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 65*2fcb4090SJohannes Berg unsigned long alloc_stack(int order, int atomic) 66995473aeSJeff Dike { 67*2fcb4090SJohannes Berg unsigned long page; 68995473aeSJeff Dike gfp_t flags = GFP_KERNEL; 69995473aeSJeff Dike 70995473aeSJeff Dike if (atomic) 71995473aeSJeff Dike flags = GFP_ATOMIC; 72*2fcb4090SJohannes Berg page = __get_free_pages(flags, order); 735c8aaceaSJeff Dike 74*2fcb4090SJohannes Berg 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(); 10209041c92SJens Axboe if (test_thread_flag(TIF_SIGPENDING) || 10309041c92SJens Axboe test_thread_flag(TIF_NOTIFY_SIGNAL)) 104ccaee5f8SIngo Molnar do_signal(regs); 1053c532798SJens Axboe if (test_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 156714acdbdSChristian Brauner int copy_thread(unsigned long clone_flags, unsigned long sp, 157457677c7SAmanieu d'Antras unsigned long arg, struct task_struct * p, unsigned long tls) 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) 191457677c7SAmanieu d'Antras ret = arch_set_tls(p, tls); 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 206a374b7cbSJohannes Berg void um_idle_sleep(void) 20706503870SJohannes Berg { 20849da38a3SJohannes Berg if (time_travel_mode != TT_MODE_OFF) 20949da38a3SJohannes Berg time_travel_sleep(); 21049da38a3SJohannes Berg else 21149da38a3SJohannes Berg os_idle_sleep(); 21206503870SJohannes Berg } 21306503870SJohannes Berg 2148198c169SRichard Weinberger void arch_cpu_idle(void) 215995473aeSJeff Dike { 2168198c169SRichard Weinberger cpu_tasks[current_thread_info()->cpu].pid = os_getpid(); 21706503870SJohannes Berg um_idle_sleep(); 21858c644baSPeter Zijlstra raw_local_irq_enable(); 219995473aeSJeff Dike } 220995473aeSJeff Dike 221995473aeSJeff Dike int __cant_sleep(void) { 222995473aeSJeff Dike return in_atomic() || irqs_disabled() || in_interrupt(); 223995473aeSJeff Dike /* Is in_interrupt() really needed? */ 224995473aeSJeff Dike } 225995473aeSJeff Dike 226995473aeSJeff Dike int user_context(unsigned long sp) 227995473aeSJeff Dike { 228995473aeSJeff Dike unsigned long stack; 229995473aeSJeff Dike 230995473aeSJeff Dike stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER); 231a5a678c8SJeff Dike return stack != (unsigned long) current_thread_info(); 232995473aeSJeff Dike } 233995473aeSJeff Dike 234995473aeSJeff Dike extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end; 235995473aeSJeff Dike 236995473aeSJeff Dike void do_uml_exitcalls(void) 237995473aeSJeff Dike { 238995473aeSJeff Dike exitcall_t *call; 239995473aeSJeff Dike 240995473aeSJeff Dike call = &__uml_exitcall_end; 241995473aeSJeff Dike while (--call >= &__uml_exitcall_begin) 242995473aeSJeff Dike (*call)(); 243995473aeSJeff Dike } 244995473aeSJeff Dike 245c0a9290eSWANG Cong char *uml_strdup(const char *string) 246995473aeSJeff Dike { 247995473aeSJeff Dike return kstrdup(string, GFP_KERNEL); 248995473aeSJeff Dike } 24973395a00SAl Viro EXPORT_SYMBOL(uml_strdup); 250995473aeSJeff Dike 251995473aeSJeff Dike int copy_to_user_proc(void __user *to, void *from, int size) 252995473aeSJeff Dike { 2536e21aec3SJeff Dike return copy_to_user(to, from, size); 254995473aeSJeff Dike } 255995473aeSJeff Dike 256995473aeSJeff Dike int copy_from_user_proc(void *to, void __user *from, int size) 257995473aeSJeff Dike { 2586e21aec3SJeff Dike return copy_from_user(to, from, size); 259995473aeSJeff Dike } 260995473aeSJeff Dike 261995473aeSJeff Dike int clear_user_proc(void __user *buf, int size) 262995473aeSJeff Dike { 2636e21aec3SJeff Dike return clear_user(buf, size); 264995473aeSJeff Dike } 265995473aeSJeff Dike 266995473aeSJeff Dike int cpu(void) 267995473aeSJeff Dike { 268a5a678c8SJeff Dike return current_thread_info()->cpu; 269995473aeSJeff Dike } 270995473aeSJeff Dike 271995473aeSJeff Dike static atomic_t using_sysemu = ATOMIC_INIT(0); 272995473aeSJeff Dike int sysemu_supported; 273995473aeSJeff Dike 274995473aeSJeff Dike void set_using_sysemu(int value) 275995473aeSJeff Dike { 276995473aeSJeff Dike if (value > sysemu_supported) 277995473aeSJeff Dike return; 278995473aeSJeff Dike atomic_set(&using_sysemu, value); 279995473aeSJeff Dike } 280995473aeSJeff Dike 281995473aeSJeff Dike int get_using_sysemu(void) 282995473aeSJeff Dike { 283995473aeSJeff Dike return atomic_read(&using_sysemu); 284995473aeSJeff Dike } 285995473aeSJeff Dike 2866613c5e8SAlexey Dobriyan static int sysemu_proc_show(struct seq_file *m, void *v) 287995473aeSJeff Dike { 2886613c5e8SAlexey Dobriyan seq_printf(m, "%d\n", get_using_sysemu()); 2896613c5e8SAlexey Dobriyan return 0; 290995473aeSJeff Dike } 291995473aeSJeff Dike 2926613c5e8SAlexey Dobriyan static int sysemu_proc_open(struct inode *inode, struct file *file) 2936613c5e8SAlexey Dobriyan { 2946613c5e8SAlexey Dobriyan return single_open(file, sysemu_proc_show, NULL); 2956613c5e8SAlexey Dobriyan } 2966613c5e8SAlexey Dobriyan 2976613c5e8SAlexey Dobriyan static ssize_t sysemu_proc_write(struct file *file, const char __user *buf, 2986613c5e8SAlexey Dobriyan size_t count, loff_t *pos) 299995473aeSJeff Dike { 300995473aeSJeff Dike char tmp[2]; 301995473aeSJeff Dike 302995473aeSJeff Dike if (copy_from_user(tmp, buf, 1)) 303995473aeSJeff Dike return -EFAULT; 304995473aeSJeff Dike 305995473aeSJeff Dike if (tmp[0] >= '0' && tmp[0] <= '2') 306995473aeSJeff Dike set_using_sysemu(tmp[0] - '0'); 307ba180fd4SJeff Dike /* We use the first char, but pretend to write everything */ 308ba180fd4SJeff Dike return count; 309995473aeSJeff Dike } 310995473aeSJeff Dike 31197a32539SAlexey Dobriyan static const struct proc_ops sysemu_proc_ops = { 31297a32539SAlexey Dobriyan .proc_open = sysemu_proc_open, 31397a32539SAlexey Dobriyan .proc_read = seq_read, 31497a32539SAlexey Dobriyan .proc_lseek = seq_lseek, 31597a32539SAlexey Dobriyan .proc_release = single_release, 31697a32539SAlexey Dobriyan .proc_write = sysemu_proc_write, 3176613c5e8SAlexey Dobriyan }; 3186613c5e8SAlexey Dobriyan 319995473aeSJeff Dike int __init make_proc_sysemu(void) 320995473aeSJeff Dike { 321995473aeSJeff Dike struct proc_dir_entry *ent; 322995473aeSJeff Dike if (!sysemu_supported) 323995473aeSJeff Dike return 0; 324995473aeSJeff Dike 32597a32539SAlexey Dobriyan ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_ops); 326995473aeSJeff Dike 327995473aeSJeff Dike if (ent == NULL) 328995473aeSJeff Dike { 329995473aeSJeff Dike printk(KERN_WARNING "Failed to register /proc/sysemu\n"); 3306e21aec3SJeff Dike return 0; 331995473aeSJeff Dike } 332995473aeSJeff Dike 333995473aeSJeff Dike return 0; 334995473aeSJeff Dike } 335995473aeSJeff Dike 336995473aeSJeff Dike late_initcall(make_proc_sysemu); 337995473aeSJeff Dike 338995473aeSJeff Dike int singlestepping(void * t) 339995473aeSJeff Dike { 340995473aeSJeff Dike struct task_struct *task = t ? t : current; 341995473aeSJeff Dike 342995473aeSJeff Dike if (!(task->ptrace & PT_DTRACE)) 343ba180fd4SJeff Dike return 0; 344995473aeSJeff Dike 345995473aeSJeff Dike if (task->thread.singlestep_syscall) 346ba180fd4SJeff Dike return 1; 347995473aeSJeff Dike 348995473aeSJeff Dike return 2; 349995473aeSJeff Dike } 350995473aeSJeff Dike 351995473aeSJeff Dike /* 352995473aeSJeff Dike * Only x86 and x86_64 have an arch_align_stack(). 353995473aeSJeff Dike * All other arches have "#define arch_align_stack(x) (x)" 354cf7bc58fSDavid Howells * in their asm/exec.h 355995473aeSJeff Dike * As this is included in UML from asm-um/system-generic.h, 356995473aeSJeff Dike * we can use it to behave as the subarch does. 357995473aeSJeff Dike */ 358995473aeSJeff Dike #ifndef arch_align_stack 359995473aeSJeff Dike unsigned long arch_align_stack(unsigned long sp) 360995473aeSJeff Dike { 361995473aeSJeff Dike if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 362995473aeSJeff Dike sp -= get_random_int() % 8192; 363995473aeSJeff Dike return sp & ~0xf; 364995473aeSJeff Dike } 365995473aeSJeff Dike #endif 366c1127465SJeff Dike 367c1127465SJeff Dike unsigned long get_wchan(struct task_struct *p) 368c1127465SJeff Dike { 369c1127465SJeff Dike unsigned long stack_page, sp, ip; 370c1127465SJeff Dike bool seen_sched = 0; 371c1127465SJeff Dike 372c1127465SJeff Dike if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING)) 373c1127465SJeff Dike return 0; 374c1127465SJeff Dike 375c1127465SJeff Dike stack_page = (unsigned long) task_stack_page(p); 376c1127465SJeff Dike /* Bail if the process has no kernel stack for some reason */ 377c1127465SJeff Dike if (stack_page == 0) 378c1127465SJeff Dike return 0; 379c1127465SJeff Dike 380c1127465SJeff Dike sp = p->thread.switch_buf->JB_SP; 381c1127465SJeff Dike /* 382c1127465SJeff Dike * Bail if the stack pointer is below the bottom of the kernel 383c1127465SJeff Dike * stack for some reason 384c1127465SJeff Dike */ 385c1127465SJeff Dike if (sp < stack_page) 386c1127465SJeff Dike return 0; 387c1127465SJeff Dike 388c1127465SJeff Dike while (sp < stack_page + THREAD_SIZE) { 389c1127465SJeff Dike ip = *((unsigned long *) sp); 390c1127465SJeff Dike if (in_sched_functions(ip)) 391c1127465SJeff Dike /* Ignore everything until we're above the scheduler */ 392c1127465SJeff Dike seen_sched = 1; 393c1127465SJeff Dike else if (kernel_text_address(ip) && seen_sched) 394c1127465SJeff Dike return ip; 395c1127465SJeff Dike 396c1127465SJeff Dike sp += sizeof(unsigned long); 397c1127465SJeff Dike } 398c1127465SJeff Dike 399c1127465SJeff Dike return 0; 400c1127465SJeff Dike } 4018192ab42SJeff Dike 4028192ab42SJeff Dike int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu) 4038192ab42SJeff Dike { 4048192ab42SJeff Dike int cpu = current_thread_info()->cpu; 4058192ab42SJeff Dike 406a78ff111SEli Cooper return save_i387_registers(userspace_pid[cpu], (unsigned long *) fpu); 4078192ab42SJeff Dike } 4088192ab42SJeff Dike 409