[mirror_ubuntu-focal-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) 2001-2007 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/fs.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>

/*
 * 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)
{
	set_thread_flag(TIF_POLLING_NRFLAG);

	/* endless idle loop with no priority at all */
	while (1) {
		while (!need_resched())
			barrier();
		preempt_enable_no_resched();
		schedule();
		preempt_disable();
		check_pgt_cache();
	}
}


#define COMMAND_GLOBAL  F_EXTEND(0xfffe0030)
#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.
	*/
}

void (*chassis_power_off)(void);

/*
 * 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 (chassis_power_off)
		chassis_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.");
}

void (*pm_power_off)(void) = machine_power_off;
EXPORT_SYMBOL(pm_power_off);

/*
 * 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);
	void *stack = task_stack_page(p);
	
	/* 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)stack + 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 CONFIG_64BIT
		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)stack
			+ (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 * __user *) regs->gr[25],
		(char __user * __user *) regs->gr[24], regs);
	if (error == 0) {
		task_lock(current);
		current->ptrace &= ~PT_DTRACE;
		task_unlock(current);
	}
	putname(filename);
out:

	return error;
}

extern int __execve(const char *filename, char *const argv[],
		char *const envp[], struct task_struct *task);
int kernel_execve(const char *filename, char *const argv[], char *const envp[])
{
	return __execve(filename, argv, envp, current);
}

unsigned long
get_wchan(struct task_struct *p)
{
	struct unwind_frame_info info;
	unsigned long ip;
	int count = 0;

	if (!p || p == current || p->state == TASK_RUNNING)
		return 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>
a8f44e38	16	* Copyright (C) 2001-2007 Helge Deller <deller at parisc-linux.org>
1da177e4 LT	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>
4e950f6f	41	#include <linux/fs.h>
1da177e4 LT	42	#include <linux/module.h>
	43	#include <linux/personality.h>
	44	#include <linux/ptrace.h>
	45	#include <linux/sched.h>
	46	#include <linux/stddef.h>
	47	#include <linux/unistd.h>
	48	#include <linux/kallsyms.h>
	49
	50	#include <asm/io.h>
0013a854	51	#include <asm/asm-offsets.h>
1da177e4 LT	52	#include <asm/pdc.h>
	53	#include <asm/pdc_chassis.h>
	54	#include <asm/pgalloc.h>
	55	#include <asm/uaccess.h>
	56	#include <asm/unwind.h>
	57
1da177e4 LT	58	/*
	59	* The idle thread. There's no useful work to be
	60	* done, so just try to conserve power and have a
	61	* low exit latency (ie sit in a loop waiting for
	62	* somebody to say that they'd like to reschedule)
	63	*/
	64	void cpu_idle(void)
	65	{
64c7c8f8 NP	66	set_thread_flag(TIF_POLLING_NRFLAG);
64c7c8f8 NP	67
1da177e4 LT	68	/* endless idle loop with no priority at all */
	69	while (1) {
	70	while (!need_resched())
	71	barrier();
5bfb5d69	72	preempt_enable_no_resched();
1da177e4	73	schedule();
5bfb5d69	74	preempt_disable();
1da177e4 LT	75	check_pgt_cache();
	76	}
	77	}
	78
	79
10992092	80	#define COMMAND_GLOBAL F_EXTEND(0xfffe0030)
1da177e4 LT	81	#define CMD_RESET 5 /* reset any module */
	82
	83	/*
	84	** The Wright Brothers and Gecko systems have a H/W problem
	85	** (Lasi...'nuf said) may cause a broadcast reset to lockup
	86	** the system. An HVERSION dependent PDC call was developed
	87	** to perform a "safe", platform specific broadcast reset instead
	88	** of kludging up all the code.
	89	**
	90	** Older machines which do not implement PDC_BROADCAST_RESET will
	91	** return (with an error) and the regular broadcast reset can be
	92	** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
	93	** the PDC call will not return (the system will be reset).
	94	*/
	95	void machine_restart(char *cmd)
	96	{
	97	#ifdef FASTBOOT_SELFTEST_SUPPORT
	98	/*
	99	** If user has modified the Firmware Selftest Bitmap,
	100	** run the tests specified in the bitmap after the
	101	** system is rebooted w/PDC_DO_RESET.
	102	**
	103	** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
	104	**
	105	** Using "directed resets" at each processor with the MEM_TOC
	106	** vector cleared will also avoid running destructive
	107	** memory self tests. (Not implemented yet)
	108	*/
	109	if (ftc_bitmap) {
	110	pdc_do_firm_test_reset(ftc_bitmap);
	111	}
	112	#endif
	113	/* set up a new led state on systems shipped with a LED State panel */
	114	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
	115
	116	/* "Normal" system reset */
	117	pdc_do_reset();
	118
	119	/* Nope...box should reset with just CMD_RESET now */
	120	gsc_writel(CMD_RESET, COMMAND_GLOBAL);
	121
	122	/* Wait for RESET to lay us to rest. */
	123	while (1) ;
	124
	125	}
	126
1da177e4 LT	127	void machine_halt(void)
	128	{
	129	/*
	130	** The LED/ChassisCodes are updated by the led_halt()
	131	** function, called by the reboot notifier chain.
	132	*/
	133	}
	134
85509c00	135	void (*chassis_power_off)(void);
1da177e4 LT	136
	137	/*
	138	* This routine is called from sys_reboot to actually turn off the
	139	* machine
	140	*/
	141	void machine_power_off(void)
	142	{
	143	/* If there is a registered power off handler, call it. */
85509c00 KM	144	if (chassis_power_off)
85509c00 KM	145	chassis_power_off();
1da177e4 LT	146
	147	/* Put the soft power button back under hardware control.
	148	* If the user had already pressed the power button, the
	149	* following call will immediately power off. */
	150	pdc_soft_power_button(0);
	151
	152	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
	153
	154	/* It seems we have no way to power the system off via
	155	* software. The user has to press the button himself. */
	156
	157	printk(KERN_EMERG "System shut down completed.\n"
	158	KERN_EMERG "Please power this system off now.");
	159	}
	160
85509c00 KM	161	void (*pm_power_off)(void) = machine_power_off;
85509c00 KM	162	EXPORT_SYMBOL(pm_power_off);
1da177e4 LT	163
	164	/*
	165	* Create a kernel thread
	166	*/
	167
	168	extern pid_t __kernel_thread(int (fn)(void ), void *arg, unsigned long flags);
	169	pid_t kernel_thread(int (fn)(void ), void *arg, unsigned long flags)
	170	{
	171
	172	/*
	173	* FIXME: Once we are sure we don't need any debug here,
	174	* kernel_thread can become a #define.
	175	*/
	176
	177	return __kernel_thread(fn, arg, flags);
	178	}
	179	EXPORT_SYMBOL(kernel_thread);
	180
	181	/*
	182	* Free current thread data structures etc..
	183	*/
	184	void exit_thread(void)
	185	{
	186	}
	187
	188	void flush_thread(void)
	189	{
	190	/* Only needs to handle fpu stuff or perf monitors.
	191	** REVISIT: several arches implement a "lazy fpu state".
	192	*/
	193	set_fs(USER_DS);
	194	}
	195
	196	void release_thread(struct task_struct *dead_task)
	197	{
	198	}
	199
	200	/*
	201	* Fill in the FPU structure for a core dump.
	202	*/
	203
	204	int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
	205	{
	206	if (regs == NULL)
	207	return 0;
	208
	209	memcpy(r, regs->fr, sizeof *r);
	210	return 1;
	211	}
	212
	213	int dump_task_fpu (struct task_struct tsk, elf_fpregset_t r)
	214	{
	215	memcpy(r, tsk->thread.regs.fr, sizeof(*r));
	216	return 1;
	217	}
	218
	219	/* Note that "fork()" is implemented in terms of clone, with
	220	parameters (SIGCHLD, regs->gr[30], regs). */
	221	int
	222	sys_clone(unsigned long clone_flags, unsigned long usp,
	223	struct pt_regs *regs)
	224	{
b2450cc1 CD	225	/* Arugments from userspace are:
	226	r26 = Clone flags.
	227	r25 = Child stack.
	228	r24 = parent_tidptr.
	229	r23 = Is the TLS storage descriptor
	230	r22 = child_tidptr
	231
	232	However, these last 3 args are only examined
	233	if the proper flags are set. */
	234	int __user *child_tidptr;
	235	int __user *parent_tidptr;
1da177e4 LT	236
	237	/* usp must be word aligned. This also prevents users from
	238	* passing in the value 1 (which is the signal for a special
	239	* return for a kernel thread) */
	240	usp = ALIGN(usp, 4);
	241
	242	/* A zero value for usp means use the current stack */
b2450cc1 CD	243	if (usp == 0)
b2450cc1 CD	244	usp = regs->gr[30];
1da177e4	245
b2450cc1 CD	246	if (clone_flags & CLONE_PARENT_SETTID)
	247	parent_tidptr = (int __user *)regs->gr[24];
	248	else
	249	parent_tidptr = NULL;
	250
	251	if (clone_flags & (CLONE_CHILD_SETTID \| CLONE_CHILD_CLEARTID))
	252	child_tidptr = (int __user *)regs->gr[22];
	253	else
	254	child_tidptr = NULL;
	255
	256	return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr);
1da177e4 LT	257	}
	258
	259	int
	260	sys_vfork(struct pt_regs *regs)
	261	{
	262	return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, regs->gr[30], regs, 0, NULL, NULL);
	263	}
	264
	265	int
	266	copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
	267	unsigned long unused, /* in ia64 this is "user_stack_size" */
	268	struct task_struct * p, struct pt_regs * pregs)
	269	{
	270	struct pt_regs * cregs = &(p->thread.regs);
40f1f0de	271	void *stack = task_stack_page(p);
1da177e4 LT	272
	273	/* We have to use void * instead of a function pointer, because
	274	* function pointers aren't a pointer to the function on 64-bit.
	275	* Make them const so the compiler knows they live in .text */
	276	extern void * const ret_from_kernel_thread;
	277	extern void * const child_return;
	278	#ifdef CONFIG_HPUX
	279	extern void * const hpux_child_return;
	280	#endif
	281
	282	cregs = pregs;
	283
	284	/* Set the return value for the child. Note that this is not
	285	actually restored by the syscall exit path, but we put it
	286	here for consistency in case of signals. */
	287	cregs->gr[28] = 0; /* child */
	288
	289	/*
	290	* We need to differentiate between a user fork and a
	291	* kernel fork. We can't use user_mode, because the
	292	* the syscall path doesn't save iaoq. Right now
	293	* We rely on the fact that kernel_thread passes
	294	* in zero for usp.
	295	*/
	296	if (usp == 1) {
	297	/* kernel thread */
40f1f0de	298	cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN;
1da177e4 LT	299	/* Must exit via ret_from_kernel_thread in order
	300	* to call schedule_tail()
	301	*/
	302	cregs->kpc = (unsigned long) &ret_from_kernel_thread;
	303	/*
	304	* Copy function and argument to be called from
	305	* ret_from_kernel_thread.
	306	*/
a8f44e38	307	#ifdef CONFIG_64BIT
1da177e4 LT	308	cregs->gr[27] = pregs->gr[27];
	309	#endif
	310	cregs->gr[26] = pregs->gr[26];
	311	cregs->gr[25] = pregs->gr[25];
	312	} else {
	313	/* user thread */
	314	/*
	315	* Note that the fork wrappers are responsible
	316	* for setting gr[21].
	317	*/
	318
	319	/* Use same stack depth as parent */
40f1f0de	320	cregs->ksp = (unsigned long)stack
1da177e4 LT	321	+ (pregs->gr[21] & (THREAD_SIZE - 1));
	322	cregs->gr[30] = usp;
	323	if (p->personality == PER_HPUX) {
	324	#ifdef CONFIG_HPUX
	325	cregs->kpc = (unsigned long) &hpux_child_return;
	326	#else
	327	BUG();
	328	#endif
	329	} else {
	330	cregs->kpc = (unsigned long) &child_return;
	331	}
b2450cc1 CD	332	/* Setup thread TLS area from the 4th parameter in clone */
	333	if (clone_flags & CLONE_SETTLS)
	334	cregs->cr27 = pregs->gr[23];
	335
1da177e4 LT	336	}
	337
	338	return 0;
	339	}
	340
	341	unsigned long thread_saved_pc(struct task_struct *t)
	342	{
	343	return t->thread.regs.kpc;
	344	}
	345
	346	/*
	347	* sys_execve() executes a new program.
	348	*/
	349
	350	asmlinkage int sys_execve(struct pt_regs *regs)
	351	{
	352	int error;
	353	char *filename;
	354
	355	filename = getname((const char __user *) regs->gr[26]);
	356	error = PTR_ERR(filename);
	357	if (IS_ERR(filename))
	358	goto out;
c2c4798e MW	359	error = do_execve(filename, (char __user * __user *) regs->gr[25],
c2c4798e MW	360	(char __user * __user *) regs->gr[24], regs);
1da177e4 LT	361	if (error == 0) {
	362	task_lock(current);
	363	current->ptrace &= ~PT_DTRACE;
	364	task_unlock(current);
	365	}
	366	putname(filename);
	367	out:
	368
	369	return error;
	370	}
	371
3db03b4a AB	372	extern int __execve(const char filename, char const argv[],
	373	char const envp[], struct task_struct task);
	374	int kernel_execve(const char filename, char const argv[], char *const envp[])
	375	{
	376	return __execve(filename, argv, envp, current);
	377	}
	378
	379	unsigned long
1da177e4 LT	380	get_wchan(struct task_struct *p)
	381	{
	382	struct unwind_frame_info info;
	383	unsigned long ip;
	384	int count = 0;
cc650a7a KM	385
	386	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	387	return 0;
	388
1da177e4 LT	389	/*
	390	* These bracket the sleeping functions..
	391	*/
	392
	393	unwind_frame_init_from_blocked_task(&info, p);
	394	do {
	395	if (unwind_once(&info) < 0)
	396	return 0;
	397	ip = info.ip;
	398	if (!in_sched_functions(ip))
	399	return ip;
	400	} while (count++ < 16);
	401	return 0;
	402	}