1995473aeSJeff Dike /* 2ba180fd4SJeff Dike * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 3995473aeSJeff Dike * Copyright 2003 PathScale, Inc. 4995473aeSJeff Dike * Licensed under the GPL 5995473aeSJeff Dike */ 6995473aeSJeff Dike 7ba180fd4SJeff Dike #include "linux/stddef.h" 8ba180fd4SJeff Dike #include "linux/err.h" 9ba180fd4SJeff Dike #include "linux/hardirq.h" 10995473aeSJeff Dike #include "linux/mm.h" 11ba180fd4SJeff Dike #include "linux/personality.h" 12995473aeSJeff Dike #include "linux/proc_fs.h" 13995473aeSJeff Dike #include "linux/ptrace.h" 14995473aeSJeff Dike #include "linux/random.h" 15ba180fd4SJeff Dike #include "linux/sched.h" 16d2753a6dSJeff Dike #include "linux/tick.h" 17ba180fd4SJeff Dike #include "linux/threads.h" 18995473aeSJeff Dike #include "asm/pgtable.h" 19995473aeSJeff Dike #include "asm/uaccess.h" 204ff83ce1SJeff Dike #include "as-layout.h" 21ba180fd4SJeff Dike #include "kern_util.h" 22995473aeSJeff Dike #include "os.h" 2377bf4400SJeff Dike #include "skas.h" 24ba180fd4SJeff Dike #include "tlb.h" 25995473aeSJeff Dike 26ba180fd4SJeff Dike /* 27ba180fd4SJeff Dike * This is a per-cpu array. A processor only modifies its entry and it only 28995473aeSJeff Dike * cares about its entry, so it's OK if another processor is modifying its 29995473aeSJeff Dike * entry. 30995473aeSJeff Dike */ 31995473aeSJeff Dike struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } }; 32995473aeSJeff Dike 336e21aec3SJeff Dike static inline int external_pid(struct task_struct *task) 34995473aeSJeff Dike { 3577bf4400SJeff Dike /* FIXME: Need to look up userspace_pid by cpu */ 36ba180fd4SJeff Dike return userspace_pid[0]; 37995473aeSJeff Dike } 38995473aeSJeff Dike 39995473aeSJeff Dike int pid_to_processor_id(int pid) 40995473aeSJeff Dike { 41995473aeSJeff Dike int i; 42995473aeSJeff Dike 43995473aeSJeff Dike for(i = 0; i < ncpus; i++) { 446e21aec3SJeff Dike if (cpu_tasks[i].pid == pid) 456e21aec3SJeff Dike return i; 46995473aeSJeff Dike } 476e21aec3SJeff Dike return -1; 48995473aeSJeff Dike } 49995473aeSJeff Dike 50995473aeSJeff Dike void free_stack(unsigned long stack, int order) 51995473aeSJeff Dike { 52995473aeSJeff Dike free_pages(stack, order); 53995473aeSJeff Dike } 54995473aeSJeff Dike 55995473aeSJeff Dike unsigned long alloc_stack(int order, int atomic) 56995473aeSJeff Dike { 57995473aeSJeff Dike unsigned long page; 58995473aeSJeff Dike gfp_t flags = GFP_KERNEL; 59995473aeSJeff Dike 60995473aeSJeff Dike if (atomic) 61995473aeSJeff Dike flags = GFP_ATOMIC; 62995473aeSJeff Dike page = __get_free_pages(flags, order); 635c8aaceaSJeff Dike 646e21aec3SJeff Dike return page; 65995473aeSJeff Dike } 66995473aeSJeff Dike 67995473aeSJeff Dike int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 68995473aeSJeff Dike { 69995473aeSJeff Dike int pid; 70995473aeSJeff Dike 71995473aeSJeff Dike current->thread.request.u.thread.proc = fn; 72995473aeSJeff Dike current->thread.request.u.thread.arg = arg; 73995473aeSJeff Dike pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0, 74995473aeSJeff Dike ¤t->thread.regs, 0, NULL, NULL); 756e21aec3SJeff Dike return pid; 76995473aeSJeff Dike } 77995473aeSJeff Dike 786e21aec3SJeff Dike static inline void set_current(struct task_struct *task) 79995473aeSJeff Dike { 80995473aeSJeff Dike cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task) 81995473aeSJeff Dike { external_pid(task), task }); 82995473aeSJeff Dike } 83995473aeSJeff Dike 84291248fdSKarol Swietlicki extern void arch_switch_to(struct task_struct *to); 8577bf4400SJeff Dike 86995473aeSJeff Dike void *_switch_to(void *prev, void *next, void *last) 87995473aeSJeff Dike { 88995473aeSJeff Dike struct task_struct *from = prev; 89995473aeSJeff Dike struct task_struct *to = next; 90995473aeSJeff Dike 91995473aeSJeff Dike to->thread.prev_sched = from; 92995473aeSJeff Dike set_current(to); 93995473aeSJeff Dike 94995473aeSJeff Dike do { 95995473aeSJeff Dike current->thread.saved_task = NULL; 9677bf4400SJeff Dike 97291248fdSKarol Swietlicki switch_threads(&from->thread.switch_buf, &to->thread.switch_buf); 9877bf4400SJeff Dike 99291248fdSKarol Swietlicki arch_switch_to(current); 10077bf4400SJeff Dike 101995473aeSJeff Dike if (current->thread.saved_task) 102995473aeSJeff Dike show_regs(&(current->thread.regs)); 103995473aeSJeff Dike next = current->thread.saved_task; 104995473aeSJeff Dike prev = current; 105995473aeSJeff Dike } while (current->thread.saved_task); 106995473aeSJeff Dike 1076e21aec3SJeff Dike return current->thread.prev_sched; 108995473aeSJeff Dike 109995473aeSJeff Dike } 110995473aeSJeff Dike 111995473aeSJeff Dike void interrupt_end(void) 112995473aeSJeff Dike { 1136e21aec3SJeff Dike if (need_resched()) 1146e21aec3SJeff Dike schedule(); 1156e21aec3SJeff Dike if (test_tsk_thread_flag(current, TIF_SIGPENDING)) 1166e21aec3SJeff Dike do_signal(); 117995473aeSJeff Dike } 118995473aeSJeff Dike 119995473aeSJeff Dike void exit_thread(void) 120995473aeSJeff Dike { 121995473aeSJeff Dike } 122995473aeSJeff Dike 123995473aeSJeff Dike void *get_current(void) 124995473aeSJeff Dike { 1256e21aec3SJeff Dike return current; 126995473aeSJeff Dike } 127995473aeSJeff Dike 12877bf4400SJeff Dike extern void schedule_tail(struct task_struct *prev); 12977bf4400SJeff Dike 130ba180fd4SJeff Dike /* 131ba180fd4SJeff Dike * This is called magically, by its address being stuffed in a jmp_buf 13277bf4400SJeff Dike * and being longjmp-d to. 13377bf4400SJeff Dike */ 13477bf4400SJeff Dike void new_thread_handler(void) 13577bf4400SJeff Dike { 13677bf4400SJeff Dike int (*fn)(void *), n; 13777bf4400SJeff Dike void *arg; 13877bf4400SJeff Dike 13977bf4400SJeff Dike if (current->thread.prev_sched != NULL) 14077bf4400SJeff Dike schedule_tail(current->thread.prev_sched); 14177bf4400SJeff Dike current->thread.prev_sched = NULL; 14277bf4400SJeff Dike 14377bf4400SJeff Dike fn = current->thread.request.u.thread.proc; 14477bf4400SJeff Dike arg = current->thread.request.u.thread.arg; 14577bf4400SJeff Dike 146ba180fd4SJeff Dike /* 147ba180fd4SJeff Dike * The return value is 1 if the kernel thread execs a process, 14877bf4400SJeff Dike * 0 if it just exits 14977bf4400SJeff Dike */ 15077bf4400SJeff Dike n = run_kernel_thread(fn, arg, ¤t->thread.exec_buf); 15177bf4400SJeff Dike if (n == 1) { 15277bf4400SJeff Dike /* Handle any immediate reschedules or signals */ 15377bf4400SJeff Dike interrupt_end(); 15477bf4400SJeff Dike userspace(¤t->thread.regs.regs); 15577bf4400SJeff Dike } 15677bf4400SJeff Dike else do_exit(0); 15777bf4400SJeff Dike } 15877bf4400SJeff Dike 15977bf4400SJeff Dike /* Called magically, see new_thread_handler above */ 16077bf4400SJeff Dike void fork_handler(void) 16177bf4400SJeff Dike { 16277bf4400SJeff Dike force_flush_all(); 16377bf4400SJeff Dike 16477bf4400SJeff Dike schedule_tail(current->thread.prev_sched); 16577bf4400SJeff Dike 166ba180fd4SJeff Dike /* 167ba180fd4SJeff Dike * XXX: if interrupt_end() calls schedule, this call to 16877bf4400SJeff Dike * arch_switch_to isn't needed. We could want to apply this to 169ba180fd4SJeff Dike * improve performance. -bb 170ba180fd4SJeff Dike */ 171291248fdSKarol Swietlicki arch_switch_to(current); 17277bf4400SJeff Dike 17377bf4400SJeff Dike current->thread.prev_sched = NULL; 17477bf4400SJeff Dike 17577bf4400SJeff Dike /* Handle any immediate reschedules or signals */ 17677bf4400SJeff Dike interrupt_end(); 17777bf4400SJeff Dike 17877bf4400SJeff Dike userspace(¤t->thread.regs.regs); 17977bf4400SJeff Dike } 18077bf4400SJeff Dike 181995473aeSJeff Dike int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, 182995473aeSJeff Dike unsigned long stack_top, struct task_struct * p, 183995473aeSJeff Dike struct pt_regs *regs) 184995473aeSJeff Dike { 18577bf4400SJeff Dike void (*handler)(void); 18677bf4400SJeff Dike int ret = 0; 187995473aeSJeff Dike 188995473aeSJeff Dike p->thread = (struct thread_struct) INIT_THREAD; 189995473aeSJeff Dike 19077bf4400SJeff Dike if (current->thread.forking) { 19177bf4400SJeff Dike memcpy(&p->thread.regs.regs, ®s->regs, 19277bf4400SJeff Dike sizeof(p->thread.regs.regs)); 19318badddaSJeff Dike REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.gp, 0); 19477bf4400SJeff Dike if (sp != 0) 19518badddaSJeff Dike REGS_SP(p->thread.regs.regs.gp) = sp; 196995473aeSJeff Dike 19777bf4400SJeff Dike handler = fork_handler; 19877bf4400SJeff Dike 19977bf4400SJeff Dike arch_copy_thread(¤t->thread.arch, &p->thread.arch); 20077bf4400SJeff Dike } 20177bf4400SJeff Dike else { 202d25f2e12SJeff Dike get_safe_registers(p->thread.regs.regs.gp); 20377bf4400SJeff Dike p->thread.request.u.thread = current->thread.request.u.thread; 20477bf4400SJeff Dike handler = new_thread_handler; 20577bf4400SJeff Dike } 20677bf4400SJeff Dike 20777bf4400SJeff Dike new_thread(task_stack_page(p), &p->thread.switch_buf, handler); 20877bf4400SJeff Dike 20977bf4400SJeff Dike if (current->thread.forking) { 210995473aeSJeff Dike clear_flushed_tls(p); 211995473aeSJeff Dike 212995473aeSJeff Dike /* 213995473aeSJeff Dike * Set a new TLS for the child thread? 214995473aeSJeff Dike */ 215995473aeSJeff Dike if (clone_flags & CLONE_SETTLS) 216995473aeSJeff Dike ret = arch_copy_tls(p); 21777bf4400SJeff Dike } 218995473aeSJeff Dike 219995473aeSJeff Dike return ret; 220995473aeSJeff Dike } 221995473aeSJeff Dike 222995473aeSJeff Dike void initial_thread_cb(void (*proc)(void *), void *arg) 223995473aeSJeff Dike { 224995473aeSJeff Dike int save_kmalloc_ok = kmalloc_ok; 225995473aeSJeff Dike 226995473aeSJeff Dike kmalloc_ok = 0; 2276aa802ceSJeff Dike initial_thread_cb_skas(proc, arg); 228995473aeSJeff Dike kmalloc_ok = save_kmalloc_ok; 229995473aeSJeff Dike } 230995473aeSJeff Dike 231995473aeSJeff Dike void default_idle(void) 232995473aeSJeff Dike { 233b160fb63SJeff Dike unsigned long long nsecs; 234b160fb63SJeff Dike 235995473aeSJeff Dike while(1) { 236995473aeSJeff Dike /* endless idle loop with no priority at all */ 237995473aeSJeff Dike 238995473aeSJeff Dike /* 239995473aeSJeff Dike * although we are an idle CPU, we do not want to 240995473aeSJeff Dike * get into the scheduler unnecessarily. 241995473aeSJeff Dike */ 242995473aeSJeff Dike if (need_resched()) 243995473aeSJeff Dike schedule(); 244995473aeSJeff Dike 245d2753a6dSJeff Dike tick_nohz_stop_sched_tick(); 246b160fb63SJeff Dike nsecs = disable_timer(); 247b160fb63SJeff Dike idle_sleep(nsecs); 248d2753a6dSJeff Dike tick_nohz_restart_sched_tick(); 249995473aeSJeff Dike } 250995473aeSJeff Dike } 251995473aeSJeff Dike 252995473aeSJeff Dike void cpu_idle(void) 253995473aeSJeff Dike { 254a5a678c8SJeff Dike cpu_tasks[current_thread_info()->cpu].pid = os_getpid(); 25577bf4400SJeff Dike default_idle(); 256995473aeSJeff Dike } 257995473aeSJeff Dike 258995473aeSJeff Dike void dump_thread(struct pt_regs *regs, struct user *u) 259995473aeSJeff Dike { 260995473aeSJeff Dike } 261995473aeSJeff Dike 262995473aeSJeff Dike int __cant_sleep(void) { 263995473aeSJeff Dike return in_atomic() || irqs_disabled() || in_interrupt(); 264995473aeSJeff Dike /* Is in_interrupt() really needed? */ 265995473aeSJeff Dike } 266995473aeSJeff Dike 267995473aeSJeff Dike int user_context(unsigned long sp) 268995473aeSJeff Dike { 269995473aeSJeff Dike unsigned long stack; 270995473aeSJeff Dike 271995473aeSJeff Dike stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER); 272a5a678c8SJeff Dike return stack != (unsigned long) current_thread_info(); 273995473aeSJeff Dike } 274995473aeSJeff Dike 275995473aeSJeff Dike extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end; 276995473aeSJeff Dike 277995473aeSJeff Dike void do_uml_exitcalls(void) 278995473aeSJeff Dike { 279995473aeSJeff Dike exitcall_t *call; 280995473aeSJeff Dike 281995473aeSJeff Dike call = &__uml_exitcall_end; 282995473aeSJeff Dike while (--call >= &__uml_exitcall_begin) 283995473aeSJeff Dike (*call)(); 284995473aeSJeff Dike } 285995473aeSJeff Dike 286c0a9290eSWANG Cong char *uml_strdup(const char *string) 287995473aeSJeff Dike { 288995473aeSJeff Dike return kstrdup(string, GFP_KERNEL); 289995473aeSJeff Dike } 290995473aeSJeff Dike 291995473aeSJeff Dike int copy_to_user_proc(void __user *to, void *from, int size) 292995473aeSJeff Dike { 2936e21aec3SJeff Dike return copy_to_user(to, from, size); 294995473aeSJeff Dike } 295995473aeSJeff Dike 296995473aeSJeff Dike int copy_from_user_proc(void *to, void __user *from, int size) 297995473aeSJeff Dike { 2986e21aec3SJeff Dike return copy_from_user(to, from, size); 299995473aeSJeff Dike } 300995473aeSJeff Dike 301995473aeSJeff Dike int clear_user_proc(void __user *buf, int size) 302995473aeSJeff Dike { 3036e21aec3SJeff Dike return clear_user(buf, size); 304995473aeSJeff Dike } 305995473aeSJeff Dike 306995473aeSJeff Dike int strlen_user_proc(char __user *str) 307995473aeSJeff Dike { 3086e21aec3SJeff Dike return strlen_user(str); 309995473aeSJeff Dike } 310995473aeSJeff Dike 311995473aeSJeff Dike int smp_sigio_handler(void) 312995473aeSJeff Dike { 313995473aeSJeff Dike #ifdef CONFIG_SMP 314a5a678c8SJeff Dike int cpu = current_thread_info()->cpu; 315995473aeSJeff Dike IPI_handler(cpu); 316995473aeSJeff Dike if (cpu != 0) 3176e21aec3SJeff Dike return 1; 318995473aeSJeff Dike #endif 3196e21aec3SJeff Dike return 0; 320995473aeSJeff Dike } 321995473aeSJeff Dike 322995473aeSJeff Dike int cpu(void) 323995473aeSJeff Dike { 324a5a678c8SJeff Dike return current_thread_info()->cpu; 325995473aeSJeff Dike } 326995473aeSJeff Dike 327995473aeSJeff Dike static atomic_t using_sysemu = ATOMIC_INIT(0); 328995473aeSJeff Dike int sysemu_supported; 329995473aeSJeff Dike 330995473aeSJeff Dike void set_using_sysemu(int value) 331995473aeSJeff Dike { 332995473aeSJeff Dike if (value > sysemu_supported) 333995473aeSJeff Dike return; 334995473aeSJeff Dike atomic_set(&using_sysemu, value); 335995473aeSJeff Dike } 336995473aeSJeff Dike 337995473aeSJeff Dike int get_using_sysemu(void) 338995473aeSJeff Dike { 339995473aeSJeff Dike return atomic_read(&using_sysemu); 340995473aeSJeff Dike } 341995473aeSJeff Dike 342995473aeSJeff Dike static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data) 343995473aeSJeff Dike { 344ba180fd4SJeff Dike if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) 345ba180fd4SJeff Dike /* No overflow */ 346995473aeSJeff Dike *eof = 1; 347995473aeSJeff Dike 348995473aeSJeff Dike return strlen(buf); 349995473aeSJeff Dike } 350995473aeSJeff Dike 351995473aeSJeff Dike static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data) 352995473aeSJeff Dike { 353995473aeSJeff Dike char tmp[2]; 354995473aeSJeff Dike 355995473aeSJeff Dike if (copy_from_user(tmp, buf, 1)) 356995473aeSJeff Dike return -EFAULT; 357995473aeSJeff Dike 358995473aeSJeff Dike if (tmp[0] >= '0' && tmp[0] <= '2') 359995473aeSJeff Dike set_using_sysemu(tmp[0] - '0'); 360ba180fd4SJeff Dike /* We use the first char, but pretend to write everything */ 361ba180fd4SJeff Dike return count; 362995473aeSJeff Dike } 363995473aeSJeff Dike 364995473aeSJeff Dike int __init make_proc_sysemu(void) 365995473aeSJeff Dike { 366995473aeSJeff Dike struct proc_dir_entry *ent; 367995473aeSJeff Dike if (!sysemu_supported) 368995473aeSJeff Dike return 0; 369995473aeSJeff Dike 370995473aeSJeff Dike ent = create_proc_entry("sysemu", 0600, &proc_root); 371995473aeSJeff Dike 372995473aeSJeff Dike if (ent == NULL) 373995473aeSJeff Dike { 374995473aeSJeff Dike printk(KERN_WARNING "Failed to register /proc/sysemu\n"); 3756e21aec3SJeff Dike return 0; 376995473aeSJeff Dike } 377995473aeSJeff Dike 378995473aeSJeff Dike ent->read_proc = proc_read_sysemu; 379995473aeSJeff Dike ent->write_proc = proc_write_sysemu; 380995473aeSJeff Dike 381995473aeSJeff Dike return 0; 382995473aeSJeff Dike } 383995473aeSJeff Dike 384995473aeSJeff Dike late_initcall(make_proc_sysemu); 385995473aeSJeff Dike 386995473aeSJeff Dike int singlestepping(void * t) 387995473aeSJeff Dike { 388995473aeSJeff Dike struct task_struct *task = t ? t : current; 389995473aeSJeff Dike 390995473aeSJeff Dike if ( ! (task->ptrace & PT_DTRACE) ) 391ba180fd4SJeff Dike return 0; 392995473aeSJeff Dike 393995473aeSJeff Dike if (task->thread.singlestep_syscall) 394ba180fd4SJeff Dike return 1; 395995473aeSJeff Dike 396995473aeSJeff Dike return 2; 397995473aeSJeff Dike } 398995473aeSJeff Dike 399995473aeSJeff Dike /* 400995473aeSJeff Dike * Only x86 and x86_64 have an arch_align_stack(). 401995473aeSJeff Dike * All other arches have "#define arch_align_stack(x) (x)" 402995473aeSJeff Dike * in their asm/system.h 403995473aeSJeff Dike * As this is included in UML from asm-um/system-generic.h, 404995473aeSJeff Dike * we can use it to behave as the subarch does. 405995473aeSJeff Dike */ 406995473aeSJeff Dike #ifndef arch_align_stack 407995473aeSJeff Dike unsigned long arch_align_stack(unsigned long sp) 408995473aeSJeff Dike { 409995473aeSJeff Dike if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 410995473aeSJeff Dike sp -= get_random_int() % 8192; 411995473aeSJeff Dike return sp & ~0xf; 412995473aeSJeff Dike } 413995473aeSJeff Dike #endif 414c1127465SJeff Dike 415c1127465SJeff Dike unsigned long get_wchan(struct task_struct *p) 416c1127465SJeff Dike { 417c1127465SJeff Dike unsigned long stack_page, sp, ip; 418c1127465SJeff Dike bool seen_sched = 0; 419c1127465SJeff Dike 420c1127465SJeff Dike if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING)) 421c1127465SJeff Dike return 0; 422c1127465SJeff Dike 423c1127465SJeff Dike stack_page = (unsigned long) task_stack_page(p); 424c1127465SJeff Dike /* Bail if the process has no kernel stack for some reason */ 425c1127465SJeff Dike if (stack_page == 0) 426c1127465SJeff Dike return 0; 427c1127465SJeff Dike 428c1127465SJeff Dike sp = p->thread.switch_buf->JB_SP; 429c1127465SJeff Dike /* 430c1127465SJeff Dike * Bail if the stack pointer is below the bottom of the kernel 431c1127465SJeff Dike * stack for some reason 432c1127465SJeff Dike */ 433c1127465SJeff Dike if (sp < stack_page) 434c1127465SJeff Dike return 0; 435c1127465SJeff Dike 436c1127465SJeff Dike while (sp < stack_page + THREAD_SIZE) { 437c1127465SJeff Dike ip = *((unsigned long *) sp); 438c1127465SJeff Dike if (in_sched_functions(ip)) 439c1127465SJeff Dike /* Ignore everything until we're above the scheduler */ 440c1127465SJeff Dike seen_sched = 1; 441c1127465SJeff Dike else if (kernel_text_address(ip) && seen_sched) 442c1127465SJeff Dike return ip; 443c1127465SJeff Dike 444c1127465SJeff Dike sp += sizeof(unsigned long); 445c1127465SJeff Dike } 446c1127465SJeff Dike 447c1127465SJeff Dike return 0; 448c1127465SJeff Dike } 4498192ab42SJeff Dike 4508192ab42SJeff Dike int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu) 4518192ab42SJeff Dike { 4528192ab42SJeff Dike int cpu = current_thread_info()->cpu; 4538192ab42SJeff Dike 4548192ab42SJeff Dike return save_fp_registers(userspace_pid[cpu], (unsigned long *) fpu); 4558192ab42SJeff Dike } 4568192ab42SJeff Dike 457