arch/m68knommu/kernel/process.c - maze/linux - Git at Google

 /*
  *  linux/arch/m68knommu/kernel/process.c
  *
  *  Copyright (C) 1995  Hamish Macdonald
  *
  *  68060 fixes by Jesper Skov
  *
  *  uClinux changes
  *  Copyright (C) 2000-2002, David McCullough <davidm@snapgear.com>
  */

 /*
  * This file handles the architecture-dependent parts of process handling..
  */

 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
 #include <linux/smp_lock.h>
 #include <linux/stddef.h>
 #include <linux/unistd.h>
 #include <linux/ptrace.h>
 #include <linux/slab.h>
 #include <linux/user.h>
 #include <linux/interrupt.h>
 #include <linux/reboot.h>
 #include <linux/fs.h>

 #include <asm/uaccess.h>
 #include <asm/system.h>
 #include <asm/traps.h>
 #include <asm/machdep.h>
 #include <asm/setup.h>
 #include <asm/pgtable.h>

 asmlinkage void ret_from_fork(void);

 /*
  * The following aren't currently used.
  */
 void (*pm_idle)(void);
 EXPORT_SYMBOL(pm_idle);

 void (*pm_power_off)(void);
 EXPORT_SYMBOL(pm_power_off);

 /*
  * The idle loop on an m68knommu..
  */
 static void default_idle(void)
 {
 	local_irq_disable();
  	while (!need_resched()) {
 		/* This stop will re-enable interrupts */
  		__asm__("stop #0x2000" : : : "cc");
 		local_irq_disable();
 	}
 	local_irq_enable();
 }

 void (*idle)(void) = default_idle;

 /*
  * The idle thread. There's no useful work to be
  * done, so just try to conserve power and have a
  * low exit latency (ie sit in a loop waiting for
  * somebody to say that they'd like to reschedule)
  */
 void cpu_idle(void)
 {
 	/* endless idle loop with no priority at all */
 	while (1) {
 		idle();
 		preempt_enable_no_resched();
 		schedule();
 		preempt_disable();
 	}
 }

 void machine_restart(char * __unused)
 {
 	if (mach_reset)
 		mach_reset();
 	for (;;);
 }

 void machine_halt(void)
 {
 	if (mach_halt)
 		mach_halt();
 	for (;;);
 }

 void machine_power_off(void)
 {
 	if (mach_power_off)
 		mach_power_off();
 	for (;;);
 }

 void show_regs(struct pt_regs * regs)
 {
 	printk(KERN_NOTICE "\n");
 	printk(KERN_NOTICE "Format %02x  Vector: %04x  PC: %08lx  Status: %04x    %s\n",
 	       regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
 	printk(KERN_NOTICE "ORIG_D0: %08lx  D0: %08lx  A2: %08lx  A1: %08lx\n",
 	       regs->orig_d0, regs->d0, regs->a2, regs->a1);
 	printk(KERN_NOTICE "A0: %08lx  D5: %08lx  D4: %08lx\n",
 	       regs->a0, regs->d5, regs->d4);
 	printk(KERN_NOTICE "D3: %08lx  D2: %08lx  D1: %08lx\n",
 	       regs->d3, regs->d2, regs->d1);
 	if (!(regs->sr & PS_S))
 		printk(KERN_NOTICE "USP: %08lx\n", rdusp());
 }

 /*
  * Create a kernel thread
  */
 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 {
 	int retval;
 	long clone_arg = flags | CLONE_VM;
 	mm_segment_t fs;

 	fs = get_fs();
 	set_fs(KERNEL_DS);

 	__asm__ __volatile__ (
 			"movel	%%sp, %%d2\n\t"
 			"movel	%5, %%d1\n\t"
 			"movel	%1, %%d0\n\t"
 			"trap	#0\n\t"
 			"cmpl	%%sp, %%d2\n\t"
 			"jeq	1f\n\t"
 			"movel	%3, %%sp@-\n\t"
 			"jsr	%4@\n\t"
 			"movel	%2, %%d0\n\t"
 			"trap	#0\n"
 			"1:\n\t"
 			"movel	%%d0, %0\n"
 		: "=d" (retval)
 		: "i" (__NR_clone),
 		  "i" (__NR_exit),
 		  "a" (arg),
 		  "a" (fn),
 		  "a" (clone_arg)
 		: "cc", "%d0", "%d1", "%d2");

 	set_fs(fs);
 	return retval;
 }

 void flush_thread(void)
 {
 #ifdef CONFIG_FPU
 	unsigned long zero = 0;
 #endif
 	set_fs(USER_DS);
 	current->thread.fs = __USER_DS;
 #ifdef CONFIG_FPU
 	if (!FPU_IS_EMU)
 		asm volatile (".chip 68k/68881\n\t"
 			      "frestore %0@\n\t"
 			      ".chip 68k" : : "a" (&zero));
 #endif
 }

 /*
  * "m68k_fork()".. By the time we get here, the
  * non-volatile registers have also been saved on the
  * stack. We do some ugly pointer stuff here.. (see
  * also copy_thread)
  */

 asmlinkage int m68k_fork(struct pt_regs *regs)
 {
 	/* fork almost works, enough to trick you into looking elsewhere :-( */
 	return(-EINVAL);
 }

 asmlinkage int m68k_vfork(struct pt_regs *regs)
 {
 	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
 }

 asmlinkage int m68k_clone(struct pt_regs *regs)
 {
 	unsigned long clone_flags;
 	unsigned long newsp;

 	/* syscall2 puts clone_flags in d1 and usp in d2 */
 	clone_flags = regs->d1;
 	newsp = regs->d2;
 	if (!newsp)
 		newsp = rdusp();
         return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
 }

 int copy_thread(unsigned long clone_flags,
 		unsigned long usp, unsigned long topstk,
 		struct task_struct * p, struct pt_regs * regs)
 {
 	struct pt_regs * childregs;
 	struct switch_stack * childstack, *stack;
 	unsigned long *retp;

 	childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;

 	*childregs = *regs;
 	childregs->d0 = 0;

 	retp = ((unsigned long *) regs);
 	stack = ((struct switch_stack *) retp) - 1;

 	childstack = ((struct switch_stack *) childregs) - 1;
 	*childstack = *stack;
 	childstack->retpc = (unsigned long)ret_from_fork;

 	p->thread.usp = usp;
 	p->thread.ksp = (unsigned long)childstack;
 	/*
 	 * Must save the current SFC/DFC value, NOT the value when
 	 * the parent was last descheduled - RGH  10-08-96
 	 */
 	p->thread.fs = get_fs().seg;

 #ifdef CONFIG_FPU
 	if (!FPU_IS_EMU) {
 		/* Copy the current fpu state */
 		asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");

 		if (p->thread.fpstate[0])
 		  asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
 				"fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
 				: : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0])
 				: "memory");
 		/* Restore the state in case the fpu was busy */
 		asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
 	}
 #endif

 	return 0;
 }

 /* Fill in the fpu structure for a core dump.  */

 int dump_fpu(struct pt_regs *regs, struct user_m68kfp_struct *fpu)
 {
 #ifdef CONFIG_FPU
 	char fpustate[216];

 	if (FPU_IS_EMU) {
 		int i;

 		memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
 		memcpy(fpu->fpregs, current->thread.fp, 96);
 		/* Convert internal fpu reg representation
 		 * into long double format
 		 */
 		for (i = 0; i < 24; i += 3)
 			fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
 			                 ((fpu->fpregs[i] & 0x0000ffff) << 16);
 		return 1;
 	}

 	/* First dump the fpu context to avoid protocol violation.  */
 	asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
 	if (!fpustate[0])
 		return 0;

 	asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
 		:: "m" (fpu->fpcntl[0])
 		: "memory");
 	asm volatile ("fmovemx %/fp0-%/fp7,%0"
 		:: "m" (fpu->fpregs[0])
 		: "memory");
 #endif
 	return 1;
 }

 /*
  *	Generic dumping code. Used for panic and debug.
  */
 void dump(struct pt_regs *fp)
 {
 	unsigned long	*sp;
 	unsigned char	*tp;
 	int		i;

 	printk(KERN_EMERG "\n" KERN_EMERG "CURRENT PROCESS:\n" KERN_EMERG "\n");
 	printk(KERN_EMERG "COMM=%s PID=%d\n", current->comm, current->pid);

 	if (current->mm) {
 		printk(KERN_EMERG "TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 			(int) current->mm->start_code,
 			(int) current->mm->end_code,
 			(int) current->mm->start_data,
 			(int) current->mm->end_data,
 			(int) current->mm->end_data,
 			(int) current->mm->brk);
 		printk(KERN_EMERG "USER-STACK=%08x KERNEL-STACK=%08x\n"
 			KERN_EMERG "\n",
 			(int) current->mm->start_stack,
 			(int)(((unsigned long) current) + THREAD_SIZE));
 	}

 	printk(KERN_EMERG "PC: %08lx\n", fp->pc);
 	printk(KERN_EMERG "SR: %08lx    SP: %08lx\n", (long) fp->sr, (long) fp);
 	printk(KERN_EMERG "d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
 		fp->d0, fp->d1, fp->d2, fp->d3);
 	printk(KERN_EMERG "d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
 		fp->d4, fp->d5, fp->a0, fp->a1);
 	printk(KERN_EMERG "\n" KERN_EMERG "USP: %08x   TRAPFRAME: %08x\n",
 		(unsigned int) rdusp(), (unsigned int) fp);

 	printk(KERN_EMERG "\n" KERN_EMERG "CODE:");
 	tp = ((unsigned char *) fp->pc) - 0x20;
 	for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
 		if ((i % 0x10) == 0)
 			printk("\n" KERN_EMERG "%08x: ", (int) (tp + i));
 		printk("%08x ", (int) *sp++);
 	}
 	printk("\n" KERN_EMERG "\n");

 	printk(KERN_EMERG "KERNEL STACK:");
 	tp = ((unsigned char *) fp) - 0x40;
 	for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
 		if ((i % 0x10) == 0)
 			printk("\n" KERN_EMERG "%08x: ", (int) (tp + i));
 		printk("%08x ", (int) *sp++);
 	}
 	printk("\n" KERN_EMERG "\n");

 	printk(KERN_EMERG "USER STACK:");
 	tp = (unsigned char *) (rdusp() - 0x10);
 	for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
 		if ((i % 0x10) == 0)
 			printk("\n" KERN_EMERG "%08x: ", (int) (tp + i));
 		printk("%08x ", (int) *sp++);
 	}
 	printk("\n" KERN_EMERG "\n");
 }

 /*
  * sys_execve() executes a new program.
  */
 asmlinkage int sys_execve(char *name, char **argv, char **envp)
 {
 	int error;
 	char * filename;
 	struct pt_regs *regs = (struct pt_regs *) &name;

 	lock_kernel();
 	filename = getname(name);
 	error = PTR_ERR(filename);
 	if (IS_ERR(filename))
 		goto out;
 	error = do_execve(filename, argv, envp, regs);
 	putname(filename);
 out:
 	unlock_kernel();
 	return error;
 }

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

 	stack_page = (unsigned long)p;
 	fp = ((struct switch_stack *)p->thread.ksp)->a6;
 	do {
 		if (fp < stack_page+sizeof(struct thread_info) ||
 		    fp >= THREAD_SIZE-8+stack_page)
 			return 0;
 		pc = ((unsigned long *)fp)[1];
 		if (!in_sched_functions(pc))
 			return pc;
 		fp = *(unsigned long *) fp;
 	} while (count++ < 16);
 	return 0;
 }

 /*
  * Return saved PC of a blocked thread.
  */
 unsigned long thread_saved_pc(struct task_struct *tsk)
 {
 	struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;

 	/* Check whether the thread is blocked in resume() */
 	if (in_sched_functions(sw->retpc))
 		return ((unsigned long *)sw->a6)[1];
 	else
 		return sw->retpc;
 }
	/*
	* linux/arch/m68knommu/kernel/process.c
	*
	* Copyright (C) 1995 Hamish Macdonald
	*
	* 68060 fixes by Jesper Skov
	*
	* uClinux changes
	* Copyright (C) 2000-2002, David McCullough <davidm@snapgear.com>
	*/

	/*
	* This file handles the architecture-dependent parts of process handling..
	*/

	#include <linux/module.h>
	#include <linux/errno.h>
	#include <linux/sched.h>
	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/smp.h>
	#include <linux/smp_lock.h>
	#include <linux/stddef.h>
	#include <linux/unistd.h>
	#include <linux/ptrace.h>
	#include <linux/slab.h>
	#include <linux/user.h>
	#include <linux/interrupt.h>
	#include <linux/reboot.h>
	#include <linux/fs.h>

	#include <asm/uaccess.h>
	#include <asm/system.h>
	#include <asm/traps.h>
	#include <asm/machdep.h>
	#include <asm/setup.h>
	#include <asm/pgtable.h>

	asmlinkage void ret_from_fork(void);

	/*
	* The following aren't currently used.
	*/
	void (*pm_idle)(void);
	EXPORT_SYMBOL(pm_idle);

	void (*pm_power_off)(void);
	EXPORT_SYMBOL(pm_power_off);

	/*
	* The idle loop on an m68knommu..
	*/
	static void default_idle(void)
	{
	local_irq_disable();
	while (!need_resched()) {
	/* This stop will re-enable interrupts */
	__asm__("stop #0x2000" : : : "cc");
	local_irq_disable();
	}
	local_irq_enable();
	}

	void (*idle)(void) = default_idle;

	/*
	* The idle thread. There's no useful work to be
	* done, so just try to conserve power and have a
	* low exit latency (ie sit in a loop waiting for
	* somebody to say that they'd like to reschedule)
	*/
	void cpu_idle(void)
	{
	/* endless idle loop with no priority at all */
	while (1) {
	idle();
	preempt_enable_no_resched();
	schedule();
	preempt_disable();
	}
	}

	void machine_restart(char * __unused)
	{
	if (mach_reset)
	mach_reset();
	for (;;);
	}

	void machine_halt(void)
	{
	if (mach_halt)
	mach_halt();
	for (;;);
	}

	void machine_power_off(void)
	{
	if (mach_power_off)
	mach_power_off();
	for (;;);
	}

	void show_regs(struct pt_regs * regs)
	{
	printk(KERN_NOTICE "\n");
	printk(KERN_NOTICE "Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
	regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
	printk(KERN_NOTICE "ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
	regs->orig_d0, regs->d0, regs->a2, regs->a1);
	printk(KERN_NOTICE "A0: %08lx D5: %08lx D4: %08lx\n",
	regs->a0, regs->d5, regs->d4);
	printk(KERN_NOTICE "D3: %08lx D2: %08lx D1: %08lx\n",
	regs->d3, regs->d2, regs->d1);
	if (!(regs->sr & PS_S))
	printk(KERN_NOTICE "USP: %08lx\n", rdusp());
	}

	/*
	* Create a kernel thread
	*/
	int kernel_thread(int (fn)(void ), void * arg, unsigned long flags)
	{
	int retval;
	long clone_arg = flags \| CLONE_VM;
	mm_segment_t fs;

	fs = get_fs();
	set_fs(KERNEL_DS);

	__asm__ __volatile__ (
	"movel %%sp, %%d2\n\t"
	"movel %5, %%d1\n\t"
	"movel %1, %%d0\n\t"
	"trap #0\n\t"
	"cmpl %%sp, %%d2\n\t"
	"jeq 1f\n\t"
	"movel %3, %%sp@-\n\t"
	"jsr %4@\n\t"
	"movel %2, %%d0\n\t"
	"trap #0\n"
	"1:\n\t"
	"movel %%d0, %0\n"
	: "=d" (retval)
	: "i" (__NR_clone),
	"i" (__NR_exit),
	"a" (arg),
	"a" (fn),
	"a" (clone_arg)
	: "cc", "%d0", "%d1", "%d2");

	set_fs(fs);
	return retval;
	}

	void flush_thread(void)
	{
	#ifdef CONFIG_FPU
	unsigned long zero = 0;
	#endif
	set_fs(USER_DS);
	current->thread.fs = __USER_DS;
	#ifdef CONFIG_FPU
	if (!FPU_IS_EMU)
	asm volatile (".chip 68k/68881\n\t"
	"frestore %0@\n\t"
	".chip 68k" : : "a" (&zero));
	#endif
	}

	/*
	* "m68k_fork()".. By the time we get here, the
	* non-volatile registers have also been saved on the
	* stack. We do some ugly pointer stuff here.. (see
	* also copy_thread)
	*/

	asmlinkage int m68k_fork(struct pt_regs *regs)
	{
	/* fork almost works, enough to trick you into looking elsewhere :-( */
	return(-EINVAL);
	}

	asmlinkage int m68k_vfork(struct pt_regs *regs)
	{
	return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, rdusp(), regs, 0, NULL, NULL);
	}

	asmlinkage int m68k_clone(struct pt_regs *regs)
	{
	unsigned long clone_flags;
	unsigned long newsp;

	/* syscall2 puts clone_flags in d1 and usp in d2 */
	clone_flags = regs->d1;
	newsp = regs->d2;
	if (!newsp)
	newsp = rdusp();
	return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
	}

	int copy_thread(unsigned long clone_flags,
	unsigned long usp, unsigned long topstk,
	struct task_struct * p, struct pt_regs * regs)
	{
	struct pt_regs * childregs;
	struct switch_stack * childstack, *stack;
	unsigned long *retp;

	childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;

	childregs = regs;
	childregs->d0 = 0;

	retp = ((unsigned long *) regs);
	stack = ((struct switch_stack *) retp) - 1;

	childstack = ((struct switch_stack *) childregs) - 1;
	childstack = stack;
	childstack->retpc = (unsigned long)ret_from_fork;

	p->thread.usp = usp;
	p->thread.ksp = (unsigned long)childstack;
	/*
	* Must save the current SFC/DFC value, NOT the value when
	* the parent was last descheduled - RGH 10-08-96
	*/
	p->thread.fs = get_fs().seg;

	#ifdef CONFIG_FPU
	if (!FPU_IS_EMU) {
	/* Copy the current fpu state */
	asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");

	if (p->thread.fpstate[0])
	asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
	"fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
	: : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0])
	: "memory");
	/* Restore the state in case the fpu was busy */
	asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
	}
	#endif

	return 0;
	}

	/* Fill in the fpu structure for a core dump. */

	int dump_fpu(struct pt_regs regs, struct user_m68kfp_struct fpu)
	{
	#ifdef CONFIG_FPU
	char fpustate[216];

	if (FPU_IS_EMU) {
	int i;

	memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
	memcpy(fpu->fpregs, current->thread.fp, 96);
	/* Convert internal fpu reg representation
	* into long double format
	*/
	for (i = 0; i < 24; i += 3)
	fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) \|
	((fpu->fpregs[i] & 0x0000ffff) << 16);
	return 1;
	}

	/* First dump the fpu context to avoid protocol violation. */
	asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
	if (!fpustate[0])
	return 0;

	asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
	:: "m" (fpu->fpcntl[0])
	: "memory");
	asm volatile ("fmovemx %/fp0-%/fp7,%0"
	:: "m" (fpu->fpregs[0])
	: "memory");
	#endif
	return 1;
	}

	/*
	* Generic dumping code. Used for panic and debug.
	*/
	void dump(struct pt_regs *fp)
	{
	unsigned long *sp;
	unsigned char *tp;
	int i;

	printk(KERN_EMERG "\n" KERN_EMERG "CURRENT PROCESS:\n" KERN_EMERG "\n");
	printk(KERN_EMERG "COMM=%s PID=%d\n", current->comm, current->pid);

	if (current->mm) {
	printk(KERN_EMERG "TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
	(int) current->mm->start_code,
	(int) current->mm->end_code,
	(int) current->mm->start_data,
	(int) current->mm->end_data,
	(int) current->mm->end_data,
	(int) current->mm->brk);
	printk(KERN_EMERG "USER-STACK=%08x KERNEL-STACK=%08x\n"
	KERN_EMERG "\n",
	(int) current->mm->start_stack,
	(int)(((unsigned long) current) + THREAD_SIZE));
	}

	printk(KERN_EMERG "PC: %08lx\n", fp->pc);
	printk(KERN_EMERG "SR: %08lx SP: %08lx\n", (long) fp->sr, (long) fp);
	printk(KERN_EMERG "d0: %08lx d1: %08lx d2: %08lx d3: %08lx\n",
	fp->d0, fp->d1, fp->d2, fp->d3);
	printk(KERN_EMERG "d4: %08lx d5: %08lx a0: %08lx a1: %08lx\n",
	fp->d4, fp->d5, fp->a0, fp->a1);
	printk(KERN_EMERG "\n" KERN_EMERG "USP: %08x TRAPFRAME: %08x\n",
	(unsigned int) rdusp(), (unsigned int) fp);

	printk(KERN_EMERG "\n" KERN_EMERG "CODE:");
	tp = ((unsigned char *) fp->pc) - 0x20;
	for (sp = (unsigned long *) tp, i = 0; (i < 0x40); i += 4) {
	if ((i % 0x10) == 0)
	printk("\n" KERN_EMERG "%08x: ", (int) (tp + i));
	printk("%08x ", (int) *sp++);
	}
	printk("\n" KERN_EMERG "\n");

	printk(KERN_EMERG "KERNEL STACK:");
	tp = ((unsigned char *) fp) - 0x40;
	for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
	if ((i % 0x10) == 0)
	printk("\n" KERN_EMERG "%08x: ", (int) (tp + i));
	printk("%08x ", (int) *sp++);
	}
	printk("\n" KERN_EMERG "\n");

	printk(KERN_EMERG "USER STACK:");
	tp = (unsigned char *) (rdusp() - 0x10);
	for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
	if ((i % 0x10) == 0)
	printk("\n" KERN_EMERG "%08x: ", (int) (tp + i));
	printk("%08x ", (int) *sp++);
	}
	printk("\n" KERN_EMERG "\n");
	}

	/*
	* sys_execve() executes a new program.
	*/
	asmlinkage int sys_execve(char name, char argv, char *envp)
	{
	int error;
	char * filename;
	struct pt_regs regs = (struct pt_regs ) &name;

	lock_kernel();
	filename = getname(name);
	error = PTR_ERR(filename);
	if (IS_ERR(filename))
	goto out;
	error = do_execve(filename, argv, envp, regs);
	putname(filename);
	out:
	unlock_kernel();
	return error;
	}

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

	stack_page = (unsigned long)p;
	fp = ((struct switch_stack *)p->thread.ksp)->a6;
	do {
	if (fp < stack_page+sizeof(struct thread_info) \|\|
	fp >= THREAD_SIZE-8+stack_page)
	return 0;
	pc = ((unsigned long *)fp)[1];
	if (!in_sched_functions(pc))
	return pc;
	fp = (unsigned long ) fp;
	} while (count++ < 16);
	return 0;
	}

	/*
	* Return saved PC of a blocked thread.
	*/
	unsigned long thread_saved_pc(struct task_struct *tsk)
	{
	struct switch_stack sw = (struct switch_stack )tsk->thread.ksp;

	/* Check whether the thread is blocked in resume() */
	if (in_sched_functions(sw->retpc))
	return ((unsigned long *)sw->a6)[1];
	else
	return sw->retpc;
	}