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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/sched/debug.h>
16#include <linux/sched/task.h>
17#include <linux/sched/task_stack.h>
18#include <linux/kernel.h>
19#include <linux/mm.h>
20#include <linux/stddef.h>
21#include <linux/unistd.h>
22#include <linux/user.h>
23#include <linux/interrupt.h>
24#include <linux/init.h>
25#include <linux/elfcore.h>
26#include <linux/pm.h>
27#include <linux/tick.h>
28#include <linux/utsname.h>
29#include <linux/uaccess.h>
30#include <linux/random.h>
31#include <linux/hw_breakpoint.h>
32#include <linux/leds.h>
33
34#include <asm/processor.h>
35#include <asm/thread_notify.h>
36#include <asm/stacktrace.h>
37#include <asm/system_misc.h>
38#include <asm/mach/time.h>
39#include <asm/tls.h>
40#include <asm/vdso.h>
41
42#ifdef CONFIG_CC_STACKPROTECTOR
43#include <linux/stackprotector.h>
44unsigned long __stack_chk_guard __read_mostly;
45EXPORT_SYMBOL(__stack_chk_guard);
46#endif
47
48static const char *processor_modes[] __maybe_unused = {
49 "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
50 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
51 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "MON_32" , "ABT_32" ,
52 "UK8_32" , "UK9_32" , "HYP_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
53};
54
55static const char *isa_modes[] __maybe_unused = {
56 "ARM" , "Thumb" , "Jazelle", "ThumbEE"
57};
58
59/*
60 * This is our default idle handler.
61 */
62
63void (*arm_pm_idle)(void);
64
65/*
66 * Called from the core idle loop.
67 */
68
69void arch_cpu_idle(void)
70{
71 if (arm_pm_idle)
72 arm_pm_idle();
73 else
74 cpu_do_idle();
75 local_irq_enable();
76}
77
78void arch_cpu_idle_prepare(void)
79{
80 local_fiq_enable();
81}
82
83void arch_cpu_idle_enter(void)
84{
85 ledtrig_cpu(CPU_LED_IDLE_START);
86#ifdef CONFIG_PL310_ERRATA_769419
87 wmb();
88#endif
89}
90
91void arch_cpu_idle_exit(void)
92{
93 ledtrig_cpu(CPU_LED_IDLE_END);
94}
95
96void __show_regs(struct pt_regs *regs)
97{
98 unsigned long flags;
99 char buf[64];
100#ifndef CONFIG_CPU_V7M
101 unsigned int domain, fs;
102#ifdef CONFIG_CPU_SW_DOMAIN_PAN
103 /*
104 * Get the domain register for the parent context. In user
105 * mode, we don't save the DACR, so lets use what it should
106 * be. For other modes, we place it after the pt_regs struct.
107 */
108 if (user_mode(regs)) {
109 domain = DACR_UACCESS_ENABLE;
110 fs = get_fs();
111 } else {
112 domain = to_svc_pt_regs(regs)->dacr;
113 fs = to_svc_pt_regs(regs)->addr_limit;
114 }
115#else
116 domain = get_domain();
117 fs = get_fs();
118#endif
119#endif
120
121 show_regs_print_info(KERN_DEFAULT);
122
123 printk("PC is at %pS\n", (void *)instruction_pointer(regs));
124 printk("LR is at %pS\n", (void *)regs->ARM_lr);
125 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n",
126 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr);
127 printk("sp : %08lx ip : %08lx fp : %08lx\n",
128 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
129 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
130 regs->ARM_r10, regs->ARM_r9,
131 regs->ARM_r8);
132 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
133 regs->ARM_r7, regs->ARM_r6,
134 regs->ARM_r5, regs->ARM_r4);
135 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
136 regs->ARM_r3, regs->ARM_r2,
137 regs->ARM_r1, regs->ARM_r0);
138
139 flags = regs->ARM_cpsr;
140 buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
141 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
142 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
143 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
144 buf[4] = '\0';
145
146#ifndef CONFIG_CPU_V7M
147 {
148 const char *segment;
149
150 if ((domain & domain_mask(DOMAIN_USER)) ==
151 domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
152 segment = "none";
153 else if (fs == get_ds())
154 segment = "kernel";
155 else
156 segment = "user";
157
158 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
159 buf, interrupts_enabled(regs) ? "n" : "ff",
160 fast_interrupts_enabled(regs) ? "n" : "ff",
161 processor_modes[processor_mode(regs)],
162 isa_modes[isa_mode(regs)], segment);
163 }
164#else
165 printk("xPSR: %08lx\n", regs->ARM_cpsr);
166#endif
167
168#ifdef CONFIG_CPU_CP15
169 {
170 unsigned int ctrl;
171
172 buf[0] = '\0';
173#ifdef CONFIG_CPU_CP15_MMU
174 {
175 unsigned int transbase;
176 asm("mrc p15, 0, %0, c2, c0\n\t"
177 : "=r" (transbase));
178 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
179 transbase, domain);
180 }
181#endif
182 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
183
184 printk("Control: %08x%s\n", ctrl, buf);
185 }
186#endif
187}
188
189void show_regs(struct pt_regs * regs)
190{
191 __show_regs(regs);
192 dump_stack();
193}
194
195ATOMIC_NOTIFIER_HEAD(thread_notify_head);
196
197EXPORT_SYMBOL_GPL(thread_notify_head);
198
199/*
200 * Free current thread data structures etc..
201 */
202void exit_thread(struct task_struct *tsk)
203{
204 thread_notify(THREAD_NOTIFY_EXIT, task_thread_info(tsk));
205}
206
207void flush_thread(void)
208{
209 struct thread_info *thread = current_thread_info();
210 struct task_struct *tsk = current;
211
212 flush_ptrace_hw_breakpoint(tsk);
213
214 memset(thread->used_cp, 0, sizeof(thread->used_cp));
215 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
216 memset(&thread->fpstate, 0, sizeof(union fp_state));
217
218 flush_tls();
219
220 thread_notify(THREAD_NOTIFY_FLUSH, thread);
221}
222
223void release_thread(struct task_struct *dead_task)
224{
225}
226
227asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
228
229int
230copy_thread(unsigned long clone_flags, unsigned long stack_start,
231 unsigned long stk_sz, struct task_struct *p)
232{
233 struct thread_info *thread = task_thread_info(p);
234 struct pt_regs *childregs = task_pt_regs(p);
235
236 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
237
238#ifdef CONFIG_CPU_USE_DOMAINS
239 /*
240 * Copy the initial value of the domain access control register
241 * from the current thread: thread->addr_limit will have been
242 * copied from the current thread via setup_thread_stack() in
243 * kernel/fork.c
244 */
245 thread->cpu_domain = get_domain();
246#endif
247
248 if (likely(!(p->flags & PF_KTHREAD))) {
249 *childregs = *current_pt_regs();
250 childregs->ARM_r0 = 0;
251 if (stack_start)
252 childregs->ARM_sp = stack_start;
253 } else {
254 memset(childregs, 0, sizeof(struct pt_regs));
255 thread->cpu_context.r4 = stk_sz;
256 thread->cpu_context.r5 = stack_start;
257 childregs->ARM_cpsr = SVC_MODE;
258 }
259 thread->cpu_context.pc = (unsigned long)ret_from_fork;
260 thread->cpu_context.sp = (unsigned long)childregs;
261
262 clear_ptrace_hw_breakpoint(p);
263
264 if (clone_flags & CLONE_SETTLS)
265 thread->tp_value[0] = childregs->ARM_r3;
266 thread->tp_value[1] = get_tpuser();
267
268 thread_notify(THREAD_NOTIFY_COPY, thread);
269
270 return 0;
271}
272
273/*
274 * Fill in the task's elfregs structure for a core dump.
275 */
276int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
277{
278 elf_core_copy_regs(elfregs, task_pt_regs(t));
279 return 1;
280}
281
282/*
283 * fill in the fpe structure for a core dump...
284 */
285int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
286{
287 struct thread_info *thread = current_thread_info();
288 int used_math = thread->used_cp[1] | thread->used_cp[2];
289
290 if (used_math)
291 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
292
293 return used_math != 0;
294}
295EXPORT_SYMBOL(dump_fpu);
296
297unsigned long get_wchan(struct task_struct *p)
298{
299 struct stackframe frame;
300 unsigned long stack_page;
301 int count = 0;
302 if (!p || p == current || p->state == TASK_RUNNING)
303 return 0;
304
305 frame.fp = thread_saved_fp(p);
306 frame.sp = thread_saved_sp(p);
307 frame.lr = 0; /* recovered from the stack */
308 frame.pc = thread_saved_pc(p);
309 stack_page = (unsigned long)task_stack_page(p);
310 do {
311 if (frame.sp < stack_page ||
312 frame.sp >= stack_page + THREAD_SIZE ||
313 unwind_frame(&frame) < 0)
314 return 0;
315 if (!in_sched_functions(frame.pc))
316 return frame.pc;
317 } while (count ++ < 16);
318 return 0;
319}
320
321unsigned long arch_randomize_brk(struct mm_struct *mm)
322{
323 return randomize_page(mm->brk, 0x02000000);
324}
325
326#ifdef CONFIG_MMU
327#ifdef CONFIG_KUSER_HELPERS
328/*
329 * The vectors page is always readable from user space for the
330 * atomic helpers. Insert it into the gate_vma so that it is visible
331 * through ptrace and /proc/<pid>/mem.
332 */
333static struct vm_area_struct gate_vma = {
334 .vm_start = 0xffff0000,
335 .vm_end = 0xffff0000 + PAGE_SIZE,
336 .vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC,
337};
338
339static int __init gate_vma_init(void)
340{
341 gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
342 return 0;
343}
344arch_initcall(gate_vma_init);
345
346struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
347{
348 return &gate_vma;
349}
350
351int in_gate_area(struct mm_struct *mm, unsigned long addr)
352{
353 return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
354}
355
356int in_gate_area_no_mm(unsigned long addr)
357{
358 return in_gate_area(NULL, addr);
359}
360#define is_gate_vma(vma) ((vma) == &gate_vma)
361#else
362#define is_gate_vma(vma) 0
363#endif
364
365const char *arch_vma_name(struct vm_area_struct *vma)
366{
367 return is_gate_vma(vma) ? "[vectors]" : NULL;
368}
369
370/* If possible, provide a placement hint at a random offset from the
371 * stack for the sigpage and vdso pages.
372 */
373static unsigned long sigpage_addr(const struct mm_struct *mm,
374 unsigned int npages)
375{
376 unsigned long offset;
377 unsigned long first;
378 unsigned long last;
379 unsigned long addr;
380 unsigned int slots;
381
382 first = PAGE_ALIGN(mm->start_stack);
383
384 last = TASK_SIZE - (npages << PAGE_SHIFT);
385
386 /* No room after stack? */
387 if (first > last)
388 return 0;
389
390 /* Just enough room? */
391 if (first == last)
392 return first;
393
394 slots = ((last - first) >> PAGE_SHIFT) + 1;
395
396 offset = get_random_int() % slots;
397
398 addr = first + (offset << PAGE_SHIFT);
399
400 return addr;
401}
402
403static struct page *signal_page;
404extern struct page *get_signal_page(void);
405
406static int sigpage_mremap(const struct vm_special_mapping *sm,
407 struct vm_area_struct *new_vma)
408{
409 current->mm->context.sigpage = new_vma->vm_start;
410 return 0;
411}
412
413static const struct vm_special_mapping sigpage_mapping = {
414 .name = "[sigpage]",
415 .pages = &signal_page,
416 .mremap = sigpage_mremap,
417};
418
419int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
420{
421 struct mm_struct *mm = current->mm;
422 struct vm_area_struct *vma;
423 unsigned long npages;
424 unsigned long addr;
425 unsigned long hint;
426 int ret = 0;
427
428 if (!signal_page)
429 signal_page = get_signal_page();
430 if (!signal_page)
431 return -ENOMEM;
432
433 npages = 1; /* for sigpage */
434 npages += vdso_total_pages;
435
436 if (down_write_killable(&mm->mmap_sem))
437 return -EINTR;
438 hint = sigpage_addr(mm, npages);
439 addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0);
440 if (IS_ERR_VALUE(addr)) {
441 ret = addr;
442 goto up_fail;
443 }
444
445 vma = _install_special_mapping(mm, addr, PAGE_SIZE,
446 VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
447 &sigpage_mapping);
448
449 if (IS_ERR(vma)) {
450 ret = PTR_ERR(vma);
451 goto up_fail;
452 }
453
454 mm->context.sigpage = addr;
455
456 /* Unlike the sigpage, failure to install the vdso is unlikely
457 * to be fatal to the process, so no error check needed
458 * here.
459 */
460 arm_install_vdso(mm, addr + PAGE_SIZE);
461
462 up_fail:
463 up_write(&mm->mmap_sem);
464 return ret;
465}
466#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