1995473aeSJeff Dike /* 22eb5f31bSAnton Ivanov * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk}) 32eb5f31bSAnton Ivanov * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de) 4ba180fd4SJeff Dike * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 5995473aeSJeff Dike * Copyright 2003 PathScale, Inc. 6995473aeSJeff Dike * Licensed under the GPL 7995473aeSJeff Dike */ 8995473aeSJeff Dike 9c5d4bb17SJeff Dike #include <linux/stddef.h> 10c5d4bb17SJeff Dike #include <linux/err.h> 11c5d4bb17SJeff Dike #include <linux/hardirq.h> 12c5d4bb17SJeff Dike #include <linux/mm.h> 136613c5e8SAlexey Dobriyan #include <linux/module.h> 14c5d4bb17SJeff Dike #include <linux/personality.h> 15c5d4bb17SJeff Dike #include <linux/proc_fs.h> 16c5d4bb17SJeff Dike #include <linux/ptrace.h> 17c5d4bb17SJeff Dike #include <linux/random.h> 185a0e3ad6STejun Heo #include <linux/slab.h> 19c5d4bb17SJeff Dike #include <linux/sched.h> 20b17b0153SIngo Molnar #include <linux/sched/debug.h> 2129930025SIngo Molnar #include <linux/sched/task.h> 2268db0cf1SIngo Molnar #include <linux/sched/task_stack.h> 236613c5e8SAlexey Dobriyan #include <linux/seq_file.h> 24c5d4bb17SJeff Dike #include <linux/tick.h> 25c5d4bb17SJeff Dike #include <linux/threads.h> 26d50349b0SAl Viro #include <linux/tracehook.h> 27c5d4bb17SJeff Dike #include <asm/current.h> 28c5d4bb17SJeff Dike #include <asm/pgtable.h> 29445c5786SAl Viro #include <asm/mmu_context.h> 307c0f6ba6SLinus Torvalds #include <linux/uaccess.h> 3137185b33SAl Viro #include <as-layout.h> 3237185b33SAl Viro #include <kern_util.h> 3337185b33SAl Viro #include <os.h> 3437185b33SAl Viro #include <skas.h> 352eb5f31bSAnton Ivanov #include <timer-internal.h> 36995473aeSJeff Dike 37ba180fd4SJeff Dike /* 38ba180fd4SJeff Dike * This is a per-cpu array. A processor only modifies its entry and it only 39995473aeSJeff Dike * cares about its entry, so it's OK if another processor is modifying its 40995473aeSJeff Dike * entry. 41995473aeSJeff Dike */ 42995473aeSJeff Dike struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } }; 43995473aeSJeff Dike 442dc5802aSKarol Swietlicki static inline int external_pid(void) 45995473aeSJeff Dike { 4677bf4400SJeff Dike /* FIXME: Need to look up userspace_pid by cpu */ 47ba180fd4SJeff Dike return userspace_pid[0]; 48995473aeSJeff Dike } 49995473aeSJeff Dike 50995473aeSJeff Dike int pid_to_processor_id(int pid) 51995473aeSJeff Dike { 52995473aeSJeff Dike int i; 53995473aeSJeff Dike 54995473aeSJeff Dike for (i = 0; i < ncpus; i++) { 556e21aec3SJeff Dike if (cpu_tasks[i].pid == pid) 566e21aec3SJeff Dike return i; 57995473aeSJeff Dike } 586e21aec3SJeff Dike return -1; 59995473aeSJeff Dike } 60995473aeSJeff Dike 61995473aeSJeff Dike void free_stack(unsigned long stack, int order) 62995473aeSJeff Dike { 63995473aeSJeff Dike free_pages(stack, order); 64995473aeSJeff Dike } 65995473aeSJeff Dike 66995473aeSJeff Dike unsigned long alloc_stack(int order, int atomic) 67995473aeSJeff Dike { 68995473aeSJeff Dike unsigned long page; 69995473aeSJeff Dike gfp_t flags = GFP_KERNEL; 70995473aeSJeff Dike 71995473aeSJeff Dike if (atomic) 72995473aeSJeff Dike flags = GFP_ATOMIC; 73995473aeSJeff Dike page = __get_free_pages(flags, order); 745c8aaceaSJeff Dike 756e21aec3SJeff Dike return page; 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) 812dc5802aSKarol Swietlicki { external_pid(), task }); 82995473aeSJeff Dike } 83995473aeSJeff Dike 84291248fdSKarol Swietlicki extern void arch_switch_to(struct task_struct *to); 8577bf4400SJeff Dike 8676b278edSRichard Weinberger void *__switch_to(struct task_struct *from, struct task_struct *to) 87995473aeSJeff Dike { 88995473aeSJeff Dike to->thread.prev_sched = from; 89995473aeSJeff Dike set_current(to); 90995473aeSJeff Dike 91a1850e9cSRichard Weinberger switch_threads(&from->thread.switch_buf, &to->thread.switch_buf); 92291248fdSKarol Swietlicki arch_switch_to(current); 9377bf4400SJeff Dike 946e21aec3SJeff Dike return current->thread.prev_sched; 95995473aeSJeff Dike } 96995473aeSJeff Dike 97995473aeSJeff Dike void interrupt_end(void) 98995473aeSJeff Dike { 99ccaee5f8SIngo Molnar struct pt_regs *regs = ¤t->thread.regs; 100ccaee5f8SIngo Molnar 1016e21aec3SJeff Dike if (need_resched()) 1026e21aec3SJeff Dike schedule(); 103d50349b0SAl Viro if (test_thread_flag(TIF_SIGPENDING)) 104ccaee5f8SIngo Molnar do_signal(regs); 105a42c6dedSAl Viro if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) 106ccaee5f8SIngo Molnar tracehook_notify_resume(regs); 107995473aeSJeff Dike } 108995473aeSJeff Dike 109c2220b2aSAl Viro int get_current_pid(void) 110995473aeSJeff Dike { 111c2220b2aSAl Viro return task_pid_nr(current); 112995473aeSJeff Dike } 113995473aeSJeff Dike 114ba180fd4SJeff Dike /* 115ba180fd4SJeff Dike * This is called magically, by its address being stuffed in a jmp_buf 11677bf4400SJeff Dike * and being longjmp-d to. 11777bf4400SJeff Dike */ 11877bf4400SJeff Dike void new_thread_handler(void) 11977bf4400SJeff Dike { 12077bf4400SJeff Dike int (*fn)(void *), n; 12177bf4400SJeff Dike void *arg; 12277bf4400SJeff Dike 12377bf4400SJeff Dike if (current->thread.prev_sched != NULL) 12477bf4400SJeff Dike schedule_tail(current->thread.prev_sched); 12577bf4400SJeff Dike current->thread.prev_sched = NULL; 12677bf4400SJeff Dike 12777bf4400SJeff Dike fn = current->thread.request.u.thread.proc; 12877bf4400SJeff Dike arg = current->thread.request.u.thread.arg; 12977bf4400SJeff Dike 130ba180fd4SJeff Dike /* 13122e2430dSAl Viro * callback returns only if the kernel thread execs a process 13277bf4400SJeff Dike */ 13322e2430dSAl Viro n = fn(arg); 1346f602afdSThomas Meyer userspace(¤t->thread.regs.regs, current_thread_info()->aux_fp_regs); 13577bf4400SJeff Dike } 13677bf4400SJeff Dike 13777bf4400SJeff Dike /* Called magically, see new_thread_handler above */ 13877bf4400SJeff Dike void fork_handler(void) 13977bf4400SJeff Dike { 14077bf4400SJeff Dike force_flush_all(); 14177bf4400SJeff Dike 14277bf4400SJeff Dike schedule_tail(current->thread.prev_sched); 14377bf4400SJeff Dike 144ba180fd4SJeff Dike /* 145ba180fd4SJeff Dike * XXX: if interrupt_end() calls schedule, this call to 14677bf4400SJeff Dike * arch_switch_to isn't needed. We could want to apply this to 147ba180fd4SJeff Dike * improve performance. -bb 148ba180fd4SJeff Dike */ 149291248fdSKarol Swietlicki arch_switch_to(current); 15077bf4400SJeff Dike 15177bf4400SJeff Dike current->thread.prev_sched = NULL; 15277bf4400SJeff Dike 1536f602afdSThomas Meyer userspace(¤t->thread.regs.regs, current_thread_info()->aux_fp_regs); 15477bf4400SJeff Dike } 15577bf4400SJeff Dike 1566f2c55b8SAlexey Dobriyan int copy_thread(unsigned long clone_flags, unsigned long sp, 157afa86fc4SAl Viro unsigned long arg, struct task_struct * p) 158995473aeSJeff Dike { 15977bf4400SJeff Dike void (*handler)(void); 160d2ce4e92SAl Viro int kthread = current->flags & PF_KTHREAD; 16177bf4400SJeff Dike int ret = 0; 162995473aeSJeff Dike 163995473aeSJeff Dike p->thread = (struct thread_struct) INIT_THREAD; 164995473aeSJeff Dike 165d2ce4e92SAl Viro if (!kthread) { 1662b067fc9SAl Viro memcpy(&p->thread.regs.regs, current_pt_regs(), 16777bf4400SJeff Dike sizeof(p->thread.regs.regs)); 168a3170d2eSAl Viro PT_REGS_SET_SYSCALL_RETURN(&p->thread.regs, 0); 16977bf4400SJeff Dike if (sp != 0) 17018badddaSJeff Dike REGS_SP(p->thread.regs.regs.gp) = sp; 171995473aeSJeff Dike 17277bf4400SJeff Dike handler = fork_handler; 17377bf4400SJeff Dike 17477bf4400SJeff Dike arch_copy_thread(¤t->thread.arch, &p->thread.arch); 175d2ce4e92SAl Viro } else { 176fbfe9c84SIngo van Lil get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp); 1771f02ab4aSAl Viro p->thread.request.u.thread.proc = (int (*)(void *))sp; 1781f02ab4aSAl Viro p->thread.request.u.thread.arg = (void *)arg; 17977bf4400SJeff Dike handler = new_thread_handler; 18077bf4400SJeff Dike } 18177bf4400SJeff Dike 18277bf4400SJeff Dike new_thread(task_stack_page(p), &p->thread.switch_buf, handler); 18377bf4400SJeff Dike 184d2ce4e92SAl Viro if (!kthread) { 185995473aeSJeff Dike clear_flushed_tls(p); 186995473aeSJeff Dike 187995473aeSJeff Dike /* 188995473aeSJeff Dike * Set a new TLS for the child thread? 189995473aeSJeff Dike */ 190995473aeSJeff Dike if (clone_flags & CLONE_SETTLS) 191995473aeSJeff Dike ret = arch_copy_tls(p); 19277bf4400SJeff Dike } 193995473aeSJeff Dike 194995473aeSJeff Dike return ret; 195995473aeSJeff Dike } 196995473aeSJeff Dike 197995473aeSJeff Dike void initial_thread_cb(void (*proc)(void *), void *arg) 198995473aeSJeff Dike { 199995473aeSJeff Dike int save_kmalloc_ok = kmalloc_ok; 200995473aeSJeff Dike 201995473aeSJeff Dike kmalloc_ok = 0; 2026aa802ceSJeff Dike initial_thread_cb_skas(proc, arg); 203995473aeSJeff Dike kmalloc_ok = save_kmalloc_ok; 204995473aeSJeff Dike } 205995473aeSJeff Dike 2068198c169SRichard Weinberger void arch_cpu_idle(void) 207995473aeSJeff Dike { 2088198c169SRichard Weinberger cpu_tasks[current_thread_info()->cpu].pid = os_getpid(); 2092eb5f31bSAnton Ivanov os_idle_sleep(UM_NSEC_PER_SEC); 2108198c169SRichard Weinberger local_irq_enable(); 211995473aeSJeff Dike } 212995473aeSJeff Dike 213995473aeSJeff Dike int __cant_sleep(void) { 214995473aeSJeff Dike return in_atomic() || irqs_disabled() || in_interrupt(); 215995473aeSJeff Dike /* Is in_interrupt() really needed? */ 216995473aeSJeff Dike } 217995473aeSJeff Dike 218995473aeSJeff Dike int user_context(unsigned long sp) 219995473aeSJeff Dike { 220995473aeSJeff Dike unsigned long stack; 221995473aeSJeff Dike 222995473aeSJeff Dike stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER); 223a5a678c8SJeff Dike return stack != (unsigned long) current_thread_info(); 224995473aeSJeff Dike } 225995473aeSJeff Dike 226995473aeSJeff Dike extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end; 227995473aeSJeff Dike 228995473aeSJeff Dike void do_uml_exitcalls(void) 229995473aeSJeff Dike { 230995473aeSJeff Dike exitcall_t *call; 231995473aeSJeff Dike 232995473aeSJeff Dike call = &__uml_exitcall_end; 233995473aeSJeff Dike while (--call >= &__uml_exitcall_begin) 234995473aeSJeff Dike (*call)(); 235995473aeSJeff Dike } 236995473aeSJeff Dike 237c0a9290eSWANG Cong char *uml_strdup(const char *string) 238995473aeSJeff Dike { 239995473aeSJeff Dike return kstrdup(string, GFP_KERNEL); 240995473aeSJeff Dike } 24173395a00SAl Viro EXPORT_SYMBOL(uml_strdup); 242995473aeSJeff Dike 243995473aeSJeff Dike int copy_to_user_proc(void __user *to, void *from, int size) 244995473aeSJeff Dike { 2456e21aec3SJeff Dike return copy_to_user(to, from, size); 246995473aeSJeff Dike } 247995473aeSJeff Dike 248995473aeSJeff Dike int copy_from_user_proc(void *to, void __user *from, int size) 249995473aeSJeff Dike { 2506e21aec3SJeff Dike return copy_from_user(to, from, size); 251995473aeSJeff Dike } 252995473aeSJeff Dike 253995473aeSJeff Dike int clear_user_proc(void __user *buf, int size) 254995473aeSJeff Dike { 2556e21aec3SJeff Dike return clear_user(buf, size); 256995473aeSJeff Dike } 257995473aeSJeff Dike 258995473aeSJeff Dike int cpu(void) 259995473aeSJeff Dike { 260a5a678c8SJeff Dike return current_thread_info()->cpu; 261995473aeSJeff Dike } 262995473aeSJeff Dike 263995473aeSJeff Dike static atomic_t using_sysemu = ATOMIC_INIT(0); 264995473aeSJeff Dike int sysemu_supported; 265995473aeSJeff Dike 266995473aeSJeff Dike void set_using_sysemu(int value) 267995473aeSJeff Dike { 268995473aeSJeff Dike if (value > sysemu_supported) 269995473aeSJeff Dike return; 270995473aeSJeff Dike atomic_set(&using_sysemu, value); 271995473aeSJeff Dike } 272995473aeSJeff Dike 273995473aeSJeff Dike int get_using_sysemu(void) 274995473aeSJeff Dike { 275995473aeSJeff Dike return atomic_read(&using_sysemu); 276995473aeSJeff Dike } 277995473aeSJeff Dike 2786613c5e8SAlexey Dobriyan static int sysemu_proc_show(struct seq_file *m, void *v) 279995473aeSJeff Dike { 2806613c5e8SAlexey Dobriyan seq_printf(m, "%d\n", get_using_sysemu()); 2816613c5e8SAlexey Dobriyan return 0; 282995473aeSJeff Dike } 283995473aeSJeff Dike 2846613c5e8SAlexey Dobriyan static int sysemu_proc_open(struct inode *inode, struct file *file) 2856613c5e8SAlexey Dobriyan { 2866613c5e8SAlexey Dobriyan return single_open(file, sysemu_proc_show, NULL); 2876613c5e8SAlexey Dobriyan } 2886613c5e8SAlexey Dobriyan 2896613c5e8SAlexey Dobriyan static ssize_t sysemu_proc_write(struct file *file, const char __user *buf, 2906613c5e8SAlexey Dobriyan size_t count, loff_t *pos) 291995473aeSJeff Dike { 292995473aeSJeff Dike char tmp[2]; 293995473aeSJeff Dike 294995473aeSJeff Dike if (copy_from_user(tmp, buf, 1)) 295995473aeSJeff Dike return -EFAULT; 296995473aeSJeff Dike 297995473aeSJeff Dike if (tmp[0] >= '0' && tmp[0] <= '2') 298995473aeSJeff Dike set_using_sysemu(tmp[0] - '0'); 299ba180fd4SJeff Dike /* We use the first char, but pretend to write everything */ 300ba180fd4SJeff Dike return count; 301995473aeSJeff Dike } 302995473aeSJeff Dike 3036613c5e8SAlexey Dobriyan static const struct file_operations sysemu_proc_fops = { 3046613c5e8SAlexey Dobriyan .owner = THIS_MODULE, 3056613c5e8SAlexey Dobriyan .open = sysemu_proc_open, 3066613c5e8SAlexey Dobriyan .read = seq_read, 3076613c5e8SAlexey Dobriyan .llseek = seq_lseek, 3086613c5e8SAlexey Dobriyan .release = single_release, 3096613c5e8SAlexey Dobriyan .write = sysemu_proc_write, 3106613c5e8SAlexey Dobriyan }; 3116613c5e8SAlexey Dobriyan 312995473aeSJeff Dike int __init make_proc_sysemu(void) 313995473aeSJeff Dike { 314995473aeSJeff Dike struct proc_dir_entry *ent; 315995473aeSJeff Dike if (!sysemu_supported) 316995473aeSJeff Dike return 0; 317995473aeSJeff Dike 3186613c5e8SAlexey Dobriyan ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_fops); 319995473aeSJeff Dike 320995473aeSJeff Dike if (ent == NULL) 321995473aeSJeff Dike { 322995473aeSJeff Dike printk(KERN_WARNING "Failed to register /proc/sysemu\n"); 3236e21aec3SJeff Dike return 0; 324995473aeSJeff Dike } 325995473aeSJeff Dike 326995473aeSJeff Dike return 0; 327995473aeSJeff Dike } 328995473aeSJeff Dike 329995473aeSJeff Dike late_initcall(make_proc_sysemu); 330995473aeSJeff Dike 331995473aeSJeff Dike int singlestepping(void * t) 332995473aeSJeff Dike { 333995473aeSJeff Dike struct task_struct *task = t ? t : current; 334995473aeSJeff Dike 335995473aeSJeff Dike if (!(task->ptrace & PT_DTRACE)) 336ba180fd4SJeff Dike return 0; 337995473aeSJeff Dike 338995473aeSJeff Dike if (task->thread.singlestep_syscall) 339ba180fd4SJeff Dike return 1; 340995473aeSJeff Dike 341995473aeSJeff Dike return 2; 342995473aeSJeff Dike } 343995473aeSJeff Dike 344995473aeSJeff Dike /* 345995473aeSJeff Dike * Only x86 and x86_64 have an arch_align_stack(). 346995473aeSJeff Dike * All other arches have "#define arch_align_stack(x) (x)" 347cf7bc58fSDavid Howells * in their asm/exec.h 348995473aeSJeff Dike * As this is included in UML from asm-um/system-generic.h, 349995473aeSJeff Dike * we can use it to behave as the subarch does. 350995473aeSJeff Dike */ 351995473aeSJeff Dike #ifndef arch_align_stack 352995473aeSJeff Dike unsigned long arch_align_stack(unsigned long sp) 353995473aeSJeff Dike { 354995473aeSJeff Dike if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 355995473aeSJeff Dike sp -= get_random_int() % 8192; 356995473aeSJeff Dike return sp & ~0xf; 357995473aeSJeff Dike } 358995473aeSJeff Dike #endif 359c1127465SJeff Dike 360c1127465SJeff Dike unsigned long get_wchan(struct task_struct *p) 361c1127465SJeff Dike { 362c1127465SJeff Dike unsigned long stack_page, sp, ip; 363c1127465SJeff Dike bool seen_sched = 0; 364c1127465SJeff Dike 365c1127465SJeff Dike if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING)) 366c1127465SJeff Dike return 0; 367c1127465SJeff Dike 368c1127465SJeff Dike stack_page = (unsigned long) task_stack_page(p); 369c1127465SJeff Dike /* Bail if the process has no kernel stack for some reason */ 370c1127465SJeff Dike if (stack_page == 0) 371c1127465SJeff Dike return 0; 372c1127465SJeff Dike 373c1127465SJeff Dike sp = p->thread.switch_buf->JB_SP; 374c1127465SJeff Dike /* 375c1127465SJeff Dike * Bail if the stack pointer is below the bottom of the kernel 376c1127465SJeff Dike * stack for some reason 377c1127465SJeff Dike */ 378c1127465SJeff Dike if (sp < stack_page) 379c1127465SJeff Dike return 0; 380c1127465SJeff Dike 381c1127465SJeff Dike while (sp < stack_page + THREAD_SIZE) { 382c1127465SJeff Dike ip = *((unsigned long *) sp); 383c1127465SJeff Dike if (in_sched_functions(ip)) 384c1127465SJeff Dike /* Ignore everything until we're above the scheduler */ 385c1127465SJeff Dike seen_sched = 1; 386c1127465SJeff Dike else if (kernel_text_address(ip) && seen_sched) 387c1127465SJeff Dike return ip; 388c1127465SJeff Dike 389c1127465SJeff Dike sp += sizeof(unsigned long); 390c1127465SJeff Dike } 391c1127465SJeff Dike 392c1127465SJeff Dike return 0; 393c1127465SJeff Dike } 3948192ab42SJeff Dike 3958192ab42SJeff Dike int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu) 3968192ab42SJeff Dike { 3978192ab42SJeff Dike int cpu = current_thread_info()->cpu; 3988192ab42SJeff Dike 399a78ff111SEli Cooper return save_i387_registers(userspace_pid[cpu], (unsigned long *) fpu); 4008192ab42SJeff Dike } 4018192ab42SJeff Dike 402