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1/*
2 * linux/arch/arm/kernel/process.c
3 *
4 * Copyright (C) 1996-2000 Russell King - Converted to ARM.
5 * Original Copyright (C) 1995 Linus Torvalds
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11#include <stdarg.h>
12
13#include <linux/module.h>
14#include <linux/sched.h>
15#include <linux/kernel.h>
16#include <linux/mm.h>
17#include <linux/stddef.h>
18#include <linux/unistd.h>
19#include <linux/user.h>
20#include <linux/delay.h>
21#include <linux/reboot.h>
22#include <linux/interrupt.h>
23#include <linux/kallsyms.h>
24#include <linux/init.h>
25#include <linux/cpu.h>
26#include <linux/elfcore.h>
27#include <linux/pm.h>
28#include <linux/tick.h>
29#include <linux/utsname.h>
30#include <linux/uaccess.h>
31#include <linux/random.h>
32#include <linux/hw_breakpoint.h>
33#include <linux/cpuidle.h>
34
35#include <asm/cacheflush.h>
36#include <asm/leds.h>
37#include <asm/processor.h>
38#include <asm/system.h>
39#include <asm/thread_notify.h>
40#include <asm/stacktrace.h>
41#include <asm/mach/time.h>
42
43#ifdef CONFIG_CC_STACKPROTECTOR
44#include <linux/stackprotector.h>
45unsigned long __stack_chk_guard __read_mostly;
46EXPORT_SYMBOL(__stack_chk_guard);
47#endif
48
49static const char *processor_modes[] = {
50 "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
51 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
52 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
53 "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
54};
55
56static const char *isa_modes[] = {
57 "ARM" , "Thumb" , "Jazelle", "ThumbEE"
58};
59
60extern void setup_mm_for_reboot(char mode);
61
62static volatile int hlt_counter;
63
64#include <mach/system.h>
65
66void disable_hlt(void)
67{
68 hlt_counter++;
69}
70
71EXPORT_SYMBOL(disable_hlt);
72
73void enable_hlt(void)
74{
75 hlt_counter--;
76}
77
78EXPORT_SYMBOL(enable_hlt);
79
80static int __init nohlt_setup(char *__unused)
81{
82 hlt_counter = 1;
83 return 1;
84}
85
86static int __init hlt_setup(char *__unused)
87{
88 hlt_counter = 0;
89 return 1;
90}
91
92__setup("nohlt", nohlt_setup);
93__setup("hlt", hlt_setup);
94
95void arm_machine_restart(char mode, const char *cmd)
96{
97 /* Disable interrupts first */
98 local_irq_disable();
99 local_fiq_disable();
100
101 /*
102 * Tell the mm system that we are going to reboot -
103 * we may need it to insert some 1:1 mappings so that
104 * soft boot works.
105 */
106 setup_mm_for_reboot(mode);
107
108 /* Clean and invalidate caches */
109 flush_cache_all();
110
111 /* Turn off caching */
112 cpu_proc_fin();
113
114 /* Push out any further dirty data, and ensure cache is empty */
115 flush_cache_all();
116
117 /*
118 * Now call the architecture specific reboot code.
119 */
120 arch_reset(mode, cmd);
121
122 /*
123 * Whoops - the architecture was unable to reboot.
124 * Tell the user!
125 */
126 mdelay(1000);
127 printk("Reboot failed -- System halted\n");
128 while (1);
129}
130
131/*
132 * Function pointers to optional machine specific functions
133 */
134void (*pm_power_off)(void);
135EXPORT_SYMBOL(pm_power_off);
136
137void (*arm_pm_restart)(char str, const char *cmd) = arm_machine_restart;
138EXPORT_SYMBOL_GPL(arm_pm_restart);
139
140static void do_nothing(void *unused)
141{
142}
143
144/*
145 * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
146 * pm_idle and update to new pm_idle value. Required while changing pm_idle
147 * handler on SMP systems.
148 *
149 * Caller must have changed pm_idle to the new value before the call. Old
150 * pm_idle value will not be used by any CPU after the return of this function.
151 */
152void cpu_idle_wait(void)
153{
154 smp_mb();
155 /* kick all the CPUs so that they exit out of pm_idle */
156 smp_call_function(do_nothing, NULL, 1);
157}
158EXPORT_SYMBOL_GPL(cpu_idle_wait);
159
160/*
161 * This is our default idle handler. We need to disable
162 * interrupts here to ensure we don't miss a wakeup call.
163 */
164static void default_idle(void)
165{
166 if (!need_resched())
167 arch_idle();
168 local_irq_enable();
169}
170
171void (*pm_idle)(void) = default_idle;
172EXPORT_SYMBOL(pm_idle);
173
174/*
175 * The idle thread, has rather strange semantics for calling pm_idle,
176 * but this is what x86 does and we need to do the same, so that
177 * things like cpuidle get called in the same way. The only difference
178 * is that we always respect 'hlt_counter' to prevent low power idle.
179 */
180void cpu_idle(void)
181{
182 local_fiq_enable();
183
184 /* endless idle loop with no priority at all */
185 while (1) {
186 tick_nohz_stop_sched_tick(1);
187 leds_event(led_idle_start);
188 while (!need_resched()) {
189#ifdef CONFIG_HOTPLUG_CPU
190 if (cpu_is_offline(smp_processor_id()))
191 cpu_die();
192#endif
193
194 local_irq_disable();
195 if (hlt_counter) {
196 local_irq_enable();
197 cpu_relax();
198 } else {
199 stop_critical_timings();
200 if (cpuidle_idle_call())
201 pm_idle();
202 start_critical_timings();
203 /*
204 * This will eventually be removed - pm_idle
205 * functions should always return with IRQs
206 * enabled.
207 */
208 WARN_ON(irqs_disabled());
209 local_irq_enable();
210 }
211 }
212 leds_event(led_idle_end);
213 tick_nohz_restart_sched_tick();
214 preempt_enable_no_resched();
215 schedule();
216 preempt_disable();
217 }
218}
219
220static char reboot_mode = 'h';
221
222int __init reboot_setup(char *str)
223{
224 reboot_mode = str[0];
225 return 1;
226}
227
228__setup("reboot=", reboot_setup);
229
230void machine_shutdown(void)
231{
232#ifdef CONFIG_SMP
233 smp_send_stop();
234#endif
235}
236
237void machine_halt(void)
238{
239 machine_shutdown();
240 while (1);
241}
242
243void machine_power_off(void)
244{
245 machine_shutdown();
246 if (pm_power_off)
247 pm_power_off();
248}
249
250void machine_restart(char *cmd)
251{
252 machine_shutdown();
253 arm_pm_restart(reboot_mode, cmd);
254}
255
256void __show_regs(struct pt_regs *regs)
257{
258 unsigned long flags;
259 char buf[64];
260
261 printk("CPU: %d %s (%s %.*s)\n",
262 raw_smp_processor_id(), print_tainted(),
263 init_utsname()->release,
264 (int)strcspn(init_utsname()->version, " "),
265 init_utsname()->version);
266 print_symbol("PC is at %s\n", instruction_pointer(regs));
267 print_symbol("LR is at %s\n", regs->ARM_lr);
268 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
269 "sp : %08lx ip : %08lx fp : %08lx\n",
270 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
271 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
272 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
273 regs->ARM_r10, regs->ARM_r9,
274 regs->ARM_r8);
275 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
276 regs->ARM_r7, regs->ARM_r6,
277 regs->ARM_r5, regs->ARM_r4);
278 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
279 regs->ARM_r3, regs->ARM_r2,
280 regs->ARM_r1, regs->ARM_r0);
281
282 flags = regs->ARM_cpsr;
283 buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
284 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
285 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
286 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
287 buf[4] = '\0';
288
289 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
290 buf, interrupts_enabled(regs) ? "n" : "ff",
291 fast_interrupts_enabled(regs) ? "n" : "ff",
292 processor_modes[processor_mode(regs)],
293 isa_modes[isa_mode(regs)],
294 get_fs() == get_ds() ? "kernel" : "user");
295#ifdef CONFIG_CPU_CP15
296 {
297 unsigned int ctrl;
298
299 buf[0] = '\0';
300#ifdef CONFIG_CPU_CP15_MMU
301 {
302 unsigned int transbase, dac;
303 asm("mrc p15, 0, %0, c2, c0\n\t"
304 "mrc p15, 0, %1, c3, c0\n"
305 : "=r" (transbase), "=r" (dac));
306 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
307 transbase, dac);
308 }
309#endif
310 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
311
312 printk("Control: %08x%s\n", ctrl, buf);
313 }
314#endif
315}
316
317void show_regs(struct pt_regs * regs)
318{
319 printk("\n");
320 printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
321 __show_regs(regs);
322 __backtrace();
323}
324
325ATOMIC_NOTIFIER_HEAD(thread_notify_head);
326
327EXPORT_SYMBOL_GPL(thread_notify_head);
328
329/*
330 * Free current thread data structures etc..
331 */
332void exit_thread(void)
333{
334 thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
335}
336
337void flush_thread(void)
338{
339 struct thread_info *thread = current_thread_info();
340 struct task_struct *tsk = current;
341
342 flush_ptrace_hw_breakpoint(tsk);
343
344 memset(thread->used_cp, 0, sizeof(thread->used_cp));
345 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
346 memset(&thread->fpstate, 0, sizeof(union fp_state));
347
348 thread_notify(THREAD_NOTIFY_FLUSH, thread);
349}
350
351void release_thread(struct task_struct *dead_task)
352{
353}
354
355asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
356
357int
358copy_thread(unsigned long clone_flags, unsigned long stack_start,
359 unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
360{
361 struct thread_info *thread = task_thread_info(p);
362 struct pt_regs *childregs = task_pt_regs(p);
363
364 *childregs = *regs;
365 childregs->ARM_r0 = 0;
366 childregs->ARM_sp = stack_start;
367
368 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
369 thread->cpu_context.sp = (unsigned long)childregs;
370 thread->cpu_context.pc = (unsigned long)ret_from_fork;
371
372 clear_ptrace_hw_breakpoint(p);
373
374 if (clone_flags & CLONE_SETTLS)
375 thread->tp_value = regs->ARM_r3;
376
377 thread_notify(THREAD_NOTIFY_COPY, thread);
378
379 return 0;
380}
381
382/*
383 * Fill in the task's elfregs structure for a core dump.
384 */
385int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
386{
387 elf_core_copy_regs(elfregs, task_pt_regs(t));
388 return 1;
389}
390
391/*
392 * fill in the fpe structure for a core dump...
393 */
394int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
395{
396 struct thread_info *thread = current_thread_info();
397 int used_math = thread->used_cp[1] | thread->used_cp[2];
398
399 if (used_math)
400 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
401
402 return used_math != 0;
403}
404EXPORT_SYMBOL(dump_fpu);
405
406/*
407 * Shuffle the argument into the correct register before calling the
408 * thread function. r4 is the thread argument, r5 is the pointer to
409 * the thread function, and r6 points to the exit function.
410 */
411extern void kernel_thread_helper(void);
412asm( ".pushsection .text\n"
413" .align\n"
414" .type kernel_thread_helper, #function\n"
415"kernel_thread_helper:\n"
416#ifdef CONFIG_TRACE_IRQFLAGS
417" bl trace_hardirqs_on\n"
418#endif
419" msr cpsr_c, r7\n"
420" mov r0, r4\n"
421" mov lr, r6\n"
422" mov pc, r5\n"
423" .size kernel_thread_helper, . - kernel_thread_helper\n"
424" .popsection");
425
426#ifdef CONFIG_ARM_UNWIND
427extern void kernel_thread_exit(long code);
428asm( ".pushsection .text\n"
429" .align\n"
430" .type kernel_thread_exit, #function\n"
431"kernel_thread_exit:\n"
432" .fnstart\n"
433" .cantunwind\n"
434" bl do_exit\n"
435" nop\n"
436" .fnend\n"
437" .size kernel_thread_exit, . - kernel_thread_exit\n"
438" .popsection");
439#else
440#define kernel_thread_exit do_exit
441#endif
442
443/*
444 * Create a kernel thread.
445 */
446pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
447{
448 struct pt_regs regs;
449
450 memset(®s, 0, sizeof(regs));
451
452 regs.ARM_r4 = (unsigned long)arg;
453 regs.ARM_r5 = (unsigned long)fn;
454 regs.ARM_r6 = (unsigned long)kernel_thread_exit;
455 regs.ARM_r7 = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE;
456 regs.ARM_pc = (unsigned long)kernel_thread_helper;
457 regs.ARM_cpsr = regs.ARM_r7 | PSR_I_BIT;
458
459 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL);
460}
461EXPORT_SYMBOL(kernel_thread);
462
463unsigned long get_wchan(struct task_struct *p)
464{
465 struct stackframe frame;
466 int count = 0;
467 if (!p || p == current || p->state == TASK_RUNNING)
468 return 0;
469
470 frame.fp = thread_saved_fp(p);
471 frame.sp = thread_saved_sp(p);
472 frame.lr = 0; /* recovered from the stack */
473 frame.pc = thread_saved_pc(p);
474 do {
475 int ret = unwind_frame(&frame);
476 if (ret < 0)
477 return 0;
478 if (!in_sched_functions(frame.pc))
479 return frame.pc;
480 } while (count ++ < 16);
481 return 0;
482}
483
484unsigned long arch_randomize_brk(struct mm_struct *mm)
485{
486 unsigned long range_end = mm->brk + 0x02000000;
487 return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
488}
489
490#ifdef CONFIG_MMU
491/*
492 * The vectors page is always readable from user space for the
493 * atomic helpers and the signal restart code. Let's declare a mapping
494 * for it so it is visible through ptrace and /proc/<pid>/mem.
495 */
496
497int vectors_user_mapping(void)
498{
499 struct mm_struct *mm = current->mm;
500 return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
501 VM_READ | VM_EXEC |
502 VM_MAYREAD | VM_MAYEXEC |
503 VM_ALWAYSDUMP | VM_RESERVED,
504 NULL);
505}
506
507const char *arch_vma_name(struct vm_area_struct *vma)
508{
509 return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
510}
511#endif
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/arch/arm/kernel/process.c
4 *
5 * Copyright (C) 1996-2000 Russell King - Converted to ARM.
6 * Original Copyright (C) 1995 Linus Torvalds
7 */
8#include <linux/export.h>
9#include <linux/sched.h>
10#include <linux/sched/debug.h>
11#include <linux/sched/task.h>
12#include <linux/sched/task_stack.h>
13#include <linux/kernel.h>
14#include <linux/mm.h>
15#include <linux/stddef.h>
16#include <linux/unistd.h>
17#include <linux/user.h>
18#include <linux/interrupt.h>
19#include <linux/init.h>
20#include <linux/elfcore.h>
21#include <linux/pm.h>
22#include <linux/tick.h>
23#include <linux/utsname.h>
24#include <linux/uaccess.h>
25#include <linux/random.h>
26#include <linux/hw_breakpoint.h>
27#include <linux/leds.h>
28
29#include <asm/processor.h>
30#include <asm/thread_notify.h>
31#include <asm/stacktrace.h>
32#include <asm/system_misc.h>
33#include <asm/mach/time.h>
34#include <asm/tls.h>
35#include <asm/vdso.h>
36
37#include "signal.h"
38
39#if defined(CONFIG_CURRENT_POINTER_IN_TPIDRURO) || defined(CONFIG_SMP)
40DEFINE_PER_CPU(struct task_struct *, __entry_task);
41#endif
42
43#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK)
44#include <linux/stackprotector.h>
45unsigned long __stack_chk_guard __read_mostly;
46EXPORT_SYMBOL(__stack_chk_guard);
47#endif
48
49#ifndef CONFIG_CURRENT_POINTER_IN_TPIDRURO
50asmlinkage struct task_struct *__current;
51EXPORT_SYMBOL(__current);
52#endif
53
54static const char *processor_modes[] __maybe_unused = {
55 "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
56 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
57 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "MON_32" , "ABT_32" ,
58 "UK8_32" , "UK9_32" , "HYP_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
59};
60
61static const char *isa_modes[] __maybe_unused = {
62 "ARM" , "Thumb" , "Jazelle", "ThumbEE"
63};
64
65/*
66 * This is our default idle handler.
67 */
68
69void (*arm_pm_idle)(void);
70
71/*
72 * Called from the core idle loop.
73 */
74
75void arch_cpu_idle(void)
76{
77 if (arm_pm_idle)
78 arm_pm_idle();
79 else
80 cpu_do_idle();
81 raw_local_irq_enable();
82}
83
84void arch_cpu_idle_prepare(void)
85{
86 local_fiq_enable();
87}
88
89void arch_cpu_idle_enter(void)
90{
91 ledtrig_cpu(CPU_LED_IDLE_START);
92#ifdef CONFIG_PL310_ERRATA_769419
93 wmb();
94#endif
95}
96
97void arch_cpu_idle_exit(void)
98{
99 ledtrig_cpu(CPU_LED_IDLE_END);
100}
101
102void __show_regs_alloc_free(struct pt_regs *regs)
103{
104 int i;
105
106 /* check for r0 - r12 only */
107 for (i = 0; i < 13; i++) {
108 pr_alert("Register r%d information:", i);
109 mem_dump_obj((void *)regs->uregs[i]);
110 }
111}
112
113void __show_regs(struct pt_regs *regs)
114{
115 unsigned long flags;
116 char buf[64];
117#ifndef CONFIG_CPU_V7M
118 unsigned int domain;
119#ifdef CONFIG_CPU_SW_DOMAIN_PAN
120 /*
121 * Get the domain register for the parent context. In user
122 * mode, we don't save the DACR, so lets use what it should
123 * be. For other modes, we place it after the pt_regs struct.
124 */
125 if (user_mode(regs)) {
126 domain = DACR_UACCESS_ENABLE;
127 } else {
128 domain = to_svc_pt_regs(regs)->dacr;
129 }
130#else
131 domain = get_domain();
132#endif
133#endif
134
135 show_regs_print_info(KERN_DEFAULT);
136
137 printk("PC is at %pS\n", (void *)instruction_pointer(regs));
138 printk("LR is at %pS\n", (void *)regs->ARM_lr);
139 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n",
140 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr);
141 printk("sp : %08lx ip : %08lx fp : %08lx\n",
142 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
143 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
144 regs->ARM_r10, regs->ARM_r9,
145 regs->ARM_r8);
146 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
147 regs->ARM_r7, regs->ARM_r6,
148 regs->ARM_r5, regs->ARM_r4);
149 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
150 regs->ARM_r3, regs->ARM_r2,
151 regs->ARM_r1, regs->ARM_r0);
152
153 flags = regs->ARM_cpsr;
154 buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
155 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
156 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
157 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
158 buf[4] = '\0';
159
160#ifndef CONFIG_CPU_V7M
161 {
162 const char *segment;
163
164 if ((domain & domain_mask(DOMAIN_USER)) ==
165 domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
166 segment = "none";
167 else
168 segment = "user";
169
170 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
171 buf, interrupts_enabled(regs) ? "n" : "ff",
172 fast_interrupts_enabled(regs) ? "n" : "ff",
173 processor_modes[processor_mode(regs)],
174 isa_modes[isa_mode(regs)], segment);
175 }
176#else
177 printk("xPSR: %08lx\n", regs->ARM_cpsr);
178#endif
179
180#ifdef CONFIG_CPU_CP15
181 {
182 unsigned int ctrl;
183
184 buf[0] = '\0';
185#ifdef CONFIG_CPU_CP15_MMU
186 {
187 unsigned int transbase;
188 asm("mrc p15, 0, %0, c2, c0\n\t"
189 : "=r" (transbase));
190 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
191 transbase, domain);
192 }
193#endif
194 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
195
196 printk("Control: %08x%s\n", ctrl, buf);
197 }
198#endif
199}
200
201void show_regs(struct pt_regs * regs)
202{
203 __show_regs(regs);
204 dump_backtrace(regs, NULL, KERN_DEFAULT);
205}
206
207ATOMIC_NOTIFIER_HEAD(thread_notify_head);
208
209EXPORT_SYMBOL_GPL(thread_notify_head);
210
211/*
212 * Free current thread data structures etc..
213 */
214void exit_thread(struct task_struct *tsk)
215{
216 thread_notify(THREAD_NOTIFY_EXIT, task_thread_info(tsk));
217}
218
219void flush_thread(void)
220{
221 struct thread_info *thread = current_thread_info();
222 struct task_struct *tsk = current;
223
224 flush_ptrace_hw_breakpoint(tsk);
225
226 memset(thread->used_cp, 0, sizeof(thread->used_cp));
227 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
228 memset(&thread->fpstate, 0, sizeof(union fp_state));
229
230 flush_tls();
231
232 thread_notify(THREAD_NOTIFY_FLUSH, thread);
233}
234
235asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
236
237int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
238{
239 unsigned long clone_flags = args->flags;
240 unsigned long stack_start = args->stack;
241 unsigned long tls = args->tls;
242 struct thread_info *thread = task_thread_info(p);
243 struct pt_regs *childregs = task_pt_regs(p);
244
245 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
246
247#ifdef CONFIG_CPU_USE_DOMAINS
248 /*
249 * Copy the initial value of the domain access control register
250 * from the current thread: thread->addr_limit will have been
251 * copied from the current thread via setup_thread_stack() in
252 * kernel/fork.c
253 */
254 thread->cpu_domain = get_domain();
255#endif
256
257 if (likely(!args->fn)) {
258 *childregs = *current_pt_regs();
259 childregs->ARM_r0 = 0;
260 if (stack_start)
261 childregs->ARM_sp = stack_start;
262 } else {
263 memset(childregs, 0, sizeof(struct pt_regs));
264 thread->cpu_context.r4 = (unsigned long)args->fn_arg;
265 thread->cpu_context.r5 = (unsigned long)args->fn;
266 childregs->ARM_cpsr = SVC_MODE;
267 }
268 thread->cpu_context.pc = (unsigned long)ret_from_fork;
269 thread->cpu_context.sp = (unsigned long)childregs;
270
271 clear_ptrace_hw_breakpoint(p);
272
273 if (clone_flags & CLONE_SETTLS)
274 thread->tp_value[0] = tls;
275 thread->tp_value[1] = get_tpuser();
276
277 thread_notify(THREAD_NOTIFY_COPY, thread);
278
279 return 0;
280}
281
282unsigned long __get_wchan(struct task_struct *p)
283{
284 struct stackframe frame;
285 unsigned long stack_page;
286 int count = 0;
287
288 frame.fp = thread_saved_fp(p);
289 frame.sp = thread_saved_sp(p);
290 frame.lr = 0; /* recovered from the stack */
291 frame.pc = thread_saved_pc(p);
292 stack_page = (unsigned long)task_stack_page(p);
293 do {
294 if (frame.sp < stack_page ||
295 frame.sp >= stack_page + THREAD_SIZE ||
296 unwind_frame(&frame) < 0)
297 return 0;
298 if (!in_sched_functions(frame.pc))
299 return frame.pc;
300 } while (count ++ < 16);
301 return 0;
302}
303
304#ifdef CONFIG_MMU
305#ifdef CONFIG_KUSER_HELPERS
306/*
307 * The vectors page is always readable from user space for the
308 * atomic helpers. Insert it into the gate_vma so that it is visible
309 * through ptrace and /proc/<pid>/mem.
310 */
311static struct vm_area_struct gate_vma;
312
313static int __init gate_vma_init(void)
314{
315 vma_init(&gate_vma, NULL);
316 gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
317 gate_vma.vm_start = 0xffff0000;
318 gate_vma.vm_end = 0xffff0000 + PAGE_SIZE;
319 gate_vma.vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC;
320 return 0;
321}
322arch_initcall(gate_vma_init);
323
324struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
325{
326 return &gate_vma;
327}
328
329int in_gate_area(struct mm_struct *mm, unsigned long addr)
330{
331 return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
332}
333
334int in_gate_area_no_mm(unsigned long addr)
335{
336 return in_gate_area(NULL, addr);
337}
338#define is_gate_vma(vma) ((vma) == &gate_vma)
339#else
340#define is_gate_vma(vma) 0
341#endif
342
343const char *arch_vma_name(struct vm_area_struct *vma)
344{
345 return is_gate_vma(vma) ? "[vectors]" : NULL;
346}
347
348/* If possible, provide a placement hint at a random offset from the
349 * stack for the sigpage and vdso pages.
350 */
351static unsigned long sigpage_addr(const struct mm_struct *mm,
352 unsigned int npages)
353{
354 unsigned long offset;
355 unsigned long first;
356 unsigned long last;
357 unsigned long addr;
358 unsigned int slots;
359
360 first = PAGE_ALIGN(mm->start_stack);
361
362 last = TASK_SIZE - (npages << PAGE_SHIFT);
363
364 /* No room after stack? */
365 if (first > last)
366 return 0;
367
368 /* Just enough room? */
369 if (first == last)
370 return first;
371
372 slots = ((last - first) >> PAGE_SHIFT) + 1;
373
374 offset = get_random_u32_below(slots);
375
376 addr = first + (offset << PAGE_SHIFT);
377
378 return addr;
379}
380
381static struct page *signal_page;
382extern struct page *get_signal_page(void);
383
384static int sigpage_mremap(const struct vm_special_mapping *sm,
385 struct vm_area_struct *new_vma)
386{
387 current->mm->context.sigpage = new_vma->vm_start;
388 return 0;
389}
390
391static const struct vm_special_mapping sigpage_mapping = {
392 .name = "[sigpage]",
393 .pages = &signal_page,
394 .mremap = sigpage_mremap,
395};
396
397int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
398{
399 struct mm_struct *mm = current->mm;
400 struct vm_area_struct *vma;
401 unsigned long npages;
402 unsigned long addr;
403 unsigned long hint;
404 int ret = 0;
405
406 if (!signal_page)
407 signal_page = get_signal_page();
408 if (!signal_page)
409 return -ENOMEM;
410
411 npages = 1; /* for sigpage */
412 npages += vdso_total_pages;
413
414 if (mmap_write_lock_killable(mm))
415 return -EINTR;
416 hint = sigpage_addr(mm, npages);
417 addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0);
418 if (IS_ERR_VALUE(addr)) {
419 ret = addr;
420 goto up_fail;
421 }
422
423 vma = _install_special_mapping(mm, addr, PAGE_SIZE,
424 VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
425 &sigpage_mapping);
426
427 if (IS_ERR(vma)) {
428 ret = PTR_ERR(vma);
429 goto up_fail;
430 }
431
432 mm->context.sigpage = addr;
433
434 /* Unlike the sigpage, failure to install the vdso is unlikely
435 * to be fatal to the process, so no error check needed
436 * here.
437 */
438 arm_install_vdso(mm, addr + PAGE_SIZE);
439
440 up_fail:
441 mmap_write_unlock(mm);
442 return ret;
443}
444#endif