Exemplo n.º 1
0
int
fork1(struct thread *td, struct fork_req *fr)
{
	struct proc *p1, *newproc;
	struct thread *td2;
	struct vmspace *vm2;
	struct file *fp_procdesc;
	vm_ooffset_t mem_charged;
	int error, nprocs_new, ok;
	static int curfail;
	static struct timeval lastfail;
	int flags, pages;

	flags = fr->fr_flags;
	pages = fr->fr_pages;

	if ((flags & RFSTOPPED) != 0)
		MPASS(fr->fr_procp != NULL && fr->fr_pidp == NULL);
	else
		MPASS(fr->fr_procp == NULL);

	/* Check for the undefined or unimplemented flags. */
	if ((flags & ~(RFFLAGS | RFTSIGFLAGS(RFTSIGMASK))) != 0)
		return (EINVAL);

	/* Signal value requires RFTSIGZMB. */
	if ((flags & RFTSIGFLAGS(RFTSIGMASK)) != 0 && (flags & RFTSIGZMB) == 0)
		return (EINVAL);

	/* Can't copy and clear. */
	if ((flags & (RFFDG|RFCFDG)) == (RFFDG|RFCFDG))
		return (EINVAL);

	/* Check the validity of the signal number. */
	if ((flags & RFTSIGZMB) != 0 && (u_int)RFTSIGNUM(flags) > _SIG_MAXSIG)
		return (EINVAL);

	if ((flags & RFPROCDESC) != 0) {
		/* Can't not create a process yet get a process descriptor. */
		if ((flags & RFPROC) == 0)
			return (EINVAL);

		/* Must provide a place to put a procdesc if creating one. */
		if (fr->fr_pd_fd == NULL)
			return (EINVAL);

		/* Check if we are using supported flags. */
		if ((fr->fr_pd_flags & ~PD_ALLOWED_AT_FORK) != 0)
			return (EINVAL);
	}

	p1 = td->td_proc;

	/*
	 * Here we don't create a new process, but we divorce
	 * certain parts of a process from itself.
	 */
	if ((flags & RFPROC) == 0) {
		if (fr->fr_procp != NULL)
			*fr->fr_procp = NULL;
		else if (fr->fr_pidp != NULL)
			*fr->fr_pidp = 0;
		return (fork_norfproc(td, flags));
	}

	fp_procdesc = NULL;
	newproc = NULL;
	vm2 = NULL;

	/*
	 * Increment the nprocs resource before allocations occur.
	 * Although process entries are dynamically created, we still
	 * keep a global limit on the maximum number we will
	 * create. There are hard-limits as to the number of processes
	 * that can run, established by the KVA and memory usage for
	 * the process data.
	 *
	 * Don't allow a nonprivileged user to use the last ten
	 * processes; don't let root exceed the limit.
	 */
	nprocs_new = atomic_fetchadd_int(&nprocs, 1) + 1;
	if ((nprocs_new >= maxproc - 10 && priv_check_cred(td->td_ucred,
	    PRIV_MAXPROC, 0) != 0) || nprocs_new >= maxproc) {
		error = EAGAIN;
		sx_xlock(&allproc_lock);
		if (ppsratecheck(&lastfail, &curfail, 1)) {
			printf("maxproc limit exceeded by uid %u (pid %d); "
			    "see tuning(7) and login.conf(5)\n",
			    td->td_ucred->cr_ruid, p1->p_pid);
		}
		sx_xunlock(&allproc_lock);
		goto fail2;
	}

	/*
	 * If required, create a process descriptor in the parent first; we
	 * will abandon it if something goes wrong. We don't finit() until
	 * later.
	 */
	if (flags & RFPROCDESC) {
		error = procdesc_falloc(td, &fp_procdesc, fr->fr_pd_fd,
		    fr->fr_pd_flags, fr->fr_pd_fcaps);
		if (error != 0)
			goto fail2;
	}

	mem_charged = 0;
	if (pages == 0)
		pages = kstack_pages;
	/* Allocate new proc. */
	newproc = uma_zalloc(proc_zone, M_WAITOK);
	td2 = FIRST_THREAD_IN_PROC(newproc);
	if (td2 == NULL) {
		td2 = thread_alloc(pages);
		if (td2 == NULL) {
			error = ENOMEM;
			goto fail2;
		}
		proc_linkup(newproc, td2);
	} else {
		if (td2->td_kstack == 0 || td2->td_kstack_pages != pages) {
			if (td2->td_kstack != 0)
				vm_thread_dispose(td2);
			if (!thread_alloc_stack(td2, pages)) {
				error = ENOMEM;
				goto fail2;
			}
		}
	}

	if ((flags & RFMEM) == 0) {
		vm2 = vmspace_fork(p1->p_vmspace, &mem_charged);
		if (vm2 == NULL) {
			error = ENOMEM;
			goto fail2;
		}
		if (!swap_reserve(mem_charged)) {
			/*
			 * The swap reservation failed. The accounting
			 * from the entries of the copied vm2 will be
			 * subtracted in vmspace_free(), so force the
			 * reservation there.
			 */
			swap_reserve_force(mem_charged);
			error = ENOMEM;
			goto fail2;
		}
	} else
		vm2 = NULL;

	/*
	 * XXX: This is ugly; when we copy resource usage, we need to bump
	 *      per-cred resource counters.
	 */
	proc_set_cred_init(newproc, crhold(td->td_ucred));

	/*
	 * Initialize resource accounting for the child process.
	 */
	error = racct_proc_fork(p1, newproc);
	if (error != 0) {
		error = EAGAIN;
		goto fail1;
	}

#ifdef MAC
	mac_proc_init(newproc);
#endif
	newproc->p_klist = knlist_alloc(&newproc->p_mtx);
	STAILQ_INIT(&newproc->p_ktr);

	/* We have to lock the process tree while we look for a pid. */
	sx_slock(&proctree_lock);
	sx_xlock(&allproc_lock);

	/*
	 * Increment the count of procs running with this uid. Don't allow
	 * a nonprivileged user to exceed their current limit.
	 *
	 * XXXRW: Can we avoid privilege here if it's not needed?
	 */
	error = priv_check_cred(td->td_ucred, PRIV_PROC_LIMIT, 0);
	if (error == 0)
		ok = chgproccnt(td->td_ucred->cr_ruidinfo, 1, 0);
	else {
		ok = chgproccnt(td->td_ucred->cr_ruidinfo, 1,
		    lim_cur(td, RLIMIT_NPROC));
	}
	if (ok) {
		do_fork(td, fr, newproc, td2, vm2, fp_procdesc);
		return (0);
	}

	error = EAGAIN;
	sx_sunlock(&proctree_lock);
	sx_xunlock(&allproc_lock);
#ifdef MAC
	mac_proc_destroy(newproc);
#endif
	racct_proc_exit(newproc);
fail1:
	crfree(newproc->p_ucred);
	newproc->p_ucred = NULL;
fail2:
	if (vm2 != NULL)
		vmspace_free(vm2);
	uma_zfree(proc_zone, newproc);
	if ((flags & RFPROCDESC) != 0 && fp_procdesc != NULL) {
		fdclose(td, fp_procdesc, *fr->fr_pd_fd);
		fdrop(fp_procdesc, td);
	}
	atomic_add_int(&nprocs, -1);
	pause("fork", hz / 2);
	return (error);
}
Exemplo n.º 2
0
void *
initarm(void *arg, void *arg2)
{
	struct pv_addr	kernel_l1pt;
	int loop;
	u_int l1pagetable;
	vm_offset_t freemempos;
	vm_offset_t afterkern;
	vm_offset_t lastaddr;

	int i;
	uint32_t memsize;

	i = 0;

	boothowto = 0;

	set_cpufuncs();
	cpufuncs.cf_sleep = s3c24x0_sleep;
	lastaddr = fake_preload_metadata();

	pcpu_init(pcpup, 0, sizeof(struct pcpu));
	PCPU_SET(curthread, &thread0);

	/* Do basic tuning, hz etc */
	init_param1();

#define KERNEL_TEXT_BASE (KERNBASE)
	freemempos = (lastaddr + PAGE_MASK) & ~PAGE_MASK;
	/* Define a macro to simplify memory allocation */
#define valloc_pages(var, np)			\
	alloc_pages((var).pv_va, (np));		\
	(var).pv_pa = (var).pv_va + (KERNPHYSADDR - KERNVIRTADDR);

#define alloc_pages(var, np)			\
	(var) = freemempos;			\
	freemempos += (np * PAGE_SIZE);		\
	memset((char *)(var), 0, ((np) * PAGE_SIZE));

	while (((freemempos - L1_TABLE_SIZE) & (L1_TABLE_SIZE - 1)) != 0)
		freemempos += PAGE_SIZE;
	valloc_pages(kernel_l1pt, L1_TABLE_SIZE / PAGE_SIZE);
	for (loop = 0; loop < NUM_KERNEL_PTS; ++loop) {
		if (!(loop % (PAGE_SIZE / L2_TABLE_SIZE_REAL))) {
			valloc_pages(kernel_pt_table[loop],
			    L2_TABLE_SIZE / PAGE_SIZE);
		} else {
			kernel_pt_table[loop].pv_va = freemempos -
			    (loop % (PAGE_SIZE / L2_TABLE_SIZE_REAL)) *
			    L2_TABLE_SIZE_REAL;
			kernel_pt_table[loop].pv_pa = 
			    kernel_pt_table[loop].pv_va - KERNVIRTADDR +
			    KERNPHYSADDR;
		}
	}
	/*
	 * Allocate a page for the system page mapped to V0x00000000
	 * This page will just contain the system vectors and can be
	 * shared by all processes.
	 */
	valloc_pages(systempage, 1);

	/* Allocate stacks for all modes */
	valloc_pages(irqstack, IRQ_STACK_SIZE);
	valloc_pages(abtstack, ABT_STACK_SIZE);
	valloc_pages(undstack, UND_STACK_SIZE);
	valloc_pages(kernelstack, KSTACK_PAGES);
	valloc_pages(msgbufpv, round_page(msgbufsize) / PAGE_SIZE);
	/*
	 * Now we start construction of the L1 page table
	 * We start by mapping the L2 page tables into the L1.
	 * This means that we can replace L1 mappings later on if necessary
	 */
	l1pagetable = kernel_l1pt.pv_va;

	/* Map the L2 pages tables in the L1 page table */
	pmap_link_l2pt(l1pagetable, ARM_VECTORS_HIGH,
	    &kernel_pt_table[KERNEL_PT_SYS]);
	for (i = 0; i < KERNEL_PT_KERN_NUM; i++)
		pmap_link_l2pt(l1pagetable, KERNBASE + i * L1_S_SIZE,
		    &kernel_pt_table[KERNEL_PT_KERN + i]);
	pmap_map_chunk(l1pagetable, KERNBASE, PHYSADDR,
	   (((uint32_t)(lastaddr) - KERNBASE) + PAGE_SIZE) & ~(PAGE_SIZE - 1),
	    VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);
	afterkern = round_page((lastaddr + L1_S_SIZE) & ~(L1_S_SIZE 
	    - 1));
	for (i = 0; i < KERNEL_PT_AFKERNEL_NUM; i++) {
		pmap_link_l2pt(l1pagetable, afterkern + i * L1_S_SIZE,
		    &kernel_pt_table[KERNEL_PT_AFKERNEL + i]);
	}

	/* Map the vector page. */
	pmap_map_entry(l1pagetable, ARM_VECTORS_HIGH, systempage.pv_pa,
	    VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);
	/* Map the stack pages */
	pmap_map_chunk(l1pagetable, irqstack.pv_va, irqstack.pv_pa,
	    IRQ_STACK_SIZE * PAGE_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);
	pmap_map_chunk(l1pagetable, abtstack.pv_va, abtstack.pv_pa,
	    ABT_STACK_SIZE * PAGE_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);
	pmap_map_chunk(l1pagetable, undstack.pv_va, undstack.pv_pa,
	    UND_STACK_SIZE * PAGE_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);
	pmap_map_chunk(l1pagetable, kernelstack.pv_va, kernelstack.pv_pa,
	    KSTACK_PAGES * PAGE_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);

	pmap_map_chunk(l1pagetable, kernel_l1pt.pv_va, kernel_l1pt.pv_pa,
	    L1_TABLE_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_PAGETABLE);
	pmap_map_chunk(l1pagetable, msgbufpv.pv_va, msgbufpv.pv_pa,
	    msgbufsize, VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);


	for (loop = 0; loop < NUM_KERNEL_PTS; ++loop) {
		pmap_map_chunk(l1pagetable, kernel_pt_table[loop].pv_va,
		    kernel_pt_table[loop].pv_pa, L2_TABLE_SIZE,
		    VM_PROT_READ|VM_PROT_WRITE, PTE_PAGETABLE);
	}

	pmap_devmap_bootstrap(l1pagetable, s3c24x0_devmap);

	cpu_domains((DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2)) | DOMAIN_CLIENT);
	setttb(kernel_l1pt.pv_pa);
	cpu_tlb_flushID();
	cpu_domains(DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2));

	/*
	 * Pages were allocated during the secondary bootstrap for the
	 * stacks for different CPU modes.
	 * We must now set the r13 registers in the different CPU modes to
	 * point to these stacks.
	 * Since the ARM stacks use STMFD etc. we must set r13 to the top end
	 * of the stack memory.
	 */

	cpu_control(CPU_CONTROL_MMU_ENABLE, CPU_CONTROL_MMU_ENABLE);
	set_stackptr(PSR_IRQ32_MODE,
	    irqstack.pv_va + IRQ_STACK_SIZE * PAGE_SIZE);
	set_stackptr(PSR_ABT32_MODE,
	    abtstack.pv_va + ABT_STACK_SIZE * PAGE_SIZE);
	set_stackptr(PSR_UND32_MODE,
	    undstack.pv_va + UND_STACK_SIZE * PAGE_SIZE);

	/*
	 * We must now clean the cache again....
	 * Cleaning may be done by reading new data to displace any
	 * dirty data in the cache. This will have happened in setttb()
	 * but since we are boot strapping the addresses used for the read
	 * may have just been remapped and thus the cache could be out
	 * of sync. A re-clean after the switch will cure this.
	 * After booting there are no gross reloations of the kernel thus
	 * this problem will not occur after initarm().
	 */
	cpu_idcache_wbinv_all();

	/* Disable all peripheral interrupts */
	ioreg_write32(S3C24X0_INTCTL_BASE + INTCTL_INTMSK, ~0);
	memsize = board_init();
	/* Find pclk for uart */
	switch(ioreg_read32(S3C24X0_GPIO_BASE + GPIO_GSTATUS1) >> 16) {
	case 0x3241:
		s3c2410_clock_freq2(S3C24X0_CLKMAN_BASE, NULL, NULL,
		    &s3c2410_pclk);
		break;
	case 0x3244:
		s3c2440_clock_freq2(S3C24X0_CLKMAN_BASE, NULL, NULL,
		    &s3c2410_pclk);
		break;
	}
	cninit();

	/* Set stack for exception handlers */
	data_abort_handler_address = (u_int)data_abort_handler;
	prefetch_abort_handler_address = (u_int)prefetch_abort_handler;
	undefined_handler_address = (u_int)undefinedinstruction_bounce;
	undefined_init();
				
	proc_linkup(&proc0, &thread0);
	thread0.td_kstack = kernelstack.pv_va;
	thread0.td_pcb = (struct pcb *)
		(thread0.td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1;
	thread0.td_pcb->pcb_flags = 0;
	thread0.td_frame = &proc0_tf;
	pcpup->pc_curpcb = thread0.td_pcb;
	
	arm_vector_init(ARM_VECTORS_HIGH, ARM_VEC_ALL);

	pmap_curmaxkvaddr = afterkern + 0x100000 * (KERNEL_PT_KERN_NUM - 1);
	/*
	 * ARM_USE_SMALL_ALLOC uses dump_avail, so it must be filled before
	 * calling pmap_bootstrap.
	 */
	dump_avail[0] = PHYSADDR;
	dump_avail[1] = PHYSADDR + memsize;
	dump_avail[2] = 0;
	dump_avail[3] = 0;
					
	pmap_bootstrap(freemempos,
	    KERNVIRTADDR + 3 * memsize,
	    &kernel_l1pt);
	msgbufp = (void*)msgbufpv.pv_va;
	msgbufinit(msgbufp, msgbufsize);
	mutex_init();

	physmem = memsize / PAGE_SIZE;

	phys_avail[0] = virtual_avail - KERNVIRTADDR + KERNPHYSADDR;
	phys_avail[1] = PHYSADDR + memsize;
	phys_avail[2] = 0;
	phys_avail[3] = 0;

	init_param2(physmem);
	kdb_init();

	return ((void *)(kernelstack.pv_va + USPACE_SVC_STACK_TOP -
	    sizeof(struct pcb)));
}