| /* |
| * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
| * Copyright 2003 PathScale, Inc. |
| * Licensed under the GPL |
| */ |
| |
| #include <linux/stddef.h> |
| #include <linux/err.h> |
| #include <linux/hardirq.h> |
| #include <linux/mm.h> |
| #include <linux/module.h> |
| #include <linux/personality.h> |
| #include <linux/proc_fs.h> |
| #include <linux/ptrace.h> |
| #include <linux/random.h> |
| #include <linux/slab.h> |
| #include <linux/sched.h> |
| #include <linux/seq_file.h> |
| #include <linux/tick.h> |
| #include <linux/threads.h> |
| #include <asm/current.h> |
| #include <asm/pgtable.h> |
| #include <asm/mmu_context.h> |
| #include <asm/uaccess.h> |
| #include "as-layout.h" |
| #include "kern_util.h" |
| #include "os.h" |
| #include "skas.h" |
| |
| /* |
| * This is a per-cpu array. A processor only modifies its entry and it only |
| * cares about its entry, so it's OK if another processor is modifying its |
| * entry. |
| */ |
| struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } }; |
| |
| static inline int external_pid(void) |
| { |
| /* FIXME: Need to look up userspace_pid by cpu */ |
| return userspace_pid[0]; |
| } |
| |
| int pid_to_processor_id(int pid) |
| { |
| int i; |
| |
| for (i = 0; i < ncpus; i++) { |
| if (cpu_tasks[i].pid == pid) |
| return i; |
| } |
| return -1; |
| } |
| |
| void free_stack(unsigned long stack, int order) |
| { |
| free_pages(stack, order); |
| } |
| |
| unsigned long alloc_stack(int order, int atomic) |
| { |
| unsigned long page; |
| gfp_t flags = GFP_KERNEL; |
| |
| if (atomic) |
| flags = GFP_ATOMIC; |
| page = __get_free_pages(flags, order); |
| |
| return page; |
| } |
| |
| int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) |
| { |
| int pid; |
| |
| current->thread.request.u.thread.proc = fn; |
| current->thread.request.u.thread.arg = arg; |
| pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0, |
| ¤t->thread.regs, 0, NULL, NULL); |
| return pid; |
| } |
| EXPORT_SYMBOL(kernel_thread); |
| |
| static inline void set_current(struct task_struct *task) |
| { |
| cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task) |
| { external_pid(), task }); |
| } |
| |
| extern void arch_switch_to(struct task_struct *to); |
| |
| void *_switch_to(void *prev, void *next, void *last) |
| { |
| struct task_struct *from = prev; |
| struct task_struct *to = next; |
| |
| to->thread.prev_sched = from; |
| set_current(to); |
| |
| do { |
| current->thread.saved_task = NULL; |
| |
| switch_threads(&from->thread.switch_buf, |
| &to->thread.switch_buf); |
| |
| arch_switch_to(current); |
| |
| if (current->thread.saved_task) |
| show_regs(&(current->thread.regs)); |
| to = current->thread.saved_task; |
| from = current; |
| } while (current->thread.saved_task); |
| |
| return current->thread.prev_sched; |
| |
| } |
| |
| void interrupt_end(void) |
| { |
| if (need_resched()) |
| schedule(); |
| if (test_tsk_thread_flag(current, TIF_SIGPENDING)) |
| do_signal(); |
| } |
| |
| void exit_thread(void) |
| { |
| } |
| |
| int get_current_pid(void) |
| { |
| return task_pid_nr(current); |
| } |
| |
| /* |
| * This is called magically, by its address being stuffed in a jmp_buf |
| * and being longjmp-d to. |
| */ |
| void new_thread_handler(void) |
| { |
| int (*fn)(void *), n; |
| void *arg; |
| |
| if (current->thread.prev_sched != NULL) |
| schedule_tail(current->thread.prev_sched); |
| current->thread.prev_sched = NULL; |
| |
| fn = current->thread.request.u.thread.proc; |
| arg = current->thread.request.u.thread.arg; |
| |
| /* |
| * The return value is 1 if the kernel thread execs a process, |
| * 0 if it just exits |
| */ |
| n = run_kernel_thread(fn, arg, ¤t->thread.exec_buf); |
| if (n == 1) { |
| /* Handle any immediate reschedules or signals */ |
| interrupt_end(); |
| userspace(¤t->thread.regs.regs); |
| } |
| else do_exit(0); |
| } |
| |
| /* Called magically, see new_thread_handler above */ |
| void fork_handler(void) |
| { |
| force_flush_all(); |
| |
| schedule_tail(current->thread.prev_sched); |
| |
| /* |
| * XXX: if interrupt_end() calls schedule, this call to |
| * arch_switch_to isn't needed. We could want to apply this to |
| * improve performance. -bb |
| */ |
| arch_switch_to(current); |
| |
| current->thread.prev_sched = NULL; |
| |
| /* Handle any immediate reschedules or signals */ |
| interrupt_end(); |
| |
| userspace(¤t->thread.regs.regs); |
| } |
| |
| int copy_thread(unsigned long clone_flags, unsigned long sp, |
| unsigned long stack_top, struct task_struct * p, |
| struct pt_regs *regs) |
| { |
| void (*handler)(void); |
| int ret = 0; |
| |
| p->thread = (struct thread_struct) INIT_THREAD; |
| |
| if (current->thread.forking) { |
| memcpy(&p->thread.regs.regs, ®s->regs, |
| sizeof(p->thread.regs.regs)); |
| REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.gp, 0); |
| if (sp != 0) |
| REGS_SP(p->thread.regs.regs.gp) = sp; |
| |
| handler = fork_handler; |
| |
| arch_copy_thread(¤t->thread.arch, &p->thread.arch); |
| } |
| else { |
| get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp); |
| p->thread.request.u.thread = current->thread.request.u.thread; |
| handler = new_thread_handler; |
| } |
| |
| new_thread(task_stack_page(p), &p->thread.switch_buf, handler); |
| |
| if (current->thread.forking) { |
| clear_flushed_tls(p); |
| |
| /* |
| * Set a new TLS for the child thread? |
| */ |
| if (clone_flags & CLONE_SETTLS) |
| ret = arch_copy_tls(p); |
| } |
| |
| return ret; |
| } |
| |
| void initial_thread_cb(void (*proc)(void *), void *arg) |
| { |
| int save_kmalloc_ok = kmalloc_ok; |
| |
| kmalloc_ok = 0; |
| initial_thread_cb_skas(proc, arg); |
| kmalloc_ok = save_kmalloc_ok; |
| } |
| |
| void default_idle(void) |
| { |
| unsigned long long nsecs; |
| |
| while (1) { |
| /* endless idle loop with no priority at all */ |
| |
| /* |
| * although we are an idle CPU, we do not want to |
| * get into the scheduler unnecessarily. |
| */ |
| if (need_resched()) |
| schedule(); |
| |
| tick_nohz_idle_enter(); |
| rcu_idle_enter(); |
| nsecs = disable_timer(); |
| idle_sleep(nsecs); |
| rcu_idle_exit(); |
| tick_nohz_idle_exit(); |
| } |
| } |
| |
| void cpu_idle(void) |
| { |
| cpu_tasks[current_thread_info()->cpu].pid = os_getpid(); |
| default_idle(); |
| } |
| |
| int __cant_sleep(void) { |
| return in_atomic() || irqs_disabled() || in_interrupt(); |
| /* Is in_interrupt() really needed? */ |
| } |
| |
| int user_context(unsigned long sp) |
| { |
| unsigned long stack; |
| |
| stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER); |
| return stack != (unsigned long) current_thread_info(); |
| } |
| |
| extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end; |
| |
| void do_uml_exitcalls(void) |
| { |
| exitcall_t *call; |
| |
| call = &__uml_exitcall_end; |
| while (--call >= &__uml_exitcall_begin) |
| (*call)(); |
| } |
| |
| char *uml_strdup(const char *string) |
| { |
| return kstrdup(string, GFP_KERNEL); |
| } |
| EXPORT_SYMBOL(uml_strdup); |
| |
| int copy_to_user_proc(void __user *to, void *from, int size) |
| { |
| return copy_to_user(to, from, size); |
| } |
| |
| int copy_from_user_proc(void *to, void __user *from, int size) |
| { |
| return copy_from_user(to, from, size); |
| } |
| |
| int clear_user_proc(void __user *buf, int size) |
| { |
| return clear_user(buf, size); |
| } |
| |
| int strlen_user_proc(char __user *str) |
| { |
| return strlen_user(str); |
| } |
| |
| int smp_sigio_handler(void) |
| { |
| #ifdef CONFIG_SMP |
| int cpu = current_thread_info()->cpu; |
| IPI_handler(cpu); |
| if (cpu != 0) |
| return 1; |
| #endif |
| return 0; |
| } |
| |
| int cpu(void) |
| { |
| return current_thread_info()->cpu; |
| } |
| |
| static atomic_t using_sysemu = ATOMIC_INIT(0); |
| int sysemu_supported; |
| |
| void set_using_sysemu(int value) |
| { |
| if (value > sysemu_supported) |
| return; |
| atomic_set(&using_sysemu, value); |
| } |
| |
| int get_using_sysemu(void) |
| { |
| return atomic_read(&using_sysemu); |
| } |
| |
| static int sysemu_proc_show(struct seq_file *m, void *v) |
| { |
| seq_printf(m, "%d\n", get_using_sysemu()); |
| return 0; |
| } |
| |
| static int sysemu_proc_open(struct inode *inode, struct file *file) |
| { |
| return single_open(file, sysemu_proc_show, NULL); |
| } |
| |
| static ssize_t sysemu_proc_write(struct file *file, const char __user *buf, |
| size_t count, loff_t *pos) |
| { |
| char tmp[2]; |
| |
| if (copy_from_user(tmp, buf, 1)) |
| return -EFAULT; |
| |
| if (tmp[0] >= '0' && tmp[0] <= '2') |
| set_using_sysemu(tmp[0] - '0'); |
| /* We use the first char, but pretend to write everything */ |
| return count; |
| } |
| |
| static const struct file_operations sysemu_proc_fops = { |
| .owner = THIS_MODULE, |
| .open = sysemu_proc_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = single_release, |
| .write = sysemu_proc_write, |
| }; |
| |
| int __init make_proc_sysemu(void) |
| { |
| struct proc_dir_entry *ent; |
| if (!sysemu_supported) |
| return 0; |
| |
| ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_fops); |
| |
| if (ent == NULL) |
| { |
| printk(KERN_WARNING "Failed to register /proc/sysemu\n"); |
| return 0; |
| } |
| |
| return 0; |
| } |
| |
| late_initcall(make_proc_sysemu); |
| |
| int singlestepping(void * t) |
| { |
| struct task_struct *task = t ? t : current; |
| |
| if (!(task->ptrace & PT_DTRACE)) |
| return 0; |
| |
| if (task->thread.singlestep_syscall) |
| return 1; |
| |
| return 2; |
| } |
| |
| /* |
| * Only x86 and x86_64 have an arch_align_stack(). |
| * All other arches have "#define arch_align_stack(x) (x)" |
| * in their asm/system.h |
| * As this is included in UML from asm-um/system-generic.h, |
| * we can use it to behave as the subarch does. |
| */ |
| #ifndef arch_align_stack |
| unsigned long arch_align_stack(unsigned long sp) |
| { |
| if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) |
| sp -= get_random_int() % 8192; |
| return sp & ~0xf; |
| } |
| #endif |
| |
| unsigned long get_wchan(struct task_struct *p) |
| { |
| unsigned long stack_page, sp, ip; |
| bool seen_sched = 0; |
| |
| if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING)) |
| return 0; |
| |
| stack_page = (unsigned long) task_stack_page(p); |
| /* Bail if the process has no kernel stack for some reason */ |
| if (stack_page == 0) |
| return 0; |
| |
| sp = p->thread.switch_buf->JB_SP; |
| /* |
| * Bail if the stack pointer is below the bottom of the kernel |
| * stack for some reason |
| */ |
| if (sp < stack_page) |
| return 0; |
| |
| while (sp < stack_page + THREAD_SIZE) { |
| ip = *((unsigned long *) sp); |
| if (in_sched_functions(ip)) |
| /* Ignore everything until we're above the scheduler */ |
| seen_sched = 1; |
| else if (kernel_text_address(ip) && seen_sched) |
| return ip; |
| |
| sp += sizeof(unsigned long); |
| } |
| |
| return 0; |
| } |
| |
| int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu) |
| { |
| int cpu = current_thread_info()->cpu; |
| |
| return save_fp_registers(userspace_pid[cpu], (unsigned long *) fpu); |
| } |
| |