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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/interrupt.h>
21#include <linux/kallsyms.h>
22#include <linux/init.h>
23#include <linux/elfcore.h>
24#include <linux/pm.h>
25#include <linux/tick.h>
26#include <linux/utsname.h>
27#include <linux/uaccess.h>
28#include <linux/random.h>
29#include <linux/hw_breakpoint.h>
30#include <linux/leds.h>
31
32#include <asm/processor.h>
33#include <asm/thread_notify.h>
34#include <asm/stacktrace.h>
35#include <asm/system_misc.h>
36#include <asm/mach/time.h>
37#include <asm/tls.h>
38#include <asm/vdso.h>
39
40#ifdef CONFIG_CC_STACKPROTECTOR
41#include <linux/stackprotector.h>
42unsigned long __stack_chk_guard __read_mostly;
43EXPORT_SYMBOL(__stack_chk_guard);
44#endif
45
46static const char *processor_modes[] __maybe_unused = {
47 "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
48 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
49 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "MON_32" , "ABT_32" ,
50 "UK8_32" , "UK9_32" , "HYP_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
51};
52
53static const char *isa_modes[] __maybe_unused = {
54 "ARM" , "Thumb" , "Jazelle", "ThumbEE"
55};
56
57/*
58 * This is our default idle handler.
59 */
60
61void (*arm_pm_idle)(void);
62
63/*
64 * Called from the core idle loop.
65 */
66
67void arch_cpu_idle(void)
68{
69 if (arm_pm_idle)
70 arm_pm_idle();
71 else
72 cpu_do_idle();
73 local_irq_enable();
74}
75
76void arch_cpu_idle_prepare(void)
77{
78 local_fiq_enable();
79}
80
81void arch_cpu_idle_enter(void)
82{
83 ledtrig_cpu(CPU_LED_IDLE_START);
84#ifdef CONFIG_PL310_ERRATA_769419
85 wmb();
86#endif
87}
88
89void arch_cpu_idle_exit(void)
90{
91 ledtrig_cpu(CPU_LED_IDLE_END);
92}
93
94void __show_regs(struct pt_regs *regs)
95{
96 unsigned long flags;
97 char buf[64];
98#ifndef CONFIG_CPU_V7M
99 unsigned int domain, fs;
100#ifdef CONFIG_CPU_SW_DOMAIN_PAN
101 /*
102 * Get the domain register for the parent context. In user
103 * mode, we don't save the DACR, so lets use what it should
104 * be. For other modes, we place it after the pt_regs struct.
105 */
106 if (user_mode(regs)) {
107 domain = DACR_UACCESS_ENABLE;
108 fs = get_fs();
109 } else {
110 domain = to_svc_pt_regs(regs)->dacr;
111 fs = to_svc_pt_regs(regs)->addr_limit;
112 }
113#else
114 domain = get_domain();
115 fs = get_fs();
116#endif
117#endif
118
119 show_regs_print_info(KERN_DEFAULT);
120
121 print_symbol("PC is at %s\n", instruction_pointer(regs));
122 print_symbol("LR is at %s\n", regs->ARM_lr);
123 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
124 "sp : %08lx ip : %08lx fp : %08lx\n",
125 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
126 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
127 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
128 regs->ARM_r10, regs->ARM_r9,
129 regs->ARM_r8);
130 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
131 regs->ARM_r7, regs->ARM_r6,
132 regs->ARM_r5, regs->ARM_r4);
133 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
134 regs->ARM_r3, regs->ARM_r2,
135 regs->ARM_r1, regs->ARM_r0);
136
137 flags = regs->ARM_cpsr;
138 buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
139 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
140 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
141 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
142 buf[4] = '\0';
143
144#ifndef CONFIG_CPU_V7M
145 {
146 const char *segment;
147
148 if ((domain & domain_mask(DOMAIN_USER)) ==
149 domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
150 segment = "none";
151 else if (fs == get_ds())
152 segment = "kernel";
153 else
154 segment = "user";
155
156 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
157 buf, interrupts_enabled(regs) ? "n" : "ff",
158 fast_interrupts_enabled(regs) ? "n" : "ff",
159 processor_modes[processor_mode(regs)],
160 isa_modes[isa_mode(regs)], segment);
161 }
162#else
163 printk("xPSR: %08lx\n", regs->ARM_cpsr);
164#endif
165
166#ifdef CONFIG_CPU_CP15
167 {
168 unsigned int ctrl;
169
170 buf[0] = '\0';
171#ifdef CONFIG_CPU_CP15_MMU
172 {
173 unsigned int transbase;
174 asm("mrc p15, 0, %0, c2, c0\n\t"
175 : "=r" (transbase));
176 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
177 transbase, domain);
178 }
179#endif
180 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
181
182 printk("Control: %08x%s\n", ctrl, buf);
183 }
184#endif
185}
186
187void show_regs(struct pt_regs * regs)
188{
189 __show_regs(regs);
190 dump_stack();
191}
192
193ATOMIC_NOTIFIER_HEAD(thread_notify_head);
194
195EXPORT_SYMBOL_GPL(thread_notify_head);
196
197/*
198 * Free current thread data structures etc..
199 */
200void exit_thread(struct task_struct *tsk)
201{
202 thread_notify(THREAD_NOTIFY_EXIT, task_thread_info(tsk));
203}
204
205void flush_thread(void)
206{
207 struct thread_info *thread = current_thread_info();
208 struct task_struct *tsk = current;
209
210 flush_ptrace_hw_breakpoint(tsk);
211
212 memset(thread->used_cp, 0, sizeof(thread->used_cp));
213 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
214 memset(&thread->fpstate, 0, sizeof(union fp_state));
215
216 flush_tls();
217
218 thread_notify(THREAD_NOTIFY_FLUSH, thread);
219}
220
221void release_thread(struct task_struct *dead_task)
222{
223}
224
225asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
226
227int
228copy_thread(unsigned long clone_flags, unsigned long stack_start,
229 unsigned long stk_sz, struct task_struct *p)
230{
231 struct thread_info *thread = task_thread_info(p);
232 struct pt_regs *childregs = task_pt_regs(p);
233
234 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
235
236#ifdef CONFIG_CPU_USE_DOMAINS
237 /*
238 * Copy the initial value of the domain access control register
239 * from the current thread: thread->addr_limit will have been
240 * copied from the current thread via setup_thread_stack() in
241 * kernel/fork.c
242 */
243 thread->cpu_domain = get_domain();
244#endif
245
246 if (likely(!(p->flags & PF_KTHREAD))) {
247 *childregs = *current_pt_regs();
248 childregs->ARM_r0 = 0;
249 if (stack_start)
250 childregs->ARM_sp = stack_start;
251 } else {
252 memset(childregs, 0, sizeof(struct pt_regs));
253 thread->cpu_context.r4 = stk_sz;
254 thread->cpu_context.r5 = stack_start;
255 childregs->ARM_cpsr = SVC_MODE;
256 }
257 thread->cpu_context.pc = (unsigned long)ret_from_fork;
258 thread->cpu_context.sp = (unsigned long)childregs;
259
260 clear_ptrace_hw_breakpoint(p);
261
262 if (clone_flags & CLONE_SETTLS)
263 thread->tp_value[0] = childregs->ARM_r3;
264 thread->tp_value[1] = get_tpuser();
265
266 thread_notify(THREAD_NOTIFY_COPY, thread);
267
268 return 0;
269}
270
271/*
272 * Fill in the task's elfregs structure for a core dump.
273 */
274int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
275{
276 elf_core_copy_regs(elfregs, task_pt_regs(t));
277 return 1;
278}
279
280/*
281 * fill in the fpe structure for a core dump...
282 */
283int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
284{
285 struct thread_info *thread = current_thread_info();
286 int used_math = thread->used_cp[1] | thread->used_cp[2];
287
288 if (used_math)
289 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
290
291 return used_math != 0;
292}
293EXPORT_SYMBOL(dump_fpu);
294
295unsigned long get_wchan(struct task_struct *p)
296{
297 struct stackframe frame;
298 unsigned long stack_page;
299 int count = 0;
300 if (!p || p == current || p->state == TASK_RUNNING)
301 return 0;
302
303 frame.fp = thread_saved_fp(p);
304 frame.sp = thread_saved_sp(p);
305 frame.lr = 0; /* recovered from the stack */
306 frame.pc = thread_saved_pc(p);
307 stack_page = (unsigned long)task_stack_page(p);
308 do {
309 if (frame.sp < stack_page ||
310 frame.sp >= stack_page + THREAD_SIZE ||
311 unwind_frame(&frame) < 0)
312 return 0;
313 if (!in_sched_functions(frame.pc))
314 return frame.pc;
315 } while (count ++ < 16);
316 return 0;
317}
318
319unsigned long arch_randomize_brk(struct mm_struct *mm)
320{
321 return randomize_page(mm->brk, 0x02000000);
322}
323
324#ifdef CONFIG_MMU
325#ifdef CONFIG_KUSER_HELPERS
326/*
327 * The vectors page is always readable from user space for the
328 * atomic helpers. Insert it into the gate_vma so that it is visible
329 * through ptrace and /proc/<pid>/mem.
330 */
331static struct vm_area_struct gate_vma = {
332 .vm_start = 0xffff0000,
333 .vm_end = 0xffff0000 + PAGE_SIZE,
334 .vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC,
335};
336
337static int __init gate_vma_init(void)
338{
339 gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
340 return 0;
341}
342arch_initcall(gate_vma_init);
343
344struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
345{
346 return &gate_vma;
347}
348
349int in_gate_area(struct mm_struct *mm, unsigned long addr)
350{
351 return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
352}
353
354int in_gate_area_no_mm(unsigned long addr)
355{
356 return in_gate_area(NULL, addr);
357}
358#define is_gate_vma(vma) ((vma) == &gate_vma)
359#else
360#define is_gate_vma(vma) 0
361#endif
362
363const char *arch_vma_name(struct vm_area_struct *vma)
364{
365 return is_gate_vma(vma) ? "[vectors]" : NULL;
366}
367
368/* If possible, provide a placement hint at a random offset from the
369 * stack for the sigpage and vdso pages.
370 */
371static unsigned long sigpage_addr(const struct mm_struct *mm,
372 unsigned int npages)
373{
374 unsigned long offset;
375 unsigned long first;
376 unsigned long last;
377 unsigned long addr;
378 unsigned int slots;
379
380 first = PAGE_ALIGN(mm->start_stack);
381
382 last = TASK_SIZE - (npages << PAGE_SHIFT);
383
384 /* No room after stack? */
385 if (first > last)
386 return 0;
387
388 /* Just enough room? */
389 if (first == last)
390 return first;
391
392 slots = ((last - first) >> PAGE_SHIFT) + 1;
393
394 offset = get_random_int() % slots;
395
396 addr = first + (offset << PAGE_SHIFT);
397
398 return addr;
399}
400
401static struct page *signal_page;
402extern struct page *get_signal_page(void);
403
404static const struct vm_special_mapping sigpage_mapping = {
405 .name = "[sigpage]",
406 .pages = &signal_page,
407};
408
409int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
410{
411 struct mm_struct *mm = current->mm;
412 struct vm_area_struct *vma;
413 unsigned long npages;
414 unsigned long addr;
415 unsigned long hint;
416 int ret = 0;
417
418 if (!signal_page)
419 signal_page = get_signal_page();
420 if (!signal_page)
421 return -ENOMEM;
422
423 npages = 1; /* for sigpage */
424 npages += vdso_total_pages;
425
426 if (down_write_killable(&mm->mmap_sem))
427 return -EINTR;
428 hint = sigpage_addr(mm, npages);
429 addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0);
430 if (IS_ERR_VALUE(addr)) {
431 ret = addr;
432 goto up_fail;
433 }
434
435 vma = _install_special_mapping(mm, addr, PAGE_SIZE,
436 VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
437 &sigpage_mapping);
438
439 if (IS_ERR(vma)) {
440 ret = PTR_ERR(vma);
441 goto up_fail;
442 }
443
444 mm->context.sigpage = addr;
445
446 /* Unlike the sigpage, failure to install the vdso is unlikely
447 * to be fatal to the process, so no error check needed
448 * here.
449 */
450 arm_install_vdso(mm, addr + PAGE_SIZE);
451
452 up_fail:
453 up_write(&mm->mmap_sem);
454 return ret;
455}
456#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#include "signal.h"
40
41#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK)
42#include <linux/stackprotector.h>
43unsigned long __stack_chk_guard __read_mostly;
44EXPORT_SYMBOL(__stack_chk_guard);
45#endif
46
47static const char *processor_modes[] __maybe_unused = {
48 "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
49 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
50 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "MON_32" , "ABT_32" ,
51 "UK8_32" , "UK9_32" , "HYP_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
52};
53
54static const char *isa_modes[] __maybe_unused = {
55 "ARM" , "Thumb" , "Jazelle", "ThumbEE"
56};
57
58/*
59 * This is our default idle handler.
60 */
61
62void (*arm_pm_idle)(void);
63
64/*
65 * Called from the core idle loop.
66 */
67
68void arch_cpu_idle(void)
69{
70 if (arm_pm_idle)
71 arm_pm_idle();
72 else
73 cpu_do_idle();
74 raw_local_irq_enable();
75}
76
77void arch_cpu_idle_prepare(void)
78{
79 local_fiq_enable();
80}
81
82void arch_cpu_idle_enter(void)
83{
84 ledtrig_cpu(CPU_LED_IDLE_START);
85#ifdef CONFIG_PL310_ERRATA_769419
86 wmb();
87#endif
88}
89
90void arch_cpu_idle_exit(void)
91{
92 ledtrig_cpu(CPU_LED_IDLE_END);
93}
94
95void __show_regs_alloc_free(struct pt_regs *regs)
96{
97 int i;
98
99 /* check for r0 - r12 only */
100 for (i = 0; i < 13; i++) {
101 pr_alert("Register r%d information:", i);
102 mem_dump_obj((void *)regs->uregs[i]);
103 }
104}
105
106void __show_regs(struct pt_regs *regs)
107{
108 unsigned long flags;
109 char buf[64];
110#ifndef CONFIG_CPU_V7M
111 unsigned int domain, fs;
112#ifdef CONFIG_CPU_SW_DOMAIN_PAN
113 /*
114 * Get the domain register for the parent context. In user
115 * mode, we don't save the DACR, so lets use what it should
116 * be. For other modes, we place it after the pt_regs struct.
117 */
118 if (user_mode(regs)) {
119 domain = DACR_UACCESS_ENABLE;
120 fs = get_fs();
121 } else {
122 domain = to_svc_pt_regs(regs)->dacr;
123 fs = to_svc_pt_regs(regs)->addr_limit;
124 }
125#else
126 domain = get_domain();
127 fs = get_fs();
128#endif
129#endif
130
131 show_regs_print_info(KERN_DEFAULT);
132
133 printk("PC is at %pS\n", (void *)instruction_pointer(regs));
134 printk("LR is at %pS\n", (void *)regs->ARM_lr);
135 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n",
136 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr);
137 printk("sp : %08lx ip : %08lx fp : %08lx\n",
138 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
139 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
140 regs->ARM_r10, regs->ARM_r9,
141 regs->ARM_r8);
142 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
143 regs->ARM_r7, regs->ARM_r6,
144 regs->ARM_r5, regs->ARM_r4);
145 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
146 regs->ARM_r3, regs->ARM_r2,
147 regs->ARM_r1, regs->ARM_r0);
148
149 flags = regs->ARM_cpsr;
150 buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
151 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
152 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
153 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
154 buf[4] = '\0';
155
156#ifndef CONFIG_CPU_V7M
157 {
158 const char *segment;
159
160 if ((domain & domain_mask(DOMAIN_USER)) ==
161 domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
162 segment = "none";
163 else if (fs == KERNEL_DS)
164 segment = "kernel";
165 else
166 segment = "user";
167
168 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
169 buf, interrupts_enabled(regs) ? "n" : "ff",
170 fast_interrupts_enabled(regs) ? "n" : "ff",
171 processor_modes[processor_mode(regs)],
172 isa_modes[isa_mode(regs)], segment);
173 }
174#else
175 printk("xPSR: %08lx\n", regs->ARM_cpsr);
176#endif
177
178#ifdef CONFIG_CPU_CP15
179 {
180 unsigned int ctrl;
181
182 buf[0] = '\0';
183#ifdef CONFIG_CPU_CP15_MMU
184 {
185 unsigned int transbase;
186 asm("mrc p15, 0, %0, c2, c0\n\t"
187 : "=r" (transbase));
188 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
189 transbase, domain);
190 }
191#endif
192 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
193
194 printk("Control: %08x%s\n", ctrl, buf);
195 }
196#endif
197}
198
199void show_regs(struct pt_regs * regs)
200{
201 __show_regs(regs);
202 dump_stack();
203}
204
205ATOMIC_NOTIFIER_HEAD(thread_notify_head);
206
207EXPORT_SYMBOL_GPL(thread_notify_head);
208
209/*
210 * Free current thread data structures etc..
211 */
212void exit_thread(struct task_struct *tsk)
213{
214 thread_notify(THREAD_NOTIFY_EXIT, task_thread_info(tsk));
215}
216
217void flush_thread(void)
218{
219 struct thread_info *thread = current_thread_info();
220 struct task_struct *tsk = current;
221
222 flush_ptrace_hw_breakpoint(tsk);
223
224 memset(thread->used_cp, 0, sizeof(thread->used_cp));
225 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
226 memset(&thread->fpstate, 0, sizeof(union fp_state));
227
228 flush_tls();
229
230 thread_notify(THREAD_NOTIFY_FLUSH, thread);
231}
232
233void release_thread(struct task_struct *dead_task)
234{
235}
236
237asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
238
239int copy_thread(unsigned long clone_flags, unsigned long stack_start,
240 unsigned long stk_sz, struct task_struct *p, unsigned long tls)
241{
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(!(p->flags & (PF_KTHREAD | PF_IO_WORKER)))) {
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 = stk_sz;
265 thread->cpu_context.r5 = stack_start;
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#ifdef CONFIG_STACKPROTECTOR_PER_TASK
280 thread->stack_canary = p->stack_canary;
281#endif
282
283 return 0;
284}
285
286unsigned long get_wchan(struct task_struct *p)
287{
288 struct stackframe frame;
289 unsigned long stack_page;
290 int count = 0;
291 if (!p || p == current || task_is_running(p))
292 return 0;
293
294 frame.fp = thread_saved_fp(p);
295 frame.sp = thread_saved_sp(p);
296 frame.lr = 0; /* recovered from the stack */
297 frame.pc = thread_saved_pc(p);
298 stack_page = (unsigned long)task_stack_page(p);
299 do {
300 if (frame.sp < stack_page ||
301 frame.sp >= stack_page + THREAD_SIZE ||
302 unwind_frame(&frame) < 0)
303 return 0;
304 if (!in_sched_functions(frame.pc))
305 return frame.pc;
306 } while (count ++ < 16);
307 return 0;
308}
309
310#ifdef CONFIG_MMU
311#ifdef CONFIG_KUSER_HELPERS
312/*
313 * The vectors page is always readable from user space for the
314 * atomic helpers. Insert it into the gate_vma so that it is visible
315 * through ptrace and /proc/<pid>/mem.
316 */
317static struct vm_area_struct gate_vma;
318
319static int __init gate_vma_init(void)
320{
321 vma_init(&gate_vma, NULL);
322 gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
323 gate_vma.vm_start = 0xffff0000;
324 gate_vma.vm_end = 0xffff0000 + PAGE_SIZE;
325 gate_vma.vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC;
326 return 0;
327}
328arch_initcall(gate_vma_init);
329
330struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
331{
332 return &gate_vma;
333}
334
335int in_gate_area(struct mm_struct *mm, unsigned long addr)
336{
337 return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
338}
339
340int in_gate_area_no_mm(unsigned long addr)
341{
342 return in_gate_area(NULL, addr);
343}
344#define is_gate_vma(vma) ((vma) == &gate_vma)
345#else
346#define is_gate_vma(vma) 0
347#endif
348
349const char *arch_vma_name(struct vm_area_struct *vma)
350{
351 return is_gate_vma(vma) ? "[vectors]" : NULL;
352}
353
354/* If possible, provide a placement hint at a random offset from the
355 * stack for the sigpage and vdso pages.
356 */
357static unsigned long sigpage_addr(const struct mm_struct *mm,
358 unsigned int npages)
359{
360 unsigned long offset;
361 unsigned long first;
362 unsigned long last;
363 unsigned long addr;
364 unsigned int slots;
365
366 first = PAGE_ALIGN(mm->start_stack);
367
368 last = TASK_SIZE - (npages << PAGE_SHIFT);
369
370 /* No room after stack? */
371 if (first > last)
372 return 0;
373
374 /* Just enough room? */
375 if (first == last)
376 return first;
377
378 slots = ((last - first) >> PAGE_SHIFT) + 1;
379
380 offset = get_random_int() % slots;
381
382 addr = first + (offset << PAGE_SHIFT);
383
384 return addr;
385}
386
387static struct page *signal_page;
388extern struct page *get_signal_page(void);
389
390static int sigpage_mremap(const struct vm_special_mapping *sm,
391 struct vm_area_struct *new_vma)
392{
393 current->mm->context.sigpage = new_vma->vm_start;
394 return 0;
395}
396
397static const struct vm_special_mapping sigpage_mapping = {
398 .name = "[sigpage]",
399 .pages = &signal_page,
400 .mremap = sigpage_mremap,
401};
402
403int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
404{
405 struct mm_struct *mm = current->mm;
406 struct vm_area_struct *vma;
407 unsigned long npages;
408 unsigned long addr;
409 unsigned long hint;
410 int ret = 0;
411
412 if (!signal_page)
413 signal_page = get_signal_page();
414 if (!signal_page)
415 return -ENOMEM;
416
417 npages = 1; /* for sigpage */
418 npages += vdso_total_pages;
419
420 if (mmap_write_lock_killable(mm))
421 return -EINTR;
422 hint = sigpage_addr(mm, npages);
423 addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0);
424 if (IS_ERR_VALUE(addr)) {
425 ret = addr;
426 goto up_fail;
427 }
428
429 vma = _install_special_mapping(mm, addr, PAGE_SIZE,
430 VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
431 &sigpage_mapping);
432
433 if (IS_ERR(vma)) {
434 ret = PTR_ERR(vma);
435 goto up_fail;
436 }
437
438 mm->context.sigpage = addr;
439
440 /* Unlike the sigpage, failure to install the vdso is unlikely
441 * to be fatal to the process, so no error check needed
442 * here.
443 */
444 arm_install_vdso(mm, addr + PAGE_SIZE);
445
446 up_fail:
447 mmap_write_unlock(mm);
448 return ret;
449}
450#endif