ia32_signal.c

LINUX 2.6.17.4的源码

}

static int
restore_sigcontext_ia32 (struct pt_regs *regs, struct sigcontext_ia32 __user *sc, int *peax)
{
	unsigned int err = 0;

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

	if (!access_ok(VERIFY_READ, sc, sizeof(*sc)))
		return(-EFAULT);

#define COPY(ia64x, ia32x)	err |= __get_user(regs->ia64x, &sc->ia32x)

#define copyseg_gs(tmp)		(regs->r16 |= (unsigned long) (tmp) << 48)
#define copyseg_fs(tmp)		(regs->r16 |= (unsigned long) (tmp) << 32)
#define copyseg_cs(tmp)		(regs->r17 |= tmp)
#define copyseg_ss(tmp)		(regs->r17 |= (unsigned long) (tmp) << 16)
#define copyseg_es(tmp)		(regs->r16 |= (unsigned long) (tmp) << 16)
#define copyseg_ds(tmp)		(regs->r16 |= tmp)

#define COPY_SEG(seg)					\
	{						\
		unsigned short tmp;			\
		err |= __get_user(tmp, &sc->seg);	\
		copyseg_##seg(tmp);			\
	}
#define COPY_SEG_STRICT(seg)				\
	{						\
		unsigned short tmp;			\
		err |= __get_user(tmp, &sc->seg);	\
		copyseg_##seg(tmp|3);			\
	}

	/* To make COPY_SEGs easier, we zero r16, r17 */
	regs->r16 = 0;
	regs->r17 = 0;

	COPY_SEG(gs);
	COPY_SEG(fs);
	COPY_SEG(es);
	COPY_SEG(ds);
	COPY(r15, edi);
	COPY(r14, esi);
	COPY(r13, ebp);
	COPY(r12, esp);
	COPY(r11, ebx);
	COPY(r10, edx);
	COPY(r9, ecx);
	COPY(cr_iip, eip);
	COPY_SEG_STRICT(cs);
	COPY_SEG_STRICT(ss);
	ia32_load_segment_descriptors(current);
	{
		unsigned int tmpflags;
		unsigned long flag;

		/*
		 *  IA32 `eflags' is not part of `pt_regs', it's in an ar register which
		 *  is part of the thread context.  Fortunately, we are executing in the
		 *  IA32 process's context.
		 */
		err |= __get_user(tmpflags, &sc->eflags);
		flag = ia64_getreg(_IA64_REG_AR_EFLAG);
		flag &= ~0x40DD5;
		flag |= (tmpflags & 0x40DD5);
		ia64_setreg(_IA64_REG_AR_EFLAG, flag);

		regs->r1 = -1;	/* disable syscall checks, r1 is orig_eax */
	}

	{
		struct _fpstate_ia32 __user *buf = NULL;
		u32    fpstate_ptr;
		err |= get_user(fpstate_ptr, &(sc->fpstate));
		buf = compat_ptr(fpstate_ptr);
		if (buf) {
			err |= restore_ia32_fpstate_live(buf);
		}
	}

#if 0
	{
		struct _fpstate * buf;
		err |= __get_user(buf, &sc->fpstate);
		if (buf) {
			if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
				goto badframe;
			err |= restore_i387(buf);
		}
	}
#endif

	err |= __get_user(*peax, &sc->eax);
	return err;

#if 0
  badframe:
	return 1;
#endif
}

/*
 * Determine which stack to use..
 */
static inline void __user *
get_sigframe (struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
{
	unsigned long esp;

	/* Default to using normal stack (truncate off sign-extension of bit 31: */
	esp = (unsigned int) regs->r12;

	/* This is the X/Open sanctioned signal stack switching.  */
	if (ka->sa.sa_flags & SA_ONSTACK) {
		if (!on_sig_stack(esp))
			esp = current->sas_ss_sp + current->sas_ss_size;
	}
	/* Legacy stack switching not supported */

	return (void __user *)((esp - frame_size) & -8ul);
}

static int
setup_frame_ia32 (int sig, struct k_sigaction *ka, sigset_t *set, struct pt_regs * regs)
{
	struct exec_domain *ed = current_thread_info()->exec_domain;
	struct sigframe_ia32 __user *frame;
	int err = 0;

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

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

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

	err |= setup_sigcontext_ia32(&frame->sc, &frame->fpstate, regs, set->sig[0]);

	if (_COMPAT_NSIG_WORDS > 1)
		err |= __copy_to_user(frame->extramask, (char *) &set->sig + 4,
				      sizeof(frame->extramask));

	/* Set up to return from userspace.  If provided, use a stub
	   already in userspace.  */
	if (ka->sa.sa_flags & SA_RESTORER) {
		unsigned int restorer = IA32_SA_RESTORER(ka);
		err |= __put_user(restorer, &frame->pretcode);
	} else {
		/* Pointing to restorer in ia32 gate page */
		err |= __put_user(IA32_GATE_OFFSET, &frame->pretcode);
	}

	/* This is popl %eax ; movl $,%eax ; int $0x80
	 * and there for historical reasons only.
	 * See arch/i386/kernel/signal.c
	 */

	err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
	err |= __put_user(__IA32_NR_sigreturn, (int __user *)(frame->retcode+2));
	err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));

	if (err)
		goto give_sigsegv;

	/* Set up registers for signal handler */
	regs->r12 = (unsigned long) frame;
	regs->cr_iip = IA32_SA_HANDLER(ka);

	set_fs(USER_DS);

#if 0
	regs->eflags &= ~TF_MASK;
#endif

#if 0
	printk("SIG deliver (%s:%d): sig=%d sp=%p pc=%lx ra=%x\n",
               current->comm, current->pid, sig, (void *) frame, regs->cr_iip, frame->pretcode);
#endif

	return 1;

  give_sigsegv:
	force_sigsegv(sig, current);
	return 0;
}

static int
setup_rt_frame_ia32 (int sig, struct k_sigaction *ka, siginfo_t *info,
		     sigset_t *set, struct pt_regs * regs)
{
	struct exec_domain *ed = current_thread_info()->exec_domain;
	compat_uptr_t pinfo, puc;
	struct rt_sigframe_ia32 __user *frame;
	int err = 0;

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

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

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

	pinfo = (long __user) &frame->info;
	puc = (long __user) &frame->uc;
	err |= __put_user(pinfo, &frame->pinfo);
	err |= __put_user(puc, &frame->puc);
	err |= copy_siginfo_to_user32(&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(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
	err |= __put_user(sas_ss_flags(regs->r12), &frame->uc.uc_stack.ss_flags);
	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	err |= setup_sigcontext_ia32(&frame->uc.uc_mcontext, &frame->fpstate, regs, set->sig[0]);
	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	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) {
		unsigned int restorer = IA32_SA_RESTORER(ka);
		err |= __put_user(restorer, &frame->pretcode);
	} else {
		/* Pointing to rt_restorer in ia32 gate page */
		err |= __put_user(IA32_GATE_OFFSET + 8, &frame->pretcode);
	}

	/* This is movl $,%eax ; int $0x80
	 * and there for historical reasons only.
	 * See arch/i386/kernel/signal.c
	 */

	err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
	err |= __put_user(__IA32_NR_rt_sigreturn, (int __user *)(frame->retcode+1));
	err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));

	if (err)
		goto give_sigsegv;

	/* Set up registers for signal handler */
	regs->r12 = (unsigned long) frame;
	regs->cr_iip = IA32_SA_HANDLER(ka);

	set_fs(USER_DS);

#if 0
	regs->eflags &= ~TF_MASK;
#endif

#if 0
	printk("SIG deliver (%s:%d): sp=%p pc=%lx ra=%x\n",
               current->comm, current->pid, (void *) frame, regs->cr_iip, frame->pretcode);
#endif

	return 1;

give_sigsegv:
	force_sigsegv(sig, current);
	return 0;
}

int
ia32_setup_frame1 (int sig, struct k_sigaction *ka, siginfo_t *info,
		   sigset_t *set, struct pt_regs *regs)
{
       /* Set up the stack frame */
       if (ka->sa.sa_flags & SA_SIGINFO)
               return setup_rt_frame_ia32(sig, ka, info, set, regs);
       else
               return setup_frame_ia32(sig, ka, set, regs);
}

asmlinkage long
sys32_sigreturn (int arg0, int arg1, int arg2, int arg3, int arg4, int arg5,
		 int arg6, int arg7, struct pt_regs regs)
{
	unsigned long esp = (unsigned int) regs.r12;
	struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(esp - 8);
	sigset_t set;
	int eax;

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;

	if (__get_user(set.sig[0], &frame->sc.oldmask)
	    || (_COMPAT_NSIG_WORDS > 1 && __copy_from_user((char *) &set.sig + 4, &frame->extramask,
							 sizeof(frame->extramask))))
		goto badframe;

	sigdelsetmask(&set, ~_BLOCKABLE);
	spin_lock_irq(&current->sighand->siglock);
	current->blocked = set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	if (restore_sigcontext_ia32(&regs, &frame->sc, &eax))
		goto badframe;
	return eax;

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

asmlinkage long
sys32_rt_sigreturn (int arg0, int arg1, int arg2, int arg3, int arg4,
		    int arg5, int arg6, int arg7, struct pt_regs regs)
{
	unsigned long esp = (unsigned int) regs.r12;
	struct rt_sigframe_ia32 __user *frame = (struct rt_sigframe_ia32 __user *)(esp - 4);
	sigset_t set;
	int eax;

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
		goto badframe;

	sigdelsetmask(&set, ~_BLOCKABLE);
	spin_lock_irq(&current->sighand->siglock);
	current->blocked =  set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	if (restore_sigcontext_ia32(&regs, &frame->uc.uc_mcontext, &eax))
		goto badframe;

	/* It is more difficult to avoid calling this function than to
	   call it and ignore errors.  */
	do_sigaltstack((stack_t __user *) &frame->uc.uc_stack, NULL, esp);

	return eax;

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