signal.c

优龙2410linux2.6.8内核源代码

	sigdelsetmask(&set, ~_BLOCKABLE);
	spin_lock_irq(&current->sighand->siglock);
	current->blocked = set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
	return;
segv:
	send_sig(SIGSEGV, current, 1);
}

/* Checks if the fp is valid */
static inline int invalid_frame_pointer(void __user *fp, int fplen)
{
	if ((((unsigned long) fp) & 7) ||
	    !__access_ok((unsigned long)fp, fplen) ||
	    ((sparc_cpu_model == sun4 || sparc_cpu_model == sun4c) &&
	     ((unsigned long) fp < 0xe0000000 && (unsigned long) fp >= 0x20000000)))
		return 1;
	
	return 0;
}

static inline void __user *get_sigframe(struct sigaction *sa, struct pt_regs *regs, unsigned long framesize)
{
	unsigned long sp;

	sp = regs->u_regs[UREG_FP];

	/* This is the X/Open sanctioned signal stack switching.  */
	if (sa->sa_flags & SA_ONSTACK) {
		if (!on_sig_stack(sp) && !((current->sas_ss_sp + current->sas_ss_size) & 7))
			sp = current->sas_ss_sp + current->sas_ss_size;
	}
	return (void __user *)(sp - framesize);
}

static inline void
setup_frame(struct sigaction *sa, struct pt_regs *regs, int signr, sigset_t *oldset, siginfo_t *info)
{
	struct signal_sframe __user *sframep;
	struct sigcontext __user *sc;
	int window = 0, err;
	unsigned long pc = regs->pc;
	unsigned long npc = regs->npc;
	struct thread_info *tp = current_thread_info();
	void __user *sig_address;
	int sig_code;

	synchronize_user_stack();
	sframep = (struct signal_sframe __user *)
		get_sigframe(sa, regs, SF_ALIGNEDSZ);
	if (invalid_frame_pointer(sframep, sizeof(*sframep))){
		/* Don't change signal code and address, so that
		 * post mortem debuggers can have a look.
		 */
		goto sigill_and_return;
	}

	sc = &sframep->sig_context;

	/* We've already made sure frame pointer isn't in kernel space... */
	err  = __put_user((sas_ss_flags(regs->u_regs[UREG_FP]) == SS_ONSTACK),
			 &sc->sigc_onstack);
	err |= __put_user(oldset->sig[0], &sc->sigc_mask);
	err |= __copy_to_user(sframep->extramask, &oldset->sig[1],
			      (_NSIG_WORDS - 1) * sizeof(unsigned int));
	err |= __put_user(regs->u_regs[UREG_FP], &sc->sigc_sp);
	err |= __put_user(pc, &sc->sigc_pc);
	err |= __put_user(npc, &sc->sigc_npc);
	err |= __put_user(regs->psr, &sc->sigc_psr);
	err |= __put_user(regs->u_regs[UREG_G1], &sc->sigc_g1);
	err |= __put_user(regs->u_regs[UREG_I0], &sc->sigc_o0);
	err |= __put_user(tp->w_saved, &sc->sigc_oswins);
	if (tp->w_saved)
		for (window = 0; window < tp->w_saved; window++) {
			put_user((char *)tp->rwbuf_stkptrs[window],
				 &sc->sigc_spbuf[window]);
			err |= __copy_to_user(&sc->sigc_wbuf[window],
					      &tp->reg_window[window],
					      sizeof(struct reg_window));
		}
	else
		err |= __copy_to_user(sframep, (char *) regs->u_regs[UREG_FP],
				      sizeof(struct reg_window));

	tp->w_saved = 0; /* So process is allowed to execute. */

	err |= __put_user(signr, &sframep->sig_num);
	sig_address = NULL;
	sig_code = 0;
	if (SI_FROMKERNEL (info) && (info->si_code & __SI_MASK) == __SI_FAULT) {
		sig_address = info->si_addr;
		switch (signr) {
		case SIGSEGV:
			switch (info->si_code) {
			case SEGV_MAPERR: sig_code = SUBSIG_NOMAPPING; break;
			default: sig_code = SUBSIG_PROTECTION; break;
			}
			break;
		case SIGILL:
			switch (info->si_code) {
			case ILL_ILLOPC: sig_code = SUBSIG_ILLINST; break;
			case ILL_PRVOPC: sig_code = SUBSIG_PRIVINST; break;
			case ILL_ILLTRP: sig_code = SUBSIG_BADTRAP(info->si_trapno); break;
			default: sig_code = SUBSIG_STACK; break;
			}
			break;
		case SIGFPE:
			switch (info->si_code) {
			case FPE_INTDIV: sig_code = SUBSIG_IDIVZERO; break;
			case FPE_INTOVF: sig_code = SUBSIG_FPINTOVFL; break;
			case FPE_FLTDIV: sig_code = SUBSIG_FPDIVZERO; break;
			case FPE_FLTOVF: sig_code = SUBSIG_FPOVFLOW; break;
			case FPE_FLTUND: sig_code = SUBSIG_FPUNFLOW; break;
			case FPE_FLTRES: sig_code = SUBSIG_FPINEXACT; break;
			case FPE_FLTINV: sig_code = SUBSIG_FPOPERROR; break;
			default: sig_code = SUBSIG_FPERROR; break;
			}
			break;
		case SIGBUS:
			switch (info->si_code) {
			case BUS_ADRALN: sig_code = SUBSIG_ALIGNMENT; break;
			case BUS_ADRERR: sig_code = SUBSIG_MISCERROR; break;
			default: sig_code = SUBSIG_BUSTIMEOUT; break;
			}
			break;
		case SIGEMT:
			switch (info->si_code) {
			case EMT_TAGOVF: sig_code = SUBSIG_TAG; break;
			}
			break;
		case SIGSYS:
			if (info->si_code == (__SI_FAULT|0x100)) {
				/* See sys_sunos.c */
				sig_code = info->si_trapno;
				break;
			}
		default:
			sig_address = NULL;
		}
	}
	err |= __put_user((long)sig_address, &sframep->sig_address);
	err |= __put_user(sig_code, &sframep->sig_code);
	err |= __put_user(sc, &sframep->sig_scptr);
	if (err)
		goto sigsegv;

	regs->u_regs[UREG_FP] = (unsigned long) sframep;
	regs->pc = (unsigned long) sa->sa_handler;
	regs->npc = (regs->pc + 4);
	return;

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


static inline int
save_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
{
	int err = 0;
#ifdef CONFIG_SMP
	if (test_tsk_thread_flag(current, TIF_USEDFPU)) {
		put_psr(get_psr() | PSR_EF);
		fpsave(&current->thread.float_regs[0], &current->thread.fsr,
		       &current->thread.fpqueue[0], &current->thread.fpqdepth);
		regs->psr &= ~(PSR_EF);
		clear_tsk_thread_flag(current, TIF_USEDFPU);
	}
#else
	if (current == last_task_used_math) {
		put_psr(get_psr() | PSR_EF);
		fpsave(&current->thread.float_regs[0], &current->thread.fsr,
		       &current->thread.fpqueue[0], &current->thread.fpqdepth);
		last_task_used_math = NULL;
		regs->psr &= ~(PSR_EF);
	}
#endif
	err |= __copy_to_user(&fpu->si_float_regs[0],
			      &current->thread.float_regs[0],
			      (sizeof(unsigned long) * 32));
	err |= __put_user(current->thread.fsr, &fpu->si_fsr);
	err |= __put_user(current->thread.fpqdepth, &fpu->si_fpqdepth);
	if (current->thread.fpqdepth != 0)
		err |= __copy_to_user(&fpu->si_fpqueue[0],
				      &current->thread.fpqueue[0],
				      ((sizeof(unsigned long) +
				      (sizeof(unsigned long *)))*16));
	current->used_math = 0;
	return err;
}

static inline void
new_setup_frame(struct k_sigaction *ka, struct pt_regs *regs,
		int signo, sigset_t *oldset)
{
	struct new_signal_frame __user *sf;
	int sigframe_size, err;

	/* 1. Make sure everything is clean */
	synchronize_user_stack();

	sigframe_size = NF_ALIGNEDSZ;
	if (!current->used_math)
		sigframe_size -= sizeof(__siginfo_fpu_t);

	sf = (struct new_signal_frame __user *)
		get_sigframe(&ka->sa, regs, sigframe_size);

	if (invalid_frame_pointer(sf, sigframe_size))
		goto sigill_and_return;

	if (current_thread_info()->w_saved != 0)
		goto sigill_and_return;

	/* 2. Save the current process state */
	err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));
	
	err |= __put_user(0, &sf->extra_size);

	if (current->used_math) {
		err |= save_fpu_state(regs, &sf->fpu_state);
		err |= __put_user(&sf->fpu_state, &sf->fpu_save);
	} else {
		err |= __put_user(0, &sf->fpu_save);
	}

	err |= __put_user(oldset->sig[0], &sf->info.si_mask);
	err |= __copy_to_user(sf->extramask, &oldset->sig[1],
			      (_NSIG_WORDS - 1) * sizeof(unsigned int));
	err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
			      sizeof(struct reg_window));
	if (err)
		goto sigsegv;
	
	/* 3. signal handler back-trampoline and parameters */
	regs->u_regs[UREG_FP] = (unsigned long) sf;
	regs->u_regs[UREG_I0] = signo;
	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;

	/* 4. signal handler */
	regs->pc = (unsigned long) ka->sa.sa_handler;
	regs->npc = (regs->pc + 4);

	/* 5. return to kernel instructions */
	if (ka->ka_restorer)
		regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
	else {
		regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);

		/* mov __NR_sigreturn, %g1 */
		err |= __put_user(0x821020d8, &sf->insns[0]);

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

		/* Flush instruction space. */
		flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
	}
	return;

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

static inline void
new_setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
		   int signo, sigset_t *oldset, siginfo_t *info)
{
	struct rt_signal_frame __user *sf;
	int sigframe_size;
	unsigned int psr;
	int err;

	synchronize_user_stack();
	sigframe_size = RT_ALIGNEDSZ;
	if (!current->used_math)
		sigframe_size -= sizeof(__siginfo_fpu_t);
	sf = (struct rt_signal_frame __user *)
		get_sigframe(&ka->sa, regs, sigframe_size);
	if (invalid_frame_pointer(sf, sigframe_size))
		goto sigill;
	if (current_thread_info()->w_saved != 0)
		goto sigill;

	err  = __put_user(regs->pc, &sf->regs.pc);
	err |= __put_user(regs->npc, &sf->regs.npc);
	err |= __put_user(regs->y, &sf->regs.y);
	psr = regs->psr;
	if (current->used_math)
		psr |= PSR_EF;
	err |= __put_user(psr, &sf->regs.psr);
	err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
	err |= __put_user(0, &sf->extra_size);

	if (psr & PSR_EF) {
		err |= save_fpu_state(regs, &sf->fpu_state);
		err |= __put_user(&sf->fpu_state, &sf->fpu_save);
	} else {
		err |= __put_user(0, &sf->fpu_save);
	}
	err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
	
	/* 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);
	
	err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
			      sizeof(struct reg_window));	

	err |= copy_siginfo_to_user(&sf->info, info);

	if (err)
		goto sigsegv;

	regs->u_regs[UREG_FP] = (unsigned long) sf;
	regs->u_regs[UREG_I0] = signo;
	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;

	regs->pc = (unsigned long) ka->sa.sa_handler;
	regs->npc = (regs->pc + 4);

	if (ka->ka_restorer)
		regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
	else {
		regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);

		/* mov __NR_sigreturn, %g1 */
		err |= __put_user(0x821020d8, &sf->insns[0]);

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

		/* Flush instruction space. */
		flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
	}
	return;

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

/* Setup a Solaris stack frame */
static inline void
setup_svr4_frame(struct sigaction *sa, unsigned long pc, unsigned long npc,
		 struct pt_regs *regs, int signr, sigset_t *oldset)
{
	svr4_signal_frame_t __user *sfp;
	svr4_gregset_t  __user *gr;
	svr4_siginfo_t  __user *si;
	svr4_mcontext_t __user *mc;
	svr4_gwindows_t __user *gw;
	svr4_ucontext_t __user *uc;
	svr4_sigset_t	setv;
	struct thread_info *tp = current_thread_info();
	int window = 0, err;

	synchronize_user_stack();
	sfp = (svr4_signal_frame_t __user *)
		get_sigframe(sa, regs, SVR4_SF_ALIGNED + sizeof(struct reg_window));

	if (invalid_frame_pointer(sfp, sizeof(*sfp)))
		goto sigill_and_return;

	/* Start with a clean frame pointer and fill it */
	err = __clear_user(sfp, sizeof(*sfp));

	/* Setup convenience variables */
	si = &sfp->si;
	uc = &sfp->uc;
	gw = &sfp->gw;
	mc = &uc->mcontext;
	gr = &mc->greg;
	
	/* FIXME: where am I supposed to put this?
	 * sc->sigc_onstack = old_status;
	 * anyways, it does not look like it is used for anything at all.
	 */
	setv.sigbits[0] = oldset->sig[0];
	setv.sigbits[1] = oldset->sig[1];
	if (_NSIG_WORDS >= 4) {
		setv.sigbits[2] = oldset->sig[2];
		setv.sigbits[3] = oldset->sig[3];
		err |= __copy_to_user(&uc->sigmask, &setv, sizeof(svr4_sigset_t));
	} else