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v3.5.6
  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>
 12 *    Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
 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) 2001-2007 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/fs.h>
 42#include <linux/module.h>
 43#include <linux/personality.h>
 44#include <linux/ptrace.h>
 45#include <linux/sched.h>
 46#include <linux/slab.h>
 47#include <linux/stddef.h>
 48#include <linux/unistd.h>
 49#include <linux/kallsyms.h>
 50#include <linux/uaccess.h>
 51
 52#include <asm/io.h>
 53#include <asm/asm-offsets.h>
 54#include <asm/pdc.h>
 55#include <asm/pdc_chassis.h>
 56#include <asm/pgalloc.h>
 57#include <asm/unwind.h>
 58#include <asm/sections.h>
 59
 60/*
 61 * The idle thread. There's no useful work to be
 62 * done, so just try to conserve power and have a
 63 * low exit latency (ie sit in a loop waiting for
 64 * somebody to say that they'd like to reschedule)
 65 */
 66void cpu_idle(void)
 67{
 68	set_thread_flag(TIF_POLLING_NRFLAG);
 69
 70	/* endless idle loop with no priority at all */
 71	while (1) {
 72		while (!need_resched())
 73			barrier();
 74		schedule_preempt_disabled();
 
 
 75		check_pgt_cache();
 76	}
 77}
 78
 79
 80#define COMMAND_GLOBAL  F_EXTEND(0xfffe0030)
 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*/
 95void 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
127void 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
135void (*chassis_power_off)(void);
136
137/*
138 * This routine is called from sys_reboot to actually turn off the
139 * machine 
140 */
141void machine_power_off(void)
142{
143	/* If there is a registered power off handler, call it. */
144	if (chassis_power_off)
145		chassis_power_off();
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	       "Please power this system off now.");
159}
160
161void (*pm_power_off)(void) = machine_power_off;
162EXPORT_SYMBOL(pm_power_off);
163
164/*
165 * Create a kernel thread
166 */
167
168extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
169pid_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}
179EXPORT_SYMBOL(kernel_thread);
180
181/*
182 * Free current thread data structures etc..
183 */
184void exit_thread(void)
185{
186}
187
188void 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}
194
195void release_thread(struct task_struct *dead_task)
196{
197}
198
199/*
200 * Fill in the FPU structure for a core dump.
201 */
202
203int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
204{
205	if (regs == NULL)
206		return 0;
207
208	memcpy(r, regs->fr, sizeof *r);
209	return 1;
210}
211
212int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r)
213{
214	memcpy(r, tsk->thread.regs.fr, sizeof(*r));
215	return 1;
216}
217
218/* Note that "fork()" is implemented in terms of clone, with
219   parameters (SIGCHLD, regs->gr[30], regs). */
220int
221sys_clone(unsigned long clone_flags, unsigned long usp,
222	  struct pt_regs *regs)
223{
224  	/* Arugments from userspace are:
225	   r26 = Clone flags.
226	   r25 = Child stack.
227	   r24 = parent_tidptr.
228	   r23 = Is the TLS storage descriptor 
229	   r22 = child_tidptr 
230	   
231	   However, these last 3 args are only examined
232	   if the proper flags are set. */
233	int __user *parent_tidptr = (int __user *)regs->gr[24];
234	int __user *child_tidptr  = (int __user *)regs->gr[22];
235
236	/* usp must be word aligned.  This also prevents users from
237	 * passing in the value 1 (which is the signal for a special
238	 * return for a kernel thread) */
239	usp = ALIGN(usp, 4);
240
241	/* A zero value for usp means use the current stack */
242	if (usp == 0)
243	  usp = regs->gr[30];
244
245	return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr);
246}
247
248int
249sys_vfork(struct pt_regs *regs)
250{
251	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gr[30], regs, 0, NULL, NULL);
252}
253
254int
255copy_thread(unsigned long clone_flags, unsigned long usp,
256	    unsigned long unused,	/* in ia64 this is "user_stack_size" */
257	    struct task_struct * p, struct pt_regs * pregs)
258{
259	struct pt_regs * cregs = &(p->thread.regs);
260	void *stack = task_stack_page(p);
261	
262	/* We have to use void * instead of a function pointer, because
263	 * function pointers aren't a pointer to the function on 64-bit.
264	 * Make them const so the compiler knows they live in .text */
265	extern void * const ret_from_kernel_thread;
266	extern void * const child_return;
267#ifdef CONFIG_HPUX
268	extern void * const hpux_child_return;
269#endif
270
271	*cregs = *pregs;
272
273	/* Set the return value for the child.  Note that this is not
274           actually restored by the syscall exit path, but we put it
275           here for consistency in case of signals. */
276	cregs->gr[28] = 0; /* child */
277
278	/*
279	 * We need to differentiate between a user fork and a
280	 * kernel fork. We can't use user_mode, because the
281	 * the syscall path doesn't save iaoq. Right now
282	 * We rely on the fact that kernel_thread passes
283	 * in zero for usp.
284	 */
285	if (usp == 1) {
286		/* kernel thread */
287		cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN;
288		/* Must exit via ret_from_kernel_thread in order
289		 * to call schedule_tail()
290		 */
291		cregs->kpc = (unsigned long) &ret_from_kernel_thread;
292		/*
293		 * Copy function and argument to be called from
294		 * ret_from_kernel_thread.
295		 */
296#ifdef CONFIG_64BIT
297		cregs->gr[27] = pregs->gr[27];
298#endif
299		cregs->gr[26] = pregs->gr[26];
300		cregs->gr[25] = pregs->gr[25];
301	} else {
302		/* user thread */
303		/*
304		 * Note that the fork wrappers are responsible
305		 * for setting gr[21].
306		 */
307
308		/* Use same stack depth as parent */
309		cregs->ksp = (unsigned long)stack
310			+ (pregs->gr[21] & (THREAD_SIZE - 1));
311		cregs->gr[30] = usp;
312		if (p->personality == PER_HPUX) {
313#ifdef CONFIG_HPUX
314			cregs->kpc = (unsigned long) &hpux_child_return;
315#else
316			BUG();
317#endif
318		} else {
319			cregs->kpc = (unsigned long) &child_return;
320		}
321		/* Setup thread TLS area from the 4th parameter in clone */
322		if (clone_flags & CLONE_SETTLS)
323		  cregs->cr27 = pregs->gr[23];
324	
325	}
326
327	return 0;
328}
329
330unsigned long thread_saved_pc(struct task_struct *t)
331{
332	return t->thread.regs.kpc;
333}
334
335/*
336 * sys_execve() executes a new program.
337 */
338
339asmlinkage int sys_execve(struct pt_regs *regs)
340{
341	int error;
342	char *filename;
343
344	filename = getname((const char __user *) regs->gr[26]);
345	error = PTR_ERR(filename);
346	if (IS_ERR(filename))
347		goto out;
348	error = do_execve(filename,
349			  (const char __user *const __user *) regs->gr[25],
350			  (const char __user *const __user *) regs->gr[24],
351			  regs);
352	putname(filename);
353out:
354
355	return error;
356}
357
358extern int __execve(const char *filename,
359		    const char *const argv[],
360		    const char *const envp[], struct task_struct *task);
361int kernel_execve(const char *filename,
362		  const char *const argv[],
363		  const char *const envp[])
364{
365	return __execve(filename, argv, envp, current);
366}
367
368unsigned long
369get_wchan(struct task_struct *p)
370{
371	struct unwind_frame_info info;
372	unsigned long ip;
373	int count = 0;
374
375	if (!p || p == current || p->state == TASK_RUNNING)
376		return 0;
377
378	/*
379	 * These bracket the sleeping functions..
380	 */
381
382	unwind_frame_init_from_blocked_task(&info, p);
383	do {
384		if (unwind_once(&info) < 0)
385			return 0;
386		ip = info.ip;
387		if (!in_sched_functions(ip))
388			return ip;
389	} while (count++ < 16);
390	return 0;
391}
392
393#ifdef CONFIG_64BIT
394void *dereference_function_descriptor(void *ptr)
395{
396	Elf64_Fdesc *desc = ptr;
397	void *p;
398
399	if (!probe_kernel_address(&desc->addr, p))
400		ptr = p;
401	return ptr;
402}
403#endif
v3.1
  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>
 12 *    Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
 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) 2001-2007 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/fs.h>
 42#include <linux/module.h>
 43#include <linux/personality.h>
 44#include <linux/ptrace.h>
 45#include <linux/sched.h>
 46#include <linux/slab.h>
 47#include <linux/stddef.h>
 48#include <linux/unistd.h>
 49#include <linux/kallsyms.h>
 50#include <linux/uaccess.h>
 51
 52#include <asm/io.h>
 53#include <asm/asm-offsets.h>
 54#include <asm/pdc.h>
 55#include <asm/pdc_chassis.h>
 56#include <asm/pgalloc.h>
 57#include <asm/unwind.h>
 58#include <asm/sections.h>
 59
 60/*
 61 * The idle thread. There's no useful work to be
 62 * done, so just try to conserve power and have a
 63 * low exit latency (ie sit in a loop waiting for
 64 * somebody to say that they'd like to reschedule)
 65 */
 66void cpu_idle(void)
 67{
 68	set_thread_flag(TIF_POLLING_NRFLAG);
 69
 70	/* endless idle loop with no priority at all */
 71	while (1) {
 72		while (!need_resched())
 73			barrier();
 74		preempt_enable_no_resched();
 75		schedule();
 76		preempt_disable();
 77		check_pgt_cache();
 78	}
 79}
 80
 81
 82#define COMMAND_GLOBAL  F_EXTEND(0xfffe0030)
 83#define CMD_RESET       5       /* reset any module */
 84
 85/*
 86** The Wright Brothers and Gecko systems have a H/W problem
 87** (Lasi...'nuf said) may cause a broadcast reset to lockup
 88** the system. An HVERSION dependent PDC call was developed
 89** to perform a "safe", platform specific broadcast reset instead
 90** of kludging up all the code.
 91**
 92** Older machines which do not implement PDC_BROADCAST_RESET will
 93** return (with an error) and the regular broadcast reset can be
 94** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
 95** the PDC call will not return (the system will be reset).
 96*/
 97void machine_restart(char *cmd)
 98{
 99#ifdef FASTBOOT_SELFTEST_SUPPORT
100	/*
101	 ** If user has modified the Firmware Selftest Bitmap,
102	 ** run the tests specified in the bitmap after the
103	 ** system is rebooted w/PDC_DO_RESET.
104	 **
105	 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
106	 **
107	 ** Using "directed resets" at each processor with the MEM_TOC
108	 ** vector cleared will also avoid running destructive
109	 ** memory self tests. (Not implemented yet)
110	 */
111	if (ftc_bitmap) {
112		pdc_do_firm_test_reset(ftc_bitmap);
113	}
114#endif
115	/* set up a new led state on systems shipped with a LED State panel */
116	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
117	
118	/* "Normal" system reset */
119	pdc_do_reset();
120
121	/* Nope...box should reset with just CMD_RESET now */
122	gsc_writel(CMD_RESET, COMMAND_GLOBAL);
123
124	/* Wait for RESET to lay us to rest. */
125	while (1) ;
126
127}
128
129void machine_halt(void)
130{
131	/*
132	** The LED/ChassisCodes are updated by the led_halt()
133	** function, called by the reboot notifier chain.
134	*/
135}
136
137void (*chassis_power_off)(void);
138
139/*
140 * This routine is called from sys_reboot to actually turn off the
141 * machine 
142 */
143void machine_power_off(void)
144{
145	/* If there is a registered power off handler, call it. */
146	if (chassis_power_off)
147		chassis_power_off();
148
149	/* Put the soft power button back under hardware control.
150	 * If the user had already pressed the power button, the
151	 * following call will immediately power off. */
152	pdc_soft_power_button(0);
153	
154	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
155		
156	/* It seems we have no way to power the system off via
157	 * software. The user has to press the button himself. */
158
159	printk(KERN_EMERG "System shut down completed.\n"
160	       "Please power this system off now.");
161}
162
163void (*pm_power_off)(void) = machine_power_off;
164EXPORT_SYMBOL(pm_power_off);
165
166/*
167 * Create a kernel thread
168 */
169
170extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
171pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
172{
173
174	/*
175	 * FIXME: Once we are sure we don't need any debug here,
176	 *	  kernel_thread can become a #define.
177	 */
178
179	return __kernel_thread(fn, arg, flags);
180}
181EXPORT_SYMBOL(kernel_thread);
182
183/*
184 * Free current thread data structures etc..
185 */
186void exit_thread(void)
187{
188}
189
190void flush_thread(void)
191{
192	/* Only needs to handle fpu stuff or perf monitors.
193	** REVISIT: several arches implement a "lazy fpu state".
194	*/
195	set_fs(USER_DS);
196}
197
198void release_thread(struct task_struct *dead_task)
199{
200}
201
202/*
203 * Fill in the FPU structure for a core dump.
204 */
205
206int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
207{
208	if (regs == NULL)
209		return 0;
210
211	memcpy(r, regs->fr, sizeof *r);
212	return 1;
213}
214
215int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r)
216{
217	memcpy(r, tsk->thread.regs.fr, sizeof(*r));
218	return 1;
219}
220
221/* Note that "fork()" is implemented in terms of clone, with
222   parameters (SIGCHLD, regs->gr[30], regs). */
223int
224sys_clone(unsigned long clone_flags, unsigned long usp,
225	  struct pt_regs *regs)
226{
227  	/* Arugments from userspace are:
228	   r26 = Clone flags.
229	   r25 = Child stack.
230	   r24 = parent_tidptr.
231	   r23 = Is the TLS storage descriptor 
232	   r22 = child_tidptr 
233	   
234	   However, these last 3 args are only examined
235	   if the proper flags are set. */
236	int __user *parent_tidptr = (int __user *)regs->gr[24];
237	int __user *child_tidptr  = (int __user *)regs->gr[22];
238
239	/* usp must be word aligned.  This also prevents users from
240	 * passing in the value 1 (which is the signal for a special
241	 * return for a kernel thread) */
242	usp = ALIGN(usp, 4);
243
244	/* A zero value for usp means use the current stack */
245	if (usp == 0)
246	  usp = regs->gr[30];
247
248	return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr);
249}
250
251int
252sys_vfork(struct pt_regs *regs)
253{
254	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gr[30], regs, 0, NULL, NULL);
255}
256
257int
258copy_thread(unsigned long clone_flags, unsigned long usp,
259	    unsigned long unused,	/* in ia64 this is "user_stack_size" */
260	    struct task_struct * p, struct pt_regs * pregs)
261{
262	struct pt_regs * cregs = &(p->thread.regs);
263	void *stack = task_stack_page(p);
264	
265	/* We have to use void * instead of a function pointer, because
266	 * function pointers aren't a pointer to the function on 64-bit.
267	 * Make them const so the compiler knows they live in .text */
268	extern void * const ret_from_kernel_thread;
269	extern void * const child_return;
270#ifdef CONFIG_HPUX
271	extern void * const hpux_child_return;
272#endif
273
274	*cregs = *pregs;
275
276	/* Set the return value for the child.  Note that this is not
277           actually restored by the syscall exit path, but we put it
278           here for consistency in case of signals. */
279	cregs->gr[28] = 0; /* child */
280
281	/*
282	 * We need to differentiate between a user fork and a
283	 * kernel fork. We can't use user_mode, because the
284	 * the syscall path doesn't save iaoq. Right now
285	 * We rely on the fact that kernel_thread passes
286	 * in zero for usp.
287	 */
288	if (usp == 1) {
289		/* kernel thread */
290		cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN;
291		/* Must exit via ret_from_kernel_thread in order
292		 * to call schedule_tail()
293		 */
294		cregs->kpc = (unsigned long) &ret_from_kernel_thread;
295		/*
296		 * Copy function and argument to be called from
297		 * ret_from_kernel_thread.
298		 */
299#ifdef CONFIG_64BIT
300		cregs->gr[27] = pregs->gr[27];
301#endif
302		cregs->gr[26] = pregs->gr[26];
303		cregs->gr[25] = pregs->gr[25];
304	} else {
305		/* user thread */
306		/*
307		 * Note that the fork wrappers are responsible
308		 * for setting gr[21].
309		 */
310
311		/* Use same stack depth as parent */
312		cregs->ksp = (unsigned long)stack
313			+ (pregs->gr[21] & (THREAD_SIZE - 1));
314		cregs->gr[30] = usp;
315		if (p->personality == PER_HPUX) {
316#ifdef CONFIG_HPUX
317			cregs->kpc = (unsigned long) &hpux_child_return;
318#else
319			BUG();
320#endif
321		} else {
322			cregs->kpc = (unsigned long) &child_return;
323		}
324		/* Setup thread TLS area from the 4th parameter in clone */
325		if (clone_flags & CLONE_SETTLS)
326		  cregs->cr27 = pregs->gr[23];
327	
328	}
329
330	return 0;
331}
332
333unsigned long thread_saved_pc(struct task_struct *t)
334{
335	return t->thread.regs.kpc;
336}
337
338/*
339 * sys_execve() executes a new program.
340 */
341
342asmlinkage int sys_execve(struct pt_regs *regs)
343{
344	int error;
345	char *filename;
346
347	filename = getname((const char __user *) regs->gr[26]);
348	error = PTR_ERR(filename);
349	if (IS_ERR(filename))
350		goto out;
351	error = do_execve(filename,
352			  (const char __user *const __user *) regs->gr[25],
353			  (const char __user *const __user *) regs->gr[24],
354			  regs);
355	putname(filename);
356out:
357
358	return error;
359}
360
361extern int __execve(const char *filename,
362		    const char *const argv[],
363		    const char *const envp[], struct task_struct *task);
364int kernel_execve(const char *filename,
365		  const char *const argv[],
366		  const char *const envp[])
367{
368	return __execve(filename, argv, envp, current);
369}
370
371unsigned long
372get_wchan(struct task_struct *p)
373{
374	struct unwind_frame_info info;
375	unsigned long ip;
376	int count = 0;
377
378	if (!p || p == current || p->state == TASK_RUNNING)
379		return 0;
380
381	/*
382	 * These bracket the sleeping functions..
383	 */
384
385	unwind_frame_init_from_blocked_task(&info, p);
386	do {
387		if (unwind_once(&info) < 0)
388			return 0;
389		ip = info.ip;
390		if (!in_sched_functions(ip))
391			return ip;
392	} while (count++ < 16);
393	return 0;
394}
395
396#ifdef CONFIG_64BIT
397void *dereference_function_descriptor(void *ptr)
398{
399	Elf64_Fdesc *desc = ptr;
400	void *p;
401
402	if (!probe_kernel_address(&desc->addr, p))
403		ptr = p;
404	return ptr;
405}
406#endif