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 7c5d4bb17SJeff Dike #include <linux/stddef.h> 8c5d4bb17SJeff Dike #include <linux/err.h> 9c5d4bb17SJeff Dike #include <linux/hardirq.h> 10c5d4bb17SJeff Dike #include <linux/gfp.h> 11c5d4bb17SJeff Dike #include <linux/mm.h> 12c5d4bb17SJeff Dike #include <linux/personality.h> 13c5d4bb17SJeff Dike #include <linux/proc_fs.h> 14c5d4bb17SJeff Dike #include <linux/ptrace.h> 15c5d4bb17SJeff Dike #include <linux/random.h> 16c5d4bb17SJeff Dike #include <linux/sched.h> 17c5d4bb17SJeff Dike #include <linux/tick.h> 18c5d4bb17SJeff Dike #include <linux/threads.h> 19c5d4bb17SJeff Dike #include <asm/current.h> 20c5d4bb17SJeff Dike #include <asm/pgtable.h> 21c5d4bb17SJeff Dike #include <asm/uaccess.h> 224ff83ce1SJeff Dike #include "as-layout.h" 23ba180fd4SJeff Dike #include "kern_util.h" 24995473aeSJeff Dike #include "os.h" 2577bf4400SJeff Dike #include "skas.h" 26ba180fd4SJeff Dike #include "tlb.h" 27995473aeSJeff Dike 28ba180fd4SJeff Dike /* 29ba180fd4SJeff Dike * This is a per-cpu array. A processor only modifies its entry and it only 30995473aeSJeff Dike * cares about its entry, so it's OK if another processor is modifying its 31995473aeSJeff Dike * entry. 32995473aeSJeff Dike */ 33995473aeSJeff Dike struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } }; 34995473aeSJeff Dike 352dc5802aSKarol Swietlicki static inline int external_pid(void) 36995473aeSJeff Dike { 3777bf4400SJeff Dike /* FIXME: Need to look up userspace_pid by cpu */ 38ba180fd4SJeff Dike return userspace_pid[0]; 39995473aeSJeff Dike } 40995473aeSJeff Dike 41995473aeSJeff Dike int pid_to_processor_id(int pid) 42995473aeSJeff Dike { 43995473aeSJeff Dike int i; 44995473aeSJeff Dike 45995473aeSJeff Dike for (i = 0; i < ncpus; i++) { 466e21aec3SJeff Dike if (cpu_tasks[i].pid == pid) 476e21aec3SJeff Dike return i; 48995473aeSJeff Dike } 496e21aec3SJeff Dike return -1; 50995473aeSJeff Dike } 51995473aeSJeff Dike 52995473aeSJeff Dike void free_stack(unsigned long stack, int order) 53995473aeSJeff Dike { 54995473aeSJeff Dike free_pages(stack, order); 55995473aeSJeff Dike } 56995473aeSJeff Dike 57995473aeSJeff Dike unsigned long alloc_stack(int order, int atomic) 58995473aeSJeff Dike { 59995473aeSJeff Dike unsigned long page; 60995473aeSJeff Dike gfp_t flags = GFP_KERNEL; 61995473aeSJeff Dike 62995473aeSJeff Dike if (atomic) 63995473aeSJeff Dike flags = GFP_ATOMIC; 64995473aeSJeff Dike page = __get_free_pages(flags, order); 655c8aaceaSJeff Dike 666e21aec3SJeff Dike return page; 67995473aeSJeff Dike } 68995473aeSJeff Dike 69995473aeSJeff Dike int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 70995473aeSJeff Dike { 71995473aeSJeff Dike int pid; 72995473aeSJeff Dike 73995473aeSJeff Dike current->thread.request.u.thread.proc = fn; 74995473aeSJeff Dike current->thread.request.u.thread.arg = arg; 75995473aeSJeff Dike pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0, 76995473aeSJeff Dike ¤t->thread.regs, 0, NULL, NULL); 776e21aec3SJeff Dike return pid; 78995473aeSJeff Dike } 79995473aeSJeff Dike 806e21aec3SJeff Dike static inline void set_current(struct task_struct *task) 81995473aeSJeff Dike { 82995473aeSJeff Dike cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task) 832dc5802aSKarol Swietlicki { external_pid(), task }); 84995473aeSJeff Dike } 85995473aeSJeff Dike 86291248fdSKarol Swietlicki extern void arch_switch_to(struct task_struct *to); 8777bf4400SJeff Dike 88995473aeSJeff Dike void *_switch_to(void *prev, void *next, void *last) 89995473aeSJeff Dike { 90995473aeSJeff Dike struct task_struct *from = prev; 91995473aeSJeff Dike struct task_struct *to = next; 92995473aeSJeff Dike 93995473aeSJeff Dike to->thread.prev_sched = from; 94995473aeSJeff Dike set_current(to); 95995473aeSJeff Dike 96995473aeSJeff Dike do { 97995473aeSJeff Dike current->thread.saved_task = NULL; 9877bf4400SJeff Dike 99c5d4bb17SJeff Dike switch_threads(&from->thread.switch_buf, 100c5d4bb17SJeff Dike &to->thread.switch_buf); 10177bf4400SJeff Dike 102291248fdSKarol Swietlicki arch_switch_to(current); 10377bf4400SJeff Dike 104995473aeSJeff Dike if (current->thread.saved_task) 105995473aeSJeff Dike show_regs(&(current->thread.regs)); 106c5d4bb17SJeff Dike to = current->thread.saved_task; 107c5d4bb17SJeff Dike from = current; 108995473aeSJeff Dike } while (current->thread.saved_task); 109995473aeSJeff Dike 1106e21aec3SJeff Dike return current->thread.prev_sched; 111995473aeSJeff Dike 112995473aeSJeff Dike } 113995473aeSJeff Dike 114995473aeSJeff Dike void interrupt_end(void) 115995473aeSJeff Dike { 1166e21aec3SJeff Dike if (need_resched()) 1176e21aec3SJeff Dike schedule(); 1186e21aec3SJeff Dike if (test_tsk_thread_flag(current, TIF_SIGPENDING)) 1196e21aec3SJeff Dike do_signal(); 120995473aeSJeff Dike } 121995473aeSJeff Dike 122995473aeSJeff Dike void exit_thread(void) 123995473aeSJeff Dike { 124995473aeSJeff Dike } 125995473aeSJeff Dike 126995473aeSJeff Dike void *get_current(void) 127995473aeSJeff Dike { 1286e21aec3SJeff Dike return current; 129995473aeSJeff Dike } 130995473aeSJeff Dike 131ba180fd4SJeff Dike /* 132ba180fd4SJeff Dike * This is called magically, by its address being stuffed in a jmp_buf 13377bf4400SJeff Dike * and being longjmp-d to. 13477bf4400SJeff Dike */ 13577bf4400SJeff Dike void new_thread_handler(void) 13677bf4400SJeff Dike { 13777bf4400SJeff Dike int (*fn)(void *), n; 13877bf4400SJeff Dike void *arg; 13977bf4400SJeff Dike 14077bf4400SJeff Dike if (current->thread.prev_sched != NULL) 14177bf4400SJeff Dike schedule_tail(current->thread.prev_sched); 14277bf4400SJeff Dike current->thread.prev_sched = NULL; 14377bf4400SJeff Dike 14477bf4400SJeff Dike fn = current->thread.request.u.thread.proc; 14577bf4400SJeff Dike arg = current->thread.request.u.thread.arg; 14677bf4400SJeff Dike 147ba180fd4SJeff Dike /* 148ba180fd4SJeff Dike * The return value is 1 if the kernel thread execs a process, 14977bf4400SJeff Dike * 0 if it just exits 15077bf4400SJeff Dike */ 15177bf4400SJeff Dike n = run_kernel_thread(fn, arg, ¤t->thread.exec_buf); 15277bf4400SJeff Dike if (n == 1) { 15377bf4400SJeff Dike /* Handle any immediate reschedules or signals */ 15477bf4400SJeff Dike interrupt_end(); 15577bf4400SJeff Dike userspace(¤t->thread.regs.regs); 15677bf4400SJeff Dike } 15777bf4400SJeff Dike else do_exit(0); 15877bf4400SJeff Dike } 15977bf4400SJeff Dike 16077bf4400SJeff Dike /* Called magically, see new_thread_handler above */ 16177bf4400SJeff Dike void fork_handler(void) 16277bf4400SJeff Dike { 16377bf4400SJeff Dike force_flush_all(); 16477bf4400SJeff Dike 16577bf4400SJeff Dike schedule_tail(current->thread.prev_sched); 16677bf4400SJeff Dike 167ba180fd4SJeff Dike /* 168ba180fd4SJeff Dike * XXX: if interrupt_end() calls schedule, this call to 16977bf4400SJeff Dike * arch_switch_to isn't needed. We could want to apply this to 170ba180fd4SJeff Dike * improve performance. -bb 171ba180fd4SJeff Dike */ 172291248fdSKarol Swietlicki arch_switch_to(current); 17377bf4400SJeff Dike 17477bf4400SJeff Dike current->thread.prev_sched = NULL; 17577bf4400SJeff Dike 17677bf4400SJeff Dike /* Handle any immediate reschedules or signals */ 17777bf4400SJeff Dike interrupt_end(); 17877bf4400SJeff Dike 17977bf4400SJeff Dike userspace(¤t->thread.regs.regs); 18077bf4400SJeff Dike } 18177bf4400SJeff Dike 182995473aeSJeff Dike int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, 183995473aeSJeff Dike unsigned long stack_top, struct task_struct * p, 184995473aeSJeff Dike struct pt_regs *regs) 185995473aeSJeff Dike { 18677bf4400SJeff Dike void (*handler)(void); 18777bf4400SJeff Dike int ret = 0; 188995473aeSJeff Dike 189995473aeSJeff Dike p->thread = (struct thread_struct) INIT_THREAD; 190995473aeSJeff Dike 19177bf4400SJeff Dike if (current->thread.forking) { 19277bf4400SJeff Dike memcpy(&p->thread.regs.regs, ®s->regs, 19377bf4400SJeff Dike sizeof(p->thread.regs.regs)); 19418badddaSJeff Dike REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.gp, 0); 19577bf4400SJeff Dike if (sp != 0) 19618badddaSJeff Dike REGS_SP(p->thread.regs.regs.gp) = sp; 197995473aeSJeff Dike 19877bf4400SJeff Dike handler = fork_handler; 19977bf4400SJeff Dike 20077bf4400SJeff Dike arch_copy_thread(¤t->thread.arch, &p->thread.arch); 20177bf4400SJeff Dike } 20277bf4400SJeff Dike else { 203d25f2e12SJeff Dike get_safe_registers(p->thread.regs.regs.gp); 20477bf4400SJeff Dike p->thread.request.u.thread = current->thread.request.u.thread; 20577bf4400SJeff Dike handler = new_thread_handler; 20677bf4400SJeff Dike } 20777bf4400SJeff Dike 20877bf4400SJeff Dike new_thread(task_stack_page(p), &p->thread.switch_buf, handler); 20977bf4400SJeff Dike 21077bf4400SJeff Dike if (current->thread.forking) { 211995473aeSJeff Dike clear_flushed_tls(p); 212995473aeSJeff Dike 213995473aeSJeff Dike /* 214995473aeSJeff Dike * Set a new TLS for the child thread? 215995473aeSJeff Dike */ 216995473aeSJeff Dike if (clone_flags & CLONE_SETTLS) 217995473aeSJeff Dike ret = arch_copy_tls(p); 21877bf4400SJeff Dike } 219995473aeSJeff Dike 220995473aeSJeff Dike return ret; 221995473aeSJeff Dike } 222995473aeSJeff Dike 223995473aeSJeff Dike void initial_thread_cb(void (*proc)(void *), void *arg) 224995473aeSJeff Dike { 225995473aeSJeff Dike int save_kmalloc_ok = kmalloc_ok; 226995473aeSJeff Dike 227995473aeSJeff Dike kmalloc_ok = 0; 2286aa802ceSJeff Dike initial_thread_cb_skas(proc, arg); 229995473aeSJeff Dike kmalloc_ok = save_kmalloc_ok; 230995473aeSJeff Dike } 231995473aeSJeff Dike 232995473aeSJeff Dike void default_idle(void) 233995473aeSJeff Dike { 234b160fb63SJeff Dike unsigned long long nsecs; 235b160fb63SJeff Dike 236995473aeSJeff Dike while (1) { 237995473aeSJeff Dike /* endless idle loop with no priority at all */ 238995473aeSJeff Dike 239995473aeSJeff Dike /* 240995473aeSJeff Dike * although we are an idle CPU, we do not want to 241995473aeSJeff Dike * get into the scheduler unnecessarily. 242995473aeSJeff Dike */ 243995473aeSJeff Dike if (need_resched()) 244995473aeSJeff Dike schedule(); 245995473aeSJeff Dike 246b8f8c3cfSThomas Gleixner tick_nohz_stop_sched_tick(1); 247b160fb63SJeff Dike nsecs = disable_timer(); 248b160fb63SJeff Dike idle_sleep(nsecs); 249d2753a6dSJeff Dike tick_nohz_restart_sched_tick(); 250995473aeSJeff Dike } 251995473aeSJeff Dike } 252995473aeSJeff Dike 253995473aeSJeff Dike void cpu_idle(void) 254995473aeSJeff Dike { 255a5a678c8SJeff Dike cpu_tasks[current_thread_info()->cpu].pid = os_getpid(); 25677bf4400SJeff Dike default_idle(); 257995473aeSJeff Dike } 258995473aeSJeff Dike 259995473aeSJeff Dike int __cant_sleep(void) { 260995473aeSJeff Dike return in_atomic() || irqs_disabled() || in_interrupt(); 261995473aeSJeff Dike /* Is in_interrupt() really needed? */ 262995473aeSJeff Dike } 263995473aeSJeff Dike 264995473aeSJeff Dike int user_context(unsigned long sp) 265995473aeSJeff Dike { 266995473aeSJeff Dike unsigned long stack; 267995473aeSJeff Dike 268995473aeSJeff Dike stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER); 269a5a678c8SJeff Dike return stack != (unsigned long) current_thread_info(); 270995473aeSJeff Dike } 271995473aeSJeff Dike 272995473aeSJeff Dike extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end; 273995473aeSJeff Dike 274995473aeSJeff Dike void do_uml_exitcalls(void) 275995473aeSJeff Dike { 276995473aeSJeff Dike exitcall_t *call; 277995473aeSJeff Dike 278995473aeSJeff Dike call = &__uml_exitcall_end; 279995473aeSJeff Dike while (--call >= &__uml_exitcall_begin) 280995473aeSJeff Dike (*call)(); 281995473aeSJeff Dike } 282995473aeSJeff Dike 283c0a9290eSWANG Cong char *uml_strdup(const char *string) 284995473aeSJeff Dike { 285995473aeSJeff Dike return kstrdup(string, GFP_KERNEL); 286995473aeSJeff Dike } 287995473aeSJeff Dike 288995473aeSJeff Dike int copy_to_user_proc(void __user *to, void *from, int size) 289995473aeSJeff Dike { 2906e21aec3SJeff Dike return copy_to_user(to, from, size); 291995473aeSJeff Dike } 292995473aeSJeff Dike 293995473aeSJeff Dike int copy_from_user_proc(void *to, void __user *from, int size) 294995473aeSJeff Dike { 2956e21aec3SJeff Dike return copy_from_user(to, from, size); 296995473aeSJeff Dike } 297995473aeSJeff Dike 298995473aeSJeff Dike int clear_user_proc(void __user *buf, int size) 299995473aeSJeff Dike { 3006e21aec3SJeff Dike return clear_user(buf, size); 301995473aeSJeff Dike } 302995473aeSJeff Dike 303995473aeSJeff Dike int strlen_user_proc(char __user *str) 304995473aeSJeff Dike { 3056e21aec3SJeff Dike return strlen_user(str); 306995473aeSJeff Dike } 307995473aeSJeff Dike 308995473aeSJeff Dike int smp_sigio_handler(void) 309995473aeSJeff Dike { 310995473aeSJeff Dike #ifdef CONFIG_SMP 311a5a678c8SJeff Dike int cpu = current_thread_info()->cpu; 312995473aeSJeff Dike IPI_handler(cpu); 313995473aeSJeff Dike if (cpu != 0) 3146e21aec3SJeff Dike return 1; 315995473aeSJeff Dike #endif 3166e21aec3SJeff Dike return 0; 317995473aeSJeff Dike } 318995473aeSJeff Dike 319995473aeSJeff Dike int cpu(void) 320995473aeSJeff Dike { 321a5a678c8SJeff Dike return current_thread_info()->cpu; 322995473aeSJeff Dike } 323995473aeSJeff Dike 324995473aeSJeff Dike static atomic_t using_sysemu = ATOMIC_INIT(0); 325995473aeSJeff Dike int sysemu_supported; 326995473aeSJeff Dike 327995473aeSJeff Dike void set_using_sysemu(int value) 328995473aeSJeff Dike { 329995473aeSJeff Dike if (value > sysemu_supported) 330995473aeSJeff Dike return; 331995473aeSJeff Dike atomic_set(&using_sysemu, value); 332995473aeSJeff Dike } 333995473aeSJeff Dike 334995473aeSJeff Dike int get_using_sysemu(void) 335995473aeSJeff Dike { 336995473aeSJeff Dike return atomic_read(&using_sysemu); 337995473aeSJeff Dike } 338995473aeSJeff Dike 339995473aeSJeff Dike static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data) 340995473aeSJeff Dike { 341ba180fd4SJeff Dike if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) 342ba180fd4SJeff Dike /* No overflow */ 343995473aeSJeff Dike *eof = 1; 344995473aeSJeff Dike 345995473aeSJeff Dike return strlen(buf); 346995473aeSJeff Dike } 347995473aeSJeff Dike 348995473aeSJeff Dike static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data) 349995473aeSJeff Dike { 350995473aeSJeff Dike char tmp[2]; 351995473aeSJeff Dike 352995473aeSJeff Dike if (copy_from_user(tmp, buf, 1)) 353995473aeSJeff Dike return -EFAULT; 354995473aeSJeff Dike 355995473aeSJeff Dike if (tmp[0] >= '0' && tmp[0] <= '2') 356995473aeSJeff Dike set_using_sysemu(tmp[0] - '0'); 357ba180fd4SJeff Dike /* We use the first char, but pretend to write everything */ 358ba180fd4SJeff Dike return count; 359995473aeSJeff Dike } 360995473aeSJeff Dike 361995473aeSJeff Dike int __init make_proc_sysemu(void) 362995473aeSJeff Dike { 363995473aeSJeff Dike struct proc_dir_entry *ent; 364995473aeSJeff Dike if (!sysemu_supported) 365995473aeSJeff Dike return 0; 366995473aeSJeff Dike 367c74c120aSAlexey Dobriyan ent = create_proc_entry("sysemu", 0600, NULL); 368995473aeSJeff Dike 369995473aeSJeff Dike if (ent == NULL) 370995473aeSJeff Dike { 371995473aeSJeff Dike printk(KERN_WARNING "Failed to register /proc/sysemu\n"); 3726e21aec3SJeff Dike return 0; 373995473aeSJeff Dike } 374995473aeSJeff Dike 375995473aeSJeff Dike ent->read_proc = proc_read_sysemu; 376995473aeSJeff Dike ent->write_proc = proc_write_sysemu; 377995473aeSJeff Dike 378995473aeSJeff Dike return 0; 379995473aeSJeff Dike } 380995473aeSJeff Dike 381995473aeSJeff Dike late_initcall(make_proc_sysemu); 382995473aeSJeff Dike 383995473aeSJeff Dike int singlestepping(void * t) 384995473aeSJeff Dike { 385995473aeSJeff Dike struct task_struct *task = t ? t : current; 386995473aeSJeff Dike 387995473aeSJeff Dike if (!(task->ptrace & PT_DTRACE)) 388ba180fd4SJeff Dike return 0; 389995473aeSJeff Dike 390995473aeSJeff Dike if (task->thread.singlestep_syscall) 391ba180fd4SJeff Dike return 1; 392995473aeSJeff Dike 393995473aeSJeff Dike return 2; 394995473aeSJeff Dike } 395995473aeSJeff Dike 396995473aeSJeff Dike /* 397995473aeSJeff Dike * Only x86 and x86_64 have an arch_align_stack(). 398995473aeSJeff Dike * All other arches have "#define arch_align_stack(x) (x)" 399995473aeSJeff Dike * in their asm/system.h 400995473aeSJeff Dike * As this is included in UML from asm-um/system-generic.h, 401995473aeSJeff Dike * we can use it to behave as the subarch does. 402995473aeSJeff Dike */ 403995473aeSJeff Dike #ifndef arch_align_stack 404995473aeSJeff Dike unsigned long arch_align_stack(unsigned long sp) 405995473aeSJeff Dike { 406995473aeSJeff Dike if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 407995473aeSJeff Dike sp -= get_random_int() % 8192; 408995473aeSJeff Dike return sp & ~0xf; 409995473aeSJeff Dike } 410995473aeSJeff Dike #endif 411c1127465SJeff Dike 412c1127465SJeff Dike unsigned long get_wchan(struct task_struct *p) 413c1127465SJeff Dike { 414c1127465SJeff Dike unsigned long stack_page, sp, ip; 415c1127465SJeff Dike bool seen_sched = 0; 416c1127465SJeff Dike 417c1127465SJeff Dike if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING)) 418c1127465SJeff Dike return 0; 419c1127465SJeff Dike 420c1127465SJeff Dike stack_page = (unsigned long) task_stack_page(p); 421c1127465SJeff Dike /* Bail if the process has no kernel stack for some reason */ 422c1127465SJeff Dike if (stack_page == 0) 423c1127465SJeff Dike return 0; 424c1127465SJeff Dike 425c1127465SJeff Dike sp = p->thread.switch_buf->JB_SP; 426c1127465SJeff Dike /* 427c1127465SJeff Dike * Bail if the stack pointer is below the bottom of the kernel 428c1127465SJeff Dike * stack for some reason 429c1127465SJeff Dike */ 430c1127465SJeff Dike if (sp < stack_page) 431c1127465SJeff Dike return 0; 432c1127465SJeff Dike 433c1127465SJeff Dike while (sp < stack_page + THREAD_SIZE) { 434c1127465SJeff Dike ip = *((unsigned long *) sp); 435c1127465SJeff Dike if (in_sched_functions(ip)) 436c1127465SJeff Dike /* Ignore everything until we're above the scheduler */ 437c1127465SJeff Dike seen_sched = 1; 438c1127465SJeff Dike else if (kernel_text_address(ip) && seen_sched) 439c1127465SJeff Dike return ip; 440c1127465SJeff Dike 441c1127465SJeff Dike sp += sizeof(unsigned long); 442c1127465SJeff Dike } 443c1127465SJeff Dike 444c1127465SJeff Dike return 0; 445c1127465SJeff Dike } 4468192ab42SJeff Dike 4478192ab42SJeff Dike int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu) 4488192ab42SJeff Dike { 4498192ab42SJeff Dike int cpu = current_thread_info()->cpu; 4508192ab42SJeff Dike 4518192ab42SJeff Dike return save_fp_registers(userspace_pid[cpu], (unsigned long *) fpu); 4528192ab42SJeff Dike } 4538192ab42SJeff Dike 454