[deliverable/linux.git] / arch / s390 / kernel / process.c

/*
 * This file handles the architecture dependent parts of process handling.
 *
 *    Copyright IBM Corp. 1999,2009
 *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
 *		 Hartmut Penner <hp@de.ibm.com>,
 *		 Denis Joseph Barrow,
 */

#include <linux/compiler.h>
#include <linux/cpu.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/tick.h>
#include <linux/personality.h>
#include <linux/syscalls.h>
#include <linux/compat.h>
#include <linux/kprobes.h>
#include <linux/random.h>
#include <linux/module.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/irq.h>
#include <asm/timer.h>
#include <asm/nmi.h>
#include <asm/compat.h>
#include <asm/smp.h>
#include "entry.h"

asmlinkage void ret_from_fork(void) asm ("ret_from_fork");

/*
 * Return saved PC of a blocked thread. used in kernel/sched.
 * resume in entry.S does not create a new stack frame, it
 * just stores the registers %r6-%r15 to the frame given by
 * schedule. We want to return the address of the caller of
 * schedule, so we have to walk the backchain one time to
 * find the frame schedule() store its return address.
 */
unsigned long thread_saved_pc(struct task_struct *tsk)
{
	struct stack_frame *sf, *low, *high;

	if (!tsk || !task_stack_page(tsk))
		return 0;
	low = task_stack_page(tsk);
	high = (struct stack_frame *) task_pt_regs(tsk);
	sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN);
	if (sf <= low || sf > high)
		return 0;
	sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
	if (sf <= low || sf > high)
		return 0;
	return sf->gprs[8];
}

/*
 * The idle loop on a S390...
 */
static void default_idle(void)
{
	if (cpu_is_offline(smp_processor_id()))
		cpu_die();
	local_irq_disable();
	if (need_resched()) {
		local_irq_enable();
		return;
	}
	local_mcck_disable();
	if (test_thread_flag(TIF_MCCK_PENDING)) {
		local_mcck_enable();
		local_irq_enable();
		s390_handle_mcck();
		return;
	}
	trace_hardirqs_on();
	/* Don't trace preempt off for idle. */
	stop_critical_timings();
	/* Stop virtual timer and halt the cpu. */
	vtime_stop_cpu();
	/* Reenable preemption tracer. */
	start_critical_timings();
}

void cpu_idle(void)
{
	for (;;) {
		tick_nohz_stop_sched_tick(1);
		while (!need_resched())
			default_idle();
		tick_nohz_restart_sched_tick();
		preempt_enable_no_resched();
		schedule();
		preempt_disable();
	}
}

extern void __kprobes kernel_thread_starter(void);

asm(
	".section .kprobes.text, \"ax\"\n"
	".global kernel_thread_starter\n"
	"kernel_thread_starter:\n"
	"    la    2,0(10)\n"
	"    basr  14,9\n"
	"    la    2,0\n"
	"    br    11\n"
	".previous\n");

int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
	struct pt_regs regs;

	memset(&regs, 0, sizeof(regs));
	regs.psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
	regs.psw.addr = (unsigned long) kernel_thread_starter | PSW_ADDR_AMODE;
	regs.gprs[9] = (unsigned long) fn;
	regs.gprs[10] = (unsigned long) arg;
	regs.gprs[11] = (unsigned long) do_exit;
	regs.orig_gpr2 = -1;

	/* Ok, create the new process.. */
	return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
		       0, &regs, 0, NULL, NULL);
}
EXPORT_SYMBOL(kernel_thread);

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

void flush_thread(void)
{
}

void release_thread(struct task_struct *dead_task)
{
}

int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
		unsigned long unused,
		struct task_struct *p, struct pt_regs *regs)
{
	struct thread_info *ti;
	struct fake_frame
	{
		struct stack_frame sf;
		struct pt_regs childregs;
	} *frame;

	frame = container_of(task_pt_regs(p), struct fake_frame, childregs);
	p->thread.ksp = (unsigned long) frame;
	/* Store access registers to kernel stack of new process. */
	frame->childregs = *regs;
	frame->childregs.gprs[2] = 0;	/* child returns 0 on fork. */
	frame->childregs.gprs[15] = new_stackp;
	frame->sf.back_chain = 0;

	/* new return point is ret_from_fork */
	frame->sf.gprs[8] = (unsigned long) ret_from_fork;

	/* fake return stack for resume(), don't go back to schedule */
	frame->sf.gprs[9] = (unsigned long) frame;

	/* Save access registers to new thread structure. */
	save_access_regs(&p->thread.acrs[0]);

#ifndef CONFIG_64BIT
	/*
	 * save fprs to current->thread.fp_regs to merge them with
	 * the emulated registers and then copy the result to the child.
	 */
	save_fp_regs(&current->thread.fp_regs);
	memcpy(&p->thread.fp_regs, &current->thread.fp_regs,
	       sizeof(s390_fp_regs));
	/* Set a new TLS ?  */
	if (clone_flags & CLONE_SETTLS)
		p->thread.acrs[0] = regs->gprs[6];
#else /* CONFIG_64BIT */
	/* Save the fpu registers to new thread structure. */
	save_fp_regs(&p->thread.fp_regs);
	/* Set a new TLS ?  */
	if (clone_flags & CLONE_SETTLS) {
		if (is_compat_task()) {
			p->thread.acrs[0] = (unsigned int) regs->gprs[6];
		} else {
			p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32);
			p->thread.acrs[1] = (unsigned int) regs->gprs[6];
		}
	}
#endif /* CONFIG_64BIT */
	/* start new process with ar4 pointing to the correct address space */
	p->thread.mm_segment = get_fs();
	/* Don't copy debug registers */
	memset(&p->thread.per_user, 0, sizeof(p->thread.per_user));
	memset(&p->thread.per_event, 0, sizeof(p->thread.per_event));
	clear_tsk_thread_flag(p, TIF_SINGLE_STEP);
	clear_tsk_thread_flag(p, TIF_PER_TRAP);
	/* Initialize per thread user and system timer values */
	ti = task_thread_info(p);
	ti->user_timer = 0;
	ti->system_timer = 0;
	return 0;
}

SYSCALL_DEFINE0(fork)
{
	struct pt_regs *regs = task_pt_regs(current);
	return do_fork(SIGCHLD, regs->gprs[15], regs, 0, NULL, NULL);
}

SYSCALL_DEFINE4(clone, unsigned long, newsp, unsigned long, clone_flags,
		int __user *, parent_tidptr, int __user *, child_tidptr)
{
	struct pt_regs *regs = task_pt_regs(current);

	if (!newsp)
		newsp = regs->gprs[15];
	return do_fork(clone_flags, newsp, regs, 0,
		       parent_tidptr, child_tidptr);
}

/*
 * This is trivial, and on the face of it looks like it
 * could equally well be done in user mode.
 *
 * Not so, for quite unobvious reasons - register pressure.
 * In user mode vfork() cannot have a stack frame, and if
 * done by calling the "clone()" system call directly, you
 * do not have enough call-clobbered registers to hold all
 * the information you need.
 */
SYSCALL_DEFINE0(vfork)
{
	struct pt_regs *regs = task_pt_regs(current);
	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,
		       regs->gprs[15], regs, 0, NULL, NULL);
}

asmlinkage void execve_tail(void)
{
	current->thread.fp_regs.fpc = 0;
	if (MACHINE_HAS_IEEE)
		asm volatile("sfpc %0,%0" : : "d" (0));
}

/*
 * sys_execve() executes a new program.
 */
SYSCALL_DEFINE3(execve, const char __user *, name,
		const char __user *const __user *, argv,
		const char __user *const __user *, envp)
{
	struct pt_regs *regs = task_pt_regs(current);
	char *filename;
	long rc;

	filename = getname(name);
	rc = PTR_ERR(filename);
	if (IS_ERR(filename))
		return rc;
	rc = do_execve(filename, argv, envp, regs);
	if (rc)
		goto out;
	execve_tail();
	rc = regs->gprs[2];
out:
	putname(filename);
	return rc;
}

/*
 * fill in the FPU structure for a core dump.
 */
int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
{
#ifndef CONFIG_64BIT
	/*
	 * save fprs to current->thread.fp_regs to merge them with
	 * the emulated registers and then copy the result to the dump.
	 */
	save_fp_regs(&current->thread.fp_regs);
	memcpy(fpregs, &current->thread.fp_regs, sizeof(s390_fp_regs));
#else /* CONFIG_64BIT */
	save_fp_regs(fpregs);
#endif /* CONFIG_64BIT */
	return 1;
}
EXPORT_SYMBOL(dump_fpu);

unsigned long get_wchan(struct task_struct *p)
{
	struct stack_frame *sf, *low, *high;
	unsigned long return_address;
	int count;

	if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p))
		return 0;
	low = task_stack_page(p);
	high = (struct stack_frame *) task_pt_regs(p);
	sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN);
	if (sf <= low || sf > high)
		return 0;
	for (count = 0; count < 16; count++) {
		sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
		if (sf <= low || sf > high)
			return 0;
		return_address = sf->gprs[8] & PSW_ADDR_INSN;
		if (!in_sched_functions(return_address))
			return return_address;
	}
	return 0;
}

unsigned long arch_align_stack(unsigned long sp)
{
	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
		sp -= get_random_int() & ~PAGE_MASK;
	return sp & ~0xf;
}

static inline unsigned long brk_rnd(void)
{
	/* 8MB for 32bit, 1GB for 64bit */
	if (is_32bit_task())
		return (get_random_int() & 0x7ffUL) << PAGE_SHIFT;
	else
		return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT;
}

unsigned long arch_randomize_brk(struct mm_struct *mm)
{
	unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd());

	if (ret < mm->brk)
		return mm->brk;
	return ret;
}

unsigned long randomize_et_dyn(unsigned long base)
{
	unsigned long ret = PAGE_ALIGN(base + brk_rnd());

	if (!(current->flags & PF_RANDOMIZE))
		return base;
	if (ret < base)
		return base;
	return ret;
}
Commit	Line	Data
1da177e4	1	/*
cbdc2292	2	* This file handles the architecture dependent parts of process handling.
1da177e4	3	*
cbdc2292 HC	4	* Copyright IBM Corp. 1999,2009
	5	* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
	6	* Hartmut Penner <hp@de.ibm.com>,
	7	* Denis Joseph Barrow,
1da177e4 LT	8	*/
1da177e4 LT	9
1da177e4 LT	10	#include <linux/compiler.h>
1da177e4 LT	11	#include <linux/cpu.h>
1da177e4 LT	12	#include <linux/sched.h>
	13	#include <linux/kernel.h>
	14	#include <linux/mm.h>
	15	#include <linux/smp.h>
5a0e3ad6	16	#include <linux/slab.h>
1da177e4	17	#include <linux/interrupt.h>
5a62b192	18	#include <linux/tick.h>
9887a1fc	19	#include <linux/personality.h>
26689452	20	#include <linux/syscalls.h>
3e86a8c6	21	#include <linux/compat.h>
860dba45	22	#include <linux/kprobes.h>
9887a1fc	23	#include <linux/random.h>
3af6fb68	24	#include <linux/module.h>
1da177e4 LT	25	#include <asm/system.h>
	26	#include <asm/io.h>
	27	#include <asm/processor.h>
	28	#include <asm/irq.h>
	29	#include <asm/timer.h>
f5daba1d	30	#include <asm/nmi.h>
3af6fb68	31	#include <asm/compat.h>
da7f51c1	32	#include <asm/smp.h>
a806170e	33	#include "entry.h"
1da177e4	34
94c12cc7	35	asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
1da177e4 LT	36
	37	/*
	38	* Return saved PC of a blocked thread. used in kernel/sched.
	39	* resume in entry.S does not create a new stack frame, it
	40	* just stores the registers %r6-%r15 to the frame given by
	41	* schedule. We want to return the address of the caller of
	42	* schedule, so we have to walk the backchain one time to
	43	* find the frame schedule() store its return address.
	44	*/
	45	unsigned long thread_saved_pc(struct task_struct *tsk)
	46	{
eb33c190	47	struct stack_frame sf, low, *high;
1da177e4	48
eb33c190 HC	49	if (!tsk \|\| !task_stack_page(tsk))
	50	return 0;
	51	low = task_stack_page(tsk);
	52	high = (struct stack_frame *) task_pt_regs(tsk);
	53	sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN);
	54	if (sf <= low \|\| sf > high)
	55	return 0;
	56	sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
	57	if (sf <= low \|\| sf > high)
	58	return 0;
1da177e4 LT	59	return sf->gprs[8];
	60	}
	61
1da177e4 LT	62	/*
	63	* The idle loop on a S390...
	64	*/
cdb04527	65	static void default_idle(void)
1da177e4	66	{
da7f51c1	67	if (cpu_is_offline(smp_processor_id()))
1da177e4	68	cpu_die();
6931be08 HC	69	local_irq_disable();
	70	if (need_resched()) {
	71	local_irq_enable();
	72	return;
	73	}
77fa2245 HC	74	local_mcck_disable();
	75	if (test_thread_flag(TIF_MCCK_PENDING)) {
	76	local_mcck_enable();
	77	local_irq_enable();
	78	s390_handle_mcck();
	79	return;
	80	}
1f194a4c	81	trace_hardirqs_on();
632448f6 HC	82	/* Don't trace preempt off for idle. */
632448f6 HC	83	stop_critical_timings();
9cfb9b3c MS	84	/* Stop virtual timer and halt the cpu. */
	85	vtime_stop_cpu();
	86	/* Reenable preemption tracer. */
632448f6	87	start_critical_timings();
1da177e4 LT	88	}
	89
	90	void cpu_idle(void)
	91	{
5bfb5d69	92	for (;;) {
e338125b	93	tick_nohz_stop_sched_tick(1);
5bfb5d69 NP	94	while (!need_resched())
5bfb5d69 NP	95	default_idle();
5a62b192	96	tick_nohz_restart_sched_tick();
5bfb5d69 NP	97	preempt_enable_no_resched();
	98	schedule();
	99	preempt_disable();
	100	}
1da177e4 LT	101	}
1da177e4 LT	102
860dba45	103	extern void __kprobes kernel_thread_starter(void);
1da177e4	104
94c12cc7	105	asm(
860dba45 MS	106	".section .kprobes.text, \"ax\"\n"
860dba45 MS	107	".global kernel_thread_starter\n"
1da177e4 LT	108	"kernel_thread_starter:\n"
	109	" la 2,0(10)\n"
	110	" basr 14,9\n"
	111	" la 2,0\n"
860dba45 MS	112	" br 11\n"
860dba45 MS	113	".previous\n");
1da177e4 LT	114
	115	int kernel_thread(int (fn)(void ), void * arg, unsigned long flags)
	116	{
	117	struct pt_regs regs;
	118
	119	memset(&regs, 0, sizeof(regs));
c1821c2e	120	regs.psw.mask = psw_kernel_bits \| PSW_MASK_IO \| PSW_MASK_EXT;
1da177e4 LT	121	regs.psw.addr = (unsigned long) kernel_thread_starter \| PSW_ADDR_AMODE;
	122	regs.gprs[9] = (unsigned long) fn;
	123	regs.gprs[10] = (unsigned long) arg;
	124	regs.gprs[11] = (unsigned long) do_exit;
	125	regs.orig_gpr2 = -1;
	126
	127	/* Ok, create the new process.. */
	128	return do_fork(flags \| CLONE_VM \| CLONE_UNTRACED,
	129	0, &regs, 0, NULL, NULL);
	130	}
1485c5c8	131	EXPORT_SYMBOL(kernel_thread);
1da177e4 LT	132
	133	/*
	134	* Free current thread data structures etc..
	135	*/
	136	void exit_thread(void)
	137	{
	138	}
	139
	140	void flush_thread(void)
	141	{
1da177e4 LT	142	}
	143
	144	void release_thread(struct task_struct *dead_task)
	145	{
	146	}
	147
6f2c55b8	148	int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
cbdc2292 HC	149	unsigned long unused,
cbdc2292 HC	150	struct task_struct p, struct pt_regs regs)
1da177e4	151	{
5168ce2c	152	struct thread_info *ti;
cbdc2292 HC	153	struct fake_frame
	154	{
	155	struct stack_frame sf;
	156	struct pt_regs childregs;
	157	} *frame;
	158
	159	frame = container_of(task_pt_regs(p), struct fake_frame, childregs);
	160	p->thread.ksp = (unsigned long) frame;
1da177e4	161	/* Store access registers to kernel stack of new process. */
cbdc2292	162	frame->childregs = *regs;
1da177e4	163	frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */
cbdc2292 HC	164	frame->childregs.gprs[15] = new_stackp;
cbdc2292 HC	165	frame->sf.back_chain = 0;
1da177e4	166
cbdc2292 HC	167	/* new return point is ret_from_fork */
cbdc2292 HC	168	frame->sf.gprs[8] = (unsigned long) ret_from_fork;
1da177e4	169
cbdc2292 HC	170	/* fake return stack for resume(), don't go back to schedule */
cbdc2292 HC	171	frame->sf.gprs[9] = (unsigned long) frame;
1da177e4 LT	172
	173	/* Save access registers to new thread structure. */
	174	save_access_regs(&p->thread.acrs[0]);
	175
347a8dc3	176	#ifndef CONFIG_64BIT
cbdc2292	177	/*
1da177e4 LT	178	* save fprs to current->thread.fp_regs to merge them with
	179	* the emulated registers and then copy the result to the child.
	180	*/
	181	save_fp_regs(&current->thread.fp_regs);
	182	memcpy(&p->thread.fp_regs, &current->thread.fp_regs,
	183	sizeof(s390_fp_regs));
1da177e4 LT	184	/* Set a new TLS ? */
	185	if (clone_flags & CLONE_SETTLS)
	186	p->thread.acrs[0] = regs->gprs[6];
347a8dc3	187	#else /* CONFIG_64BIT */
1da177e4 LT	188	/* Save the fpu registers to new thread structure. */
1da177e4 LT	189	save_fp_regs(&p->thread.fp_regs);
1da177e4 LT	190	/* Set a new TLS ? */
1da177e4 LT	191	if (clone_flags & CLONE_SETTLS) {
7757591a	192	if (is_compat_task()) {
1da177e4 LT	193	p->thread.acrs[0] = (unsigned int) regs->gprs[6];
	194	} else {
	195	p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32);
	196	p->thread.acrs[1] = (unsigned int) regs->gprs[6];
	197	}
	198	}
347a8dc3	199	#endif /* CONFIG_64BIT */
1da177e4 LT	200	/* start new process with ar4 pointing to the correct address space */
1da177e4 LT	201	p->thread.mm_segment = get_fs();
cbdc2292	202	/* Don't copy debug registers */
5e9a2692 MS	203	memset(&p->thread.per_user, 0, sizeof(p->thread.per_user));
5e9a2692 MS	204	memset(&p->thread.per_event, 0, sizeof(p->thread.per_event));
f8d5faf7	205	clear_tsk_thread_flag(p, TIF_SINGLE_STEP);
5e9a2692	206	clear_tsk_thread_flag(p, TIF_PER_TRAP);
5168ce2c HC	207	/* Initialize per thread user and system timer values */
	208	ti = task_thread_info(p);
	209	ti->user_timer = 0;
	210	ti->system_timer = 0;
cbdc2292	211	return 0;
1da177e4 LT	212	}
1da177e4 LT	213
26689452	214	SYSCALL_DEFINE0(fork)
1da177e4	215	{
03ff9a23 MS	216	struct pt_regs *regs = task_pt_regs(current);
03ff9a23 MS	217	return do_fork(SIGCHLD, regs->gprs[15], regs, 0, NULL, NULL);
1da177e4 LT	218	}
1da177e4 LT	219
2d70ca23 HC	220	SYSCALL_DEFINE4(clone, unsigned long, newsp, unsigned long, clone_flags,
2d70ca23 HC	221	int __user , parent_tidptr, int __user , child_tidptr)
1da177e4	222	{
03ff9a23	223	struct pt_regs *regs = task_pt_regs(current);
1da177e4	224
03ff9a23 MS	225	if (!newsp)
	226	newsp = regs->gprs[15];
	227	return do_fork(clone_flags, newsp, regs, 0,
1da177e4 LT	228	parent_tidptr, child_tidptr);
	229	}
	230
	231	/*
	232	* This is trivial, and on the face of it looks like it
	233	* could equally well be done in user mode.
	234	*
	235	* Not so, for quite unobvious reasons - register pressure.
	236	* In user mode vfork() cannot have a stack frame, and if
	237	* done by calling the "clone()" system call directly, you
	238	* do not have enough call-clobbered registers to hold all
	239	* the information you need.
	240	*/
26689452	241	SYSCALL_DEFINE0(vfork)
1da177e4	242	{
03ff9a23	243	struct pt_regs *regs = task_pt_regs(current);
1da177e4	244	return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD,
03ff9a23 MS	245	regs->gprs[15], regs, 0, NULL, NULL);
	246	}
	247
	248	asmlinkage void execve_tail(void)
	249	{
03ff9a23 MS	250	current->thread.fp_regs.fpc = 0;
	251	if (MACHINE_HAS_IEEE)
	252	asm volatile("sfpc %0,%0" : : "d" (0));
1da177e4 LT	253	}
	254
	255	/*
	256	* sys_execve() executes a new program.
	257	*/
d7627467 DH	258	SYSCALL_DEFINE3(execve, const char __user *, name,
	259	const char __user const __user , argv,
	260	const char __user const __user , envp)
1da177e4	261	{
03ff9a23 MS	262	struct pt_regs *regs = task_pt_regs(current);
03ff9a23 MS	263	char *filename;
3e86a8c6	264	long rc;
03ff9a23	265
3e86a8c6 HC	266	filename = getname(name);
	267	rc = PTR_ERR(filename);
	268	if (IS_ERR(filename))
	269	return rc;
	270	rc = do_execve(filename, argv, envp, regs);
	271	if (rc)
03ff9a23	272	goto out;
03ff9a23	273	execve_tail();
3e86a8c6	274	rc = regs->gprs[2];
1da177e4	275	out:
3e86a8c6 HC	276	putname(filename);
3e86a8c6 HC	277	return rc;
1da177e4 LT	278	}
1da177e4 LT	279
1da177e4 LT	280	/*
	281	* fill in the FPU structure for a core dump.
	282	*/
	283	int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
	284	{
347a8dc3	285	#ifndef CONFIG_64BIT
cbdc2292	286	/*
1da177e4 LT	287	* save fprs to current->thread.fp_regs to merge them with
	288	* the emulated registers and then copy the result to the dump.
	289	*/
	290	save_fp_regs(&current->thread.fp_regs);
	291	memcpy(fpregs, &current->thread.fp_regs, sizeof(s390_fp_regs));
347a8dc3	292	#else /* CONFIG_64BIT */
1da177e4	293	save_fp_regs(fpregs);
347a8dc3	294	#endif /* CONFIG_64BIT */
1da177e4 LT	295	return 1;
1da177e4 LT	296	}
1485c5c8	297	EXPORT_SYMBOL(dump_fpu);
1da177e4	298
1da177e4 LT	299	unsigned long get_wchan(struct task_struct *p)
	300	{
	301	struct stack_frame sf, low, *high;
	302	unsigned long return_address;
	303	int count;
	304
30af7120	305	if (!p \|\| p == current \|\| p->state == TASK_RUNNING \|\| !task_stack_page(p))
1da177e4	306	return 0;
30af7120 AV	307	low = task_stack_page(p);
30af7120 AV	308	high = (struct stack_frame *) task_pt_regs(p);
1da177e4 LT	309	sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN);
	310	if (sf <= low \|\| sf > high)
	311	return 0;
	312	for (count = 0; count < 16; count++) {
	313	sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
	314	if (sf <= low \|\| sf > high)
	315	return 0;
	316	return_address = sf->gprs[8] & PSW_ADDR_INSN;
	317	if (!in_sched_functions(return_address))
	318	return return_address;
	319	}
	320	return 0;
	321	}
9887a1fc HC	322
	323	unsigned long arch_align_stack(unsigned long sp)
	324	{
	325	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
	326	sp -= get_random_int() & ~PAGE_MASK;
	327	return sp & ~0xf;
	328	}
33519182 HC	329
	330	static inline unsigned long brk_rnd(void)
	331	{
	332	/* 8MB for 32bit, 1GB for 64bit */
	333	if (is_32bit_task())
	334	return (get_random_int() & 0x7ffUL) << PAGE_SHIFT;
	335	else
	336	return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT;
	337	}
	338
	339	unsigned long arch_randomize_brk(struct mm_struct *mm)
	340	{
	341	unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd());
	342
	343	if (ret < mm->brk)
	344	return mm->brk;
	345	return ret;
	346	}
d2c9dfcc HC	347
	348	unsigned long randomize_et_dyn(unsigned long base)
	349	{
	350	unsigned long ret = PAGE_ALIGN(base + brk_rnd());
	351
	352	if (!(current->flags & PF_RANDOMIZE))
	353	return base;
	354	if (ret < base)
	355	return base;
	356	return ret;
	357	}