10d1fb0a4SAlex Dewar // SPDX-License-Identifier: GPL-2.0 2995473aeSJeff Dike /* 32eb5f31bSAnton Ivanov * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk}) 42eb5f31bSAnton Ivanov * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de) 5ba180fd4SJeff Dike * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 6995473aeSJeff Dike * Copyright 2003 PathScale, Inc. 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> 28445c5786SAl Viro #include <asm/mmu_context.h> 297c0f6ba6SLinus Torvalds #include <linux/uaccess.h> 3037185b33SAl Viro #include <as-layout.h> 3137185b33SAl Viro #include <kern_util.h> 3237185b33SAl Viro #include <os.h> 3337185b33SAl Viro #include <skas.h> 34f185063bSJohannes Berg #include <linux/time-internal.h> 35995473aeSJeff Dike 36ba180fd4SJeff Dike /* 37ba180fd4SJeff Dike * This is a per-cpu array. A processor only modifies its entry and it only 38995473aeSJeff Dike * cares about its entry, so it's OK if another processor is modifying its 39995473aeSJeff Dike * entry. 40995473aeSJeff Dike */ 41995473aeSJeff Dike struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } }; 42995473aeSJeff Dike 432dc5802aSKarol Swietlicki static inline int external_pid(void) 44995473aeSJeff Dike { 4577bf4400SJeff Dike /* FIXME: Need to look up userspace_pid by cpu */ 46ba180fd4SJeff Dike return userspace_pid[0]; 47995473aeSJeff Dike } 48995473aeSJeff Dike 49995473aeSJeff Dike int pid_to_processor_id(int pid) 50995473aeSJeff Dike { 51995473aeSJeff Dike int i; 52995473aeSJeff Dike 53995473aeSJeff Dike for (i = 0; i < ncpus; i++) { 546e21aec3SJeff Dike if (cpu_tasks[i].pid == pid) 556e21aec3SJeff Dike return i; 56995473aeSJeff Dike } 576e21aec3SJeff Dike return -1; 58995473aeSJeff Dike } 59995473aeSJeff Dike 60995473aeSJeff Dike void free_stack(unsigned long stack, int order) 61995473aeSJeff Dike { 62995473aeSJeff Dike free_pages(stack, order); 63995473aeSJeff Dike } 64995473aeSJeff Dike 65995473aeSJeff Dike unsigned long alloc_stack(int order, int atomic) 66995473aeSJeff Dike { 67995473aeSJeff Dike unsigned long page; 68995473aeSJeff Dike gfp_t flags = GFP_KERNEL; 69995473aeSJeff Dike 70995473aeSJeff Dike if (atomic) 71995473aeSJeff Dike flags = GFP_ATOMIC; 72995473aeSJeff Dike page = __get_free_pages(flags, order); 735c8aaceaSJeff Dike 746e21aec3SJeff Dike return page; 75995473aeSJeff Dike } 76995473aeSJeff Dike 776e21aec3SJeff Dike static inline void set_current(struct task_struct *task) 78995473aeSJeff Dike { 79995473aeSJeff Dike cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task) 802dc5802aSKarol Swietlicki { external_pid(), task }); 81995473aeSJeff Dike } 82995473aeSJeff Dike 83291248fdSKarol Swietlicki extern void arch_switch_to(struct task_struct *to); 8477bf4400SJeff Dike 8576b278edSRichard Weinberger void *__switch_to(struct task_struct *from, struct task_struct *to) 86995473aeSJeff Dike { 87995473aeSJeff Dike to->thread.prev_sched = from; 88995473aeSJeff Dike set_current(to); 89995473aeSJeff Dike 90a1850e9cSRichard Weinberger switch_threads(&from->thread.switch_buf, &to->thread.switch_buf); 91291248fdSKarol Swietlicki arch_switch_to(current); 9277bf4400SJeff Dike 936e21aec3SJeff Dike return current->thread.prev_sched; 94995473aeSJeff Dike } 95995473aeSJeff Dike 96995473aeSJeff Dike void interrupt_end(void) 97995473aeSJeff Dike { 98ccaee5f8SIngo Molnar struct pt_regs *regs = ¤t->thread.regs; 99ccaee5f8SIngo Molnar 1006e21aec3SJeff Dike if (need_resched()) 1016e21aec3SJeff Dike schedule(); 102d50349b0SAl Viro if (test_thread_flag(TIF_SIGPENDING)) 103ccaee5f8SIngo Molnar do_signal(regs); 1043c532798SJens Axboe if (test_thread_flag(TIF_NOTIFY_RESUME)) 105ccaee5f8SIngo Molnar tracehook_notify_resume(regs); 106995473aeSJeff Dike } 107995473aeSJeff Dike 108c2220b2aSAl Viro int get_current_pid(void) 109995473aeSJeff Dike { 110c2220b2aSAl Viro return task_pid_nr(current); 111995473aeSJeff Dike } 112995473aeSJeff Dike 113ba180fd4SJeff Dike /* 114ba180fd4SJeff Dike * This is called magically, by its address being stuffed in a jmp_buf 11577bf4400SJeff Dike * and being longjmp-d to. 11677bf4400SJeff Dike */ 11777bf4400SJeff Dike void new_thread_handler(void) 11877bf4400SJeff Dike { 11977bf4400SJeff Dike int (*fn)(void *), n; 12077bf4400SJeff Dike void *arg; 12177bf4400SJeff Dike 12277bf4400SJeff Dike if (current->thread.prev_sched != NULL) 12377bf4400SJeff Dike schedule_tail(current->thread.prev_sched); 12477bf4400SJeff Dike current->thread.prev_sched = NULL; 12577bf4400SJeff Dike 12677bf4400SJeff Dike fn = current->thread.request.u.thread.proc; 12777bf4400SJeff Dike arg = current->thread.request.u.thread.arg; 12877bf4400SJeff Dike 129ba180fd4SJeff Dike /* 13022e2430dSAl Viro * callback returns only if the kernel thread execs a process 13177bf4400SJeff Dike */ 13222e2430dSAl Viro n = fn(arg); 1336f602afdSThomas Meyer userspace(¤t->thread.regs.regs, current_thread_info()->aux_fp_regs); 13477bf4400SJeff Dike } 13577bf4400SJeff Dike 13677bf4400SJeff Dike /* Called magically, see new_thread_handler above */ 13777bf4400SJeff Dike void fork_handler(void) 13877bf4400SJeff Dike { 13977bf4400SJeff Dike force_flush_all(); 14077bf4400SJeff Dike 14177bf4400SJeff Dike schedule_tail(current->thread.prev_sched); 14277bf4400SJeff Dike 143ba180fd4SJeff Dike /* 144ba180fd4SJeff Dike * XXX: if interrupt_end() calls schedule, this call to 14577bf4400SJeff Dike * arch_switch_to isn't needed. We could want to apply this to 146ba180fd4SJeff Dike * improve performance. -bb 147ba180fd4SJeff Dike */ 148291248fdSKarol Swietlicki arch_switch_to(current); 14977bf4400SJeff Dike 15077bf4400SJeff Dike current->thread.prev_sched = NULL; 15177bf4400SJeff Dike 1526f602afdSThomas Meyer userspace(¤t->thread.regs.regs, current_thread_info()->aux_fp_regs); 15377bf4400SJeff Dike } 15477bf4400SJeff Dike 155714acdbdSChristian Brauner int copy_thread(unsigned long clone_flags, unsigned long sp, 156457677c7SAmanieu d'Antras unsigned long arg, struct task_struct * p, unsigned long tls) 157995473aeSJeff Dike { 15877bf4400SJeff Dike void (*handler)(void); 159d2ce4e92SAl Viro int kthread = current->flags & PF_KTHREAD; 16077bf4400SJeff Dike int ret = 0; 161995473aeSJeff Dike 162995473aeSJeff Dike p->thread = (struct thread_struct) INIT_THREAD; 163995473aeSJeff Dike 164d2ce4e92SAl Viro if (!kthread) { 1652b067fc9SAl Viro memcpy(&p->thread.regs.regs, current_pt_regs(), 16677bf4400SJeff Dike sizeof(p->thread.regs.regs)); 167a3170d2eSAl Viro PT_REGS_SET_SYSCALL_RETURN(&p->thread.regs, 0); 16877bf4400SJeff Dike if (sp != 0) 16918badddaSJeff Dike REGS_SP(p->thread.regs.regs.gp) = sp; 170995473aeSJeff Dike 17177bf4400SJeff Dike handler = fork_handler; 17277bf4400SJeff Dike 17377bf4400SJeff Dike arch_copy_thread(¤t->thread.arch, &p->thread.arch); 174d2ce4e92SAl Viro } else { 175fbfe9c84SIngo van Lil get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp); 1761f02ab4aSAl Viro p->thread.request.u.thread.proc = (int (*)(void *))sp; 1771f02ab4aSAl Viro p->thread.request.u.thread.arg = (void *)arg; 17877bf4400SJeff Dike handler = new_thread_handler; 17977bf4400SJeff Dike } 18077bf4400SJeff Dike 18177bf4400SJeff Dike new_thread(task_stack_page(p), &p->thread.switch_buf, handler); 18277bf4400SJeff Dike 183d2ce4e92SAl Viro if (!kthread) { 184995473aeSJeff Dike clear_flushed_tls(p); 185995473aeSJeff Dike 186995473aeSJeff Dike /* 187995473aeSJeff Dike * Set a new TLS for the child thread? 188995473aeSJeff Dike */ 189995473aeSJeff Dike if (clone_flags & CLONE_SETTLS) 190457677c7SAmanieu d'Antras ret = arch_set_tls(p, tls); 19177bf4400SJeff Dike } 192995473aeSJeff Dike 193995473aeSJeff Dike return ret; 194995473aeSJeff Dike } 195995473aeSJeff Dike 196995473aeSJeff Dike void initial_thread_cb(void (*proc)(void *), void *arg) 197995473aeSJeff Dike { 198995473aeSJeff Dike int save_kmalloc_ok = kmalloc_ok; 199995473aeSJeff Dike 200995473aeSJeff Dike kmalloc_ok = 0; 2016aa802ceSJeff Dike initial_thread_cb_skas(proc, arg); 202995473aeSJeff Dike kmalloc_ok = save_kmalloc_ok; 203995473aeSJeff Dike } 204995473aeSJeff Dike 20506503870SJohannes Berg static void um_idle_sleep(void) 20606503870SJohannes Berg { 20706503870SJohannes Berg unsigned long long duration = UM_NSEC_PER_SEC; 20806503870SJohannes Berg 20906503870SJohannes Berg if (time_travel_mode != TT_MODE_OFF) { 21006503870SJohannes Berg time_travel_sleep(duration); 21106503870SJohannes Berg } else { 21206503870SJohannes Berg os_idle_sleep(duration); 21306503870SJohannes Berg } 21406503870SJohannes Berg } 21506503870SJohannes Berg 2168198c169SRichard Weinberger void arch_cpu_idle(void) 217995473aeSJeff Dike { 2188198c169SRichard Weinberger cpu_tasks[current_thread_info()->cpu].pid = os_getpid(); 21906503870SJohannes Berg um_idle_sleep(); 22058c644baSPeter Zijlstra raw_local_irq_enable(); 221995473aeSJeff Dike } 222995473aeSJeff Dike 223995473aeSJeff Dike int __cant_sleep(void) { 224995473aeSJeff Dike return in_atomic() || irqs_disabled() || in_interrupt(); 225995473aeSJeff Dike /* Is in_interrupt() really needed? */ 226995473aeSJeff Dike } 227995473aeSJeff Dike 228995473aeSJeff Dike int user_context(unsigned long sp) 229995473aeSJeff Dike { 230995473aeSJeff Dike unsigned long stack; 231995473aeSJeff Dike 232995473aeSJeff Dike stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER); 233a5a678c8SJeff Dike return stack != (unsigned long) current_thread_info(); 234995473aeSJeff Dike } 235995473aeSJeff Dike 236995473aeSJeff Dike extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end; 237995473aeSJeff Dike 238995473aeSJeff Dike void do_uml_exitcalls(void) 239995473aeSJeff Dike { 240995473aeSJeff Dike exitcall_t *call; 241995473aeSJeff Dike 242995473aeSJeff Dike call = &__uml_exitcall_end; 243995473aeSJeff Dike while (--call >= &__uml_exitcall_begin) 244995473aeSJeff Dike (*call)(); 245995473aeSJeff Dike } 246995473aeSJeff Dike 247c0a9290eSWANG Cong char *uml_strdup(const char *string) 248995473aeSJeff Dike { 249995473aeSJeff Dike return kstrdup(string, GFP_KERNEL); 250995473aeSJeff Dike } 25173395a00SAl Viro EXPORT_SYMBOL(uml_strdup); 252995473aeSJeff Dike 253995473aeSJeff Dike int copy_to_user_proc(void __user *to, void *from, int size) 254995473aeSJeff Dike { 2556e21aec3SJeff Dike return copy_to_user(to, from, size); 256995473aeSJeff Dike } 257995473aeSJeff Dike 258995473aeSJeff Dike int copy_from_user_proc(void *to, void __user *from, int size) 259995473aeSJeff Dike { 2606e21aec3SJeff Dike return copy_from_user(to, from, size); 261995473aeSJeff Dike } 262995473aeSJeff Dike 263995473aeSJeff Dike int clear_user_proc(void __user *buf, int size) 264995473aeSJeff Dike { 2656e21aec3SJeff Dike return clear_user(buf, size); 266995473aeSJeff Dike } 267995473aeSJeff Dike 268995473aeSJeff Dike int cpu(void) 269995473aeSJeff Dike { 270a5a678c8SJeff Dike return current_thread_info()->cpu; 271995473aeSJeff Dike } 272995473aeSJeff Dike 273995473aeSJeff Dike static atomic_t using_sysemu = ATOMIC_INIT(0); 274995473aeSJeff Dike int sysemu_supported; 275995473aeSJeff Dike 276995473aeSJeff Dike void set_using_sysemu(int value) 277995473aeSJeff Dike { 278995473aeSJeff Dike if (value > sysemu_supported) 279995473aeSJeff Dike return; 280995473aeSJeff Dike atomic_set(&using_sysemu, value); 281995473aeSJeff Dike } 282995473aeSJeff Dike 283995473aeSJeff Dike int get_using_sysemu(void) 284995473aeSJeff Dike { 285995473aeSJeff Dike return atomic_read(&using_sysemu); 286995473aeSJeff Dike } 287995473aeSJeff Dike 2886613c5e8SAlexey Dobriyan static int sysemu_proc_show(struct seq_file *m, void *v) 289995473aeSJeff Dike { 2906613c5e8SAlexey Dobriyan seq_printf(m, "%d\n", get_using_sysemu()); 2916613c5e8SAlexey Dobriyan return 0; 292995473aeSJeff Dike } 293995473aeSJeff Dike 2946613c5e8SAlexey Dobriyan static int sysemu_proc_open(struct inode *inode, struct file *file) 2956613c5e8SAlexey Dobriyan { 2966613c5e8SAlexey Dobriyan return single_open(file, sysemu_proc_show, NULL); 2976613c5e8SAlexey Dobriyan } 2986613c5e8SAlexey Dobriyan 2996613c5e8SAlexey Dobriyan static ssize_t sysemu_proc_write(struct file *file, const char __user *buf, 3006613c5e8SAlexey Dobriyan size_t count, loff_t *pos) 301995473aeSJeff Dike { 302995473aeSJeff Dike char tmp[2]; 303995473aeSJeff Dike 304995473aeSJeff Dike if (copy_from_user(tmp, buf, 1)) 305995473aeSJeff Dike return -EFAULT; 306995473aeSJeff Dike 307995473aeSJeff Dike if (tmp[0] >= '0' && tmp[0] <= '2') 308995473aeSJeff Dike set_using_sysemu(tmp[0] - '0'); 309ba180fd4SJeff Dike /* We use the first char, but pretend to write everything */ 310ba180fd4SJeff Dike return count; 311995473aeSJeff Dike } 312995473aeSJeff Dike 31397a32539SAlexey Dobriyan static const struct proc_ops sysemu_proc_ops = { 31497a32539SAlexey Dobriyan .proc_open = sysemu_proc_open, 31597a32539SAlexey Dobriyan .proc_read = seq_read, 31697a32539SAlexey Dobriyan .proc_lseek = seq_lseek, 31797a32539SAlexey Dobriyan .proc_release = single_release, 31897a32539SAlexey Dobriyan .proc_write = sysemu_proc_write, 3196613c5e8SAlexey Dobriyan }; 3206613c5e8SAlexey Dobriyan 321995473aeSJeff Dike int __init make_proc_sysemu(void) 322995473aeSJeff Dike { 323995473aeSJeff Dike struct proc_dir_entry *ent; 324995473aeSJeff Dike if (!sysemu_supported) 325995473aeSJeff Dike return 0; 326995473aeSJeff Dike 32797a32539SAlexey Dobriyan ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_ops); 328995473aeSJeff Dike 329995473aeSJeff Dike if (ent == NULL) 330995473aeSJeff Dike { 331995473aeSJeff Dike printk(KERN_WARNING "Failed to register /proc/sysemu\n"); 3326e21aec3SJeff Dike return 0; 333995473aeSJeff Dike } 334995473aeSJeff Dike 335995473aeSJeff Dike return 0; 336995473aeSJeff Dike } 337995473aeSJeff Dike 338995473aeSJeff Dike late_initcall(make_proc_sysemu); 339995473aeSJeff Dike 340995473aeSJeff Dike int singlestepping(void * t) 341995473aeSJeff Dike { 342995473aeSJeff Dike struct task_struct *task = t ? t : current; 343995473aeSJeff Dike 344995473aeSJeff Dike if (!(task->ptrace & PT_DTRACE)) 345ba180fd4SJeff Dike return 0; 346995473aeSJeff Dike 347995473aeSJeff Dike if (task->thread.singlestep_syscall) 348ba180fd4SJeff Dike return 1; 349995473aeSJeff Dike 350995473aeSJeff Dike return 2; 351995473aeSJeff Dike } 352995473aeSJeff Dike 353995473aeSJeff Dike /* 354995473aeSJeff Dike * Only x86 and x86_64 have an arch_align_stack(). 355995473aeSJeff Dike * All other arches have "#define arch_align_stack(x) (x)" 356cf7bc58fSDavid Howells * in their asm/exec.h 357995473aeSJeff Dike * As this is included in UML from asm-um/system-generic.h, 358995473aeSJeff Dike * we can use it to behave as the subarch does. 359995473aeSJeff Dike */ 360995473aeSJeff Dike #ifndef arch_align_stack 361995473aeSJeff Dike unsigned long arch_align_stack(unsigned long sp) 362995473aeSJeff Dike { 363995473aeSJeff Dike if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 364995473aeSJeff Dike sp -= get_random_int() % 8192; 365995473aeSJeff Dike return sp & ~0xf; 366995473aeSJeff Dike } 367995473aeSJeff Dike #endif 368c1127465SJeff Dike 369c1127465SJeff Dike unsigned long get_wchan(struct task_struct *p) 370c1127465SJeff Dike { 371c1127465SJeff Dike unsigned long stack_page, sp, ip; 372c1127465SJeff Dike bool seen_sched = 0; 373c1127465SJeff Dike 374c1127465SJeff Dike if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING)) 375c1127465SJeff Dike return 0; 376c1127465SJeff Dike 377c1127465SJeff Dike stack_page = (unsigned long) task_stack_page(p); 378c1127465SJeff Dike /* Bail if the process has no kernel stack for some reason */ 379c1127465SJeff Dike if (stack_page == 0) 380c1127465SJeff Dike return 0; 381c1127465SJeff Dike 382c1127465SJeff Dike sp = p->thread.switch_buf->JB_SP; 383c1127465SJeff Dike /* 384c1127465SJeff Dike * Bail if the stack pointer is below the bottom of the kernel 385c1127465SJeff Dike * stack for some reason 386c1127465SJeff Dike */ 387c1127465SJeff Dike if (sp < stack_page) 388c1127465SJeff Dike return 0; 389c1127465SJeff Dike 390c1127465SJeff Dike while (sp < stack_page + THREAD_SIZE) { 391c1127465SJeff Dike ip = *((unsigned long *) sp); 392c1127465SJeff Dike if (in_sched_functions(ip)) 393c1127465SJeff Dike /* Ignore everything until we're above the scheduler */ 394c1127465SJeff Dike seen_sched = 1; 395c1127465SJeff Dike else if (kernel_text_address(ip) && seen_sched) 396c1127465SJeff Dike return ip; 397c1127465SJeff Dike 398c1127465SJeff Dike sp += sizeof(unsigned long); 399c1127465SJeff Dike } 400c1127465SJeff Dike 401c1127465SJeff Dike return 0; 402c1127465SJeff Dike } 4038192ab42SJeff Dike 4048192ab42SJeff Dike int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu) 4058192ab42SJeff Dike { 4068192ab42SJeff Dike int cpu = current_thread_info()->cpu; 4078192ab42SJeff Dike 408a78ff111SEli Cooper return save_i387_registers(userspace_pid[cpu], (unsigned long *) fpu); 4098192ab42SJeff Dike } 4108192ab42SJeff Dike 411