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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/export.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/leds.h>
34#include <linux/reboot.h>
35
36#include <asm/cacheflush.h>
37#include <asm/idmap.h>
38#include <asm/processor.h>
39#include <asm/thread_notify.h>
40#include <asm/stacktrace.h>
41#include <asm/system_misc.h>
42#include <asm/mach/time.h>
43#include <asm/tls.h>
44
45#ifdef CONFIG_CC_STACKPROTECTOR
46#include <linux/stackprotector.h>
47unsigned long __stack_chk_guard __read_mostly;
48EXPORT_SYMBOL(__stack_chk_guard);
49#endif
50
51static const char *processor_modes[] __maybe_unused = {
52 "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
53 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
54 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
55 "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
56};
57
58static const char *isa_modes[] __maybe_unused = {
59 "ARM" , "Thumb" , "Jazelle", "ThumbEE"
60};
61
62extern void call_with_stack(void (*fn)(void *), void *arg, void *sp);
63typedef void (*phys_reset_t)(unsigned long);
64
65/*
66 * A temporary stack to use for CPU reset. This is static so that we
67 * don't clobber it with the identity mapping. When running with this
68 * stack, any references to the current task *will not work* so you
69 * should really do as little as possible before jumping to your reset
70 * code.
71 */
72static u64 soft_restart_stack[16];
73
74static void __soft_restart(void *addr)
75{
76 phys_reset_t phys_reset;
77
78 /* Take out a flat memory mapping. */
79 setup_mm_for_reboot();
80
81 /* Clean and invalidate caches */
82 flush_cache_all();
83
84 /* Turn off caching */
85 cpu_proc_fin();
86
87 /* Push out any further dirty data, and ensure cache is empty */
88 flush_cache_all();
89
90 /* Switch to the identity mapping. */
91 phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset);
92 phys_reset((unsigned long)addr);
93
94 /* Should never get here. */
95 BUG();
96}
97
98void soft_restart(unsigned long addr)
99{
100 u64 *stack = soft_restart_stack + ARRAY_SIZE(soft_restart_stack);
101
102 /* Disable interrupts first */
103 raw_local_irq_disable();
104 local_fiq_disable();
105
106 /* Disable the L2 if we're the last man standing. */
107 if (num_online_cpus() == 1)
108 outer_disable();
109
110 /* Change to the new stack and continue with the reset. */
111 call_with_stack(__soft_restart, (void *)addr, (void *)stack);
112
113 /* Should never get here. */
114 BUG();
115}
116
117static void null_restart(enum reboot_mode reboot_mode, const char *cmd)
118{
119}
120
121/*
122 * Function pointers to optional machine specific functions
123 */
124void (*pm_power_off)(void);
125EXPORT_SYMBOL(pm_power_off);
126
127void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd) = null_restart;
128EXPORT_SYMBOL_GPL(arm_pm_restart);
129
130/*
131 * This is our default idle handler.
132 */
133
134void (*arm_pm_idle)(void);
135
136/*
137 * Called from the core idle loop.
138 */
139
140void arch_cpu_idle(void)
141{
142 if (arm_pm_idle)
143 arm_pm_idle();
144 else
145 cpu_do_idle();
146 local_irq_enable();
147}
148
149void arch_cpu_idle_prepare(void)
150{
151 local_fiq_enable();
152}
153
154void arch_cpu_idle_enter(void)
155{
156 ledtrig_cpu(CPU_LED_IDLE_START);
157#ifdef CONFIG_PL310_ERRATA_769419
158 wmb();
159#endif
160}
161
162void arch_cpu_idle_exit(void)
163{
164 ledtrig_cpu(CPU_LED_IDLE_END);
165}
166
167#ifdef CONFIG_HOTPLUG_CPU
168void arch_cpu_idle_dead(void)
169{
170 cpu_die();
171}
172#endif
173
174/*
175 * Called by kexec, immediately prior to machine_kexec().
176 *
177 * This must completely disable all secondary CPUs; simply causing those CPUs
178 * to execute e.g. a RAM-based pin loop is not sufficient. This allows the
179 * kexec'd kernel to use any and all RAM as it sees fit, without having to
180 * avoid any code or data used by any SW CPU pin loop. The CPU hotplug
181 * functionality embodied in disable_nonboot_cpus() to achieve this.
182 */
183void machine_shutdown(void)
184{
185 disable_nonboot_cpus();
186}
187
188/*
189 * Halting simply requires that the secondary CPUs stop performing any
190 * activity (executing tasks, handling interrupts). smp_send_stop()
191 * achieves this.
192 */
193void machine_halt(void)
194{
195 local_irq_disable();
196 smp_send_stop();
197
198 local_irq_disable();
199 while (1);
200}
201
202/*
203 * Power-off simply requires that the secondary CPUs stop performing any
204 * activity (executing tasks, handling interrupts). smp_send_stop()
205 * achieves this. When the system power is turned off, it will take all CPUs
206 * with it.
207 */
208void machine_power_off(void)
209{
210 local_irq_disable();
211 smp_send_stop();
212
213 if (pm_power_off)
214 pm_power_off();
215}
216
217/*
218 * Restart requires that the secondary CPUs stop performing any activity
219 * while the primary CPU resets the system. Systems with a single CPU can
220 * use soft_restart() as their machine descriptor's .restart hook, since that
221 * will cause the only available CPU to reset. Systems with multiple CPUs must
222 * provide a HW restart implementation, to ensure that all CPUs reset at once.
223 * This is required so that any code running after reset on the primary CPU
224 * doesn't have to co-ordinate with other CPUs to ensure they aren't still
225 * executing pre-reset code, and using RAM that the primary CPU's code wishes
226 * to use. Implementing such co-ordination would be essentially impossible.
227 */
228void machine_restart(char *cmd)
229{
230 local_irq_disable();
231 smp_send_stop();
232
233 arm_pm_restart(reboot_mode, cmd);
234
235 /* Give a grace period for failure to restart of 1s */
236 mdelay(1000);
237
238 /* Whoops - the platform was unable to reboot. Tell the user! */
239 printk("Reboot failed -- System halted\n");
240 local_irq_disable();
241 while (1);
242}
243
244void __show_regs(struct pt_regs *regs)
245{
246 unsigned long flags;
247 char buf[64];
248
249 show_regs_print_info(KERN_DEFAULT);
250
251 print_symbol("PC is at %s\n", instruction_pointer(regs));
252 print_symbol("LR is at %s\n", regs->ARM_lr);
253 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
254 "sp : %08lx ip : %08lx fp : %08lx\n",
255 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
256 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
257 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
258 regs->ARM_r10, regs->ARM_r9,
259 regs->ARM_r8);
260 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
261 regs->ARM_r7, regs->ARM_r6,
262 regs->ARM_r5, regs->ARM_r4);
263 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
264 regs->ARM_r3, regs->ARM_r2,
265 regs->ARM_r1, regs->ARM_r0);
266
267 flags = regs->ARM_cpsr;
268 buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
269 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
270 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
271 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
272 buf[4] = '\0';
273
274#ifndef CONFIG_CPU_V7M
275 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
276 buf, interrupts_enabled(regs) ? "n" : "ff",
277 fast_interrupts_enabled(regs) ? "n" : "ff",
278 processor_modes[processor_mode(regs)],
279 isa_modes[isa_mode(regs)],
280 get_fs() == get_ds() ? "kernel" : "user");
281#else
282 printk("xPSR: %08lx\n", regs->ARM_cpsr);
283#endif
284
285#ifdef CONFIG_CPU_CP15
286 {
287 unsigned int ctrl;
288
289 buf[0] = '\0';
290#ifdef CONFIG_CPU_CP15_MMU
291 {
292 unsigned int transbase, dac;
293 asm("mrc p15, 0, %0, c2, c0\n\t"
294 "mrc p15, 0, %1, c3, c0\n"
295 : "=r" (transbase), "=r" (dac));
296 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
297 transbase, dac);
298 }
299#endif
300 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
301
302 printk("Control: %08x%s\n", ctrl, buf);
303 }
304#endif
305}
306
307void show_regs(struct pt_regs * regs)
308{
309 printk("\n");
310 __show_regs(regs);
311 dump_stack();
312}
313
314ATOMIC_NOTIFIER_HEAD(thread_notify_head);
315
316EXPORT_SYMBOL_GPL(thread_notify_head);
317
318/*
319 * Free current thread data structures etc..
320 */
321void exit_thread(void)
322{
323 thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
324}
325
326void flush_thread(void)
327{
328 struct thread_info *thread = current_thread_info();
329 struct task_struct *tsk = current;
330
331 flush_ptrace_hw_breakpoint(tsk);
332
333 memset(thread->used_cp, 0, sizeof(thread->used_cp));
334 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
335 memset(&thread->fpstate, 0, sizeof(union fp_state));
336
337 thread_notify(THREAD_NOTIFY_FLUSH, thread);
338}
339
340void release_thread(struct task_struct *dead_task)
341{
342}
343
344asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
345
346int
347copy_thread(unsigned long clone_flags, unsigned long stack_start,
348 unsigned long stk_sz, struct task_struct *p)
349{
350 struct thread_info *thread = task_thread_info(p);
351 struct pt_regs *childregs = task_pt_regs(p);
352
353 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
354
355 if (likely(!(p->flags & PF_KTHREAD))) {
356 *childregs = *current_pt_regs();
357 childregs->ARM_r0 = 0;
358 if (stack_start)
359 childregs->ARM_sp = stack_start;
360 } else {
361 memset(childregs, 0, sizeof(struct pt_regs));
362 thread->cpu_context.r4 = stk_sz;
363 thread->cpu_context.r5 = stack_start;
364 childregs->ARM_cpsr = SVC_MODE;
365 }
366 thread->cpu_context.pc = (unsigned long)ret_from_fork;
367 thread->cpu_context.sp = (unsigned long)childregs;
368
369 clear_ptrace_hw_breakpoint(p);
370
371 if (clone_flags & CLONE_SETTLS)
372 thread->tp_value[0] = childregs->ARM_r3;
373 thread->tp_value[1] = get_tpuser();
374
375 thread_notify(THREAD_NOTIFY_COPY, thread);
376
377 return 0;
378}
379
380/*
381 * Fill in the task's elfregs structure for a core dump.
382 */
383int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
384{
385 elf_core_copy_regs(elfregs, task_pt_regs(t));
386 return 1;
387}
388
389/*
390 * fill in the fpe structure for a core dump...
391 */
392int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
393{
394 struct thread_info *thread = current_thread_info();
395 int used_math = thread->used_cp[1] | thread->used_cp[2];
396
397 if (used_math)
398 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
399
400 return used_math != 0;
401}
402EXPORT_SYMBOL(dump_fpu);
403
404unsigned long get_wchan(struct task_struct *p)
405{
406 struct stackframe frame;
407 unsigned long stack_page;
408 int count = 0;
409 if (!p || p == current || p->state == TASK_RUNNING)
410 return 0;
411
412 frame.fp = thread_saved_fp(p);
413 frame.sp = thread_saved_sp(p);
414 frame.lr = 0; /* recovered from the stack */
415 frame.pc = thread_saved_pc(p);
416 stack_page = (unsigned long)task_stack_page(p);
417 do {
418 if (frame.sp < stack_page ||
419 frame.sp >= stack_page + THREAD_SIZE ||
420 unwind_frame(&frame) < 0)
421 return 0;
422 if (!in_sched_functions(frame.pc))
423 return frame.pc;
424 } while (count ++ < 16);
425 return 0;
426}
427
428unsigned long arch_randomize_brk(struct mm_struct *mm)
429{
430 unsigned long range_end = mm->brk + 0x02000000;
431 return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
432}
433
434#ifdef CONFIG_MMU
435#ifdef CONFIG_KUSER_HELPERS
436/*
437 * The vectors page is always readable from user space for the
438 * atomic helpers. Insert it into the gate_vma so that it is visible
439 * through ptrace and /proc/<pid>/mem.
440 */
441static struct vm_area_struct gate_vma = {
442 .vm_start = 0xffff0000,
443 .vm_end = 0xffff0000 + PAGE_SIZE,
444 .vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC,
445};
446
447static int __init gate_vma_init(void)
448{
449 gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
450 return 0;
451}
452arch_initcall(gate_vma_init);
453
454struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
455{
456 return &gate_vma;
457}
458
459int in_gate_area(struct mm_struct *mm, unsigned long addr)
460{
461 return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
462}
463
464int in_gate_area_no_mm(unsigned long addr)
465{
466 return in_gate_area(NULL, addr);
467}
468#define is_gate_vma(vma) ((vma) == &gate_vma)
469#else
470#define is_gate_vma(vma) 0
471#endif
472
473const char *arch_vma_name(struct vm_area_struct *vma)
474{
475 return is_gate_vma(vma) ? "[vectors]" :
476 (vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ?
477 "[sigpage]" : NULL;
478}
479
480static struct page *signal_page;
481extern struct page *get_signal_page(void);
482
483int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
484{
485 struct mm_struct *mm = current->mm;
486 unsigned long addr;
487 int ret;
488
489 if (!signal_page)
490 signal_page = get_signal_page();
491 if (!signal_page)
492 return -ENOMEM;
493
494 down_write(&mm->mmap_sem);
495 addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
496 if (IS_ERR_VALUE(addr)) {
497 ret = addr;
498 goto up_fail;
499 }
500
501 ret = install_special_mapping(mm, addr, PAGE_SIZE,
502 VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
503 &signal_page);
504
505 if (ret == 0)
506 mm->context.sigpage = addr;
507
508 up_fail:
509 up_write(&mm->mmap_sem);
510 return ret;
511}
512#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