signal32.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

{
	struct rt_signal_frame32 *sf;
	unsigned int psr;
	unsigned pc, npc, fpu_save;
	sigset_t set;
	sigset_t32 seta;
	stack_t st;
	int err, i;
	
	synchronize_user_stack();
	regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
	sf = (struct rt_signal_frame32 *) regs->u_regs [UREG_FP];

	/* 1. Make sure we are not getting garbage from the user */
	if (verify_area (VERIFY_READ, sf, sizeof (*sf))	||
	    (((unsigned long) sf) & 3))
		goto segv;

	get_user(pc, &sf->regs.pc);
	__get_user(npc, &sf->regs.npc);

	if ((pc | npc) & 3)
		goto segv;

	if ((current->thread.flags & SPARC_FLAG_32BIT) != 0) {
		pc &= 0xffffffff;
		npc &= 0xffffffff;
	}
	regs->tpc = pc;
	regs->tnpc = npc;

	/* 2. Restore the state */
	err = __get_user(regs->y, &sf->regs.y);
	err |= __get_user(psr, &sf->regs.psr);
	
	for (i = UREG_G1; i <= UREG_I7; i++)
		err |= __get_user(regs->u_regs[i], &sf->regs.u_regs[i]);
	if ((psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS) {
		err |= __get_user(i, &sf->v8plus.g_upper[0]);
		if (i == SIGINFO_EXTRA_V8PLUS_MAGIC) {
			for (i = UREG_G1; i <= UREG_I7; i++)
				err |= __get_user(((u32 *)regs->u_regs)[2*i], &sf->v8plus.g_upper[i]);
		}
	}

	/* User can only change condition codes in %tstate. */
	regs->tstate &= ~(TSTATE_ICC|TSTATE_XCC);
	regs->tstate |= psr_to_tstate_icc(psr);

	err |= __get_user(fpu_save, &sf->fpu_save);
	if (fpu_save)
		err |= restore_fpu_state32(regs, &sf->fpu_state);
	err |= copy_from_user(&seta, &sf->mask, sizeof(sigset_t32));
	err |= __get_user((long)st.ss_sp, &sf->stack.ss_sp);
	err |= __get_user(st.ss_flags, &sf->stack.ss_flags);
	err |= __get_user(st.ss_size, &sf->stack.ss_size);
	if (err)
		goto segv;
		
	/* It is more difficult to avoid calling this function than to
	   call it and ignore errors.  */
	do_sigaltstack(&st, NULL, (unsigned long)sf);
	
	switch (_NSIG_WORDS) {
		case 4: set.sig[3] = seta.sig[6] + (((long)seta.sig[7]) << 32);
		case 3: set.sig[2] = seta.sig[4] + (((long)seta.sig[5]) << 32);
		case 2: set.sig[1] = seta.sig[2] + (((long)seta.sig[3]) << 32);
		case 1: set.sig[0] = seta.sig[0] + (((long)seta.sig[1]) << 32);
	}
	sigdelsetmask(&set, ~_BLOCKABLE);
	spin_lock_irq(&current->sigmask_lock);
	current->blocked = set;
	recalc_sigpending(current);
	spin_unlock_irq(&current->sigmask_lock);
	return;
segv:
	do_exit(SIGSEGV);
}

/* Checks if the fp is valid */
static int invalid_frame_pointer(void *fp, int fplen)
{
	if ((((unsigned long) fp) & 7) || ((unsigned long)fp) > 0x100000000ULL - fplen)
		return 1;
	return 0;
}

static inline void *get_sigframe(struct sigaction *sa, struct pt_regs *regs, unsigned long framesize)
{
	unsigned long sp;
	
	regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
	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 *)(sp - framesize);
}

static void
setup_frame32(struct sigaction *sa, struct pt_regs *regs, int signr, sigset_t *oldset, siginfo_t *info)
{
	struct signal_sframe32 *sframep;
	struct sigcontext32 *sc;
	unsigned seta[_NSIG_WORDS32];
	int err = 0;
	void *sig_address;
	int sig_code;
	unsigned long pc = regs->tpc;
	unsigned long npc = regs->tnpc;
	
#if 0	
	int window = 0;
#endif	
	unsigned psr;

	if ((current->thread.flags & SPARC_FLAG_32BIT) != 0) {
		pc &= 0xffffffff;
		npc &= 0xffffffff;
	}

	synchronize_user_stack();
	save_and_clear_fpu();

	sframep = (struct signal_sframe32 *)get_sigframe(sa, regs, SF_ALIGNEDSZ);
	if (invalid_frame_pointer (sframep, sizeof(*sframep))){
#ifdef DEBUG_SIGNALS /* fills up the console logs during crashme runs, yuck... */
		printk("%s [%d]: User has trashed signal stack\n",
		       current->comm, current->pid);
		printk("Sigstack ptr %p handler at pc<%016lx> for sig<%d>\n",
		       sframep, pc, signr);
#endif
		/* Don't change signal code and address, so that
		 * post mortem debuggers can have a look.
		 */
		do_exit(SIGILL);
	}

	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);
	
	switch (_NSIG_WORDS) {
	case 4: seta[7] = (oldset->sig[3] >> 32);
	        seta[6] = oldset->sig[3];
	case 3: seta[5] = (oldset->sig[2] >> 32);
	        seta[4] = oldset->sig[2];
	case 2: seta[3] = (oldset->sig[1] >> 32);
	        seta[2] = oldset->sig[1];
	case 1: seta[1] = (oldset->sig[0] >> 32);
	        seta[0] = oldset->sig[0];
	}
	err |= __put_user(seta[0], &sc->sigc_mask);
	err |= __copy_to_user(sframep->extramask, seta + 1,
			      (_NSIG_WORDS32 - 1) * sizeof(unsigned));
	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);
	psr = tstate_to_psr (regs->tstate);
	if(current->thread.fpsaved[0] & FPRS_FEF)
		psr |= PSR_EF;
	err |= __put_user(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(current->thread.w_saved, &sc->sigc_oswins);
#if 0
/* w_saved is not currently used... */
	if(current->thread.w_saved)
		for(window = 0; window < current->thread.w_saved; window++) {
			sc->sigc_spbuf[window] =
				(char *)current->thread.rwbuf_stkptrs[window];
			err |= copy_to_user(&sc->sigc_wbuf[window],
					    &current->thread.reg_window[window],
					    sizeof(struct reg_window));
		}
	else
#endif	
		err |= copy_in_user((u32 *)sframep,
				    (u32 *)(regs->u_regs[UREG_FP]),
				    sizeof(struct reg_window32));
		       
	current->thread.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_sunos32.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((u64)sc, &sframep->sig_scptr);
	if (err)
		goto sigsegv;

	regs->u_regs[UREG_FP] = (unsigned long) sframep;
	regs->tpc = (unsigned long) sa->sa_handler;
	regs->tnpc = (regs->tpc + 4);
	if ((current->thread.flags & SPARC_FLAG_32BIT) != 0) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}
	return;

sigsegv:
	do_exit(SIGSEGV);
}


static inline int save_fpu_state32(struct pt_regs *regs, __siginfo_fpu_t *fpu)
{
	unsigned long *fpregs = (unsigned long *)(((char *)current) + AOFF_task_fpregs);
	unsigned long fprs;
	int err = 0;
	
	fprs = current->thread.fpsaved[0];
	if (fprs & FPRS_DL)
		err |= copy_to_user(&fpu->si_float_regs[0], fpregs,
				    (sizeof(unsigned int) * 32));
	if (fprs & FPRS_DU)
		err |= copy_to_user(&fpu->si_float_regs[32], fpregs+16,
				    (sizeof(unsigned int) * 32));
	err |= __put_user(current->thread.xfsr[0], &fpu->si_fsr);
	err |= __put_user(current->thread.gsr[0], &fpu->si_gsr);
	err |= __put_user(fprs, &fpu->si_fprs);

	return err;
}

static inline void new_setup_frame32(struct k_sigaction *ka, struct pt_regs *regs,
				     int signo, sigset_t *oldset)
{
	struct new_signal_frame32 *sf;
	int sigframe_size;
	u32 psr;
	int i, err;
	unsigned seta[_NSIG_WORDS32];

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

	sf = (struct new_signal_frame32 *)get_sigframe(&ka->sa, regs, sigframe_size);
	
	if (invalid_frame_pointer (sf, sigframe_size)) {
#ifdef DEBUG_SIGNALS
		printk("new_setup_frame32(%s:%d): invalid_frame_pointer(%p, %d)\n",
		       current->comm, current->pid, sf, sigframe_size);
#endif
		goto sigill;
	}

	if (current->thread.w_saved != 0) {
#ifdef DEBUG_SIGNALS
		printk ("%s[%d]: Invalid user stack frame for "
			"signal delivery.\n", current->comm, current->pid);
#endif
		goto sigill;
	}

	/* 2. Save the current process state */
	if ((current->thread.flags & SPARC_FLAG_32BIT) != 0) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}
	err  = put_user(regs->tpc, &sf->info.si_regs.pc);
	err |= __put_user(regs->tnpc, &sf->info.si_regs.npc);
	err |= __put_user(regs->y, &sf->info.si_regs.y);
	psr = tstate_to_psr (regs->tstate);
	if(current->thread.fpsaved[0] & FPRS_FEF)
		psr |= PSR_EF;
	err |= __put_user(psr, &sf->info.si_regs.psr);
	for (i = 0; i < 16; i++)
		err |= __put_user(regs->u_regs[i], &sf->info.si_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]);

	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);
	}

	switch (_NSIG_WORDS) {
	case 4: seta[7] = (oldset->sig[3] >> 32);
	        seta[6] = oldset->sig[3];
	case 3: seta[5] = (oldset->sig[2] >> 32);
	        seta[4] = oldset->sig[2];
	case 2: seta[3] = (oldset->sig[1] >> 32);
	        seta[2] = oldset->sig[1];
	case 1: seta[1] = (oldset->sig[0] >> 32);
	        seta[0] = oldset->sig[0];
	}
	err |= __put_user(seta[0], &sf->info.si_mask);
	err |= __copy_to_user(sf->extramask, seta + 1,
			      (_NSIG_WORDS32 - 1) * sizeof(unsigned));

	err |= copy_in_user((u32 *)sf,
			    (u32 *)(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] = signo;
	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;

	/* 4. signal handler */
	regs->tpc = (unsigned long) ka->sa.sa_handler;
	regs->tnpc = (regs->tpc + 4);
	if ((current->thread.flags & SPARC_FLAG_32BIT) != 0) {
		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);
		pmd_t *pmdp = pmd_offset(pgdp, address);
		pte_t *ptep = pte_offset(pmdp, address);

		regs->u_regs[UREG_I7] = (unsigned long) (&(sf->insns[0]) - 2);
	
		err  = __put_user(0x821020d8, &sf->insns[0]); /*mov __NR_sigreturn, %g1*/
		err |= __put_user(0x91d02010, &sf->insns[1]); /*t 0x10*/
		if(err)
			goto sigsegv;