signal32.c

linux-2.6.15.6

	/* Setup the signal information.  Solaris expects a bunch of
	 * information to be passed to the signal handler, we don't provide
	 * that much currently, should use siginfo.
	 */
	err |= __put_user(signr, &si->siginfo.signo);
	err |= __put_user(SVR4_SINOINFO, &si->siginfo.code);
	if (err)
		goto sigsegv;

	regs->u_regs[UREG_FP] = (unsigned long) sfp;
	regs->tpc = (unsigned long) sa->sa_handler;
	regs->tnpc = (regs->tpc + 4);
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}

	/* Arguments passed to signal handler */
	if (regs->u_regs[14]){
		struct reg_window32 __user *rw = (struct reg_window32 __user *)
			(regs->u_regs[14] & 0x00000000ffffffffUL);

		err |= __put_user(signr, &rw->ins[0]);
		err |= __put_user((u64)si, &rw->ins[1]);
		err |= __put_user((u64)uc, &rw->ins[2]);
		err |= __put_user((u64)sfp, &rw->ins[6]);	/* frame pointer */
		if (err)
			goto sigsegv;

		regs->u_regs[UREG_I0] = signr;
		regs->u_regs[UREG_I1] = (u32)(u64) si;
		regs->u_regs[UREG_I2] = (u32)(u64) uc;
	}
	return;

sigsegv:
	force_sigsegv(signr, current);
}

asmlinkage int
svr4_getcontext(svr4_ucontext_t __user *uc, struct pt_regs *regs)
{
	svr4_gregset_t  __user *gr;
	svr4_mcontext_t __user *mc;
	svr4_sigset_t setv;
	int i, err;
	u32 psr;

	synchronize_user_stack();
	save_and_clear_fpu();
	
	if (get_thread_wsaved())
		do_exit(SIGSEGV);

	err = clear_user(uc, sizeof(*uc));

	/* Setup convenience variables */
	mc = &uc->mcontext;
	gr = &mc->greg;

	setv.sigbits[0] = current->blocked.sig[0];
	setv.sigbits[1] = (current->blocked.sig[0] >> 32);
	if (_NSIG_WORDS >= 2) {
		setv.sigbits[2] = current->blocked.sig[1];
		setv.sigbits[3] = (current->blocked.sig[1] >> 32);
		err |= __copy_to_user(&uc->sigmask, &setv, sizeof(svr4_sigset_t));
	} else
		err |= __copy_to_user(&uc->sigmask, &setv, 2 * sizeof(unsigned));

	/* Store registers */
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}
	err |= __put_user(regs->tpc, &uc->mcontext.greg[SVR4_PC]);
	err |= __put_user(regs->tnpc, &uc->mcontext.greg[SVR4_NPC]);

	psr = tstate_to_psr(regs->tstate) & ~PSR_EF;		   
	if (current_thread_info()->fpsaved[0] & FPRS_FEF)
		psr |= PSR_EF;
	err |= __put_user(psr, &uc->mcontext.greg[SVR4_PSR]);

	err |= __put_user(regs->y, &uc->mcontext.greg[SVR4_Y]);
	
	/* Copy g[1..7] and o[0..7] registers */
	for (i = 0; i < 7; i++)
		err |= __put_user(regs->u_regs[UREG_G1+i], (&(*gr)[SVR4_G1])+i);
	for (i = 0; i < 8; i++)
		err |= __put_user(regs->u_regs[UREG_I0+i], (&(*gr)[SVR4_O0])+i);

	/* Setup sigaltstack */
	err |= __put_user(current->sas_ss_sp, &uc->stack.sp);
	err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &uc->stack.flags);
	err |= __put_user(current->sas_ss_size, &uc->stack.size);

	/* The register file is not saved
	 * we have already stuffed all of it with sync_user_stack
	 */
	return (err ? -EFAULT : 0);
}


/* Set the context for a svr4 application, this is Solaris way to sigreturn */
asmlinkage int svr4_setcontext(svr4_ucontext_t __user *c, struct pt_regs *regs)
{
	svr4_gregset_t  __user *gr;
	mm_segment_t old_fs;
	u32 pc, npc, psr, u_ss_sp;
	sigset_t set;
	svr4_sigset_t setv;
	int i, err;
	stack_t st;
	
	/* Fixme: restore windows, or is this already taken care of in
	 * svr4_setup_frame when sync_user_windows is done?
	 */
	flush_user_windows();
	
	if (get_thread_wsaved())
		goto sigsegv;

	if (((unsigned long) c) & 3){
		printk("Unaligned structure passed\n");
		goto sigsegv;
	}

	if (!__access_ok(c, sizeof(*c))) {
		/* Miguel, add nice debugging msg _here_. ;-) */
		goto sigsegv;
	}

	/* Check for valid PC and nPC */
	gr = &c->mcontext.greg;
	err = __get_user(pc, &((*gr)[SVR4_PC]));
	err |= __get_user(npc, &((*gr)[SVR4_NPC]));
	if ((pc | npc) & 3)
		goto sigsegv;
	
	/* Retrieve information from passed ucontext */
	/* note that nPC is ored a 1, this is used to inform entry.S */
	/* that we don't want it to mess with our PC and nPC */
	
	err |= copy_from_user(&setv, &c->sigmask, sizeof(svr4_sigset_t));
	set.sig[0] = setv.sigbits[0] | (((long)setv.sigbits[1]) << 32);
	if (_NSIG_WORDS >= 2)
		set.sig[1] = setv.sigbits[2] | (((long)setv.sigbits[3]) << 32);
	
	err |= __get_user(u_ss_sp, &c->stack.sp);
	st.ss_sp = compat_ptr(u_ss_sp);
	err |= __get_user(st.ss_flags, &c->stack.flags);
	err |= __get_user(st.ss_size, &c->stack.size);
	if (err)
		goto sigsegv;
		
	/* It is more difficult to avoid calling this function than to
	   call it and ignore errors.  */
	old_fs = get_fs();
	set_fs(KERNEL_DS);
	do_sigaltstack((stack_t __user *) &st, NULL, regs->u_regs[UREG_I6]);
	set_fs(old_fs);
	
	sigdelsetmask(&set, ~_BLOCKABLE);
	spin_lock_irq(&current->sighand->siglock);
	current->blocked = set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
	regs->tpc = pc;
	regs->tnpc = npc | 1;
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}
	err |= __get_user(regs->y, &((*gr)[SVR4_Y]));
	err |= __get_user(psr, &((*gr)[SVR4_PSR]));
	regs->tstate &= ~(TSTATE_ICC|TSTATE_XCC);
	regs->tstate |= psr_to_tstate_icc(psr);

	/* Restore g[1..7] and o[0..7] registers */
	for (i = 0; i < 7; i++)
		err |= __get_user(regs->u_regs[UREG_G1+i], (&(*gr)[SVR4_G1])+i);
	for (i = 0; i < 8; i++)
		err |= __get_user(regs->u_regs[UREG_I0+i], (&(*gr)[SVR4_O0])+i);
	if (err)
		goto sigsegv;

	return -EINTR;
sigsegv:
	return -EFAULT;
}

static void setup_rt_frame32(struct k_sigaction *ka, struct pt_regs *regs,
			     unsigned long signr, sigset_t *oldset,
			     siginfo_t *info)
{
	struct rt_signal_frame32 __user *sf;
	int sigframe_size;
	u32 psr;
	int i, err;
	compat_sigset_t seta;

	/* 1. Make sure everything is clean */
	synchronize_user_stack();
	save_and_clear_fpu();
	
	sigframe_size = RT_ALIGNEDSZ;
	if (!(current_thread_info()->fpsaved[0] & FPRS_FEF))
		sigframe_size -= sizeof(__siginfo_fpu_t);

	sf = (struct rt_signal_frame32 __user *)
		get_sigframe(&ka->sa, regs, sigframe_size);
	
	if (invalid_frame_pointer(sf, sigframe_size))
		goto sigill;

	if (get_thread_wsaved() != 0)
		goto sigill;

	/* 2. Save the current process state */
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}
	err  = put_user(regs->tpc, &sf->regs.pc);
	err |= __put_user(regs->tnpc, &sf->regs.npc);
	err |= __put_user(regs->y, &sf->regs.y);
	psr = tstate_to_psr(regs->tstate);
	if (current_thread_info()->fpsaved[0] & FPRS_FEF)
		psr |= PSR_EF;
	err |= __put_user(psr, &sf->regs.psr);
	for (i = 0; i < 16; i++)
		err |= __put_user(regs->u_regs[i], &sf->regs.u_regs[i]);
	err |= __put_user(sizeof(siginfo_extra_v8plus_t), &sf->extra_size);
	err |= __put_user(SIGINFO_EXTRA_V8PLUS_MAGIC, &sf->v8plus.g_upper[0]);
	for (i = 1; i < 16; i++)
		err |= __put_user(((u32 *)regs->u_regs)[2*i],
				  &sf->v8plus.g_upper[i]);
	err |= __put_user((regs->tstate & TSTATE_ASI) >> 24UL,
			  &sf->v8plus.asi);

	if (psr & PSR_EF) {
		err |= save_fpu_state32(regs, &sf->fpu_state);
		err |= __put_user((u64)&sf->fpu_state, &sf->fpu_save);
	} else {
		err |= __put_user(0, &sf->fpu_save);
	}

	/* Update the siginfo structure.  */
	err |= copy_siginfo_to_user32(&sf->info, info);
	
	/* Setup sigaltstack */
	err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
	err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
	err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);

	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(compat_sigset_t));

	err |= copy_in_user((u32 __user *)sf,
			    (u32 __user *)(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 (test_thread_flag(TIF_32BIT)) {
		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);
		pud_t *pudp = pud_offset(pgdp, address);
		pmd_t *pmdp = pmd_offset(pudp, address);
		pte_t *ptep;

		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;

		preempt_disable();
		ptep = pte_offset_map(pmdp, address);
		if (pte_present(*ptep)) {
			unsigned long page = (unsigned long)
				page_address(pte_page(*ptep));

			wmb();
			__asm__ __volatile__("flush	%0 + %1"
					     : /* no outputs */
					     : "r" (page),
					       "r" (address & (PAGE_SIZE - 1))
					     : "memory");
		}
		pte_unmap(ptep);
		preempt_enable();
	}
	return;

sigill:
	do_exit(SIGILL);
sigsegv:
	force_sigsegv(signr, current);
}

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 (test_thread_flag(TIF_NEWSIGNALS))
			new_setup_frame32(ka, regs, signr, oldset);
		else
			setup_frame32(&ka->sa, regs, signr, oldset, info);
	}
	spin_lock_irq(&current->sighand->siglock);
	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
	if (!(ka->sa.sa_flags & SA_NOMASK))
		sigaddset(&current->blocked,signr);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
}

static inline void syscall_restart32(unsigned long orig_i0, struct pt_regs *regs,
				     struct sigaction *sa)
{
	switch (regs->u_regs[UREG_I0]) {
	case ERESTART_RESTARTBLOCK:
	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;
	}
}

/* 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.
 */
int do_signal32(sigset_t *oldset, struct pt_regs * regs,
		unsigned long orig_i0, int restart_syscall)
{
	siginfo_t info;
	struct signal_deliver_cookie cookie;
	struct k_sigaction ka;
	int signr;
	int svr4_signal = current->personality == PER_SVR4;
	
	cookie.restart_syscall = restart_syscall;
	cookie.orig_i0 = orig_i0;

	signr = get_signal_to_deliver(&info, &ka, regs, &cookie);
	if (signr > 0) {
		if (cookie.restart_syscall)
			syscall_restart32(orig_i0, regs, &ka.sa);
		handle_signal32(signr, &ka, &info, oldset,
				regs, svr4_signal);
		return 1;
	}
	if (cookie.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] = cookie.orig_i0;
		regs->tpc -= 4;
		regs->tnpc -= 4;
	}
	if (cookie.restart_syscall &&
	    regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
		regs->u_regs[UREG_G1] = __NR_restart_syscall;
		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 __user *ssptr =
		(struct sigstack32 __user *)((unsigned long)(u_ssptr));
	struct sigstack32 __user *ossptr =
		(struct sigstack32 __user *)((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) {
		u32 ss_sp;

		if (get_user(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 long do_sys32_sigaltstack(u32 ussa, u32 uossa, unsigned long sp)
{
	stack_t uss, uoss;
	u32 u_ss_sp = 0;
	int ret;
	mm_segment_t old_fs;
	stack_t32 __user *uss32 = compat_ptr(ussa);
	stack_t32 __user *uoss32 = compat_ptr(uossa);
	
	if (ussa && (get_user(u_ss_sp, &uss32->ss_sp) ||
		    __get_user(uss.ss_flags, &uss32->ss_flags) ||
		    __get_user(uss.ss_size, &uss32->ss_size)))
		return -EFAULT;
	uss.ss_sp = compat_ptr(u_ss_sp);
	old_fs = get_fs();
	set_fs(KERNEL_DS);
	ret = do_sigaltstack(ussa ? (stack_t __user *) &uss : NULL,
			     uossa ? (stack_t __user *) &uoss : NULL, sp);
	set_fs(old_fs);
	if (!ret && uossa && (put_user(ptr_to_compat(uoss.ss_sp), &uoss32->ss_sp) ||
		    __put_user(uoss.ss_flags, &uoss32->ss_flags) ||
		    __put_user(uoss.ss_size, &uoss32->ss_size)))
		return -EFAULT;
	return ret;
}