arch/alpha/kernel/process.c - android_kernel_htc_msm8960 - Gitiles

 /*
  *  linux/arch/alpha/kernel/process.c
  *
  *  Copyright (C) 1995  Linus Torvalds
  */

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

 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
 #include <linux/stddef.h>
 #include <linux/unistd.h>
 #include <linux/ptrace.h>
 #include <linux/user.h>
 #include <linux/time.h>
 #include <linux/major.h>
 #include <linux/stat.h>
 #include <linux/vt.h>
 #include <linux/mman.h>
 #include <linux/elfcore.h>
 #include <linux/reboot.h>
 #include <linux/tty.h>
 #include <linux/console.h>
 #include <linux/slab.h>

 #include <asm/reg.h>
 #include <asm/uaccess.h>
 #include <asm/system.h>
 #include <asm/io.h>
 #include <asm/pgtable.h>
 #include <asm/hwrpb.h>
 #include <asm/fpu.h>

 #include "proto.h"
 #include "pci_impl.h"

 /*
  * Power off function, if any
  */
 void (*pm_power_off)(void) = machine_power_off;
 EXPORT_SYMBOL(pm_power_off);

 void
 cpu_idle(void)
 {
 	set_thread_flag(TIF_POLLING_NRFLAG);

 	while (1) {
 		/* FIXME -- EV6 and LCA45 know how to power down
 		   the CPU.  */

 		while (!need_resched())
 			cpu_relax();
 		schedule();
 	}
 }


 struct halt_info {
 	int mode;
 	char *restart_cmd;
 };

 static void
 common_shutdown_1(void *generic_ptr)
 {
 	struct halt_info *how = (struct halt_info *)generic_ptr;
 	struct percpu_struct *cpup;
 	unsigned long *pflags, flags;
 	int cpuid = smp_processor_id();

 	/* No point in taking interrupts anymore. */
 	local_irq_disable();

 	cpup = (struct percpu_struct *)
 			((unsigned long)hwrpb + hwrpb->processor_offset
 			 + hwrpb->processor_size * cpuid);
 	pflags = &cpup->flags;
 	flags = *pflags;

 	/* Clear reason to "default"; clear "bootstrap in progress". */
 	flags &= ~0x00ff0001UL;

 #ifdef CONFIG_SMP
 	/* Secondaries halt here. */
 	if (cpuid != boot_cpuid) {
 		flags |= 0x00040000UL; /* "remain halted" */
 		*pflags = flags;
 		set_cpu_present(cpuid, false);
 		set_cpu_possible(cpuid, false);
 		halt();
 	}
 #endif

 	if (how->mode == LINUX_REBOOT_CMD_RESTART) {
 		if (!how->restart_cmd) {
 			flags |= 0x00020000UL; /* "cold bootstrap" */
 		} else {
 			/* For SRM, we could probably set environment
 			   variables to get this to work.  We'd have to
 			   delay this until after srm_paging_stop unless
 			   we ever got srm_fixup working.

 			   At the moment, SRM will use the last boot device,
 			   but the file and flags will be the defaults, when
 			   doing a "warm" bootstrap.  */
 			flags |= 0x00030000UL; /* "warm bootstrap" */
 		}
 	} else {
 		flags |= 0x00040000UL; /* "remain halted" */
 	}
 	*pflags = flags;

 #ifdef CONFIG_SMP
 	/* Wait for the secondaries to halt. */
 	set_cpu_present(boot_cpuid, false);
 	set_cpu_possible(boot_cpuid, false);
 	while (cpus_weight(cpu_present_map))
 		barrier();
 #endif

 	/* If booted from SRM, reset some of the original environment. */
 	if (alpha_using_srm) {
 #ifdef CONFIG_DUMMY_CONSOLE
 		/* If we've gotten here after SysRq-b, leave interrupt
 		   context before taking over the console. */
 		if (in_interrupt())
 			irq_exit();
 		/* This has the effect of resetting the VGA video origin.  */
 		take_over_console(&dummy_con, 0, MAX_NR_CONSOLES-1, 1);
 #endif
 		pci_restore_srm_config();
 		set_hae(srm_hae);
 	}

 	if (alpha_mv.kill_arch)
 		alpha_mv.kill_arch(how->mode);

 	if (! alpha_using_srm && how->mode != LINUX_REBOOT_CMD_RESTART) {
 		/* Unfortunately, since MILO doesn't currently understand
 		   the hwrpb bits above, we can't reliably halt the
 		   processor and keep it halted.  So just loop.  */
 		return;
 	}

 	if (alpha_using_srm)
 		srm_paging_stop();

 	halt();
 }

 static void
 common_shutdown(int mode, char *restart_cmd)
 {
 	struct halt_info args;
 	args.mode = mode;
 	args.restart_cmd = restart_cmd;
 	on_each_cpu(common_shutdown_1, &args, 0);
 }

 void
 machine_restart(char *restart_cmd)
 {
 	common_shutdown(LINUX_REBOOT_CMD_RESTART, restart_cmd);
 }


 void
 machine_halt(void)
 {
 	common_shutdown(LINUX_REBOOT_CMD_HALT, NULL);
 }


 void
 machine_power_off(void)
 {
 	common_shutdown(LINUX_REBOOT_CMD_POWER_OFF, NULL);
 }


 /* Used by sysrq-p, among others.  I don't believe r9-r15 are ever
    saved in the context it's used.  */

 void
 show_regs(struct pt_regs *regs)
 {
 	dik_show_regs(regs, NULL);
 }

 /*
  * Re-start a thread when doing execve()
  */
 void
 start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
 {
 	set_fs(USER_DS);
 	regs->pc = pc;
 	regs->ps = 8;
 	wrusp(sp);
 }
 EXPORT_SYMBOL(start_thread);

 /*
  * Free current thread data structures etc..
  */
 void
 exit_thread(void)
 {
 }

 void
 flush_thread(void)
 {
 	/* Arrange for each exec'ed process to start off with a clean slate
 	   with respect to the FPU.  This is all exceptions disabled.  */
 	current_thread_info()->ieee_state = 0;
 	wrfpcr(FPCR_DYN_NORMAL | ieee_swcr_to_fpcr(0));

 	/* Clean slate for TLS.  */
 	current_thread_info()->pcb.unique = 0;
 }

 void
 release_thread(struct task_struct *dead_task)
 {
 }

 /*
  * "alpha_clone()".. 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)
  *
  * Notice that "fork()" is implemented in terms of clone,
  * with parameters (SIGCHLD, 0).
  */
 int
 alpha_clone(unsigned long clone_flags, unsigned long usp,
 	    int __user *parent_tid, int __user *child_tid,
 	    unsigned long tls_value, struct pt_regs *regs)
 {
 	if (!usp)
 		usp = rdusp();

 	return do_fork(clone_flags, usp, regs, 0, parent_tid, child_tid);
 }

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

 /*
  * Copy an alpha thread..
  *
  * Note the "stack_offset" stuff: when returning to kernel mode, we need
  * to have some extra stack-space for the kernel stack that still exists
  * after the "ret_from_fork".  When returning to user mode, we only want
  * the space needed by the syscall stack frame (ie "struct pt_regs").
  * Use the passed "regs" pointer to determine how much space we need
  * for a kernel fork().
  */

 int
 copy_thread(unsigned long clone_flags, unsigned long usp,
 	    unsigned long unused,
 	    struct task_struct * p, struct pt_regs * regs)
 {
 	extern void ret_from_fork(void);

 	struct thread_info *childti = task_thread_info(p);
 	struct pt_regs * childregs;
 	struct switch_stack * childstack, *stack;
 	unsigned long stack_offset, settls;

 	stack_offset = PAGE_SIZE - sizeof(struct pt_regs);
 	if (!(regs->ps & 8))
 		stack_offset = (PAGE_SIZE-1) & (unsigned long) regs;
 	childregs = (struct pt_regs *)
 	  (stack_offset + PAGE_SIZE + task_stack_page(p));

 	*childregs = *regs;
 	settls = regs->r20;
 	childregs->r0 = 0;
 	childregs->r19 = 0;
 	childregs->r20 = 1;	/* OSF/1 has some strange fork() semantics.  */
 	regs->r20 = 0;
 	stack = ((struct switch_stack *) regs) - 1;
 	childstack = ((struct switch_stack *) childregs) - 1;
 	*childstack = *stack;
 	childstack->r26 = (unsigned long) ret_from_fork;
 	childti->pcb.usp = usp;
 	childti->pcb.ksp = (unsigned long) childstack;
 	childti->pcb.flags = 1;	/* set FEN, clear everything else */

 	/* Set a new TLS for the child thread?  Peek back into the
 	   syscall arguments that we saved on syscall entry.  Oops,
 	   except we'd have clobbered it with the parent/child set
 	   of r20.  Read the saved copy.  */
 	/* Note: if CLONE_SETTLS is not set, then we must inherit the
 	   value from the parent, which will have been set by the block
 	   copy in dup_task_struct.  This is non-intuitive, but is
 	   required for proper operation in the case of a threaded
 	   application calling fork.  */
 	if (clone_flags & CLONE_SETTLS)
 		childti->pcb.unique = settls;

 	return 0;
 }

 /*
  * Fill in the user structure for a ELF core dump.
  */
 void
 dump_elf_thread(elf_greg_t *dest, struct pt_regs *pt, struct thread_info *ti)
 {
 	/* switch stack follows right below pt_regs: */
 	struct switch_stack * sw = ((struct switch_stack *) pt) - 1;

 	dest[ 0] = pt->r0;
 	dest[ 1] = pt->r1;
 	dest[ 2] = pt->r2;
 	dest[ 3] = pt->r3;
 	dest[ 4] = pt->r4;
 	dest[ 5] = pt->r5;
 	dest[ 6] = pt->r6;
 	dest[ 7] = pt->r7;
 	dest[ 8] = pt->r8;
 	dest[ 9] = sw->r9;
 	dest[10] = sw->r10;
 	dest[11] = sw->r11;
 	dest[12] = sw->r12;
 	dest[13] = sw->r13;
 	dest[14] = sw->r14;
 	dest[15] = sw->r15;
 	dest[16] = pt->r16;
 	dest[17] = pt->r17;
 	dest[18] = pt->r18;
 	dest[19] = pt->r19;
 	dest[20] = pt->r20;
 	dest[21] = pt->r21;
 	dest[22] = pt->r22;
 	dest[23] = pt->r23;
 	dest[24] = pt->r24;
 	dest[25] = pt->r25;
 	dest[26] = pt->r26;
 	dest[27] = pt->r27;
 	dest[28] = pt->r28;
 	dest[29] = pt->gp;
 	dest[30] = rdusp();
 	dest[31] = pt->pc;

 	/* Once upon a time this was the PS value.  Which is stupid
 	   since that is always 8 for usermode.  Usurped for the more
 	   useful value of the thread's UNIQUE field.  */
 	dest[32] = ti->pcb.unique;
 }
 EXPORT_SYMBOL(dump_elf_thread);

 int
 dump_elf_task(elf_greg_t *dest, struct task_struct *task)
 {
 	dump_elf_thread(dest, task_pt_regs(task), task_thread_info(task));
 	return 1;
 }
 EXPORT_SYMBOL(dump_elf_task);

 int
 dump_elf_task_fp(elf_fpreg_t *dest, struct task_struct *task)
 {
 	struct switch_stack *sw = (struct switch_stack *)task_pt_regs(task) - 1;
 	memcpy(dest, sw->fp, 32 * 8);
 	return 1;
 }
 EXPORT_SYMBOL(dump_elf_task_fp);

 /*
  * sys_execve() executes a new program.
  */
 asmlinkage int
 do_sys_execve(char __user *ufilename, char __user * __user *argv,
 	      char __user * __user *envp, struct pt_regs *regs)
 {
 	int error;
 	char *filename;

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

 /*
  * Return saved PC of a blocked thread.  This assumes the frame
  * pointer is the 6th saved long on the kernel stack and that the
  * saved return address is the first long in the frame.  This all
  * holds provided the thread blocked through a call to schedule() ($15
  * is the frame pointer in schedule() and $15 is saved at offset 48 by
  * entry.S:do_switch_stack).
  *
  * Under heavy swap load I've seen this lose in an ugly way.  So do
  * some extra sanity checking on the ranges we expect these pointers
  * to be in so that we can fail gracefully.  This is just for ps after
  * all.  -- r~
  */

 unsigned long
 thread_saved_pc(struct task_struct *t)
 {
 	unsigned long base = (unsigned long)task_stack_page(t);
 	unsigned long fp, sp = task_thread_info(t)->pcb.ksp;

 	if (sp > base && sp+6*8 < base + 16*1024) {
 		fp = ((unsigned long*)sp)[6];
 		if (fp > sp && fp < base + 16*1024)
 			return *(unsigned long *)fp;
 	}

 	return 0;
 }

 unsigned long
 get_wchan(struct task_struct *p)
 {
 	unsigned long schedule_frame;
 	unsigned long pc;
 	if (!p || p == current || p->state == TASK_RUNNING)
 		return 0;
 	/*
 	 * This one depends on the frame size of schedule().  Do a
 	 * "disass schedule" in gdb to find the frame size.  Also, the
 	 * code assumes that sleep_on() follows immediately after
 	 * interruptible_sleep_on() and that add_timer() follows
 	 * immediately after interruptible_sleep().  Ugly, isn't it?
 	 * Maybe adding a wchan field to task_struct would be better,
 	 * after all...
 	 */

 	pc = thread_saved_pc(p);
 	if (in_sched_functions(pc)) {
 		schedule_frame = ((unsigned long *)task_thread_info(p)->pcb.ksp)[6];
 		return ((unsigned long *)schedule_frame)[12];
 	}
 	return pc;
 }
	/*
	* linux/arch/alpha/kernel/process.c
	*
	* Copyright (C) 1995 Linus Torvalds
	*/

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

	#include <linux/errno.h>
	#include <linux/module.h>
	#include <linux/sched.h>
	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/smp.h>
	#include <linux/stddef.h>
	#include <linux/unistd.h>
	#include <linux/ptrace.h>
	#include <linux/user.h>
	#include <linux/time.h>
	#include <linux/major.h>
	#include <linux/stat.h>
	#include <linux/vt.h>
	#include <linux/mman.h>
	#include <linux/elfcore.h>
	#include <linux/reboot.h>
	#include <linux/tty.h>
	#include <linux/console.h>
	#include <linux/slab.h>

	#include <asm/reg.h>
	#include <asm/uaccess.h>
	#include <asm/system.h>
	#include <asm/io.h>
	#include <asm/pgtable.h>
	#include <asm/hwrpb.h>
	#include <asm/fpu.h>

	#include "proto.h"
	#include "pci_impl.h"

	/*
	* Power off function, if any
	*/
	void (*pm_power_off)(void) = machine_power_off;
	EXPORT_SYMBOL(pm_power_off);

	void
	cpu_idle(void)
	{
	set_thread_flag(TIF_POLLING_NRFLAG);

	while (1) {
	/* FIXME -- EV6 and LCA45 know how to power down
	the CPU. */

	while (!need_resched())
	cpu_relax();
	schedule();
	}
	}


	struct halt_info {
	int mode;
	char *restart_cmd;
	};

	static void
	common_shutdown_1(void *generic_ptr)
	{
	struct halt_info how = (struct halt_info )generic_ptr;
	struct percpu_struct *cpup;
	unsigned long *pflags, flags;
	int cpuid = smp_processor_id();

	/* No point in taking interrupts anymore. */
	local_irq_disable();

	cpup = (struct percpu_struct *)
	((unsigned long)hwrpb + hwrpb->processor_offset
	+ hwrpb->processor_size * cpuid);
	pflags = &cpup->flags;
	flags = *pflags;

	/* Clear reason to "default"; clear "bootstrap in progress". */
	flags &= ~0x00ff0001UL;

	#ifdef CONFIG_SMP
	/* Secondaries halt here. */
	if (cpuid != boot_cpuid) {
	flags \|= 0x00040000UL; /* "remain halted" */
	*pflags = flags;
	set_cpu_present(cpuid, false);
	set_cpu_possible(cpuid, false);
	halt();
	}
	#endif

	if (how->mode == LINUX_REBOOT_CMD_RESTART) {
	if (!how->restart_cmd) {
	flags \|= 0x00020000UL; /* "cold bootstrap" */
	} else {
	/* For SRM, we could probably set environment
	variables to get this to work. We'd have to
	delay this until after srm_paging_stop unless
	we ever got srm_fixup working.

	At the moment, SRM will use the last boot device,
	but the file and flags will be the defaults, when
	doing a "warm" bootstrap. */
	flags \|= 0x00030000UL; /* "warm bootstrap" */
	}
	} else {
	flags \|= 0x00040000UL; /* "remain halted" */
	}
	*pflags = flags;

	#ifdef CONFIG_SMP
	/* Wait for the secondaries to halt. */
	set_cpu_present(boot_cpuid, false);
	set_cpu_possible(boot_cpuid, false);
	while (cpus_weight(cpu_present_map))
	barrier();
	#endif

	/* If booted from SRM, reset some of the original environment. */
	if (alpha_using_srm) {
	#ifdef CONFIG_DUMMY_CONSOLE
	/* If we've gotten here after SysRq-b, leave interrupt
	context before taking over the console. */
	if (in_interrupt())
	irq_exit();
	/* This has the effect of resetting the VGA video origin. */
	take_over_console(&dummy_con, 0, MAX_NR_CONSOLES-1, 1);
	#endif
	pci_restore_srm_config();
	set_hae(srm_hae);
	}

	if (alpha_mv.kill_arch)
	alpha_mv.kill_arch(how->mode);

	if (! alpha_using_srm && how->mode != LINUX_REBOOT_CMD_RESTART) {
	/* Unfortunately, since MILO doesn't currently understand
	the hwrpb bits above, we can't reliably halt the
	processor and keep it halted. So just loop. */
	return;
	}

	if (alpha_using_srm)
	srm_paging_stop();

	halt();
	}

	static void
	common_shutdown(int mode, char *restart_cmd)
	{
	struct halt_info args;
	args.mode = mode;
	args.restart_cmd = restart_cmd;
	on_each_cpu(common_shutdown_1, &args, 0);
	}

	void
	machine_restart(char *restart_cmd)
	{
	common_shutdown(LINUX_REBOOT_CMD_RESTART, restart_cmd);
	}


	void
	machine_halt(void)
	{
	common_shutdown(LINUX_REBOOT_CMD_HALT, NULL);
	}


	void
	machine_power_off(void)
	{
	common_shutdown(LINUX_REBOOT_CMD_POWER_OFF, NULL);
	}


	/* Used by sysrq-p, among others. I don't believe r9-r15 are ever
	saved in the context it's used. */

	void
	show_regs(struct pt_regs *regs)
	{
	dik_show_regs(regs, NULL);
	}

	/*
	* Re-start a thread when doing execve()
	*/
	void
	start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
	{
	set_fs(USER_DS);
	regs->pc = pc;
	regs->ps = 8;
	wrusp(sp);
	}
	EXPORT_SYMBOL(start_thread);

	/*
	* Free current thread data structures etc..
	*/
	void
	exit_thread(void)
	{
	}

	void
	flush_thread(void)
	{
	/* Arrange for each exec'ed process to start off with a clean slate
	with respect to the FPU. This is all exceptions disabled. */
	current_thread_info()->ieee_state = 0;
	wrfpcr(FPCR_DYN_NORMAL \| ieee_swcr_to_fpcr(0));

	/* Clean slate for TLS. */
	current_thread_info()->pcb.unique = 0;
	}

	void
	release_thread(struct task_struct *dead_task)
	{
	}

	/*
	* "alpha_clone()".. 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)
	*
	* Notice that "fork()" is implemented in terms of clone,
	* with parameters (SIGCHLD, 0).
	*/
	int
	alpha_clone(unsigned long clone_flags, unsigned long usp,
	int __user parent_tid, int __user child_tid,
	unsigned long tls_value, struct pt_regs *regs)
	{
	if (!usp)
	usp = rdusp();

	return do_fork(clone_flags, usp, regs, 0, parent_tid, child_tid);
	}

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

	/*
	* Copy an alpha thread..
	*
	* Note the "stack_offset" stuff: when returning to kernel mode, we need
	* to have some extra stack-space for the kernel stack that still exists
	* after the "ret_from_fork". When returning to user mode, we only want
	* the space needed by the syscall stack frame (ie "struct pt_regs").
	* Use the passed "regs" pointer to determine how much space we need
	* for a kernel fork().
	*/

	int
	copy_thread(unsigned long clone_flags, unsigned long usp,
	unsigned long unused,
	struct task_struct * p, struct pt_regs * regs)
	{
	extern void ret_from_fork(void);

	struct thread_info *childti = task_thread_info(p);
	struct pt_regs * childregs;
	struct switch_stack * childstack, *stack;
	unsigned long stack_offset, settls;

	stack_offset = PAGE_SIZE - sizeof(struct pt_regs);
	if (!(regs->ps & 8))
	stack_offset = (PAGE_SIZE-1) & (unsigned long) regs;
	childregs = (struct pt_regs *)
	(stack_offset + PAGE_SIZE + task_stack_page(p));

	childregs = regs;
	settls = regs->r20;
	childregs->r0 = 0;
	childregs->r19 = 0;
	childregs->r20 = 1; /* OSF/1 has some strange fork() semantics. */
	regs->r20 = 0;
	stack = ((struct switch_stack *) regs) - 1;
	childstack = ((struct switch_stack *) childregs) - 1;
	childstack = stack;
	childstack->r26 = (unsigned long) ret_from_fork;
	childti->pcb.usp = usp;
	childti->pcb.ksp = (unsigned long) childstack;
	childti->pcb.flags = 1; /* set FEN, clear everything else */

	/* Set a new TLS for the child thread? Peek back into the
	syscall arguments that we saved on syscall entry. Oops,
	except we'd have clobbered it with the parent/child set
	of r20. Read the saved copy. */
	/* Note: if CLONE_SETTLS is not set, then we must inherit the
	value from the parent, which will have been set by the block
	copy in dup_task_struct. This is non-intuitive, but is
	required for proper operation in the case of a threaded
	application calling fork. */
	if (clone_flags & CLONE_SETTLS)
	childti->pcb.unique = settls;

	return 0;
	}

	/*
	* Fill in the user structure for a ELF core dump.
	*/
	void
	dump_elf_thread(elf_greg_t dest, struct pt_regs pt, struct thread_info *ti)
	{
	/* switch stack follows right below pt_regs: */
	struct switch_stack * sw = ((struct switch_stack *) pt) - 1;

	dest[ 0] = pt->r0;
	dest[ 1] = pt->r1;
	dest[ 2] = pt->r2;
	dest[ 3] = pt->r3;
	dest[ 4] = pt->r4;
	dest[ 5] = pt->r5;
	dest[ 6] = pt->r6;
	dest[ 7] = pt->r7;
	dest[ 8] = pt->r8;
	dest[ 9] = sw->r9;
	dest[10] = sw->r10;
	dest[11] = sw->r11;
	dest[12] = sw->r12;
	dest[13] = sw->r13;
	dest[14] = sw->r14;
	dest[15] = sw->r15;
	dest[16] = pt->r16;
	dest[17] = pt->r17;
	dest[18] = pt->r18;
	dest[19] = pt->r19;
	dest[20] = pt->r20;
	dest[21] = pt->r21;
	dest[22] = pt->r22;
	dest[23] = pt->r23;
	dest[24] = pt->r24;
	dest[25] = pt->r25;
	dest[26] = pt->r26;
	dest[27] = pt->r27;
	dest[28] = pt->r28;
	dest[29] = pt->gp;
	dest[30] = rdusp();
	dest[31] = pt->pc;

	/* Once upon a time this was the PS value. Which is stupid
	since that is always 8 for usermode. Usurped for the more
	useful value of the thread's UNIQUE field. */
	dest[32] = ti->pcb.unique;
	}
	EXPORT_SYMBOL(dump_elf_thread);

	int
	dump_elf_task(elf_greg_t dest, struct task_struct task)
	{
	dump_elf_thread(dest, task_pt_regs(task), task_thread_info(task));
	return 1;
	}
	EXPORT_SYMBOL(dump_elf_task);

	int
	dump_elf_task_fp(elf_fpreg_t dest, struct task_struct task)
	{
	struct switch_stack sw = (struct switch_stack )task_pt_regs(task) - 1;
	memcpy(dest, sw->fp, 32 * 8);
	return 1;
	}
	EXPORT_SYMBOL(dump_elf_task_fp);

	/*
	* sys_execve() executes a new program.
	*/
	asmlinkage int
	do_sys_execve(char __user ufilename, char __user __user *argv,
	char __user * __user envp, struct pt_regs regs)
	{
	int error;
	char *filename;

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

	/*
	* Return saved PC of a blocked thread. This assumes the frame
	* pointer is the 6th saved long on the kernel stack and that the
	* saved return address is the first long in the frame. This all
	* holds provided the thread blocked through a call to schedule() ($15
	* is the frame pointer in schedule() and $15 is saved at offset 48 by
	* entry.S:do_switch_stack).
	*
	* Under heavy swap load I've seen this lose in an ugly way. So do
	* some extra sanity checking on the ranges we expect these pointers
	* to be in so that we can fail gracefully. This is just for ps after
	* all. -- r~
	*/

	unsigned long
	thread_saved_pc(struct task_struct *t)
	{
	unsigned long base = (unsigned long)task_stack_page(t);
	unsigned long fp, sp = task_thread_info(t)->pcb.ksp;

	if (sp > base && sp+68 < base + 161024) {
	fp = ((unsigned long*)sp)[6];
	if (fp > sp && fp < base + 16*1024)
	return (unsigned long )fp;
	}

	return 0;
	}

	unsigned long
	get_wchan(struct task_struct *p)
	{
	unsigned long schedule_frame;
	unsigned long pc;
	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	return 0;
	/*
	* This one depends on the frame size of schedule(). Do a
	* "disass schedule" in gdb to find the frame size. Also, the
	* code assumes that sleep_on() follows immediately after
	* interruptible_sleep_on() and that add_timer() follows
	* immediately after interruptible_sleep(). Ugly, isn't it?
	* Maybe adding a wchan field to task_struct would be better,
	* after all...
	*/

	pc = thread_saved_pc(p);
	if (in_sched_functions(pc)) {
	schedule_frame = ((unsigned long *)task_thread_info(p)->pcb.ksp)[6];
	return ((unsigned long *)schedule_frame)[12];
	}
	return pc;
	}