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3b2ce0b178
linux/arch/ia64/kernel/process.c
Petr Tesarik 3b2ce0b178 [IA64] Synchronize kernel RSE to user-space and back 
This is base kernel patch for ptrace RSE bug. It's basically a backport
from the utrace RSE patch I sent out several weeks ago. please review.

when a thread is stopped (ptraced), debugger might change thread's user
stack (change memory directly), and we must avoid the RSE stored in
kernel to override user stack (user space's RSE is newer than kernel's
in the case). To workaround the issue, we copy kernel RSE to user RSE
before the task is stopped, so user RSE has updated data.  we then copy
user RSE to kernel after the task is resummed from traced stop and
kernel will use the newer RSE to return to user.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
CC: Roland McGrath <roland@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-02-08 12:01:18 -08:00

875 lines
23 KiB
C
Raw Blame History

/*
* Architecture-specific setup.
*
* Copyright (C) 1998-2003 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
* 04/11/17 Ashok Raj <ashok.raj@intel.com> Added CPU Hotplug Support
*
* 2005-10-07 Keith Owens <kaos@sgi.com>
* Add notify_die() hooks.
*/
#include <linux/cpu.h>
#include <linux/pm.h>
#include <linux/elf.h>
#include <linux/errno.h>
#include <linux/kallsyms.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/personality.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/stddef.h>
#include <linux/thread_info.h>
#include <linux/unistd.h>
#include <linux/efi.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/kdebug.h>
#include <linux/utsname.h>
#include <asm/cpu.h>
#include <asm/delay.h>
#include <asm/elf.h>
#include <asm/ia32.h>
#include <asm/irq.h>
#include <asm/kexec.h>
#include <asm/pgalloc.h>
#include <asm/processor.h>
#include <asm/sal.h>
#include <asm/tlbflush.h>
#include <asm/uaccess.h>
#include <asm/unwind.h>
#include <asm/user.h>
#include "entry.h"
#ifdef CONFIG_PERFMON
# include <asm/perfmon.h>
#endif
#include "sigframe.h"
void (*ia64_mark_idle)(int);
static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
unsigned long boot_option_idle_override = 0;
EXPORT_SYMBOL(boot_option_idle_override);
void
ia64_do_show_stack (struct unw_frame_info *info, void *arg)
{
unsigned long ip, sp, bsp;
char buf[128]; /* don't make it so big that it overflows the stack! */
printk("\nCall Trace:\n");
do {
unw_get_ip(info, &ip);
if (ip == 0)
break;
unw_get_sp(info, &sp);
unw_get_bsp(info, &bsp);
snprintf(buf, sizeof(buf),
" [<%016lx>] %%s\n"
" sp=%016lx bsp=%016lx\n",
ip, sp, bsp);
print_symbol(buf, ip);
} while (unw_unwind(info) >= 0);
}
void
show_stack (struct task_struct *task, unsigned long *sp)
{
if (!task)
unw_init_running(ia64_do_show_stack, NULL);
else {
struct unw_frame_info info;
unw_init_from_blocked_task(&info, task);
ia64_do_show_stack(&info, NULL);
}
}
void
dump_stack (void)
{
show_stack(NULL, NULL);
}
EXPORT_SYMBOL(dump_stack);
void
show_regs (struct pt_regs *regs)
{
unsigned long ip = regs->cr_iip + ia64_psr(regs)->ri;
print_modules();
printk("\nPid: %d, CPU %d, comm: %20s\n", task_pid_nr(current),
smp_processor_id(), current->comm);
printk("psr : %016lx ifs : %016lx ip : [<%016lx>] %s (%s)\n",
regs->cr_ipsr, regs->cr_ifs, ip, print_tainted(),
init_utsname()->release);
print_symbol("ip is at %s\n", ip);
printk("unat: %016lx pfs : %016lx rsc : %016lx\n",
regs->ar_unat, regs->ar_pfs, regs->ar_rsc);
printk("rnat: %016lx bsps: %016lx pr : %016lx\n",
regs->ar_rnat, regs->ar_bspstore, regs->pr);
printk("ldrs: %016lx ccv : %016lx fpsr: %016lx\n",
regs->loadrs, regs->ar_ccv, regs->ar_fpsr);
printk("csd : %016lx ssd : %016lx\n", regs->ar_csd, regs->ar_ssd);
printk("b0 : %016lx b6 : %016lx b7 : %016lx\n", regs->b0, regs->b6, regs->b7);
printk("f6 : %05lx%016lx f7 : %05lx%016lx\n",
regs->f6.u.bits[1], regs->f6.u.bits[0],
regs->f7.u.bits[1], regs->f7.u.bits[0]);
printk("f8 : %05lx%016lx f9 : %05lx%016lx\n",
regs->f8.u.bits[1], regs->f8.u.bits[0],
regs->f9.u.bits[1], regs->f9.u.bits[0]);
printk("f10 : %05lx%016lx f11 : %05lx%016lx\n",
regs->f10.u.bits[1], regs->f10.u.bits[0],
regs->f11.u.bits[1], regs->f11.u.bits[0]);
printk("r1 : %016lx r2 : %016lx r3 : %016lx\n", regs->r1, regs->r2, regs->r3);
printk("r8 : %016lx r9 : %016lx r10 : %016lx\n", regs->r8, regs->r9, regs->r10);
printk("r11 : %016lx r12 : %016lx r13 : %016lx\n", regs->r11, regs->r12, regs->r13);
printk("r14 : %016lx r15 : %016lx r16 : %016lx\n", regs->r14, regs->r15, regs->r16);
printk("r17 : %016lx r18 : %016lx r19 : %016lx\n", regs->r17, regs->r18, regs->r19);
printk("r20 : %016lx r21 : %016lx r22 : %016lx\n", regs->r20, regs->r21, regs->r22);
printk("r23 : %016lx r24 : %016lx r25 : %016lx\n", regs->r23, regs->r24, regs->r25);
printk("r26 : %016lx r27 : %016lx r28 : %016lx\n", regs->r26, regs->r27, regs->r28);
printk("r29 : %016lx r30 : %016lx r31 : %016lx\n", regs->r29, regs->r30, regs->r31);
if (user_mode(regs)) {
/* print the stacked registers */
unsigned long val, *bsp, ndirty;
int i, sof, is_nat = 0;
sof = regs->cr_ifs & 0x7f; /* size of frame */
ndirty = (regs->loadrs >> 19);
bsp = ia64_rse_skip_regs((unsigned long *) regs->ar_bspstore, ndirty);
for (i = 0; i < sof; ++i) {
get_user(val, (unsigned long __user *) ia64_rse_skip_regs(bsp, i));
printk("r%-3u:%c%016lx%s", 32 + i, is_nat ? '*' : ' ', val,
((i == sof - 1) || (i % 3) == 2) ? "\n" : " ");
}
} else
show_stack(NULL, NULL);
}
void tsk_clear_notify_resume(struct task_struct *tsk)
{
#ifdef CONFIG_PERFMON
if (tsk->thread.pfm_needs_checking)
return;
#endif
if (test_ti_thread_flag(task_thread_info(tsk), TIF_RESTORE_RSE))
return;
clear_ti_thread_flag(task_thread_info(tsk), TIF_NOTIFY_RESUME);
}
void
do_notify_resume_user (sigset_t *unused, struct sigscratch *scr, long in_syscall)
{
if (fsys_mode(current, &scr->pt)) {
/* defer signal-handling etc. until we return to privilege-level 0. */
if (!ia64_psr(&scr->pt)->lp)
ia64_psr(&scr->pt)->lp = 1;
return;
}
#ifdef CONFIG_PERFMON
if (current->thread.pfm_needs_checking)
pfm_handle_work();
#endif
/* deal with pending signal delivery */
if (test_thread_flag(TIF_SIGPENDING)||test_thread_flag(TIF_RESTORE_SIGMASK))
ia64_do_signal(scr, in_syscall);
/* copy user rbs to kernel rbs */
if (unlikely(test_thread_flag(TIF_RESTORE_RSE)))
ia64_sync_krbs();
}
static int pal_halt = 1;
static int can_do_pal_halt = 1;
static int __init nohalt_setup(char * str)
{
pal_halt = can_do_pal_halt = 0;
return 1;
}
__setup("nohalt", nohalt_setup);
void
update_pal_halt_status(int status)
{
can_do_pal_halt = pal_halt && status;
}
/*
* We use this if we don't have any better idle routine..
*/
void
default_idle (void)
{
local_irq_enable();
while (!need_resched()) {
if (can_do_pal_halt) {
local_irq_disable();
if (!need_resched()) {
safe_halt();
}
local_irq_enable();
} else
cpu_relax();
}
}
#ifdef CONFIG_HOTPLUG_CPU
/* We don't actually take CPU down, just spin without interrupts. */
static inline void play_dead(void)
{
extern void ia64_cpu_local_tick (void);
unsigned int this_cpu = smp_processor_id();
/* Ack it */
__get_cpu_var(cpu_state) = CPU_DEAD;
max_xtp();
local_irq_disable();
idle_task_exit();
ia64_jump_to_sal(&sal_boot_rendez_state[this_cpu]);
/*
* The above is a point of no-return, the processor is
* expected to be in SAL loop now.
*/
BUG();
}
#else
static inline void play_dead(void)
{
BUG();
}
#endif /* CONFIG_HOTPLUG_CPU */
void cpu_idle_wait(void)
{
unsigned int cpu, this_cpu = get_cpu();
cpumask_t map;
cpumask_t tmp = current->cpus_allowed;
set_cpus_allowed(current, cpumask_of_cpu(this_cpu));
put_cpu();
cpus_clear(map);
for_each_online_cpu(cpu) {
per_cpu(cpu_idle_state, cpu) = 1;
cpu_set(cpu, map);
}
__get_cpu_var(cpu_idle_state) = 0;
wmb();
do {
ssleep(1);
for_each_online_cpu(cpu) {
if (cpu_isset(cpu, map) && !per_cpu(cpu_idle_state, cpu))
cpu_clear(cpu, map);
}
cpus_and(map, map, cpu_online_map);
} while (!cpus_empty(map));
set_cpus_allowed(current, tmp);
}
EXPORT_SYMBOL_GPL(cpu_idle_wait);
void __attribute__((noreturn))
cpu_idle (void)
{
void (*mark_idle)(int) = ia64_mark_idle;
int cpu = smp_processor_id();
/* endless idle loop with no priority at all */
while (1) {
if (can_do_pal_halt) {
current_thread_info()->status &= ~TS_POLLING;
/*
* TS_POLLING-cleared state must be visible before we
* test NEED_RESCHED:
*/
smp_mb();
} else {
current_thread_info()->status |= TS_POLLING;
}
if (!need_resched()) {
void (*idle)(void);
#ifdef CONFIG_SMP
min_xtp();
#endif
if (__get_cpu_var(cpu_idle_state))
__get_cpu_var(cpu_idle_state) = 0;
rmb();
if (mark_idle)
(*mark_idle)(1);
idle = pm_idle;
if (!idle)
idle = default_idle;
(*idle)();
if (mark_idle)
(*mark_idle)(0);
#ifdef CONFIG_SMP
normal_xtp();
#endif
}
preempt_enable_no_resched();
schedule();
preempt_disable();
check_pgt_cache();
if (cpu_is_offline(cpu))
play_dead();
}
}
void
ia64_save_extra (struct task_struct *task)
{
#ifdef CONFIG_PERFMON
unsigned long info;
#endif
if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
ia64_save_debug_regs(&task->thread.dbr[0]);
#ifdef CONFIG_PERFMON
if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
pfm_save_regs(task);
info = __get_cpu_var(pfm_syst_info);
if (info & PFM_CPUINFO_SYST_WIDE)
pfm_syst_wide_update_task(task, info, 0);
#endif
#ifdef CONFIG_IA32_SUPPORT
if (IS_IA32_PROCESS(task_pt_regs(task)))
ia32_save_state(task);
#endif
}
void
ia64_load_extra (struct task_struct *task)
{
#ifdef CONFIG_PERFMON
unsigned long info;
#endif
if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
ia64_load_debug_regs(&task->thread.dbr[0]);
#ifdef CONFIG_PERFMON
if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
pfm_load_regs(task);
info = __get_cpu_var(pfm_syst_info);
if (info & PFM_CPUINFO_SYST_WIDE)
pfm_syst_wide_update_task(task, info, 1);
#endif
#ifdef CONFIG_IA32_SUPPORT
if (IS_IA32_PROCESS(task_pt_regs(task)))
ia32_load_state(task);
#endif
}
/*
* Copy the state of an ia-64 thread.
*
* We get here through the following call chain:
*
* from user-level: from kernel:
*
* <clone syscall> <some kernel call frames>
* sys_clone :
* do_fork do_fork
* copy_thread copy_thread
*
* This means that the stack layout is as follows:
*
* +---------------------+ (highest addr)
* | struct pt_regs |
* +---------------------+
* | struct switch_stack |
* +---------------------+
* | |
* | memory stack |
* | | <-- sp (lowest addr)
* +---------------------+
*
* Observe that we copy the unat values that are in pt_regs and switch_stack. Spilling an
* integer to address X causes bit N in ar.unat to be set to the NaT bit of the register,
* with N=(X & 0x1ff)/8. Thus, copying the unat value preserves the NaT bits ONLY if the
* pt_regs structure in the parent is congruent to that of the child, modulo 512. Since
* the stack is page aligned and the page size is at least 4KB, this is always the case,
* so there is nothing to worry about.
*/
int
copy_thread (int nr, unsigned long clone_flags,
unsigned long user_stack_base, unsigned long user_stack_size,
struct task_struct *p, struct pt_regs *regs)
{
extern char ia64_ret_from_clone, ia32_ret_from_clone;
struct switch_stack *child_stack, *stack;
unsigned long rbs, child_rbs, rbs_size;
struct pt_regs *child_ptregs;
int retval = 0;
#ifdef CONFIG_SMP
/*
* For SMP idle threads, fork_by_hand() calls do_fork with
* NULL regs.
*/
if (!regs)
return 0;
#endif
stack = ((struct switch_stack *) regs) - 1;
child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1;
child_stack = (struct switch_stack *) child_ptregs - 1;
/* copy parent's switch_stack & pt_regs to child: */
memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack));
rbs = (unsigned long) current + IA64_RBS_OFFSET;
child_rbs = (unsigned long) p + IA64_RBS_OFFSET;
rbs_size = stack->ar_bspstore - rbs;
/* copy the parent's register backing store to the child: */
memcpy((void *) child_rbs, (void *) rbs, rbs_size);
if (likely(user_mode(child_ptregs))) {
if ((clone_flags & CLONE_SETTLS) && !IS_IA32_PROCESS(regs))
child_ptregs->r13 = regs->r16; /* see sys_clone2() in entry.S */
if (user_stack_base) {
child_ptregs->r12 = user_stack_base + user_stack_size - 16;
child_ptregs->ar_bspstore = user_stack_base;
child_ptregs->ar_rnat = 0;
child_ptregs->loadrs = 0;
}
} else {
/*
* Note: we simply preserve the relative position of
* the stack pointer here. There is no need to
* allocate a scratch area here, since that will have
* been taken care of by the caller of sys_clone()
* already.
*/
child_ptregs->r12 = (unsigned long) child_ptregs - 16; /* kernel sp */
child_ptregs->r13 = (unsigned long) p; /* set `current' pointer */
}
child_stack->ar_bspstore = child_rbs + rbs_size;
if (IS_IA32_PROCESS(regs))
child_stack->b0 = (unsigned long) &ia32_ret_from_clone;
else
child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
/* copy parts of thread_struct: */
p->thread.ksp = (unsigned long) child_stack - 16;
/* stop some PSR bits from being inherited.
* the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
* therefore we must specify them explicitly here and not include them in
* IA64_PSR_BITS_TO_CLEAR.
*/
child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
& ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
/*
* NOTE: The calling convention considers all floating point
* registers in the high partition (fph) to be scratch. Since
* the only way to get to this point is through a system call,
* we know that the values in fph are all dead. Hence, there
* is no need to inherit the fph state from the parent to the
* child and all we have to do is to make sure that
* IA64_THREAD_FPH_VALID is cleared in the child.
*
* XXX We could push this optimization a bit further by
* clearing IA64_THREAD_FPH_VALID on ANY system call.
* However, it's not clear this is worth doing. Also, it
* would be a slight deviation from the normal Linux system
* call behavior where scratch registers are preserved across
* system calls (unless used by the system call itself).
*/
# define THREAD_FLAGS_TO_CLEAR (IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID \
| IA64_THREAD_PM_VALID)
# define THREAD_FLAGS_TO_SET 0
p->thread.flags = ((current->thread.flags & ~THREAD_FLAGS_TO_CLEAR)
| THREAD_FLAGS_TO_SET);
ia64_drop_fpu(p); /* don't pick up stale state from a CPU's fph */
#ifdef CONFIG_IA32_SUPPORT
/*
* If we're cloning an IA32 task then save the IA32 extra
* state from the current task to the new task
*/
if (IS_IA32_PROCESS(task_pt_regs(current))) {
ia32_save_state(p);
if (clone_flags & CLONE_SETTLS)
retval = ia32_clone_tls(p, child_ptregs);
/* Copy partially mapped page list */
if (!retval)
retval = ia32_copy_ia64_partial_page_list(p,
clone_flags);
}
#endif
#ifdef CONFIG_PERFMON
if (current->thread.pfm_context)
pfm_inherit(p, child_ptregs);
#endif
return retval;
}
static void
do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg)
{
unsigned long mask, sp, nat_bits = 0, ar_rnat, urbs_end, cfm;
unsigned long uninitialized_var(ip); /* GCC be quiet */
elf_greg_t *dst = arg;
struct pt_regs *pt;
char nat;
int i;
memset(dst, 0, sizeof(elf_gregset_t)); /* don't leak any kernel bits to user-level */
if (unw_unwind_to_user(info) < 0)
return;
unw_get_sp(info, &sp);
pt = (struct pt_regs *) (sp + 16);
urbs_end = ia64_get_user_rbs_end(task, pt, &cfm);
if (ia64_sync_user_rbs(task, info->sw, pt->ar_bspstore, urbs_end) < 0)
return;
ia64_peek(task, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end),
&ar_rnat);
/*
* coredump format:
* r0-r31
* NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
* predicate registers (p0-p63)
* b0-b7
* ip cfm user-mask
* ar.rsc ar.bsp ar.bspstore ar.rnat
* ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
*/
/* r0 is zero */
for (i = 1, mask = (1UL << i); i < 32; ++i) {
unw_get_gr(info, i, &dst[i], &nat);
if (nat)
nat_bits |= mask;
mask <<= 1;
}
dst[32] = nat_bits;
unw_get_pr(info, &dst[33]);
for (i = 0; i < 8; ++i)
unw_get_br(info, i, &dst[34 + i]);
unw_get_rp(info, &ip);
dst[42] = ip + ia64_psr(pt)->ri;
dst[43] = cfm;
dst[44] = pt->cr_ipsr & IA64_PSR_UM;
unw_get_ar(info, UNW_AR_RSC, &dst[45]);
/*
* For bsp and bspstore, unw_get_ar() would return the kernel
* addresses, but we need the user-level addresses instead:
*/
dst[46] = urbs_end; /* note: by convention PT_AR_BSP points to the end of the urbs! */
dst[47] = pt->ar_bspstore;
dst[48] = ar_rnat;
unw_get_ar(info, UNW_AR_CCV, &dst[49]);
unw_get_ar(info, UNW_AR_UNAT, &dst[50]);
unw_get_ar(info, UNW_AR_FPSR, &dst[51]);
dst[52] = pt->ar_pfs; /* UNW_AR_PFS is == to pt->cr_ifs for interrupt frames */
unw_get_ar(info, UNW_AR_LC, &dst[53]);
unw_get_ar(info, UNW_AR_EC, &dst[54]);
unw_get_ar(info, UNW_AR_CSD, &dst[55]);
unw_get_ar(info, UNW_AR_SSD, &dst[56]);
}
void
do_dump_task_fpu (struct task_struct *task, struct unw_frame_info *info, void *arg)
{
elf_fpreg_t *dst = arg;
int i;
memset(dst, 0, sizeof(elf_fpregset_t)); /* don't leak any "random" bits */
if (unw_unwind_to_user(info) < 0)
return;
/* f0 is 0.0, f1 is 1.0 */
for (i = 2; i < 32; ++i)
unw_get_fr(info, i, dst + i);
ia64_flush_fph(task);
if ((task->thread.flags & IA64_THREAD_FPH_VALID) != 0)
memcpy(dst + 32, task->thread.fph, 96*16);
}
void
do_copy_regs (struct unw_frame_info *info, void *arg)
{
do_copy_task_regs(current, info, arg);
}
void
do_dump_fpu (struct unw_frame_info *info, void *arg)
{
do_dump_task_fpu(current, info, arg);
}
int
dump_task_regs(struct task_struct *task, elf_gregset_t *regs)
{
struct unw_frame_info tcore_info;
if (current == task) {
unw_init_running(do_copy_regs, regs);
} else {
memset(&tcore_info, 0, sizeof(tcore_info));
unw_init_from_blocked_task(&tcore_info, task);
do_copy_task_regs(task, &tcore_info, regs);
}
return 1;
}
void
ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst)
{
unw_init_running(do_copy_regs, dst);
}
int
dump_task_fpu (struct task_struct *task, elf_fpregset_t *dst)
{
struct unw_frame_info tcore_info;
if (current == task) {
unw_init_running(do_dump_fpu, dst);
} else {
memset(&tcore_info, 0, sizeof(tcore_info));
unw_init_from_blocked_task(&tcore_info, task);
do_dump_task_fpu(task, &tcore_info, dst);
}
return 1;
}
int
dump_fpu (struct pt_regs *pt, elf_fpregset_t dst)
{
unw_init_running(do_dump_fpu, dst);
return 1; /* f0-f31 are always valid so we always return 1 */
}
long
sys_execve (char __user *filename, char __user * __user *argv, char __user * __user *envp,
struct pt_regs *regs)
{
char *fname;
int error;
fname = getname(filename);
error = PTR_ERR(fname);
if (IS_ERR(fname))
goto out;
error = do_execve(fname, argv, envp, regs);
putname(fname);
out:
return error;
}
pid_t
kernel_thread (int (*fn)(void *), void *arg, unsigned long flags)
{
extern void start_kernel_thread (void);
unsigned long *helper_fptr = (unsigned long *) &start_kernel_thread;
struct {
struct switch_stack sw;
struct pt_regs pt;
} regs;
memset(&regs, 0, sizeof(regs));
regs.pt.cr_iip = helper_fptr[0]; /* set entry point (IP) */
regs.pt.r1 = helper_fptr[1]; /* set GP */
regs.pt.r9 = (unsigned long) fn; /* 1st argument */
regs.pt.r11 = (unsigned long) arg; /* 2nd argument */
/* Preserve PSR bits, except for bits 32-34 and 37-45, which we can't read. */
regs.pt.cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN;
regs.pt.cr_ifs = 1UL << 63; /* mark as valid, empty frame */
regs.sw.ar_fpsr = regs.pt.ar_fpsr = ia64_getreg(_IA64_REG_AR_FPSR);
regs.sw.ar_bspstore = (unsigned long) current + IA64_RBS_OFFSET;
regs.sw.pr = (1 << PRED_KERNEL_STACK);
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs.pt, 0, NULL, NULL);
}
EXPORT_SYMBOL(kernel_thread);
/* This gets called from kernel_thread() via ia64_invoke_thread_helper(). */
int
kernel_thread_helper (int (*fn)(void *), void *arg)
{
#ifdef CONFIG_IA32_SUPPORT
if (IS_IA32_PROCESS(task_pt_regs(current))) {
/* A kernel thread is always a 64-bit process. */
current->thread.map_base = DEFAULT_MAP_BASE;
current->thread.task_size = DEFAULT_TASK_SIZE;
ia64_set_kr(IA64_KR_IO_BASE, current->thread.old_iob);
ia64_set_kr(IA64_KR_TSSD, current->thread.old_k1);
}
#endif
return (*fn)(arg);
}
/*
* Flush thread state. This is called when a thread does an execve().
*/
void
flush_thread (void)
{
/* drop floating-point and debug-register state if it exists: */
current->thread.flags &= ~(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID);
ia64_drop_fpu(current);
#ifdef CONFIG_IA32_SUPPORT
if (IS_IA32_PROCESS(task_pt_regs(current))) {
ia32_drop_ia64_partial_page_list(current);
current->thread.task_size = IA32_PAGE_OFFSET;
set_fs(USER_DS);
memset(current->thread.tls_array, 0, sizeof(current->thread.tls_array));
}
#endif
}
/*
* Clean up state associated with current thread. This is called when
* the thread calls exit().
*/
void
exit_thread (void)
{
ia64_drop_fpu(current);
#ifdef CONFIG_PERFMON
/* if needed, stop monitoring and flush state to perfmon context */
if (current->thread.pfm_context)
pfm_exit_thread(current);
/* free debug register resources */
if (current->thread.flags & IA64_THREAD_DBG_VALID)
pfm_release_debug_registers(current);
#endif
if (IS_IA32_PROCESS(task_pt_regs(current)))
ia32_drop_ia64_partial_page_list(current);
}
unsigned long
get_wchan (struct task_struct *p)
{
struct unw_frame_info info;
unsigned long ip;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
/*
* Note: p may not be a blocked task (it could be current or
* another process running on some other CPU. Rather than
* trying to determine if p is really blocked, we just assume
* it's blocked and rely on the unwind routines to fail
* gracefully if the process wasn't really blocked after all.
* --davidm 99/12/15
*/
unw_init_from_blocked_task(&info, p);
do {
if (p->state == TASK_RUNNING)
return 0;
if (unw_unwind(&info) < 0)
return 0;
unw_get_ip(&info, &ip);
if (!in_sched_functions(ip))
return ip;
} while (count++ < 16);
return 0;
}
void
cpu_halt (void)
{
pal_power_mgmt_info_u_t power_info[8];
unsigned long min_power;
int i, min_power_state;
if (ia64_pal_halt_info(power_info) != 0)
return;
min_power_state = 0;
min_power = power_info[0].pal_power_mgmt_info_s.power_consumption;
for (i = 1; i < 8; ++i)
if (power_info[i].pal_power_mgmt_info_s.im
&& power_info[i].pal_power_mgmt_info_s.power_consumption < min_power) {
min_power = power_info[i].pal_power_mgmt_info_s.power_consumption;
min_power_state = i;
}
while (1)
ia64_pal_halt(min_power_state);
}
void machine_shutdown(void)
{
#ifdef CONFIG_HOTPLUG_CPU
int cpu;
for_each_online_cpu(cpu) {
if (cpu != smp_processor_id())
cpu_down(cpu);
}
#endif
#ifdef CONFIG_KEXEC
kexec_disable_iosapic();
#endif
}
void
machine_restart (char *restart_cmd)
{
(void) notify_die(DIE_MACHINE_RESTART, restart_cmd, NULL, 0, 0, 0);
(*efi.reset_system)(EFI_RESET_WARM, 0, 0, NULL);
}
void
machine_halt (void)
{
(void) notify_die(DIE_MACHINE_HALT, "", NULL, 0, 0, 0);
cpu_halt();
}
void
machine_power_off (void)
{
if (pm_power_off)
pm_power_off();
machine_halt();
}
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