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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 <stdarg.h>
9
10#include <linux/export.h>
11#include <linux/sched.h>
12#include <linux/sched/debug.h>
13#include <linux/sched/task.h>
14#include <linux/sched/task_stack.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/interrupt.h>
21#include <linux/init.h>
22#include <linux/elfcore.h>
23#include <linux/pm.h>
24#include <linux/tick.h>
25#include <linux/utsname.h>
26#include <linux/uaccess.h>
27#include <linux/random.h>
28#include <linux/hw_breakpoint.h>
29#include <linux/leds.h>
30
31#include <asm/processor.h>
32#include <asm/thread_notify.h>
33#include <asm/stacktrace.h>
34#include <asm/system_misc.h>
35#include <asm/mach/time.h>
36#include <asm/tls.h>
37#include <asm/vdso.h>
38
39#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK)
40#include <linux/stackprotector.h>
41unsigned long __stack_chk_guard __read_mostly;
42EXPORT_SYMBOL(__stack_chk_guard);
43#endif
44
45static const char *processor_modes[] __maybe_unused = {
46 "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
47 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
48 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "MON_32" , "ABT_32" ,
49 "UK8_32" , "UK9_32" , "HYP_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
50};
51
52static const char *isa_modes[] __maybe_unused = {
53 "ARM" , "Thumb" , "Jazelle", "ThumbEE"
54};
55
56/*
57 * This is our default idle handler.
58 */
59
60void (*arm_pm_idle)(void);
61
62/*
63 * Called from the core idle loop.
64 */
65
66void arch_cpu_idle(void)
67{
68 if (arm_pm_idle)
69 arm_pm_idle();
70 else
71 cpu_do_idle();
72 local_irq_enable();
73}
74
75void arch_cpu_idle_prepare(void)
76{
77 local_fiq_enable();
78}
79
80void arch_cpu_idle_enter(void)
81{
82 ledtrig_cpu(CPU_LED_IDLE_START);
83#ifdef CONFIG_PL310_ERRATA_769419
84 wmb();
85#endif
86}
87
88void arch_cpu_idle_exit(void)
89{
90 ledtrig_cpu(CPU_LED_IDLE_END);
91}
92
93void __show_regs(struct pt_regs *regs)
94{
95 unsigned long flags;
96 char buf[64];
97#ifndef CONFIG_CPU_V7M
98 unsigned int domain, fs;
99#ifdef CONFIG_CPU_SW_DOMAIN_PAN
100 /*
101 * Get the domain register for the parent context. In user
102 * mode, we don't save the DACR, so lets use what it should
103 * be. For other modes, we place it after the pt_regs struct.
104 */
105 if (user_mode(regs)) {
106 domain = DACR_UACCESS_ENABLE;
107 fs = get_fs();
108 } else {
109 domain = to_svc_pt_regs(regs)->dacr;
110 fs = to_svc_pt_regs(regs)->addr_limit;
111 }
112#else
113 domain = get_domain();
114 fs = get_fs();
115#endif
116#endif
117
118 show_regs_print_info(KERN_DEFAULT);
119
120 printk("PC is at %pS\n", (void *)instruction_pointer(regs));
121 printk("LR is at %pS\n", (void *)regs->ARM_lr);
122 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n",
123 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr);
124 printk("sp : %08lx ip : %08lx fp : %08lx\n",
125 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
126 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
127 regs->ARM_r10, regs->ARM_r9,
128 regs->ARM_r8);
129 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
130 regs->ARM_r7, regs->ARM_r6,
131 regs->ARM_r5, regs->ARM_r4);
132 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
133 regs->ARM_r3, regs->ARM_r2,
134 regs->ARM_r1, regs->ARM_r0);
135
136 flags = regs->ARM_cpsr;
137 buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
138 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
139 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
140 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
141 buf[4] = '\0';
142
143#ifndef CONFIG_CPU_V7M
144 {
145 const char *segment;
146
147 if ((domain & domain_mask(DOMAIN_USER)) ==
148 domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
149 segment = "none";
150 else if (fs == KERNEL_DS)
151 segment = "kernel";
152 else
153 segment = "user";
154
155 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
156 buf, interrupts_enabled(regs) ? "n" : "ff",
157 fast_interrupts_enabled(regs) ? "n" : "ff",
158 processor_modes[processor_mode(regs)],
159 isa_modes[isa_mode(regs)], segment);
160 }
161#else
162 printk("xPSR: %08lx\n", regs->ARM_cpsr);
163#endif
164
165#ifdef CONFIG_CPU_CP15
166 {
167 unsigned int ctrl;
168
169 buf[0] = '\0';
170#ifdef CONFIG_CPU_CP15_MMU
171 {
172 unsigned int transbase;
173 asm("mrc p15, 0, %0, c2, c0\n\t"
174 : "=r" (transbase));
175 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
176 transbase, domain);
177 }
178#endif
179 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
180
181 printk("Control: %08x%s\n", ctrl, buf);
182 }
183#endif
184}
185
186void show_regs(struct pt_regs * regs)
187{
188 __show_regs(regs);
189 dump_stack();
190}
191
192ATOMIC_NOTIFIER_HEAD(thread_notify_head);
193
194EXPORT_SYMBOL_GPL(thread_notify_head);
195
196/*
197 * Free current thread data structures etc..
198 */
199void exit_thread(struct task_struct *tsk)
200{
201 thread_notify(THREAD_NOTIFY_EXIT, task_thread_info(tsk));
202}
203
204void flush_thread(void)
205{
206 struct thread_info *thread = current_thread_info();
207 struct task_struct *tsk = current;
208
209 flush_ptrace_hw_breakpoint(tsk);
210
211 memset(thread->used_cp, 0, sizeof(thread->used_cp));
212 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
213 memset(&thread->fpstate, 0, sizeof(union fp_state));
214
215 flush_tls();
216
217 thread_notify(THREAD_NOTIFY_FLUSH, thread);
218}
219
220void release_thread(struct task_struct *dead_task)
221{
222}
223
224asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
225
226int
227copy_thread(unsigned long clone_flags, unsigned long stack_start,
228 unsigned long stk_sz, struct task_struct *p)
229{
230 struct thread_info *thread = task_thread_info(p);
231 struct pt_regs *childregs = task_pt_regs(p);
232
233 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
234
235#ifdef CONFIG_CPU_USE_DOMAINS
236 /*
237 * Copy the initial value of the domain access control register
238 * from the current thread: thread->addr_limit will have been
239 * copied from the current thread via setup_thread_stack() in
240 * kernel/fork.c
241 */
242 thread->cpu_domain = get_domain();
243#endif
244
245 if (likely(!(p->flags & PF_KTHREAD))) {
246 *childregs = *current_pt_regs();
247 childregs->ARM_r0 = 0;
248 if (stack_start)
249 childregs->ARM_sp = stack_start;
250 } else {
251 memset(childregs, 0, sizeof(struct pt_regs));
252 thread->cpu_context.r4 = stk_sz;
253 thread->cpu_context.r5 = stack_start;
254 childregs->ARM_cpsr = SVC_MODE;
255 }
256 thread->cpu_context.pc = (unsigned long)ret_from_fork;
257 thread->cpu_context.sp = (unsigned long)childregs;
258
259 clear_ptrace_hw_breakpoint(p);
260
261 if (clone_flags & CLONE_SETTLS)
262 thread->tp_value[0] = childregs->ARM_r3;
263 thread->tp_value[1] = get_tpuser();
264
265 thread_notify(THREAD_NOTIFY_COPY, thread);
266
267#ifdef CONFIG_STACKPROTECTOR_PER_TASK
268 thread->stack_canary = p->stack_canary;
269#endif
270
271 return 0;
272}
273
274/*
275 * Fill in the task's elfregs structure for a core dump.
276 */
277int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
278{
279 elf_core_copy_regs(elfregs, task_pt_regs(t));
280 return 1;
281}
282
283/*
284 * fill in the fpe structure for a core dump...
285 */
286int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
287{
288 struct thread_info *thread = current_thread_info();
289 int used_math = thread->used_cp[1] | thread->used_cp[2];
290
291 if (used_math)
292 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
293
294 return used_math != 0;
295}
296EXPORT_SYMBOL(dump_fpu);
297
298unsigned long get_wchan(struct task_struct *p)
299{
300 struct stackframe frame;
301 unsigned long stack_page;
302 int count = 0;
303 if (!p || p == current || p->state == TASK_RUNNING)
304 return 0;
305
306 frame.fp = thread_saved_fp(p);
307 frame.sp = thread_saved_sp(p);
308 frame.lr = 0; /* recovered from the stack */
309 frame.pc = thread_saved_pc(p);
310 stack_page = (unsigned long)task_stack_page(p);
311 do {
312 if (frame.sp < stack_page ||
313 frame.sp >= stack_page + THREAD_SIZE ||
314 unwind_frame(&frame) < 0)
315 return 0;
316 if (!in_sched_functions(frame.pc))
317 return frame.pc;
318 } while (count ++ < 16);
319 return 0;
320}
321
322#ifdef CONFIG_MMU
323#ifdef CONFIG_KUSER_HELPERS
324/*
325 * The vectors page is always readable from user space for the
326 * atomic helpers. Insert it into the gate_vma so that it is visible
327 * through ptrace and /proc/<pid>/mem.
328 */
329static struct vm_area_struct gate_vma;
330
331static int __init gate_vma_init(void)
332{
333 vma_init(&gate_vma, NULL);
334 gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
335 gate_vma.vm_start = 0xffff0000;
336 gate_vma.vm_end = 0xffff0000 + PAGE_SIZE;
337 gate_vma.vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC;
338 return 0;
339}
340arch_initcall(gate_vma_init);
341
342struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
343{
344 return &gate_vma;
345}
346
347int in_gate_area(struct mm_struct *mm, unsigned long addr)
348{
349 return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
350}
351
352int in_gate_area_no_mm(unsigned long addr)
353{
354 return in_gate_area(NULL, addr);
355}
356#define is_gate_vma(vma) ((vma) == &gate_vma)
357#else
358#define is_gate_vma(vma) 0
359#endif
360
361const char *arch_vma_name(struct vm_area_struct *vma)
362{
363 return is_gate_vma(vma) ? "[vectors]" : NULL;
364}
365
366/* If possible, provide a placement hint at a random offset from the
367 * stack for the sigpage and vdso pages.
368 */
369static unsigned long sigpage_addr(const struct mm_struct *mm,
370 unsigned int npages)
371{
372 unsigned long offset;
373 unsigned long first;
374 unsigned long last;
375 unsigned long addr;
376 unsigned int slots;
377
378 first = PAGE_ALIGN(mm->start_stack);
379
380 last = TASK_SIZE - (npages << PAGE_SHIFT);
381
382 /* No room after stack? */
383 if (first > last)
384 return 0;
385
386 /* Just enough room? */
387 if (first == last)
388 return first;
389
390 slots = ((last - first) >> PAGE_SHIFT) + 1;
391
392 offset = get_random_int() % slots;
393
394 addr = first + (offset << PAGE_SHIFT);
395
396 return addr;
397}
398
399static struct page *signal_page;
400extern struct page *get_signal_page(void);
401
402static int sigpage_mremap(const struct vm_special_mapping *sm,
403 struct vm_area_struct *new_vma)
404{
405 current->mm->context.sigpage = new_vma->vm_start;
406 return 0;
407}
408
409static const struct vm_special_mapping sigpage_mapping = {
410 .name = "[sigpage]",
411 .pages = &signal_page,
412 .mremap = sigpage_mremap,
413};
414
415int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
416{
417 struct mm_struct *mm = current->mm;
418 struct vm_area_struct *vma;
419 unsigned long npages;
420 unsigned long addr;
421 unsigned long hint;
422 int ret = 0;
423
424 if (!signal_page)
425 signal_page = get_signal_page();
426 if (!signal_page)
427 return -ENOMEM;
428
429 npages = 1; /* for sigpage */
430 npages += vdso_total_pages;
431
432 if (down_write_killable(&mm->mmap_sem))
433 return -EINTR;
434 hint = sigpage_addr(mm, npages);
435 addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0);
436 if (IS_ERR_VALUE(addr)) {
437 ret = addr;
438 goto up_fail;
439 }
440
441 vma = _install_special_mapping(mm, addr, PAGE_SIZE,
442 VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
443 &sigpage_mapping);
444
445 if (IS_ERR(vma)) {
446 ret = PTR_ERR(vma);
447 goto up_fail;
448 }
449
450 mm->context.sigpage = addr;
451
452 /* Unlike the sigpage, failure to install the vdso is unlikely
453 * to be fatal to the process, so no error check needed
454 * here.
455 */
456 arm_install_vdso(mm, addr + PAGE_SIZE);
457
458 up_fail:
459 up_write(&mm->mmap_sem);
460 return ret;
461}
462#endif