static void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
				 size_t frame_size,
				 void **fpstate)
{
	unsigned long sp;

	
	sp = regs->sp;

	
	if (ka->sa.sa_flags & SA_ONSTACK) {
		if (sas_ss_flags(sp) == 0)
			sp = current->sas_ss_sp + current->sas_ss_size;
	}

	
	else if ((regs->ss & 0xffff) != __USER32_DS &&
		!(ka->sa.sa_flags & SA_RESTORER) &&
		 ka->sa.sa_restorer)
		sp = (unsigned long) ka->sa.sa_restorer;

	if (used_math()) {
		sp = sp - sig_xstate_ia32_size;
		*fpstate = (struct _fpstate_ia32 *) sp;
		if (save_i387_xstate_ia32(*fpstate) < 0)
			return (void __user *) -1L;
	}

	sp -= frame_size;
	sp = ((sp + 4) & -16ul) - 4;
	return (void __user *) sp;
}
/*
 * Determine which stack to use..
 */
static void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
				 size_t frame_size,
				 void __user **fpstate)
{
	unsigned long sp;

	/* Default to using normal stack */
	sp = regs->sp;

	/* This is the X/Open sanctioned signal stack switching.  */
	if (ka->sa.sa_flags & SA_ONSTACK) {
		if (sas_ss_flags(sp) == 0)
			sp = current->sas_ss_sp + current->sas_ss_size;
	}

	/* This is the legacy signal stack switching. */
	else if ((regs->ss & 0xffff) != __USER32_DS &&
		!(ka->sa.sa_flags & SA_RESTORER) &&
		 ka->sa.sa_restorer)
		sp = (unsigned long) ka->sa.sa_restorer;

	if (used_math()) {
		sp = sp - sig_xstate_ia32_size;
		*fpstate = (struct _fpstate_ia32 __user *) sp;
		if (save_i387_xstate_ia32(*fpstate) < 0)
			return (void __user *) -1L;
	}

	sp -= frame_size;
	/* Align the stack pointer according to the i386 ABI,
	 * i.e. so that on function entry ((sp + 4) & 15) == 0. */
	sp = ((sp - 12) & -16ul) - 4;
	return (void __user *) sp;
}
Esempio n. 3
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static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc,
				 void __user *fpstate,
				 struct pt_regs *regs, unsigned int mask)
{
	int tmp, err = 0;

	savesegment(gs, tmp);
	err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
	savesegment(fs, tmp);
	err |= __put_user(tmp, (unsigned int __user *)&sc->fs);
	savesegment(ds, tmp);
	err |= __put_user(tmp, (unsigned int __user *)&sc->ds);
	savesegment(es, tmp);
	err |= __put_user(tmp, (unsigned int __user *)&sc->es);

	err |= __put_user(regs->di, &sc->di);
	err |= __put_user(regs->si, &sc->si);
	err |= __put_user(regs->bp, &sc->bp);
	err |= __put_user(regs->sp, &sc->sp);
	err |= __put_user(regs->bx, &sc->bx);
	err |= __put_user(regs->dx, &sc->dx);
	err |= __put_user(regs->cx, &sc->cx);
	err |= __put_user(regs->ax, &sc->ax);
	err |= __put_user(regs->cs, &sc->cs);
	err |= __put_user(regs->ss, &sc->ss);
	err |= __put_user(current->thread.trap_no, &sc->trapno);
	err |= __put_user(current->thread.error_code, &sc->err);
	err |= __put_user(regs->ip, &sc->ip);
	err |= __put_user(regs->flags, &sc->flags);
	err |= __put_user(regs->sp, &sc->sp_at_signal);

	tmp = save_i387_xstate_ia32(fpstate);
	if (tmp < 0)
		err = -EFAULT;
	else
		err |= __put_user(ptr_to_compat(tmp ? fpstate : NULL),
					&sc->fpstate);

	/* non-iBCS2 extensions.. */
	err |= __put_user(mask, &sc->oldmask);
	err |= __put_user(current->thread.cr2, &sc->cr2);

	return err;
}