[mirror_ubuntu-zesty-kernel.git] / arch / parisc / kernel / process.c

/*
 *    PARISC Architecture-dependent parts of process handling
 *    based on the work for i386
 *
 *    Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
 *    Copyright (C) 2000 Martin K Petersen <mkp at mkp.net>
 *    Copyright (C) 2000 John Marvin <jsm at parisc-linux.org>
 *    Copyright (C) 2000 David Huggins-Daines <dhd with pobox.org>
 *    Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
 *    Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org>
 *    Copyright (C) 2000 David Kennedy <dkennedy with linuxcare.com>
 *    Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
 *    Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
 *    Copyright (C) 2001 Alan Modra <amodra at parisc-linux.org>
 *    Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
 *    Copyright (C) 2001-2002 Helge Deller <deller at parisc-linux.org>
 *    Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
 *
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <stdarg.h>

#include <linux/elf.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/personality.h>
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/kallsyms.h>

#include <asm/io.h>
#include <asm/asm-offsets.h>
#include <asm/pdc.h>
#include <asm/pdc_chassis.h>
#include <asm/pgalloc.h>
#include <asm/uaccess.h>
#include <asm/unwind.h>

static int hlt_counter;

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

void disable_hlt(void)
{
	hlt_counter++;
}

EXPORT_SYMBOL(disable_hlt);

void enable_hlt(void)
{
	hlt_counter--;
}

EXPORT_SYMBOL(enable_hlt);

void default_idle(void)
{
	barrier();
}

/*
 * 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) {
		while (!need_resched())
			barrier();
		preempt_enable_no_resched();
		schedule();
		preempt_disable();
		check_pgt_cache();
	}
}


#ifdef __LP64__
#define COMMAND_GLOBAL  0xfffffffffffe0030UL
#else
#define COMMAND_GLOBAL  0xfffe0030
#endif

#define CMD_RESET       5       /* reset any module */

/*
** The Wright Brothers and Gecko systems have a H/W problem
** (Lasi...'nuf said) may cause a broadcast reset to lockup
** the system. An HVERSION dependent PDC call was developed
** to perform a "safe", platform specific broadcast reset instead
** of kludging up all the code.
**
** Older machines which do not implement PDC_BROADCAST_RESET will
** return (with an error) and the regular broadcast reset can be
** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
** the PDC call will not return (the system will be reset).
*/
void machine_restart(char *cmd)
{
#ifdef FASTBOOT_SELFTEST_SUPPORT
	/*
	 ** If user has modified the Firmware Selftest Bitmap,
	 ** run the tests specified in the bitmap after the
	 ** system is rebooted w/PDC_DO_RESET.
	 **
	 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
	 **
	 ** Using "directed resets" at each processor with the MEM_TOC
	 ** vector cleared will also avoid running destructive
	 ** memory self tests. (Not implemented yet)
	 */
	if (ftc_bitmap) {
		pdc_do_firm_test_reset(ftc_bitmap);
	}
#endif
	/* set up a new led state on systems shipped with a LED State panel */
	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
	
	/* "Normal" system reset */
	pdc_do_reset();

	/* Nope...box should reset with just CMD_RESET now */
	gsc_writel(CMD_RESET, COMMAND_GLOBAL);

	/* Wait for RESET to lay us to rest. */
	while (1) ;

}

void machine_halt(void)
{
	/*
	** The LED/ChassisCodes are updated by the led_halt()
	** function, called by the reboot notifier chain.
	*/
}


/*
 * This routine is called from sys_reboot to actually turn off the
 * machine 
 */
void machine_power_off(void)
{
	/* If there is a registered power off handler, call it. */
	if(pm_power_off)
		pm_power_off();

	/* Put the soft power button back under hardware control.
	 * If the user had already pressed the power button, the
	 * following call will immediately power off. */
	pdc_soft_power_button(0);
	
	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
		
	/* It seems we have no way to power the system off via
	 * software. The user has to press the button himself. */

	printk(KERN_EMERG "System shut down completed.\n"
	       KERN_EMERG "Please power this system off now.");
}


/*
 * Create a kernel thread
 */

extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{

	/*
	 * FIXME: Once we are sure we don't need any debug here,
	 *	  kernel_thread can become a #define.
	 */

	return __kernel_thread(fn, arg, flags);
}
EXPORT_SYMBOL(kernel_thread);

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

void flush_thread(void)
{
	/* Only needs to handle fpu stuff or perf monitors.
	** REVISIT: several arches implement a "lazy fpu state".
	*/
	set_fs(USER_DS);
}

void release_thread(struct task_struct *dead_task)
{
}

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

int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
{
	if (regs == NULL)
		return 0;

	memcpy(r, regs->fr, sizeof *r);
	return 1;
}

int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r)
{
	memcpy(r, tsk->thread.regs.fr, sizeof(*r));
	return 1;
}

/* Note that "fork()" is implemented in terms of clone, with
   parameters (SIGCHLD, regs->gr[30], regs). */
int
sys_clone(unsigned long clone_flags, unsigned long usp,
	  struct pt_regs *regs)
{
  	/* Arugments from userspace are:
	   r26 = Clone flags.
	   r25 = Child stack.
	   r24 = parent_tidptr.
	   r23 = Is the TLS storage descriptor 
	   r22 = child_tidptr 
	   
	   However, these last 3 args are only examined
	   if the proper flags are set. */
	int __user *child_tidptr;
	int __user *parent_tidptr;

	/* usp must be word aligned.  This also prevents users from
	 * passing in the value 1 (which is the signal for a special
	 * return for a kernel thread) */
	usp = ALIGN(usp, 4);

	/* A zero value for usp means use the current stack */
	if (usp == 0)
	  usp = regs->gr[30];

	if (clone_flags & CLONE_PARENT_SETTID)
	  parent_tidptr = (int __user *)regs->gr[24];
	else
	  parent_tidptr = NULL;
	
	if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID))
	  child_tidptr = (int __user *)regs->gr[22];
	else
	  child_tidptr = NULL;

	return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr);
}

int
sys_vfork(struct pt_regs *regs)
{
	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gr[30], regs, 0, NULL, NULL);
}

int
copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
	    unsigned long unused,	/* in ia64 this is "user_stack_size" */
	    struct task_struct * p, struct pt_regs * pregs)
{
	struct pt_regs * cregs = &(p->thread.regs);
	struct thread_info *ti = p->thread_info;
	
	/* We have to use void * instead of a function pointer, because
	 * function pointers aren't a pointer to the function on 64-bit.
	 * Make them const so the compiler knows they live in .text */
	extern void * const ret_from_kernel_thread;
	extern void * const child_return;
#ifdef CONFIG_HPUX
	extern void * const hpux_child_return;
#endif

	*cregs = *pregs;

	/* Set the return value for the child.  Note that this is not
           actually restored by the syscall exit path, but we put it
           here for consistency in case of signals. */
	cregs->gr[28] = 0; /* child */

	/*
	 * We need to differentiate between a user fork and a
	 * kernel fork. We can't use user_mode, because the
	 * the syscall path doesn't save iaoq. Right now
	 * We rely on the fact that kernel_thread passes
	 * in zero for usp.
	 */
	if (usp == 1) {
		/* kernel thread */
		cregs->ksp = (((unsigned long)(ti)) + THREAD_SZ_ALGN);
		/* Must exit via ret_from_kernel_thread in order
		 * to call schedule_tail()
		 */
		cregs->kpc = (unsigned long) &ret_from_kernel_thread;
		/*
		 * Copy function and argument to be called from
		 * ret_from_kernel_thread.
		 */
#ifdef __LP64__
		cregs->gr[27] = pregs->gr[27];
#endif
		cregs->gr[26] = pregs->gr[26];
		cregs->gr[25] = pregs->gr[25];
	} else {
		/* user thread */
		/*
		 * Note that the fork wrappers are responsible
		 * for setting gr[21].
		 */

		/* Use same stack depth as parent */
		cregs->ksp = ((unsigned long)(ti))
			+ (pregs->gr[21] & (THREAD_SIZE - 1));
		cregs->gr[30] = usp;
		if (p->personality == PER_HPUX) {
#ifdef CONFIG_HPUX
			cregs->kpc = (unsigned long) &hpux_child_return;
#else
			BUG();
#endif
		} else {
			cregs->kpc = (unsigned long) &child_return;
		}
		/* Setup thread TLS area from the 4th parameter in clone */
		if (clone_flags & CLONE_SETTLS)
		  cregs->cr27 = pregs->gr[23];
	
	}

	return 0;
}

unsigned long thread_saved_pc(struct task_struct *t)
{
	return t->thread.regs.kpc;
}

/*
 * sys_execve() executes a new program.
 */

asmlinkage int sys_execve(struct pt_regs *regs)
{
	int error;
	char *filename;

	filename = getname((const char __user *) regs->gr[26]);
	error = PTR_ERR(filename);
	if (IS_ERR(filename))
		goto out;
	error = do_execve(filename, (char __user **) regs->gr[25],
		(char __user **) regs->gr[24], regs);
	if (error == 0) {
		task_lock(current);
		current->ptrace &= ~PT_DTRACE;
		task_unlock(current);
	}
	putname(filename);
out:

	return error;
}

unsigned long 
get_wchan(struct task_struct *p)
{
	struct unwind_frame_info info;
	unsigned long ip;
	int count = 0;
	/*
	 * These bracket the sleeping functions..
	 */

	unwind_frame_init_from_blocked_task(&info, p);
	do {
		if (unwind_once(&info) < 0)
			return 0;
		ip = info.ip;
		if (!in_sched_functions(ip))
			return ip;
	} while (count++ < 16);
	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* PARISC Architecture-dependent parts of process handling
	3	* based on the work for i386
	4	*
	5	* Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
	6	* Copyright (C) 2000 Martin K Petersen <mkp at mkp.net>
	7	* Copyright (C) 2000 John Marvin <jsm at parisc-linux.org>
	8	* Copyright (C) 2000 David Huggins-Daines <dhd with pobox.org>
	9	* Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
	10	* Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org>
	11	* Copyright (C) 2000 David Kennedy <dkennedy with linuxcare.com>
b2450cc1	12	* Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
1da177e4 LT	13	* Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
	14	* Copyright (C) 2001 Alan Modra <amodra at parisc-linux.org>
	15	* Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
	16	* Copyright (C) 2001-2002 Helge Deller <deller at parisc-linux.org>
	17	* Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
	18	*
	19	*
	20	* This program is free software; you can redistribute it and/or modify
	21	* it under the terms of the GNU General Public License as published by
	22	* the Free Software Foundation; either version 2 of the License, or
	23	* (at your option) any later version.
	24	*
	25	* This program is distributed in the hope that it will be useful,
	26	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	27	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	28	* GNU General Public License for more details.
	29	*
	30	* You should have received a copy of the GNU General Public License
	31	* along with this program; if not, write to the Free Software
	32	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	33	*/
	34
	35	#include <stdarg.h>
	36
	37	#include <linux/elf.h>
	38	#include <linux/errno.h>
	39	#include <linux/kernel.h>
	40	#include <linux/mm.h>
	41	#include <linux/module.h>
	42	#include <linux/personality.h>
	43	#include <linux/ptrace.h>
	44	#include <linux/sched.h>
	45	#include <linux/stddef.h>
	46	#include <linux/unistd.h>
	47	#include <linux/kallsyms.h>
	48
	49	#include <asm/io.h>
0013a854	50	#include <asm/asm-offsets.h>
1da177e4 LT	51	#include <asm/pdc.h>
	52	#include <asm/pdc_chassis.h>
	53	#include <asm/pgalloc.h>
	54	#include <asm/uaccess.h>
	55	#include <asm/unwind.h>
	56
	57	static int hlt_counter;
	58
	59	/*
	60	* Power off function, if any
	61	*/
	62	void (*pm_power_off)(void);
	63
	64	void disable_hlt(void)
	65	{
	66	hlt_counter++;
	67	}
	68
	69	EXPORT_SYMBOL(disable_hlt);
	70
	71	void enable_hlt(void)
	72	{
	73	hlt_counter--;
	74	}
	75
	76	EXPORT_SYMBOL(enable_hlt);
	77
	78	void default_idle(void)
	79	{
	80	barrier();
	81	}
	82
	83	/*
	84	* The idle thread. There's no useful work to be
	85	* done, so just try to conserve power and have a
	86	* low exit latency (ie sit in a loop waiting for
	87	* somebody to say that they'd like to reschedule)
	88	*/
	89	void cpu_idle(void)
	90	{
	91	/* endless idle loop with no priority at all */
	92	while (1) {
	93	while (!need_resched())
	94	barrier();
5bfb5d69	95	preempt_enable_no_resched();
1da177e4	96	schedule();
5bfb5d69	97	preempt_disable();
1da177e4 LT	98	check_pgt_cache();
	99	}
	100	}
	101
	102
	103	#ifdef __LP64__
	104	#define COMMAND_GLOBAL 0xfffffffffffe0030UL
	105	#else
	106	#define COMMAND_GLOBAL 0xfffe0030
	107	#endif
	108
	109	#define CMD_RESET 5 /* reset any module */
	110
	111	/*
	112	** The Wright Brothers and Gecko systems have a H/W problem
	113	** (Lasi...'nuf said) may cause a broadcast reset to lockup
	114	** the system. An HVERSION dependent PDC call was developed
	115	** to perform a "safe", platform specific broadcast reset instead
	116	** of kludging up all the code.
	117	**
	118	** Older machines which do not implement PDC_BROADCAST_RESET will
	119	** return (with an error) and the regular broadcast reset can be
	120	** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
	121	** the PDC call will not return (the system will be reset).
	122	*/
	123	void machine_restart(char *cmd)
	124	{
	125	#ifdef FASTBOOT_SELFTEST_SUPPORT
	126	/*
	127	** If user has modified the Firmware Selftest Bitmap,
	128	** run the tests specified in the bitmap after the
	129	** system is rebooted w/PDC_DO_RESET.
	130	**
	131	** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
	132	**
	133	** Using "directed resets" at each processor with the MEM_TOC
	134	** vector cleared will also avoid running destructive
	135	** memory self tests. (Not implemented yet)
	136	*/
	137	if (ftc_bitmap) {
	138	pdc_do_firm_test_reset(ftc_bitmap);
	139	}
	140	#endif
	141	/* set up a new led state on systems shipped with a LED State panel */
	142	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
	143
	144	/* "Normal" system reset */
	145	pdc_do_reset();
	146
	147	/* Nope...box should reset with just CMD_RESET now */
	148	gsc_writel(CMD_RESET, COMMAND_GLOBAL);
	149
	150	/* Wait for RESET to lay us to rest. */
	151	while (1) ;
	152
	153	}
	154
1da177e4 LT	155	void machine_halt(void)
	156	{
	157	/*
	158	** The LED/ChassisCodes are updated by the led_halt()
	159	** function, called by the reboot notifier chain.
	160	*/
	161	}
	162
1da177e4 LT	163
	164	/*
	165	* This routine is called from sys_reboot to actually turn off the
	166	* machine
	167	*/
	168	void machine_power_off(void)
	169	{
	170	/* If there is a registered power off handler, call it. */
	171	if(pm_power_off)
	172	pm_power_off();
	173
	174	/* Put the soft power button back under hardware control.
	175	* If the user had already pressed the power button, the
	176	* following call will immediately power off. */
	177	pdc_soft_power_button(0);
	178
	179	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
	180
	181	/* It seems we have no way to power the system off via
	182	* software. The user has to press the button himself. */
	183
	184	printk(KERN_EMERG "System shut down completed.\n"
	185	KERN_EMERG "Please power this system off now.");
	186	}
	187
1da177e4 LT	188
	189	/*
	190	* Create a kernel thread
	191	*/
	192
	193	extern pid_t __kernel_thread(int (fn)(void ), void *arg, unsigned long flags);
	194	pid_t kernel_thread(int (fn)(void ), void *arg, unsigned long flags)
	195	{
	196
	197	/*
	198	* FIXME: Once we are sure we don't need any debug here,
	199	* kernel_thread can become a #define.
	200	*/
	201
	202	return __kernel_thread(fn, arg, flags);
	203	}
	204	EXPORT_SYMBOL(kernel_thread);
	205
	206	/*
	207	* Free current thread data structures etc..
	208	*/
	209	void exit_thread(void)
	210	{
	211	}
	212
	213	void flush_thread(void)
	214	{
	215	/* Only needs to handle fpu stuff or perf monitors.
	216	** REVISIT: several arches implement a "lazy fpu state".
	217	*/
	218	set_fs(USER_DS);
	219	}
	220
	221	void release_thread(struct task_struct *dead_task)
	222	{
	223	}
	224
	225	/*
	226	* Fill in the FPU structure for a core dump.
	227	*/
	228
	229	int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
	230	{
	231	if (regs == NULL)
	232	return 0;
	233
	234	memcpy(r, regs->fr, sizeof *r);
	235	return 1;
	236	}
	237
	238	int dump_task_fpu (struct task_struct tsk, elf_fpregset_t r)
	239	{
	240	memcpy(r, tsk->thread.regs.fr, sizeof(*r));
	241	return 1;
	242	}
	243
	244	/* Note that "fork()" is implemented in terms of clone, with
	245	parameters (SIGCHLD, regs->gr[30], regs). */
	246	int
	247	sys_clone(unsigned long clone_flags, unsigned long usp,
	248	struct pt_regs *regs)
	249	{
b2450cc1 CD	250	/* Arugments from userspace are:
	251	r26 = Clone flags.
	252	r25 = Child stack.
	253	r24 = parent_tidptr.
	254	r23 = Is the TLS storage descriptor
	255	r22 = child_tidptr
	256
	257	However, these last 3 args are only examined
	258	if the proper flags are set. */
	259	int __user *child_tidptr;
	260	int __user *parent_tidptr;
1da177e4 LT	261
	262	/* usp must be word aligned. This also prevents users from
	263	* passing in the value 1 (which is the signal for a special
	264	* return for a kernel thread) */
	265	usp = ALIGN(usp, 4);
	266
	267	/* A zero value for usp means use the current stack */
b2450cc1 CD	268	if (usp == 0)
b2450cc1 CD	269	usp = regs->gr[30];
1da177e4	270
b2450cc1 CD	271	if (clone_flags & CLONE_PARENT_SETTID)
	272	parent_tidptr = (int __user *)regs->gr[24];
	273	else
	274	parent_tidptr = NULL;
	275
	276	if (clone_flags & (CLONE_CHILD_SETTID \| CLONE_CHILD_CLEARTID))
	277	child_tidptr = (int __user *)regs->gr[22];
	278	else
	279	child_tidptr = NULL;
	280
	281	return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr);
1da177e4 LT	282	}
	283
	284	int
	285	sys_vfork(struct pt_regs *regs)
	286	{
	287	return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, regs->gr[30], regs, 0, NULL, NULL);
	288	}
	289
	290	int
	291	copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
	292	unsigned long unused, /* in ia64 this is "user_stack_size" */
	293	struct task_struct * p, struct pt_regs * pregs)
	294	{
	295	struct pt_regs * cregs = &(p->thread.regs);
	296	struct thread_info *ti = p->thread_info;
	297
	298	/* We have to use void * instead of a function pointer, because
	299	* function pointers aren't a pointer to the function on 64-bit.
	300	* Make them const so the compiler knows they live in .text */
	301	extern void * const ret_from_kernel_thread;
	302	extern void * const child_return;
	303	#ifdef CONFIG_HPUX
	304	extern void * const hpux_child_return;
	305	#endif
	306
	307	cregs = pregs;
	308
	309	/* Set the return value for the child. Note that this is not
	310	actually restored by the syscall exit path, but we put it
	311	here for consistency in case of signals. */
	312	cregs->gr[28] = 0; /* child */
	313
	314	/*
	315	* We need to differentiate between a user fork and a
	316	* kernel fork. We can't use user_mode, because the
	317	* the syscall path doesn't save iaoq. Right now
	318	* We rely on the fact that kernel_thread passes
	319	* in zero for usp.
	320	*/
	321	if (usp == 1) {
	322	/* kernel thread */
	323	cregs->ksp = (((unsigned long)(ti)) + THREAD_SZ_ALGN);
	324	/* Must exit via ret_from_kernel_thread in order
	325	* to call schedule_tail()
	326	*/
	327	cregs->kpc = (unsigned long) &ret_from_kernel_thread;
	328	/*
	329	* Copy function and argument to be called from
	330	* ret_from_kernel_thread.
	331	*/
	332	#ifdef __LP64__
	333	cregs->gr[27] = pregs->gr[27];
	334	#endif
	335	cregs->gr[26] = pregs->gr[26];
	336	cregs->gr[25] = pregs->gr[25];
	337	} else {
	338	/* user thread */
	339	/*
	340	* Note that the fork wrappers are responsible
	341	* for setting gr[21].
	342	*/
	343
	344	/* Use same stack depth as parent */
	345	cregs->ksp = ((unsigned long)(ti))
346	+ (pregs->gr[21] & (THREAD_SIZE - 1));
347	cregs->gr[30] = usp;
348	if (p->personality == PER_HPUX) {
349	#ifdef CONFIG_HPUX
350	cregs->kpc = (unsigned long) &hpux_child_return;
351	#else
352	BUG();
353	#endif
354	} else {
355	cregs->kpc = (unsigned long) &child_return;
356	}
b2450cc1 CD	357	/* Setup thread TLS area from the 4th parameter in clone */
	358	if (clone_flags & CLONE_SETTLS)
	359	cregs->cr27 = pregs->gr[23];
	360
1da177e4 LT	361	}
	362
	363	return 0;
	364	}
	365
	366	unsigned long thread_saved_pc(struct task_struct *t)
	367	{
	368	return t->thread.regs.kpc;
	369	}
	370
	371	/*
	372	* sys_execve() executes a new program.
	373	*/
	374
	375	asmlinkage int sys_execve(struct pt_regs *regs)
	376	{
	377	int error;
	378	char *filename;
	379
	380	filename = getname((const char __user *) regs->gr[26]);
	381	error = PTR_ERR(filename);
	382	if (IS_ERR(filename))
	383	goto out;
	384	error = do_execve(filename, (char __user **) regs->gr[25],
	385	(char __user **) regs->gr[24], regs);
	386	if (error == 0) {
	387	task_lock(current);
	388	current->ptrace &= ~PT_DTRACE;
	389	task_unlock(current);
	390	}
	391	putname(filename);
	392	out:
	393
	394	return error;
	395	}
	396
	397	unsigned long
	398	get_wchan(struct task_struct *p)
	399	{
	400	struct unwind_frame_info info;
	401	unsigned long ip;
	402	int count = 0;
	403	/*
	404	* These bracket the sleeping functions..
	405	*/
	406
	407	unwind_frame_init_from_blocked_task(&info, p);
	408	do {
	409	if (unwind_once(&info) < 0)
	410	return 0;
	411	ip = info.ip;
	412	if (!in_sched_functions(ip))
	413	return ip;
	414	} while (count++ < 16);
	415	return 0;
	416	}