| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk}) |
| * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de) |
| * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
| * Copyright 2003 PathScale, Inc. |
| */ |
| |
| #include <linux/stddef.h> |
| #include <linux/err.h> |
| #include <linux/hardirq.h> |
| #include <linux/mm.h> |
| #include <linux/module.h> |
| #include <linux/personality.h> |
| #include <linux/proc_fs.h> |
| #include <linux/ptrace.h> |
| #include <linux/random.h> |
| #include <linux/slab.h> |
| #include <linux/sched.h> |
| #include <linux/sched/debug.h> |
| #include <linux/sched/task.h> |
| #include <linux/sched/task_stack.h> |
| #include <linux/seq_file.h> |
| #include <linux/tick.h> |
| #include <linux/threads.h> |
| #include <linux/resume_user_mode.h> |
| #include <asm/current.h> |
| #include <asm/mmu_context.h> |
| #include <linux/uaccess.h> |
| #include <as-layout.h> |
| #include <kern_util.h> |
| #include <os.h> |
| #include <skas.h> |
| #include <registers.h> |
| #include <linux/time-internal.h> |
| #include <linux/elfcore.h> |
| |
| /* |
| * This is a per-cpu array. A processor only modifies its entry and it only |
| * cares about its entry, so it's OK if another processor is modifying its |
| * entry. |
| */ |
| struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } }; |
| |
| static inline int external_pid(void) |
| { |
| /* FIXME: Need to look up userspace_pid by cpu */ |
| return userspace_pid[0]; |
| } |
| |
| int pid_to_processor_id(int pid) |
| { |
| int i; |
| |
| for (i = 0; i < ncpus; i++) { |
| if (cpu_tasks[i].pid == pid) |
| return i; |
| } |
| return -1; |
| } |
| |
| void free_stack(unsigned long stack, int order) |
| { |
| free_pages(stack, order); |
| } |
| |
| unsigned long alloc_stack(int order, int atomic) |
| { |
| unsigned long page; |
| gfp_t flags = GFP_KERNEL; |
| |
| if (atomic) |
| flags = GFP_ATOMIC; |
| page = __get_free_pages(flags, order); |
| |
| return page; |
| } |
| |
| static inline void set_current(struct task_struct *task) |
| { |
| cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task) |
| { external_pid(), task }); |
| } |
| |
| extern void arch_switch_to(struct task_struct *to); |
| |
| void *__switch_to(struct task_struct *from, struct task_struct *to) |
| { |
| to->thread.prev_sched = from; |
| set_current(to); |
| |
| switch_threads(&from->thread.switch_buf, &to->thread.switch_buf); |
| arch_switch_to(current); |
| |
| return current->thread.prev_sched; |
| } |
| |
| void interrupt_end(void) |
| { |
| struct pt_regs *regs = ¤t->thread.regs; |
| |
| if (need_resched()) |
| schedule(); |
| if (test_thread_flag(TIF_SIGPENDING) || |
| test_thread_flag(TIF_NOTIFY_SIGNAL)) |
| do_signal(regs); |
| if (test_thread_flag(TIF_NOTIFY_RESUME)) |
| resume_user_mode_work(regs); |
| } |
| |
| int get_current_pid(void) |
| { |
| return task_pid_nr(current); |
| } |
| |
| /* |
| * This is called magically, by its address being stuffed in a jmp_buf |
| * and being longjmp-d to. |
| */ |
| void new_thread_handler(void) |
| { |
| int (*fn)(void *), n; |
| void *arg; |
| |
| if (current->thread.prev_sched != NULL) |
| schedule_tail(current->thread.prev_sched); |
| current->thread.prev_sched = NULL; |
| |
| fn = current->thread.request.u.thread.proc; |
| arg = current->thread.request.u.thread.arg; |
| |
| /* |
| * callback returns only if the kernel thread execs a process |
| */ |
| n = fn(arg); |
| userspace(¤t->thread.regs.regs, current_thread_info()->aux_fp_regs); |
| } |
| |
| /* Called magically, see new_thread_handler above */ |
| void fork_handler(void) |
| { |
| force_flush_all(); |
| |
| schedule_tail(current->thread.prev_sched); |
| |
| /* |
| * XXX: if interrupt_end() calls schedule, this call to |
| * arch_switch_to isn't needed. We could want to apply this to |
| * improve performance. -bb |
| */ |
| arch_switch_to(current); |
| |
| current->thread.prev_sched = NULL; |
| |
| userspace(¤t->thread.regs.regs, current_thread_info()->aux_fp_regs); |
| } |
| |
| int copy_thread(struct task_struct * p, const struct kernel_clone_args *args) |
| { |
| unsigned long clone_flags = args->flags; |
| unsigned long sp = args->stack; |
| unsigned long tls = args->tls; |
| void (*handler)(void); |
| int ret = 0; |
| |
| p->thread = (struct thread_struct) INIT_THREAD; |
| |
| if (!args->fn) { |
| memcpy(&p->thread.regs.regs, current_pt_regs(), |
| sizeof(p->thread.regs.regs)); |
| PT_REGS_SET_SYSCALL_RETURN(&p->thread.regs, 0); |
| if (sp != 0) |
| REGS_SP(p->thread.regs.regs.gp) = sp; |
| |
| handler = fork_handler; |
| |
| arch_copy_thread(¤t->thread.arch, &p->thread.arch); |
| } else { |
| get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp); |
| p->thread.request.u.thread.proc = args->fn; |
| p->thread.request.u.thread.arg = args->fn_arg; |
| handler = new_thread_handler; |
| } |
| |
| new_thread(task_stack_page(p), &p->thread.switch_buf, handler); |
| |
| if (!args->fn) { |
| clear_flushed_tls(p); |
| |
| /* |
| * Set a new TLS for the child thread? |
| */ |
| if (clone_flags & CLONE_SETTLS) |
| ret = arch_set_tls(p, tls); |
| } |
| |
| return ret; |
| } |
| |
| void initial_thread_cb(void (*proc)(void *), void *arg) |
| { |
| int save_kmalloc_ok = kmalloc_ok; |
| |
| kmalloc_ok = 0; |
| initial_thread_cb_skas(proc, arg); |
| kmalloc_ok = save_kmalloc_ok; |
| } |
| |
| void um_idle_sleep(void) |
| { |
| if (time_travel_mode != TT_MODE_OFF) |
| time_travel_sleep(); |
| else |
| os_idle_sleep(); |
| } |
| |
| void arch_cpu_idle(void) |
| { |
| cpu_tasks[current_thread_info()->cpu].pid = os_getpid(); |
| um_idle_sleep(); |
| } |
| |
| int __cant_sleep(void) { |
| return in_atomic() || irqs_disabled() || in_interrupt(); |
| /* Is in_interrupt() really needed? */ |
| } |
| |
| int user_context(unsigned long sp) |
| { |
| unsigned long stack; |
| |
| stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER); |
| return stack != (unsigned long) current_thread_info(); |
| } |
| |
| extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end; |
| |
| void do_uml_exitcalls(void) |
| { |
| exitcall_t *call; |
| |
| call = &__uml_exitcall_end; |
| while (--call >= &__uml_exitcall_begin) |
| (*call)(); |
| } |
| |
| char *uml_strdup(const char *string) |
| { |
| return kstrdup(string, GFP_KERNEL); |
| } |
| EXPORT_SYMBOL(uml_strdup); |
| |
| int copy_to_user_proc(void __user *to, void *from, int size) |
| { |
| return copy_to_user(to, from, size); |
| } |
| |
| int copy_from_user_proc(void *to, void __user *from, int size) |
| { |
| return copy_from_user(to, from, size); |
| } |
| |
| int clear_user_proc(void __user *buf, int size) |
| { |
| return clear_user(buf, size); |
| } |
| |
| static atomic_t using_sysemu = ATOMIC_INIT(0); |
| int sysemu_supported; |
| |
| void set_using_sysemu(int value) |
| { |
| if (value > sysemu_supported) |
| return; |
| atomic_set(&using_sysemu, value); |
| } |
| |
| int get_using_sysemu(void) |
| { |
| return atomic_read(&using_sysemu); |
| } |
| |
| static int sysemu_proc_show(struct seq_file *m, void *v) |
| { |
| seq_printf(m, "%d\n", get_using_sysemu()); |
| return 0; |
| } |
| |
| static int sysemu_proc_open(struct inode *inode, struct file *file) |
| { |
| return single_open(file, sysemu_proc_show, NULL); |
| } |
| |
| static ssize_t sysemu_proc_write(struct file *file, const char __user *buf, |
| size_t count, loff_t *pos) |
| { |
| char tmp[2]; |
| |
| if (copy_from_user(tmp, buf, 1)) |
| return -EFAULT; |
| |
| if (tmp[0] >= '0' && tmp[0] <= '2') |
| set_using_sysemu(tmp[0] - '0'); |
| /* We use the first char, but pretend to write everything */ |
| return count; |
| } |
| |
| static const struct proc_ops sysemu_proc_ops = { |
| .proc_open = sysemu_proc_open, |
| .proc_read = seq_read, |
| .proc_lseek = seq_lseek, |
| .proc_release = single_release, |
| .proc_write = sysemu_proc_write, |
| }; |
| |
| int __init make_proc_sysemu(void) |
| { |
| struct proc_dir_entry *ent; |
| if (!sysemu_supported) |
| return 0; |
| |
| ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_ops); |
| |
| if (ent == NULL) |
| { |
| printk(KERN_WARNING "Failed to register /proc/sysemu\n"); |
| return 0; |
| } |
| |
| return 0; |
| } |
| |
| late_initcall(make_proc_sysemu); |
| |
| int singlestepping(void * t) |
| { |
| struct task_struct *task = t ? t : current; |
| |
| if (!test_thread_flag(TIF_SINGLESTEP)) |
| return 0; |
| |
| if (task->thread.singlestep_syscall) |
| return 1; |
| |
| return 2; |
| } |
| |
| /* |
| * Only x86 and x86_64 have an arch_align_stack(). |
| * All other arches have "#define arch_align_stack(x) (x)" |
| * in their asm/exec.h |
| * As this is included in UML from asm-um/system-generic.h, |
| * we can use it to behave as the subarch does. |
| */ |
| #ifndef arch_align_stack |
| unsigned long arch_align_stack(unsigned long sp) |
| { |
| if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) |
| sp -= get_random_u32_below(8192); |
| return sp & ~0xf; |
| } |
| #endif |
| |
| unsigned long __get_wchan(struct task_struct *p) |
| { |
| unsigned long stack_page, sp, ip; |
| bool seen_sched = 0; |
| |
| stack_page = (unsigned long) task_stack_page(p); |
| /* Bail if the process has no kernel stack for some reason */ |
| if (stack_page == 0) |
| return 0; |
| |
| sp = p->thread.switch_buf->JB_SP; |
| /* |
| * Bail if the stack pointer is below the bottom of the kernel |
| * stack for some reason |
| */ |
| if (sp < stack_page) |
| return 0; |
| |
| while (sp < stack_page + THREAD_SIZE) { |
| ip = *((unsigned long *) sp); |
| if (in_sched_functions(ip)) |
| /* Ignore everything until we're above the scheduler */ |
| seen_sched = 1; |
| else if (kernel_text_address(ip) && seen_sched) |
| return ip; |
| |
| sp += sizeof(unsigned long); |
| } |
| |
| return 0; |
| } |
| |
| int elf_core_copy_task_fpregs(struct task_struct *t, elf_fpregset_t *fpu) |
| { |
| int cpu = current_thread_info()->cpu; |
| |
| return save_i387_registers(userspace_pid[cpu], (unsigned long *) fpu); |
| } |
| |