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kernel-ark/arch/ia64/kernel/process.c
Ian Wienand e384f41409 [IA64] set_thread_area fails in IA32 chroot 
I tried to upgrade an IA32 chroot on my IA64 to a new glibc with TLS.
It kept dying because set_thread_area was returning -ESRCH
(bugs.debian.org/451939).

I instrumented arch/ia64/ia32/sys_ia32.c:get_free_idx() and ended up
seeing output like

[pid] idx   desc->a  desc->b
-----------------------------
[2710] 0 -> c6b0ffff 40dff31b
[2710] 1 -> 0 0
[2710] 2 -> 0 0

[2710] 0 -> c6b0ffff 40dff31b
[2710] 1 -> c6b0ffff 40dff31b
[2710] 2 -> 0 0

[2711] 0 -> c6b0ffff 40dff31b
[2711] 1 -> c6b0ffff 40dff31b
[2711] 2 -> 48c0ffff 40dff317

which suggested to me that TLS pointers were surviving exec() calls,
leading to GDT pointers filling up and the eventual failure of
get_free_idx().

I think the solution is flushing the tls array on exec.

Signed-Off-By: Ian Wienand <ianw@gelato.unsw.edu.au>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2007-12-19 11:06:40 -08:00

860 lines
22 KiB
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/*
* 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
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);
}
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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