1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
  4 * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
  5 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  6 * Copyright 2003 PathScale, Inc.
 
  7 */
  8
  9#include <linux/stddef.h>
 10#include <linux/err.h>
 11#include <linux/hardirq.h>
 12#include <linux/mm.h>
 13#include <linux/module.h>
 14#include <linux/personality.h>
 15#include <linux/proc_fs.h>
 16#include <linux/ptrace.h>
 17#include <linux/random.h>
 18#include <linux/slab.h>
 19#include <linux/sched.h>
 20#include <linux/sched/debug.h>
 21#include <linux/sched/task.h>
 22#include <linux/sched/task_stack.h>
 23#include <linux/seq_file.h>
 24#include <linux/tick.h>
 25#include <linux/threads.h>
 26#include <linux/resume_user_mode.h>
 27#include <asm/current.h>
 
 28#include <asm/mmu_context.h>
 29#include <linux/uaccess.h>
 30#include <as-layout.h>
 31#include <kern_util.h>
 32#include <os.h>
 33#include <skas.h>
 34#include <registers.h>
 35#include <linux/time-internal.h>
 36#include <linux/elfcore.h>
 37
 38/*
 39 * This is a per-cpu array.  A processor only modifies its entry and it only
 40 * cares about its entry, so it's OK if another processor is modifying its
 41 * entry.
 42 */
 43struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
 44
 45static inline int external_pid(void)
 46{
 47	/* FIXME: Need to look up userspace_pid by cpu */
 48	return userspace_pid[0];
 49}
 50
 51int pid_to_processor_id(int pid)
 52{
 53	int i;
 54
 55	for (i = 0; i < ncpus; i++) {
 56		if (cpu_tasks[i].pid == pid)
 57			return i;
 58	}
 59	return -1;
 60}
 61
 62void free_stack(unsigned long stack, int order)
 63{
 64	free_pages(stack, order);
 65}
 66
 67unsigned long alloc_stack(int order, int atomic)
 68{
 69	unsigned long page;
 70	gfp_t flags = GFP_KERNEL;
 71
 72	if (atomic)
 73		flags = GFP_ATOMIC;
 74	page = __get_free_pages(flags, order);
 75
 76	return page;
 77}
 78
 79static inline void set_current(struct task_struct *task)
 80{
 81	cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
 82		{ external_pid(), task });
 83}
 84
 85extern void arch_switch_to(struct task_struct *to);
 86
 87void *__switch_to(struct task_struct *from, struct task_struct *to)
 88{
 89	to->thread.prev_sched = from;
 90	set_current(to);
 91
 92	switch_threads(&from->thread.switch_buf, &to->thread.switch_buf);
 93	arch_switch_to(current);
 94
 95	return current->thread.prev_sched;
 96}
 97
 98void interrupt_end(void)
 99{
100	struct pt_regs *regs = &current->thread.regs;
101
102	if (need_resched())
103		schedule();
104	if (test_thread_flag(TIF_SIGPENDING) ||
105	    test_thread_flag(TIF_NOTIFY_SIGNAL))
106		do_signal(regs);
107	if (test_thread_flag(TIF_NOTIFY_RESUME))
108		resume_user_mode_work(regs);
109}
110
111int get_current_pid(void)
112{
113	return task_pid_nr(current);
114}
115
116/*
117 * This is called magically, by its address being stuffed in a jmp_buf
118 * and being longjmp-d to.
119 */
120void new_thread_handler(void)
121{
122	int (*fn)(void *), n;
123	void *arg;
124
125	if (current->thread.prev_sched != NULL)
126		schedule_tail(current->thread.prev_sched);
127	current->thread.prev_sched = NULL;
128
129	fn = current->thread.request.u.thread.proc;
130	arg = current->thread.request.u.thread.arg;
131
132	/*
133	 * callback returns only if the kernel thread execs a process
134	 */
135	n = fn(arg);
136	userspace(&current->thread.regs.regs, current_thread_info()->aux_fp_regs);
137}
138
139/* Called magically, see new_thread_handler above */
140void fork_handler(void)
141{
142	force_flush_all();
143
144	schedule_tail(current->thread.prev_sched);
145
146	/*
147	 * XXX: if interrupt_end() calls schedule, this call to
148	 * arch_switch_to isn't needed. We could want to apply this to
149	 * improve performance. -bb
150	 */
151	arch_switch_to(current);
152
153	current->thread.prev_sched = NULL;
154
155	userspace(&current->thread.regs.regs, current_thread_info()->aux_fp_regs);
156}
157
158int copy_thread(struct task_struct * p, const struct kernel_clone_args *args)
 
159{
160	unsigned long clone_flags = args->flags;
161	unsigned long sp = args->stack;
162	unsigned long tls = args->tls;
163	void (*handler)(void);
 
164	int ret = 0;
165
166	p->thread = (struct thread_struct) INIT_THREAD;
167
168	if (!args->fn) {
169	  	memcpy(&p->thread.regs.regs, current_pt_regs(),
170		       sizeof(p->thread.regs.regs));
171		PT_REGS_SET_SYSCALL_RETURN(&p->thread.regs, 0);
172		if (sp != 0)
173			REGS_SP(p->thread.regs.regs.gp) = sp;
174
175		handler = fork_handler;
176
177		arch_copy_thread(&current->thread.arch, &p->thread.arch);
178	} else {
179		get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp);
180		p->thread.request.u.thread.proc = args->fn;
181		p->thread.request.u.thread.arg = args->fn_arg;
182		handler = new_thread_handler;
183	}
184
185	new_thread(task_stack_page(p), &p->thread.switch_buf, handler);
186
187	if (!args->fn) {
188		clear_flushed_tls(p);
189
190		/*
191		 * Set a new TLS for the child thread?
192		 */
193		if (clone_flags & CLONE_SETTLS)
194			ret = arch_set_tls(p, tls);
195	}
196
197	return ret;
198}
199
200void initial_thread_cb(void (*proc)(void *), void *arg)
201{
202	int save_kmalloc_ok = kmalloc_ok;
203
204	kmalloc_ok = 0;
205	initial_thread_cb_skas(proc, arg);
206	kmalloc_ok = save_kmalloc_ok;
207}
208
209void um_idle_sleep(void)
210{
211	if (time_travel_mode != TT_MODE_OFF)
212		time_travel_sleep();
213	else
214		os_idle_sleep();
215}
216
217void arch_cpu_idle(void)
218{
219	cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
220	um_idle_sleep();
221	raw_local_irq_enable();
222}
223
224int __cant_sleep(void) {
225	return in_atomic() || irqs_disabled() || in_interrupt();
226	/* Is in_interrupt() really needed? */
227}
228
229int user_context(unsigned long sp)
230{
231	unsigned long stack;
232
233	stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
234	return stack != (unsigned long) current_thread_info();
235}
236
237extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
238
239void do_uml_exitcalls(void)
240{
241	exitcall_t *call;
242
243	call = &__uml_exitcall_end;
244	while (--call >= &__uml_exitcall_begin)
245		(*call)();
246}
247
248char *uml_strdup(const char *string)
249{
250	return kstrdup(string, GFP_KERNEL);
251}
252EXPORT_SYMBOL(uml_strdup);
253
254int copy_to_user_proc(void __user *to, void *from, int size)
255{
256	return copy_to_user(to, from, size);
257}
258
259int copy_from_user_proc(void *to, void __user *from, int size)
260{
261	return copy_from_user(to, from, size);
262}
263
264int clear_user_proc(void __user *buf, int size)
265{
266	return clear_user(buf, size);
267}
268
 
 
 
 
 
 
 
 
 
 
269static atomic_t using_sysemu = ATOMIC_INIT(0);
270int sysemu_supported;
271
272void set_using_sysemu(int value)
273{
274	if (value > sysemu_supported)
275		return;
276	atomic_set(&using_sysemu, value);
277}
278
279int get_using_sysemu(void)
280{
281	return atomic_read(&using_sysemu);
282}
283
284static int sysemu_proc_show(struct seq_file *m, void *v)
285{
286	seq_printf(m, "%d\n", get_using_sysemu());
287	return 0;
288}
289
290static int sysemu_proc_open(struct inode *inode, struct file *file)
291{
292	return single_open(file, sysemu_proc_show, NULL);
293}
294
295static ssize_t sysemu_proc_write(struct file *file, const char __user *buf,
296				 size_t count, loff_t *pos)
297{
298	char tmp[2];
299
300	if (copy_from_user(tmp, buf, 1))
301		return -EFAULT;
302
303	if (tmp[0] >= '0' && tmp[0] <= '2')
304		set_using_sysemu(tmp[0] - '0');
305	/* We use the first char, but pretend to write everything */
306	return count;
307}
308
309static const struct proc_ops sysemu_proc_ops = {
310	.proc_open	= sysemu_proc_open,
311	.proc_read	= seq_read,
312	.proc_lseek	= seq_lseek,
313	.proc_release	= single_release,
314	.proc_write	= sysemu_proc_write,
 
315};
316
317int __init make_proc_sysemu(void)
318{
319	struct proc_dir_entry *ent;
320	if (!sysemu_supported)
321		return 0;
322
323	ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_ops);
324
325	if (ent == NULL)
326	{
327		printk(KERN_WARNING "Failed to register /proc/sysemu\n");
328		return 0;
329	}
330
331	return 0;
332}
333
334late_initcall(make_proc_sysemu);
335
336int singlestepping(void * t)
337{
338	struct task_struct *task = t ? t : current;
339
340	if (!test_thread_flag(TIF_SINGLESTEP))
341		return 0;
342
343	if (task->thread.singlestep_syscall)
344		return 1;
345
346	return 2;
347}
348
349/*
350 * Only x86 and x86_64 have an arch_align_stack().
351 * All other arches have "#define arch_align_stack(x) (x)"
352 * in their asm/exec.h
353 * As this is included in UML from asm-um/system-generic.h,
354 * we can use it to behave as the subarch does.
355 */
356#ifndef arch_align_stack
357unsigned long arch_align_stack(unsigned long sp)
358{
359	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
360		sp -= get_random_u32_below(8192);
361	return sp & ~0xf;
362}
363#endif
364
365unsigned long __get_wchan(struct task_struct *p)
366{
367	unsigned long stack_page, sp, ip;
368	bool seen_sched = 0;
369
 
 
 
370	stack_page = (unsigned long) task_stack_page(p);
371	/* Bail if the process has no kernel stack for some reason */
372	if (stack_page == 0)
373		return 0;
374
375	sp = p->thread.switch_buf->JB_SP;
376	/*
377	 * Bail if the stack pointer is below the bottom of the kernel
378	 * stack for some reason
379	 */
380	if (sp < stack_page)
381		return 0;
382
383	while (sp < stack_page + THREAD_SIZE) {
384		ip = *((unsigned long *) sp);
385		if (in_sched_functions(ip))
386			/* Ignore everything until we're above the scheduler */
387			seen_sched = 1;
388		else if (kernel_text_address(ip) && seen_sched)
389			return ip;
390
391		sp += sizeof(unsigned long);
392	}
393
394	return 0;
395}
396
397int elf_core_copy_task_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
398{
399	int cpu = current_thread_info()->cpu;
400
401	return save_i387_registers(userspace_pid[cpu], (unsigned long *) fpu);
402}
403

 
  1/*
  2 * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
  3 * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
  4 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  5 * Copyright 2003 PathScale, Inc.
  6 * Licensed under the GPL
  7 */
  8
  9#include <linux/stddef.h>
 10#include <linux/err.h>
 11#include <linux/hardirq.h>
 12#include <linux/mm.h>
 13#include <linux/module.h>
 14#include <linux/personality.h>
 15#include <linux/proc_fs.h>
 16#include <linux/ptrace.h>
 17#include <linux/random.h>
 18#include <linux/slab.h>
 19#include <linux/sched.h>
 
 
 
 20#include <linux/seq_file.h>
 21#include <linux/tick.h>
 22#include <linux/threads.h>
 23#include <linux/tracehook.h>
 24#include <asm/current.h>
 25#include <asm/pgtable.h>
 26#include <asm/mmu_context.h>
 27#include <linux/uaccess.h>
 28#include <as-layout.h>
 29#include <kern_util.h>
 30#include <os.h>
 31#include <skas.h>
 32#include <timer-internal.h>
 
 
 33
 34/*
 35 * This is a per-cpu array.  A processor only modifies its entry and it only
 36 * cares about its entry, so it's OK if another processor is modifying its
 37 * entry.
 38 */
 39struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
 40
 41static inline int external_pid(void)
 42{
 43	/* FIXME: Need to look up userspace_pid by cpu */
 44	return userspace_pid[0];
 45}
 46
 47int pid_to_processor_id(int pid)
 48{
 49	int i;
 50
 51	for (i = 0; i < ncpus; i++) {
 52		if (cpu_tasks[i].pid == pid)
 53			return i;
 54	}
 55	return -1;
 56}
 57
 58void free_stack(unsigned long stack, int order)
 59{
 60	free_pages(stack, order);
 61}
 62
 63unsigned long alloc_stack(int order, int atomic)
 64{
 65	unsigned long page;
 66	gfp_t flags = GFP_KERNEL;
 67
 68	if (atomic)
 69		flags = GFP_ATOMIC;
 70	page = __get_free_pages(flags, order);
 71
 72	return page;
 73}
 74
 75static inline void set_current(struct task_struct *task)
 76{
 77	cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
 78		{ external_pid(), task });
 79}
 80
 81extern void arch_switch_to(struct task_struct *to);
 82
 83void *__switch_to(struct task_struct *from, struct task_struct *to)
 84{
 85	to->thread.prev_sched = from;
 86	set_current(to);
 87
 88	switch_threads(&from->thread.switch_buf, &to->thread.switch_buf);
 89	arch_switch_to(current);
 90
 91	return current->thread.prev_sched;
 92}
 93
 94void interrupt_end(void)
 95{
 96	struct pt_regs *regs = &current->thread.regs;
 97
 98	if (need_resched())
 99		schedule();
100	if (test_thread_flag(TIF_SIGPENDING))
 
101		do_signal(regs);
102	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
103		tracehook_notify_resume(regs);
104}
105
106int get_current_pid(void)
107{
108	return task_pid_nr(current);
109}
110
111/*
112 * This is called magically, by its address being stuffed in a jmp_buf
113 * and being longjmp-d to.
114 */
115void new_thread_handler(void)
116{
117	int (*fn)(void *), n;
118	void *arg;
119
120	if (current->thread.prev_sched != NULL)
121		schedule_tail(current->thread.prev_sched);
122	current->thread.prev_sched = NULL;
123
124	fn = current->thread.request.u.thread.proc;
125	arg = current->thread.request.u.thread.arg;
126
127	/*
128	 * callback returns only if the kernel thread execs a process
129	 */
130	n = fn(arg);
131	userspace(&current->thread.regs.regs);
132}
133
134/* Called magically, see new_thread_handler above */
135void fork_handler(void)
136{
137	force_flush_all();
138
139	schedule_tail(current->thread.prev_sched);
140
141	/*
142	 * XXX: if interrupt_end() calls schedule, this call to
143	 * arch_switch_to isn't needed. We could want to apply this to
144	 * improve performance. -bb
145	 */
146	arch_switch_to(current);
147
148	current->thread.prev_sched = NULL;
149
150	userspace(&current->thread.regs.regs);
151}
152
153int copy_thread(unsigned long clone_flags, unsigned long sp,
154		unsigned long arg, struct task_struct * p)
155{
 
 
 
156	void (*handler)(void);
157	int kthread = current->flags & PF_KTHREAD;
158	int ret = 0;
159
160	p->thread = (struct thread_struct) INIT_THREAD;
161
162	if (!kthread) {
163	  	memcpy(&p->thread.regs.regs, current_pt_regs(),
164		       sizeof(p->thread.regs.regs));
165		PT_REGS_SET_SYSCALL_RETURN(&p->thread.regs, 0);
166		if (sp != 0)
167			REGS_SP(p->thread.regs.regs.gp) = sp;
168
169		handler = fork_handler;
170
171		arch_copy_thread(&current->thread.arch, &p->thread.arch);
172	} else {
173		get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp);
174		p->thread.request.u.thread.proc = (int (*)(void *))sp;
175		p->thread.request.u.thread.arg = (void *)arg;
176		handler = new_thread_handler;
177	}
178
179	new_thread(task_stack_page(p), &p->thread.switch_buf, handler);
180
181	if (!kthread) {
182		clear_flushed_tls(p);
183
184		/*
185		 * Set a new TLS for the child thread?
186		 */
187		if (clone_flags & CLONE_SETTLS)
188			ret = arch_copy_tls(p);
189	}
190
191	return ret;
192}
193
194void initial_thread_cb(void (*proc)(void *), void *arg)
195{
196	int save_kmalloc_ok = kmalloc_ok;
197
198	kmalloc_ok = 0;
199	initial_thread_cb_skas(proc, arg);
200	kmalloc_ok = save_kmalloc_ok;
201}
202
 
 
 
 
 
 
 
 
203void arch_cpu_idle(void)
204{
205	cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
206	os_idle_sleep(UM_NSEC_PER_SEC);
207	local_irq_enable();
208}
209
210int __cant_sleep(void) {
211	return in_atomic() || irqs_disabled() || in_interrupt();
212	/* Is in_interrupt() really needed? */
213}
214
215int user_context(unsigned long sp)
216{
217	unsigned long stack;
218
219	stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
220	return stack != (unsigned long) current_thread_info();
221}
222
223extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
224
225void do_uml_exitcalls(void)
226{
227	exitcall_t *call;
228
229	call = &__uml_exitcall_end;
230	while (--call >= &__uml_exitcall_begin)
231		(*call)();
232}
233
234char *uml_strdup(const char *string)
235{
236	return kstrdup(string, GFP_KERNEL);
237}
238EXPORT_SYMBOL(uml_strdup);
239
240int copy_to_user_proc(void __user *to, void *from, int size)
241{
242	return copy_to_user(to, from, size);
243}
244
245int copy_from_user_proc(void *to, void __user *from, int size)
246{
247	return copy_from_user(to, from, size);
248}
249
250int clear_user_proc(void __user *buf, int size)
251{
252	return clear_user(buf, size);
253}
254
255int strlen_user_proc(char __user *str)
256{
257	return strlen_user(str);
258}
259
260int cpu(void)
261{
262	return current_thread_info()->cpu;
263}
264
265static atomic_t using_sysemu = ATOMIC_INIT(0);
266int sysemu_supported;
267
268void set_using_sysemu(int value)
269{
270	if (value > sysemu_supported)
271		return;
272	atomic_set(&using_sysemu, value);
273}
274
275int get_using_sysemu(void)
276{
277	return atomic_read(&using_sysemu);
278}
279
280static int sysemu_proc_show(struct seq_file *m, void *v)
281{
282	seq_printf(m, "%d\n", get_using_sysemu());
283	return 0;
284}
285
286static int sysemu_proc_open(struct inode *inode, struct file *file)
287{
288	return single_open(file, sysemu_proc_show, NULL);
289}
290
291static ssize_t sysemu_proc_write(struct file *file, const char __user *buf,
292				 size_t count, loff_t *pos)
293{
294	char tmp[2];
295
296	if (copy_from_user(tmp, buf, 1))
297		return -EFAULT;
298
299	if (tmp[0] >= '0' && tmp[0] <= '2')
300		set_using_sysemu(tmp[0] - '0');
301	/* We use the first char, but pretend to write everything */
302	return count;
303}
304
305static const struct file_operations sysemu_proc_fops = {
306	.owner		= THIS_MODULE,
307	.open		= sysemu_proc_open,
308	.read		= seq_read,
309	.llseek		= seq_lseek,
310	.release	= single_release,
311	.write		= sysemu_proc_write,
312};
313
314int __init make_proc_sysemu(void)
315{
316	struct proc_dir_entry *ent;
317	if (!sysemu_supported)
318		return 0;
319
320	ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_fops);
321
322	if (ent == NULL)
323	{
324		printk(KERN_WARNING "Failed to register /proc/sysemu\n");
325		return 0;
326	}
327
328	return 0;
329}
330
331late_initcall(make_proc_sysemu);
332
333int singlestepping(void * t)
334{
335	struct task_struct *task = t ? t : current;
336
337	if (!(task->ptrace & PT_DTRACE))
338		return 0;
339
340	if (task->thread.singlestep_syscall)
341		return 1;
342
343	return 2;
344}
345
346/*
347 * Only x86 and x86_64 have an arch_align_stack().
348 * All other arches have "#define arch_align_stack(x) (x)"
349 * in their asm/exec.h
350 * As this is included in UML from asm-um/system-generic.h,
351 * we can use it to behave as the subarch does.
352 */
353#ifndef arch_align_stack
354unsigned long arch_align_stack(unsigned long sp)
355{
356	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
357		sp -= get_random_int() % 8192;
358	return sp & ~0xf;
359}
360#endif
361
362unsigned long get_wchan(struct task_struct *p)
363{
364	unsigned long stack_page, sp, ip;
365	bool seen_sched = 0;
366
367	if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING))
368		return 0;
369
370	stack_page = (unsigned long) task_stack_page(p);
371	/* Bail if the process has no kernel stack for some reason */
372	if (stack_page == 0)
373		return 0;
374
375	sp = p->thread.switch_buf->JB_SP;
376	/*
377	 * Bail if the stack pointer is below the bottom of the kernel
378	 * stack for some reason
379	 */
380	if (sp < stack_page)
381		return 0;
382
383	while (sp < stack_page + THREAD_SIZE) {
384		ip = *((unsigned long *) sp);
385		if (in_sched_functions(ip))
386			/* Ignore everything until we're above the scheduler */
387			seen_sched = 1;
388		else if (kernel_text_address(ip) && seen_sched)
389			return ip;
390
391		sp += sizeof(unsigned long);
392	}
393
394	return 0;
395}
396
397int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
398{
399	int cpu = current_thread_info()->cpu;
400
401	return save_i387_registers(userspace_pid[cpu], (unsigned long *) fpu);
402}
403