[deliverable/linux.git] / arch / arm / kernel / process.c

/*
 *  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/cpuidle.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/system_misc.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[] = {
  "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[] = {
  "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);

static void default_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 from the core idle loop.
 */
void arch_cpu_idle(void)
{
	if (cpuidle_idle_call())
		default_idle();
}

/*
 * 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';

	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");
#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
Commit	Line	Data
	1	/*
	2	* linux/arch/arm/kernel/process.c
	3	*
	4	* Copyright (C) 1996-2000 Russell King - Converted to ARM.
	5	* Original Copyright (C) 1995 Linus Torvalds
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11	#include <stdarg.h>
	12
	13	#include <linux/export.h>
	14	#include <linux/sched.h>
	15	#include <linux/kernel.h>
	16	#include <linux/mm.h>
	17	#include <linux/stddef.h>
	18	#include <linux/unistd.h>
	19	#include <linux/user.h>
	20	#include <linux/delay.h>
	21	#include <linux/reboot.h>
	22	#include <linux/interrupt.h>
	23	#include <linux/kallsyms.h>
	24	#include <linux/init.h>
	25	#include <linux/cpu.h>
	26	#include <linux/elfcore.h>
	27	#include <linux/pm.h>
	28	#include <linux/tick.h>
	29	#include <linux/utsname.h>
	30	#include <linux/uaccess.h>
	31	#include <linux/random.h>
	32	#include <linux/hw_breakpoint.h>
	33	#include <linux/cpuidle.h>
	34	#include <linux/leds.h>
	35	#include <linux/reboot.h>
	36
	37	#include <asm/cacheflush.h>
	38	#include <asm/idmap.h>
	39	#include <asm/processor.h>
	40	#include <asm/thread_notify.h>
	41	#include <asm/stacktrace.h>
	42	#include <asm/system_misc.h>
	43	#include <asm/mach/time.h>
	44	#include <asm/tls.h>
	45
	46	#ifdef CONFIG_CC_STACKPROTECTOR
	47	#include <linux/stackprotector.h>
	48	unsigned long __stack_chk_guard __read_mostly;
	49	EXPORT_SYMBOL(__stack_chk_guard);
	50	#endif
	51
	52	static const char *processor_modes[] = {
	53	"USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
	54	"UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
	55	"USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
	56	"UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
	57	};
	58
	59	static const char *isa_modes[] = {
	60	"ARM" , "Thumb" , "Jazelle", "ThumbEE"
	61	};
	62
	63	extern void call_with_stack(void (fn)(void ), void arg, void sp);
	64	typedef void (*phys_reset_t)(unsigned long);
	65
	66	/*
	67	* A temporary stack to use for CPU reset. This is static so that we
	68	* don't clobber it with the identity mapping. When running with this
	69	* stack, any references to the current task will not work so you
	70	* should really do as little as possible before jumping to your reset
	71	* code.
	72	*/
	73	static u64 soft_restart_stack[16];
	74
	75	static void __soft_restart(void *addr)
	76	{
	77	phys_reset_t phys_reset;
	78
	79	/* Take out a flat memory mapping. */
	80	setup_mm_for_reboot();
	81
	82	/* Clean and invalidate caches */
	83	flush_cache_all();
	84
	85	/* Turn off caching */
	86	cpu_proc_fin();
	87
	88	/* Push out any further dirty data, and ensure cache is empty */
	89	flush_cache_all();
	90
	91	/* Switch to the identity mapping. */
	92	phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset);
	93	phys_reset((unsigned long)addr);
	94
	95	/* Should never get here. */
	96	BUG();
	97	}
	98
	99	void soft_restart(unsigned long addr)
	100	{
	101	u64 *stack = soft_restart_stack + ARRAY_SIZE(soft_restart_stack);
	102
	103	/* Disable interrupts first */
	104	local_irq_disable();
	105	local_fiq_disable();
	106
	107	/* Disable the L2 if we're the last man standing. */
	108	if (num_online_cpus() == 1)
	109	outer_disable();
	110
	111	/* Change to the new stack and continue with the reset. */
	112	call_with_stack(__soft_restart, (void )addr, (void )stack);
	113
	114	/* Should never get here. */
	115	BUG();
	116	}
	117
	118	static void null_restart(enum reboot_mode reboot_mode, const char *cmd)
	119	{
	120	}
	121
	122	/*
	123	* Function pointers to optional machine specific functions
	124	*/
	125	void (*pm_power_off)(void);
	126	EXPORT_SYMBOL(pm_power_off);
	127
	128	void (arm_pm_restart)(enum reboot_mode reboot_mode, const char cmd) = null_restart;
	129	EXPORT_SYMBOL_GPL(arm_pm_restart);
	130
	131	/*
	132	* This is our default idle handler.
	133	*/
	134
	135	void (*arm_pm_idle)(void);
	136
	137	static void default_idle(void)
	138	{
	139	if (arm_pm_idle)
	140	arm_pm_idle();
	141	else
	142	cpu_do_idle();
	143	local_irq_enable();
	144	}
	145
	146	void arch_cpu_idle_prepare(void)
	147	{
	148	local_fiq_enable();
	149	}
	150
	151	void arch_cpu_idle_enter(void)
	152	{
	153	ledtrig_cpu(CPU_LED_IDLE_START);
	154	#ifdef CONFIG_PL310_ERRATA_769419
	155	wmb();
	156	#endif
	157	}
	158
	159	void arch_cpu_idle_exit(void)
	160	{
	161	ledtrig_cpu(CPU_LED_IDLE_END);
	162	}
	163
	164	#ifdef CONFIG_HOTPLUG_CPU
	165	void arch_cpu_idle_dead(void)
	166	{
	167	cpu_die();
	168	}
	169	#endif
	170
	171	/*
	172	* Called from the core idle loop.
	173	*/
	174	void arch_cpu_idle(void)
	175	{
	176	if (cpuidle_idle_call())
	177	default_idle();
	178	}
	179
	180	/*
	181	* Called by kexec, immediately prior to machine_kexec().
	182	*
	183	* This must completely disable all secondary CPUs; simply causing those CPUs
	184	* to execute e.g. a RAM-based pin loop is not sufficient. This allows the
	185	* kexec'd kernel to use any and all RAM as it sees fit, without having to
	186	* avoid any code or data used by any SW CPU pin loop. The CPU hotplug
	187	* functionality embodied in disable_nonboot_cpus() to achieve this.
	188	*/
	189	void machine_shutdown(void)
	190	{
	191	disable_nonboot_cpus();
	192	}
	193
	194	/*
	195	* Halting simply requires that the secondary CPUs stop performing any
	196	* activity (executing tasks, handling interrupts). smp_send_stop()
	197	* achieves this.
	198	*/
	199	void machine_halt(void)
	200	{
	201	local_irq_disable();
	202	smp_send_stop();
	203
	204	local_irq_disable();
	205	while (1);
	206	}
	207
	208	/*
	209	* Power-off simply requires that the secondary CPUs stop performing any
	210	* activity (executing tasks, handling interrupts). smp_send_stop()
	211	* achieves this. When the system power is turned off, it will take all CPUs
	212	* with it.
	213	*/
	214	void machine_power_off(void)
	215	{
	216	local_irq_disable();
	217	smp_send_stop();
	218
	219	if (pm_power_off)
	220	pm_power_off();
	221	}
	222
	223	/*
	224	* Restart requires that the secondary CPUs stop performing any activity
	225	* while the primary CPU resets the system. Systems with a single CPU can
	226	* use soft_restart() as their machine descriptor's .restart hook, since that
	227	* will cause the only available CPU to reset. Systems with multiple CPUs must
	228	* provide a HW restart implementation, to ensure that all CPUs reset at once.
	229	* This is required so that any code running after reset on the primary CPU
	230	* doesn't have to co-ordinate with other CPUs to ensure they aren't still
	231	* executing pre-reset code, and using RAM that the primary CPU's code wishes
	232	* to use. Implementing such co-ordination would be essentially impossible.
	233	*/
	234	void machine_restart(char *cmd)
	235	{
	236	local_irq_disable();
	237	smp_send_stop();
	238
	239	arm_pm_restart(reboot_mode, cmd);
	240
	241	/* Give a grace period for failure to restart of 1s */
	242	mdelay(1000);
	243
	244	/* Whoops - the platform was unable to reboot. Tell the user! */
	245	printk("Reboot failed -- System halted\n");
	246	local_irq_disable();
	247	while (1);
	248	}
	249
	250	void __show_regs(struct pt_regs *regs)
	251	{
	252	unsigned long flags;
	253	char buf[64];
	254
	255	show_regs_print_info(KERN_DEFAULT);
	256
	257	print_symbol("PC is at %s\n", instruction_pointer(regs));
	258	print_symbol("LR is at %s\n", regs->ARM_lr);
	259	printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
	260	"sp : %08lx ip : %08lx fp : %08lx\n",
	261	regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
	262	regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
	263	printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
	264	regs->ARM_r10, regs->ARM_r9,
	265	regs->ARM_r8);
	266	printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
	267	regs->ARM_r7, regs->ARM_r6,
	268	regs->ARM_r5, regs->ARM_r4);
	269	printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
	270	regs->ARM_r3, regs->ARM_r2,
	271	regs->ARM_r1, regs->ARM_r0);
	272
	273	flags = regs->ARM_cpsr;
	274	buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
	275	buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
	276	buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
	277	buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
	278	buf[4] = '\0';
	279
	280	printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
	281	buf, interrupts_enabled(regs) ? "n" : "ff",
	282	fast_interrupts_enabled(regs) ? "n" : "ff",
	283	processor_modes[processor_mode(regs)],
	284	isa_modes[isa_mode(regs)],
	285	get_fs() == get_ds() ? "kernel" : "user");
	286	#ifdef CONFIG_CPU_CP15
	287	{
	288	unsigned int ctrl;
	289
	290	buf[0] = '\0';
	291	#ifdef CONFIG_CPU_CP15_MMU
	292	{
	293	unsigned int transbase, dac;
	294	asm("mrc p15, 0, %0, c2, c0\n\t"
	295	"mrc p15, 0, %1, c3, c0\n"
	296	: "=r" (transbase), "=r" (dac));
	297	snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
	298	transbase, dac);
	299	}
	300	#endif
	301	asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
	302
	303	printk("Control: %08x%s\n", ctrl, buf);
	304	}
	305	#endif
	306	}
	307
	308	void show_regs(struct pt_regs * regs)
	309	{
	310	printk("\n");
	311	__show_regs(regs);
	312	dump_stack();
	313	}
	314
	315	ATOMIC_NOTIFIER_HEAD(thread_notify_head);
	316
	317	EXPORT_SYMBOL_GPL(thread_notify_head);
	318
	319	/*
	320	* Free current thread data structures etc..
	321	*/
	322	void exit_thread(void)
	323	{
	324	thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
	325	}
	326
	327	void flush_thread(void)
	328	{
	329	struct thread_info *thread = current_thread_info();
	330	struct task_struct *tsk = current;
	331
	332	flush_ptrace_hw_breakpoint(tsk);
	333
	334	memset(thread->used_cp, 0, sizeof(thread->used_cp));
	335	memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
	336	memset(&thread->fpstate, 0, sizeof(union fp_state));
	337
	338	thread_notify(THREAD_NOTIFY_FLUSH, thread);
	339	}
	340
	341	void release_thread(struct task_struct *dead_task)
	342	{
	343	}
	344
	345	asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
	346
	347	int
	348	copy_thread(unsigned long clone_flags, unsigned long stack_start,
	349	unsigned long stk_sz, struct task_struct *p)
	350	{
	351	struct thread_info *thread = task_thread_info(p);
	352	struct pt_regs *childregs = task_pt_regs(p);
	353
	354	memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
	355
	356	if (likely(!(p->flags & PF_KTHREAD))) {
	357	childregs = current_pt_regs();
	358	childregs->ARM_r0 = 0;
	359	if (stack_start)
	360	childregs->ARM_sp = stack_start;
	361	} else {
	362	memset(childregs, 0, sizeof(struct pt_regs));
	363	thread->cpu_context.r4 = stk_sz;
	364	thread->cpu_context.r5 = stack_start;
	365	childregs->ARM_cpsr = SVC_MODE;
	366	}
	367	thread->cpu_context.pc = (unsigned long)ret_from_fork;
	368	thread->cpu_context.sp = (unsigned long)childregs;
	369
	370	clear_ptrace_hw_breakpoint(p);
	371
	372	if (clone_flags & CLONE_SETTLS)
	373	thread->tp_value[0] = childregs->ARM_r3;
	374	thread->tp_value[1] = get_tpuser();
	375
	376	thread_notify(THREAD_NOTIFY_COPY, thread);
	377
	378	return 0;
	379	}
	380
	381	/*
	382	* Fill in the task's elfregs structure for a core dump.
	383	*/
	384	int dump_task_regs(struct task_struct t, elf_gregset_t elfregs)
	385	{
	386	elf_core_copy_regs(elfregs, task_pt_regs(t));
	387	return 1;
	388	}
	389
	390	/*
	391	* fill in the fpe structure for a core dump...
	392	*/
	393	int dump_fpu (struct pt_regs regs, struct user_fp fp)
	394	{
	395	struct thread_info *thread = current_thread_info();
	396	int used_math = thread->used_cp[1] \| thread->used_cp[2];
	397
	398	if (used_math)
	399	memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
	400
	401	return used_math != 0;
	402	}
	403	EXPORT_SYMBOL(dump_fpu);
	404
	405	unsigned long get_wchan(struct task_struct *p)
	406	{
	407	struct stackframe frame;
	408	unsigned long stack_page;
	409	int count = 0;
	410	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	411	return 0;
	412
	413	frame.fp = thread_saved_fp(p);
	414	frame.sp = thread_saved_sp(p);
	415	frame.lr = 0; /* recovered from the stack */
	416	frame.pc = thread_saved_pc(p);
	417	stack_page = (unsigned long)task_stack_page(p);
	418	do {
	419	if (frame.sp < stack_page \|\|
	420	frame.sp >= stack_page + THREAD_SIZE \|\|
	421	unwind_frame(&frame) < 0)
	422	return 0;
	423	if (!in_sched_functions(frame.pc))
	424	return frame.pc;
	425	} while (count ++ < 16);
	426	return 0;
	427	}
	428
	429	unsigned long arch_randomize_brk(struct mm_struct *mm)
	430	{
	431	unsigned long range_end = mm->brk + 0x02000000;
	432	return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
	433	}
	434
	435	#ifdef CONFIG_MMU
	436	#ifdef CONFIG_KUSER_HELPERS
	437	/*
	438	* The vectors page is always readable from user space for the
	439	* atomic helpers. Insert it into the gate_vma so that it is visible
	440	* through ptrace and /proc/<pid>/mem.
	441	*/
	442	static struct vm_area_struct gate_vma = {
	443	.vm_start = 0xffff0000,
	444	.vm_end = 0xffff0000 + PAGE_SIZE,
	445	.vm_flags = VM_READ \| VM_EXEC \| VM_MAYREAD \| VM_MAYEXEC,
	446	};
	447
	448	static int __init gate_vma_init(void)
	449	{
	450	gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
	451	return 0;
	452	}
	453	arch_initcall(gate_vma_init);
	454
	455	struct vm_area_struct get_gate_vma(struct mm_struct mm)
	456	{
	457	return &gate_vma;
	458	}
	459
	460	int in_gate_area(struct mm_struct *mm, unsigned long addr)
	461	{
	462	return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
	463	}
	464
	465	int in_gate_area_no_mm(unsigned long addr)
	466	{
	467	return in_gate_area(NULL, addr);
	468	}
	469	#define is_gate_vma(vma) ((vma) == &gate_vma)
	470	#else
	471	#define is_gate_vma(vma) 0
	472	#endif
	473
	474	const char arch_vma_name(struct vm_area_struct vma)
	475	{
	476	return is_gate_vma(vma) ? "[vectors]" :
	477	(vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ?
	478	"[sigpage]" : NULL;
	479	}
	480
	481	static struct page *signal_page;
	482	extern struct page *get_signal_page(void);
	483
	484	int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
	485	{
	486	struct mm_struct *mm = current->mm;
	487	unsigned long addr;
	488	int ret;
	489
	490	if (!signal_page)
	491	signal_page = get_signal_page();
	492	if (!signal_page)
	493	return -ENOMEM;
	494
	495	down_write(&mm->mmap_sem);
	496	addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
	497	if (IS_ERR_VALUE(addr)) {
	498	ret = addr;
	499	goto up_fail;
	500	}
	501
	502	ret = install_special_mapping(mm, addr, PAGE_SIZE,
	503	VM_READ \| VM_EXEC \| VM_MAYREAD \| VM_MAYWRITE \| VM_MAYEXEC,
	504	&signal_page);
	505
	506	if (ret == 0)
	507	mm->context.sigpage = addr;
	508
	509	up_fail:
	510	up_write(&mm->mmap_sem);
	511	return ret;
	512	}
	513	#endif