arch/arm/kernel/process.c - LeafOS-Devices/android_kernel_samsung_universal7904 - Gitiles

 /*
  *  linux/arch/arm/kernel/process.c
  *
  *  Copyright (C) 1996-2000 Russell King - Converted to ARM.
  *  Original Copyright (C) 1995  Linus Torvalds
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
 #include <stdarg.h>

 #include <linux/export.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/stddef.h>
 #include <linux/unistd.h>
 #include <linux/user.h>
 #include <linux/interrupt.h>
 #include <linux/kallsyms.h>
 #include <linux/init.h>
 #include <linux/elfcore.h>
 #include <linux/pm.h>
 #include <linux/tick.h>
 #include <linux/utsname.h>
 #include <linux/uaccess.h>
 #include <linux/random.h>
 #include <linux/hw_breakpoint.h>
 #include <linux/leds.h>

 #include <asm/processor.h>
 #include <asm/thread_notify.h>
 #include <asm/stacktrace.h>
 #include <asm/system_misc.h>
 #include <asm/mach/time.h>
 #include <asm/tls.h>
 #include <asm/vdso.h>

 #ifdef CONFIG_CC_STACKPROTECTOR
 #include <linux/stackprotector.h>
 unsigned long __stack_chk_guard __read_mostly;
 EXPORT_SYMBOL(__stack_chk_guard);
 #endif

 static const char *processor_modes[] __maybe_unused = {
   "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
   "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
   "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "MON_32" , "ABT_32" ,
   "UK8_32" , "UK9_32" , "HYP_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
 };

 static const char *isa_modes[] __maybe_unused = {
   "ARM" , "Thumb" , "Jazelle", "ThumbEE"
 };

 /*
  * This is our default idle handler.
  */

 void (*arm_pm_idle)(void);

 /*
  * Called from the core idle loop.
  */

 void arch_cpu_idle(void)
 {
 	if (arm_pm_idle)
 		arm_pm_idle();
 	else
 		cpu_do_idle();
 	local_irq_enable();
 }

 void arch_cpu_idle_prepare(void)
 {
 	local_fiq_enable();
 }

 void arch_cpu_idle_enter(void)
 {
 	idle_notifier_call_chain(IDLE_START);
 	ledtrig_cpu(CPU_LED_IDLE_START);
 #ifdef CONFIG_PL310_ERRATA_769419
 	wmb();
 #endif
 }

 void arch_cpu_idle_exit(void)
 {
 	ledtrig_cpu(CPU_LED_IDLE_END);
 	idle_notifier_call_chain(IDLE_END);
 }

 void __show_regs(struct pt_regs *regs)
 {
 	unsigned long flags;
 	char buf[64];
 #ifndef CONFIG_CPU_V7M
 	unsigned int domain;
 #ifdef CONFIG_CPU_SW_DOMAIN_PAN
 	/*
 	 * Get the domain register for the parent context. In user
 	 * mode, we don't save the DACR, so lets use what it should
 	 * be. For other modes, we place it after the pt_regs struct.
 	 */
 	if (user_mode(regs))
 		domain = DACR_UACCESS_ENABLE;
 	else
 		domain = *(unsigned int *)(regs + 1);
 #else
 	domain = get_domain();
 #endif
 #endif

 	show_regs_print_info(KERN_DEFAULT);

 	print_symbol("PC is at %s\n", instruction_pointer(regs));
 	print_symbol("LR is at %s\n", regs->ARM_lr);
 	printk("pc : [<%08lx>]    lr : [<%08lx>]    psr: %08lx\n"
 	       "sp : %08lx  ip : %08lx  fp : %08lx\n",
 		regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
 		regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
 	printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
 		regs->ARM_r10, regs->ARM_r9,
 		regs->ARM_r8);
 	printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
 		regs->ARM_r7, regs->ARM_r6,
 		regs->ARM_r5, regs->ARM_r4);
 	printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
 		regs->ARM_r3, regs->ARM_r2,
 		regs->ARM_r1, regs->ARM_r0);

 	flags = regs->ARM_cpsr;
 	buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
 	buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
 	buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
 	buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
 	buf[4] = '\0';

 #ifndef CONFIG_CPU_V7M
 	{
 		const char *segment;

 		if ((domain & domain_mask(DOMAIN_USER)) ==
 		    domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
 			segment = "none";
 		else if (get_fs() == get_ds())
 			segment = "kernel";
 		else
 			segment = "user";

 		printk("Flags: %s  IRQs o%s  FIQs o%s  Mode %s  ISA %s  Segment %s\n",
 			buf, interrupts_enabled(regs) ? "n" : "ff",
 			fast_interrupts_enabled(regs) ? "n" : "ff",
 			processor_modes[processor_mode(regs)],
 			isa_modes[isa_mode(regs)], segment);
 	}
 #else
 	printk("xPSR: %08lx\n", regs->ARM_cpsr);
 #endif

 #ifdef CONFIG_CPU_CP15
 	{
 		unsigned int ctrl;

 		buf[0] = '\0';
 #ifdef CONFIG_CPU_CP15_MMU
 		{
 			unsigned int transbase;
 			asm("mrc p15, 0, %0, c2, c0\n\t"
 			    : "=r" (transbase));
 			snprintf(buf, sizeof(buf), "  Table: %08x  DAC: %08x",
 				transbase, domain);
 		}
 #endif
 		asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));

 		printk("Control: %08x%s\n", ctrl, buf);
 	}
 #endif
 }

 void show_regs(struct pt_regs * regs)
 {
 	__show_regs(regs);
 	dump_stack();
 }

 ATOMIC_NOTIFIER_HEAD(thread_notify_head);

 EXPORT_SYMBOL_GPL(thread_notify_head);

 /*
  * Free current thread data structures etc..
  */
 void exit_thread(struct task_struct *tsk)
 {
 	thread_notify(THREAD_NOTIFY_EXIT, task_thread_info(tsk));
 }

 void flush_thread(void)
 {
 	struct thread_info *thread = current_thread_info();
 	struct task_struct *tsk = current;

 	flush_ptrace_hw_breakpoint(tsk);

 	memset(thread->used_cp, 0, sizeof(thread->used_cp));
 	memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 	memset(&thread->fpstate, 0, sizeof(union fp_state));

 	flush_tls();

 	thread_notify(THREAD_NOTIFY_FLUSH, thread);
 }

 void release_thread(struct task_struct *dead_task)
 {
 }

 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");

 int
 copy_thread(unsigned long clone_flags, unsigned long stack_start,
 	    unsigned long stk_sz, struct task_struct *p)
 {
 	struct thread_info *thread = task_thread_info(p);
 	struct pt_regs *childregs = task_pt_regs(p);

 	memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));

 #ifdef CONFIG_CPU_USE_DOMAINS
 	/*
 	 * Copy the initial value of the domain access control register
 	 * from the current thread: thread->addr_limit will have been
 	 * copied from the current thread via setup_thread_stack() in
 	 * kernel/fork.c
 	 */
 	thread->cpu_domain = get_domain();
 #endif

 	if (likely(!(p->flags & PF_KTHREAD))) {
 		*childregs = *current_pt_regs();
 		childregs->ARM_r0 = 0;
 		if (stack_start)
 			childregs->ARM_sp = stack_start;
 	} else {
 		memset(childregs, 0, sizeof(struct pt_regs));
 		thread->cpu_context.r4 = stk_sz;
 		thread->cpu_context.r5 = stack_start;
 		childregs->ARM_cpsr = SVC_MODE;
 	}
 	thread->cpu_context.pc = (unsigned long)ret_from_fork;
 	thread->cpu_context.sp = (unsigned long)childregs;

 	clear_ptrace_hw_breakpoint(p);

 	if (clone_flags & CLONE_SETTLS)
 		thread->tp_value[0] = childregs->ARM_r3;
 	thread->tp_value[1] = get_tpuser();

 	thread_notify(THREAD_NOTIFY_COPY, thread);

 	return 0;
 }

 /*
  * Fill in the task's elfregs structure for a core dump.
  */
 int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
 {
 	elf_core_copy_regs(elfregs, task_pt_regs(t));
 	return 1;
 }

 /*
  * fill in the fpe structure for a core dump...
  */
 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
 {
 	struct thread_info *thread = current_thread_info();
 	int used_math = thread->used_cp[1] | thread->used_cp[2];

 	if (used_math)
 		memcpy(fp, &thread->fpstate.soft, sizeof (*fp));

 	return used_math != 0;
 }
 EXPORT_SYMBOL(dump_fpu);

 unsigned long get_wchan(struct task_struct *p)
 {
 	struct stackframe frame;
 	unsigned long stack_page;
 	int count = 0;
 	if (!p || p == current || p->state == TASK_RUNNING)
 		return 0;

 	frame.fp = thread_saved_fp(p);
 	frame.sp = thread_saved_sp(p);
 	frame.lr = 0;			/* recovered from the stack */
 	frame.pc = thread_saved_pc(p);
 	stack_page = (unsigned long)task_stack_page(p);
 	do {
 		if (frame.sp < stack_page ||
 		    frame.sp >= stack_page + THREAD_SIZE ||
 		    unwind_frame(&frame) < 0)
 			return 0;
 		if (!in_sched_functions(frame.pc))
 			return frame.pc;
 	} while (count ++ < 16);
 	return 0;
 }

 unsigned long arch_randomize_brk(struct mm_struct *mm)
 {
 	unsigned long range_end = mm->brk + 0x02000000;
 	return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
 }

 #ifdef CONFIG_MMU
 #ifdef CONFIG_KUSER_HELPERS
 /*
  * The vectors page is always readable from user space for the
  * atomic helpers. Insert it into the gate_vma so that it is visible
  * through ptrace and /proc/<pid>/mem.
  */
 static struct vm_area_struct gate_vma = {
 	.vm_start	= 0xffff0000,
 	.vm_end		= 0xffff0000 + PAGE_SIZE,
 	.vm_flags	= VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC,
 };

 static int __init gate_vma_init(void)
 {
 	gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
 	return 0;
 }
 arch_initcall(gate_vma_init);

 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
 {
 	return &gate_vma;
 }

 int in_gate_area(struct mm_struct *mm, unsigned long addr)
 {
 	return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
 }

 int in_gate_area_no_mm(unsigned long addr)
 {
 	return in_gate_area(NULL, addr);
 }
 #define is_gate_vma(vma)	((vma) == &gate_vma)
 #else
 #define is_gate_vma(vma)	0
 #endif

 const char *arch_vma_name(struct vm_area_struct *vma)
 {
 	return is_gate_vma(vma) ? "[vectors]" : NULL;
 }

 /* If possible, provide a placement hint at a random offset from the
  * stack for the sigpage and vdso pages.
  */
 static unsigned long sigpage_addr(const struct mm_struct *mm,
 				  unsigned int npages)
 {
 	unsigned long offset;
 	unsigned long first;
 	unsigned long last;
 	unsigned long addr;
 	unsigned int slots;

 	first = PAGE_ALIGN(mm->start_stack);

 	last = TASK_SIZE - (npages << PAGE_SHIFT);

 	/* No room after stack? */
 	if (first > last)
 		return 0;

 	/* Just enough room? */
 	if (first == last)
 		return first;

 	slots = ((last - first) >> PAGE_SHIFT) + 1;

 	offset = get_random_int() % slots;

 	addr = first + (offset << PAGE_SHIFT);

 	return addr;
 }

 static struct page *signal_page;
 extern struct page *get_signal_page(void);

 static const struct vm_special_mapping sigpage_mapping = {
 	.name = "[sigpage]",
 	.pages = &signal_page,
 };

 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
 	unsigned long npages;
 	unsigned long addr;
 	unsigned long hint;
 	int ret = 0;

 	if (!signal_page)
 		signal_page = get_signal_page();
 	if (!signal_page)
 		return -ENOMEM;

 	npages = 1; /* for sigpage */
 	npages += vdso_total_pages;

 	down_write(&mm->mmap_sem);
 	hint = sigpage_addr(mm, npages);
 	addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0);
 	if (IS_ERR_VALUE(addr)) {
 		ret = addr;
 		goto up_fail;
 	}

 	vma = _install_special_mapping(mm, addr, PAGE_SIZE,
 		VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
 		&sigpage_mapping);

 	if (IS_ERR(vma)) {
 		ret = PTR_ERR(vma);
 		goto up_fail;
 	}

 	mm->context.sigpage = addr;

 	/* Unlike the sigpage, failure to install the vdso is unlikely
 	 * to be fatal to the process, so no error check needed
 	 * here.
 	 */
 	arm_install_vdso(mm, addr + PAGE_SIZE);

  up_fail:
 	up_write(&mm->mmap_sem);
 	return ret;
 }
 #endif
	/*
	* linux/arch/arm/kernel/process.c
	*
	* Copyright (C) 1996-2000 Russell King - Converted to ARM.
	* Original Copyright (C) 1995 Linus Torvalds
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/
	#include <stdarg.h>

	#include <linux/export.h>
	#include <linux/sched.h>
	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/stddef.h>
	#include <linux/unistd.h>
	#include <linux/user.h>
	#include <linux/interrupt.h>
	#include <linux/kallsyms.h>
	#include <linux/init.h>
	#include <linux/elfcore.h>
	#include <linux/pm.h>
	#include <linux/tick.h>
	#include <linux/utsname.h>
	#include <linux/uaccess.h>
	#include <linux/random.h>
	#include <linux/hw_breakpoint.h>
	#include <linux/leds.h>

	#include <asm/processor.h>
	#include <asm/thread_notify.h>
	#include <asm/stacktrace.h>
	#include <asm/system_misc.h>
	#include <asm/mach/time.h>
	#include <asm/tls.h>
	#include <asm/vdso.h>

	#ifdef CONFIG_CC_STACKPROTECTOR
	#include <linux/stackprotector.h>
	unsigned long __stack_chk_guard __read_mostly;
	EXPORT_SYMBOL(__stack_chk_guard);
	#endif

	static const char *processor_modes[] __maybe_unused = {
	"USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
	"UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
	"USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "MON_32" , "ABT_32" ,
	"UK8_32" , "UK9_32" , "HYP_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
	};

	static const char *isa_modes[] __maybe_unused = {
	"ARM" , "Thumb" , "Jazelle", "ThumbEE"
	};

	/*
	* This is our default idle handler.
	*/

	void (*arm_pm_idle)(void);

	/*
	* Called from the core idle loop.
	*/

	void arch_cpu_idle(void)
	{
	if (arm_pm_idle)
	arm_pm_idle();
	else
	cpu_do_idle();
	local_irq_enable();
	}

	void arch_cpu_idle_prepare(void)
	{
	local_fiq_enable();
	}

	void arch_cpu_idle_enter(void)
	{
	idle_notifier_call_chain(IDLE_START);
	ledtrig_cpu(CPU_LED_IDLE_START);
	#ifdef CONFIG_PL310_ERRATA_769419
	wmb();
	#endif
	}

	void arch_cpu_idle_exit(void)
	{
	ledtrig_cpu(CPU_LED_IDLE_END);
	idle_notifier_call_chain(IDLE_END);
	}

	void __show_regs(struct pt_regs *regs)
	{
	unsigned long flags;
	char buf[64];
	#ifndef CONFIG_CPU_V7M
	unsigned int domain;
	#ifdef CONFIG_CPU_SW_DOMAIN_PAN
	/*
	* Get the domain register for the parent context. In user
	* mode, we don't save the DACR, so lets use what it should
	* be. For other modes, we place it after the pt_regs struct.
	*/
	if (user_mode(regs))
	domain = DACR_UACCESS_ENABLE;
	else
	domain = (unsigned int )(regs + 1);
	#else
	domain = get_domain();
	#endif
	#endif

	show_regs_print_info(KERN_DEFAULT);

	print_symbol("PC is at %s\n", instruction_pointer(regs));
	print_symbol("LR is at %s\n", regs->ARM_lr);
	printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
	"sp : %08lx ip : %08lx fp : %08lx\n",
	regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
	regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
	printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
	regs->ARM_r10, regs->ARM_r9,
	regs->ARM_r8);
	printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
	regs->ARM_r7, regs->ARM_r6,
	regs->ARM_r5, regs->ARM_r4);
	printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
	regs->ARM_r3, regs->ARM_r2,
	regs->ARM_r1, regs->ARM_r0);

	flags = regs->ARM_cpsr;
	buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
	buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
	buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
	buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
	buf[4] = '\0';

	#ifndef CONFIG_CPU_V7M
	{
	const char *segment;

	if ((domain & domain_mask(DOMAIN_USER)) ==
	domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
	segment = "none";
	else if (get_fs() == get_ds())
	segment = "kernel";
	else
	segment = "user";

	printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
	buf, interrupts_enabled(regs) ? "n" : "ff",
	fast_interrupts_enabled(regs) ? "n" : "ff",
	processor_modes[processor_mode(regs)],
	isa_modes[isa_mode(regs)], segment);
	}
	#else
	printk("xPSR: %08lx\n", regs->ARM_cpsr);
	#endif

	#ifdef CONFIG_CPU_CP15
	{
	unsigned int ctrl;

	buf[0] = '\0';
	#ifdef CONFIG_CPU_CP15_MMU
	{
	unsigned int transbase;
	asm("mrc p15, 0, %0, c2, c0\n\t"
	: "=r" (transbase));
	snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
	transbase, domain);
	}
	#endif
	asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));

	printk("Control: %08x%s\n", ctrl, buf);
	}
	#endif
	}

	void show_regs(struct pt_regs * regs)
	{
	__show_regs(regs);
	dump_stack();
	}

	ATOMIC_NOTIFIER_HEAD(thread_notify_head);

	EXPORT_SYMBOL_GPL(thread_notify_head);

	/*
	* Free current thread data structures etc..
	*/
	void exit_thread(struct task_struct *tsk)
	{
	thread_notify(THREAD_NOTIFY_EXIT, task_thread_info(tsk));
	}

	void flush_thread(void)
	{
	struct thread_info *thread = current_thread_info();
	struct task_struct *tsk = current;

	flush_ptrace_hw_breakpoint(tsk);

	memset(thread->used_cp, 0, sizeof(thread->used_cp));
	memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
	memset(&thread->fpstate, 0, sizeof(union fp_state));

	flush_tls();

	thread_notify(THREAD_NOTIFY_FLUSH, thread);
	}

	void release_thread(struct task_struct *dead_task)
	{
	}

	asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");

	int
	copy_thread(unsigned long clone_flags, unsigned long stack_start,
	unsigned long stk_sz, struct task_struct *p)
	{
	struct thread_info *thread = task_thread_info(p);
	struct pt_regs *childregs = task_pt_regs(p);

	memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));

	#ifdef CONFIG_CPU_USE_DOMAINS
	/*
	* Copy the initial value of the domain access control register
	* from the current thread: thread->addr_limit will have been
	* copied from the current thread via setup_thread_stack() in
	* kernel/fork.c
	*/
	thread->cpu_domain = get_domain();
	#endif

	if (likely(!(p->flags & PF_KTHREAD))) {
	childregs = current_pt_regs();
	childregs->ARM_r0 = 0;
	if (stack_start)
	childregs->ARM_sp = stack_start;
	} else {
	memset(childregs, 0, sizeof(struct pt_regs));
	thread->cpu_context.r4 = stk_sz;
	thread->cpu_context.r5 = stack_start;
	childregs->ARM_cpsr = SVC_MODE;
	}
	thread->cpu_context.pc = (unsigned long)ret_from_fork;
	thread->cpu_context.sp = (unsigned long)childregs;

	clear_ptrace_hw_breakpoint(p);

	if (clone_flags & CLONE_SETTLS)
	thread->tp_value[0] = childregs->ARM_r3;
	thread->tp_value[1] = get_tpuser();

	thread_notify(THREAD_NOTIFY_COPY, thread);

	return 0;
	}

	/*
	* Fill in the task's elfregs structure for a core dump.
	*/
	int dump_task_regs(struct task_struct t, elf_gregset_t elfregs)
	{
	elf_core_copy_regs(elfregs, task_pt_regs(t));
	return 1;
	}

	/*
	* fill in the fpe structure for a core dump...
	*/
	int dump_fpu (struct pt_regs regs, struct user_fp fp)
	{
	struct thread_info *thread = current_thread_info();
	int used_math = thread->used_cp[1] \| thread->used_cp[2];

	if (used_math)
	memcpy(fp, &thread->fpstate.soft, sizeof (*fp));

	return used_math != 0;
	}
	EXPORT_SYMBOL(dump_fpu);

	unsigned long get_wchan(struct task_struct *p)
	{
	struct stackframe frame;
	unsigned long stack_page;
	int count = 0;
	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	return 0;

	frame.fp = thread_saved_fp(p);
	frame.sp = thread_saved_sp(p);
	frame.lr = 0; /* recovered from the stack */
	frame.pc = thread_saved_pc(p);
	stack_page = (unsigned long)task_stack_page(p);
	do {
	if (frame.sp < stack_page \|\|
	frame.sp >= stack_page + THREAD_SIZE \|\|
	unwind_frame(&frame) < 0)
	return 0;
	if (!in_sched_functions(frame.pc))
	return frame.pc;
	} while (count ++ < 16);
	return 0;
	}

	unsigned long arch_randomize_brk(struct mm_struct *mm)
	{
	unsigned long range_end = mm->brk + 0x02000000;
	return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
	}

	#ifdef CONFIG_MMU
	#ifdef CONFIG_KUSER_HELPERS
	/*
	* The vectors page is always readable from user space for the
	* atomic helpers. Insert it into the gate_vma so that it is visible
	* through ptrace and /proc/<pid>/mem.
	*/
	static struct vm_area_struct gate_vma = {
	.vm_start = 0xffff0000,
	.vm_end = 0xffff0000 + PAGE_SIZE,
	.vm_flags = VM_READ \| VM_EXEC \| VM_MAYREAD \| VM_MAYEXEC,
	};

	static int __init gate_vma_init(void)
	{
	gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
	return 0;
	}
	arch_initcall(gate_vma_init);

	struct vm_area_struct get_gate_vma(struct mm_struct mm)
	{
	return &gate_vma;
	}

	int in_gate_area(struct mm_struct *mm, unsigned long addr)
	{
	return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
	}

	int in_gate_area_no_mm(unsigned long addr)
	{
	return in_gate_area(NULL, addr);
	}
	#define is_gate_vma(vma) ((vma) == &gate_vma)
	#else
	#define is_gate_vma(vma) 0
	#endif

	const char arch_vma_name(struct vm_area_struct vma)
	{
	return is_gate_vma(vma) ? "[vectors]" : NULL;
	}

	/* If possible, provide a placement hint at a random offset from the
	* stack for the sigpage and vdso pages.
	*/
	static unsigned long sigpage_addr(const struct mm_struct *mm,
	unsigned int npages)
	{
	unsigned long offset;
	unsigned long first;
	unsigned long last;
	unsigned long addr;
	unsigned int slots;

	first = PAGE_ALIGN(mm->start_stack);

	last = TASK_SIZE - (npages << PAGE_SHIFT);

	/* No room after stack? */
	if (first > last)
	return 0;

	/* Just enough room? */
	if (first == last)
	return first;

	slots = ((last - first) >> PAGE_SHIFT) + 1;

	offset = get_random_int() % slots;

	addr = first + (offset << PAGE_SHIFT);

	return addr;
	}

	static struct page *signal_page;
	extern struct page *get_signal_page(void);

	static const struct vm_special_mapping sigpage_mapping = {
	.name = "[sigpage]",
	.pages = &signal_page,
	};

	int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
	{
	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma;
	unsigned long npages;
	unsigned long addr;
	unsigned long hint;
	int ret = 0;

	if (!signal_page)
	signal_page = get_signal_page();
	if (!signal_page)
	return -ENOMEM;

	npages = 1; /* for sigpage */
	npages += vdso_total_pages;

	down_write(&mm->mmap_sem);
	hint = sigpage_addr(mm, npages);
	addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0);
	if (IS_ERR_VALUE(addr)) {
	ret = addr;
	goto up_fail;
	}

	vma = _install_special_mapping(mm, addr, PAGE_SIZE,
	VM_READ \| VM_EXEC \| VM_MAYREAD \| VM_MAYWRITE \| VM_MAYEXEC,
	&sigpage_mapping);

	if (IS_ERR(vma)) {
	ret = PTR_ERR(vma);
	goto up_fail;
	}

	mm->context.sigpage = addr;

	/* Unlike the sigpage, failure to install the vdso is unlikely
	* to be fatal to the process, so no error check needed
	* here.
	*/
	arm_install_vdso(mm, addr + PAGE_SIZE);

	up_fail:
	up_write(&mm->mmap_sem);
	return ret;
	}
	#endif