si_stime, &from->si_stime);
			err |= __get_user(to->si_status, &from->si_status);
			break;
		case __SI_FAULT >> 16:
			err |= __get_user(tmp, &from->si_addr);
			to->si_addr = (void __user *)(u64) (tmp & PSW32_ADDR_INSN);
			break;
		case __SI_POLL >> 16:
			err |= __get_user(to->si_band, &from->si_band);
			err |= __get_user(to->si_fd, &from->si_fd);
			break;
		case __SI_TIMER >> 16:
			err |= __get_user(to->si_tid, &from->si_tid);
			err |= __get_user(to->si_overrun, &from->si_overrun);
			err |= __get_user(to->si_int, &from->si_int);
			break;
		default:
			break;
		}
	}
	return err;
}

asmlinkage long
sys32_sigaction(int sig, const struct old_sigaction32 __user *act,
		 struct old_sigaction32 __user *oact)
{
        struct k_sigaction new_ka, old_ka;
	unsigned long sa_handler, sa_restorer;
        int ret;

        if (act) {
		compat_old_sigset_t mask;
		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
		    __get_user(sa_handler, &act->sa_handler) ||
		    __get_user(sa_restorer, &act->sa_restorer))
			return -EFAULT;
		new_ka.sa.sa_handler = (__sighandler_t) sa_handler;
		new_ka.sa.sa_restorer = (void (*)(void)) sa_restorer;
		__get_user(new_ka.sa.sa_flags, &act->sa_flags);
		__get_user(mask, &act->sa_mask);
		siginitset(&new_ka.sa.sa_mask, mask);
        }

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

	if (!ret && oact) {
		sa_handler = (unsigned long) old_ka.sa.sa_handler;
		sa_restorer = (unsigned long) old_ka.sa.sa_restorer;
		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
		    __put_user(sa_handler, &oact->sa_handler) ||
		    __put_user(sa_restorer, &oact->sa_restorer))
			return -EFAULT;
		__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
		__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
        }

	return ret;
}

asmlinkage long
sys32_rt_sigaction(int sig, const struct sigaction32 __user *act,
	   struct sigaction32 __user *oact,  size_t sigsetsize)
{
	struct k_sigaction new_ka, old_ka;
	unsigned long sa_handler;
	int ret;
	compat_sigset_t set32;

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

	if (act) {
		ret = get_user(sa_handler, &act->sa_handler);
		ret |= __copy_from_user(&set32, &act->sa_mask,
					sizeof(compat_sigset_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) sa_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((unsigned long)old_ka.sa.sa_handler, &oact->sa_handler);
		ret |= __copy_to_user(&oact->sa_mask, &set32,
				      sizeof(compat_sigset_t));
		ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
	}

	return ret;
}

asmlinkage long
sys32_sigaltstack(const stack_t32 __user *uss, stack_t32 __user *uoss,
							struct pt_regs *regs)
{
	stack_t kss, koss;
	unsigned long ss_sp;
	int ret, err = 0;
	mm_segment_t old_fs = get_fs();

	if (uss) {
		if (!access_ok(VERIFY_READ, uss, sizeof(*uss)))
			return -EFAULT;
		err |= __get_user(ss_sp, &uss->ss_sp);
		err |= __get_user(kss.ss_size, &uss->ss_size);
		err |= __get_user(kss.ss_flags, &uss->ss_flags);
		if (err)
			return -EFAULT;
		kss.ss_sp = (void __user *) ss_sp;
	}

	set_fs (KERNEL_DS);
	ret = do_sigaltstack((stack_t __user *) (uss ? &kss : NULL),
			     (stack_t __user *) (uoss ? &koss : NULL),
			     regs->gprs[15]);
	set_fs (old_fs);

	if (!ret && uoss) {
		if (!access_ok(VERIFY_WRITE, uoss, sizeof(*uoss)))
			return -EFAULT;
		ss_sp = (unsigned long) koss.ss_sp;
		err |= __put_user(ss_sp, &uoss->ss_sp);
		err |= __put_user(koss.ss_size, &uoss->ss_size);
		err |= __put_user(koss.ss_flags, &uoss->ss_flags);
		if (err)
			return -EFAULT;
	}
	return ret;