arch/arm/kernel/process.c - maze/linux - Git at Google

 /*
  *  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/delay.h>
 #include <linux/reboot.h>
 #include <linux/interrupt.h>
 #include <linux/kallsyms.h>
 #include <linux/init.h>
 #include <linux/cpu.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 <linux/reboot.h>

 #include <asm/cacheflush.h>
 #include <asm/idmap.h>
 #include <asm/processor.h>
 #include <asm/thread_notify.h>
 #include <asm/stacktrace.h>
 #include <asm/mach/time.h>
 #include <asm/tls.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" , "UK6_32" , "ABT_32" ,
   "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
 };

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

 extern void call_with_stack(void (*fn)(void *), void *arg, void *sp);
 typedef void (*phys_reset_t)(unsigned long);

 /*
  * A temporary stack to use for CPU reset. This is static so that we
  * don't clobber it with the identity mapping. When running with this
  * stack, any references to the current task *will not work* so you
  * should really do as little as possible before jumping to your reset
  * code.
  */
 static u64 soft_restart_stack[16];

 static void __soft_restart(void *addr)
 {
 	phys_reset_t phys_reset;

 	/* Take out a flat memory mapping. */
 	setup_mm_for_reboot();

 	/* Clean and invalidate caches */
 	flush_cache_all();

 	/* Turn off caching */
 	cpu_proc_fin();

 	/* Push out any further dirty data, and ensure cache is empty */
 	flush_cache_all();

 	/* Switch to the identity mapping. */
 	phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset);
 	phys_reset((unsigned long)addr);

 	/* Should never get here. */
 	BUG();
 }

 void soft_restart(unsigned long addr)
 {
 	u64 *stack = soft_restart_stack + ARRAY_SIZE(soft_restart_stack);

 	/* Disable interrupts first */
 	local_irq_disable();
 	local_fiq_disable();

 	/* Disable the L2 if we're the last man standing. */
 	if (num_online_cpus() == 1)
 		outer_disable();

 	/* Change to the new stack and continue with the reset. */
 	call_with_stack(__soft_restart, (void *)addr, (void *)stack);

 	/* Should never get here. */
 	BUG();
 }

 static void null_restart(enum reboot_mode reboot_mode, const char *cmd)
 {
 }

 /*
  * Function pointers to optional machine specific functions
  */
 void (*pm_power_off)(void);
 EXPORT_SYMBOL(pm_power_off);

 void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd) = null_restart;
 EXPORT_SYMBOL_GPL(arm_pm_restart);

 /*
  * 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)
 {
 	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);
 }

 #ifdef CONFIG_HOTPLUG_CPU
 void arch_cpu_idle_dead(void)
 {
 	cpu_die();
 }
 #endif

 /*
  * Called by kexec, immediately prior to machine_kexec().
  *
  * This must completely disable all secondary CPUs; simply causing those CPUs
  * to execute e.g. a RAM-based pin loop is not sufficient. This allows the
  * kexec'd kernel to use any and all RAM as it sees fit, without having to
  * avoid any code or data used by any SW CPU pin loop. The CPU hotplug
  * functionality embodied in disable_nonboot_cpus() to achieve this.
  */
 void machine_shutdown(void)
 {
 	disable_nonboot_cpus();
 }

 /*
  * Halting simply requires that the secondary CPUs stop performing any
  * activity (executing tasks, handling interrupts). smp_send_stop()
  * achieves this.
  */
 void machine_halt(void)
 {
 	local_irq_disable();
 	smp_send_stop();

 	local_irq_disable();
 	while (1);
 }

 /*
  * Power-off simply requires that the secondary CPUs stop performing any
  * activity (executing tasks, handling interrupts). smp_send_stop()
  * achieves this. When the system power is turned off, it will take all CPUs
  * with it.
  */
 void machine_power_off(void)
 {
 	local_irq_disable();
 	smp_send_stop();

 	if (pm_power_off)
 		pm_power_off();
 }

 /*
  * Restart requires that the secondary CPUs stop performing any activity
  * while the primary CPU resets the system. Systems with a single CPU can
  * use soft_restart() as their machine descriptor's .restart hook, since that
  * will cause the only available CPU to reset. Systems with multiple CPUs must
  * provide a HW restart implementation, to ensure that all CPUs reset at once.
  * This is required so that any code running after reset on the primary CPU
  * doesn't have to co-ordinate with other CPUs to ensure they aren't still
  * executing pre-reset code, and using RAM that the primary CPU's code wishes
  * to use. Implementing such co-ordination would be essentially impossible.
  */
 void machine_restart(char *cmd)
 {
 	local_irq_disable();
 	smp_send_stop();

 	arm_pm_restart(reboot_mode, cmd);

 	/* Give a grace period for failure to restart of 1s */
 	mdelay(1000);

 	/* Whoops - the platform was unable to reboot. Tell the user! */
 	printk("Reboot failed -- System halted\n");
 	local_irq_disable();
 	while (1);
 }

 void __show_regs(struct pt_regs *regs)
 {
 	unsigned long flags;
 	char buf[64];

 	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
 	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)],
 		get_fs() == get_ds() ? "kernel" : "user");
 #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, dac;
 			asm("mrc p15, 0, %0, c2, c0\n\t"
 			    "mrc p15, 0, %1, c3, c0\n"
 			    : "=r" (transbase), "=r" (dac));
 			snprintf(buf, sizeof(buf), "  Table: %08x  DAC: %08x",
 			  	transbase, dac);
 		}
 #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)
 {
 	printk("\n");
 	__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(void)
 {
 	thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
 }

 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));

 	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));

 	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]" :
 		(vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ?
 		 "[sigpage]" : NULL;
 }

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

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

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

 	down_write(&mm->mmap_sem);
 	addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
 	if (IS_ERR_VALUE(addr)) {
 		ret = addr;
 		goto up_fail;
 	}

 	ret = install_special_mapping(mm, addr, PAGE_SIZE,
 		VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
 		&signal_page);

 	if (ret == 0)
 		mm->context.sigpage = addr;

  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/delay.h>
	#include <linux/reboot.h>
	#include <linux/interrupt.h>
	#include <linux/kallsyms.h>
	#include <linux/init.h>
	#include <linux/cpu.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 <linux/reboot.h>

	#include <asm/cacheflush.h>
	#include <asm/idmap.h>
	#include <asm/processor.h>
	#include <asm/thread_notify.h>
	#include <asm/stacktrace.h>
	#include <asm/mach/time.h>
	#include <asm/tls.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" , "UK6_32" , "ABT_32" ,
	"UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
	};

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

	extern void call_with_stack(void (fn)(void ), void arg, void sp);
	typedef void (*phys_reset_t)(unsigned long);

	/*
	* A temporary stack to use for CPU reset. This is static so that we
	* don't clobber it with the identity mapping. When running with this
	* stack, any references to the current task will not work so you
	* should really do as little as possible before jumping to your reset
	* code.
	*/
	static u64 soft_restart_stack[16];

	static void __soft_restart(void *addr)
	{
	phys_reset_t phys_reset;

	/* Take out a flat memory mapping. */
	setup_mm_for_reboot();

	/* Clean and invalidate caches */
	flush_cache_all();

	/* Turn off caching */
	cpu_proc_fin();

	/* Push out any further dirty data, and ensure cache is empty */
	flush_cache_all();

	/* Switch to the identity mapping. */
	phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset);
	phys_reset((unsigned long)addr);

	/* Should never get here. */
	BUG();
	}

	void soft_restart(unsigned long addr)
	{
	u64 *stack = soft_restart_stack + ARRAY_SIZE(soft_restart_stack);

	/* Disable interrupts first */
	local_irq_disable();
	local_fiq_disable();

	/* Disable the L2 if we're the last man standing. */
	if (num_online_cpus() == 1)
	outer_disable();

	/* Change to the new stack and continue with the reset. */
	call_with_stack(__soft_restart, (void )addr, (void )stack);

	/* Should never get here. */
	BUG();
	}

	static void null_restart(enum reboot_mode reboot_mode, const char *cmd)
	{
	}

	/*
	* Function pointers to optional machine specific functions
	*/
	void (*pm_power_off)(void);
	EXPORT_SYMBOL(pm_power_off);

	void (arm_pm_restart)(enum reboot_mode reboot_mode, const char cmd) = null_restart;
	EXPORT_SYMBOL_GPL(arm_pm_restart);

	/*
	* 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)
	{
	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);
	}

	#ifdef CONFIG_HOTPLUG_CPU
	void arch_cpu_idle_dead(void)
	{
	cpu_die();
	}
	#endif

	/*
	* Called by kexec, immediately prior to machine_kexec().
	*
	* This must completely disable all secondary CPUs; simply causing those CPUs
	* to execute e.g. a RAM-based pin loop is not sufficient. This allows the
	* kexec'd kernel to use any and all RAM as it sees fit, without having to
	* avoid any code or data used by any SW CPU pin loop. The CPU hotplug
	* functionality embodied in disable_nonboot_cpus() to achieve this.
	*/
	void machine_shutdown(void)
	{
	disable_nonboot_cpus();
	}

	/*
	* Halting simply requires that the secondary CPUs stop performing any
	* activity (executing tasks, handling interrupts). smp_send_stop()
	* achieves this.
	*/
	void machine_halt(void)
	{
	local_irq_disable();
	smp_send_stop();

	local_irq_disable();
	while (1);
	}

	/*
	* Power-off simply requires that the secondary CPUs stop performing any
	* activity (executing tasks, handling interrupts). smp_send_stop()
	* achieves this. When the system power is turned off, it will take all CPUs
	* with it.
	*/
	void machine_power_off(void)
	{
	local_irq_disable();
	smp_send_stop();

	if (pm_power_off)
	pm_power_off();
	}

	/*
	* Restart requires that the secondary CPUs stop performing any activity
	* while the primary CPU resets the system. Systems with a single CPU can
	* use soft_restart() as their machine descriptor's .restart hook, since that
	* will cause the only available CPU to reset. Systems with multiple CPUs must
	* provide a HW restart implementation, to ensure that all CPUs reset at once.
	* This is required so that any code running after reset on the primary CPU
	* doesn't have to co-ordinate with other CPUs to ensure they aren't still
	* executing pre-reset code, and using RAM that the primary CPU's code wishes
	* to use. Implementing such co-ordination would be essentially impossible.
	*/
	void machine_restart(char *cmd)
	{
	local_irq_disable();
	smp_send_stop();

	arm_pm_restart(reboot_mode, cmd);

	/* Give a grace period for failure to restart of 1s */
	mdelay(1000);

	/* Whoops - the platform was unable to reboot. Tell the user! */
	printk("Reboot failed -- System halted\n");
	local_irq_disable();
	while (1);
	}

	void __show_regs(struct pt_regs *regs)
	{
	unsigned long flags;
	char buf[64];

	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
	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)],
	get_fs() == get_ds() ? "kernel" : "user");
	#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, dac;
	asm("mrc p15, 0, %0, c2, c0\n\t"
	"mrc p15, 0, %1, c3, c0\n"
	: "=r" (transbase), "=r" (dac));
	snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
	transbase, dac);
	}
	#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)
	{
	printk("\n");
	__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(void)
	{
	thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
	}

	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));

	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));

	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]" :
	(vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ?
	"[sigpage]" : NULL;
	}

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

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

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

	down_write(&mm->mmap_sem);
	addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
	if (IS_ERR_VALUE(addr)) {
	ret = addr;
	goto up_fail;
	}

	ret = install_special_mapping(mm, addr, PAGE_SIZE,
	VM_READ \| VM_EXEC \| VM_MAYREAD \| VM_MAYWRITE \| VM_MAYEXEC,
	&signal_page);

	if (ret == 0)
	mm->context.sigpage = addr;

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