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58c644ba51
We call arch_cpu_idle() with RCU disabled, but then use local_irq_{en,dis}able(), which invokes tracing, which relies on RCU. Switch all arch_cpu_idle() implementations to use raw_local_irq_{en,dis}able() and carefully manage the lockdep,rcu,tracing state like we do in entry. (XXX: we really should change arch_cpu_idle() to not return with interrupts enabled) Reported-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org
304 lines
7.7 KiB
C
304 lines
7.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* PARISC Architecture-dependent parts of process handling
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* based on the work for i386
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*
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* Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
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* Copyright (C) 2000 Martin K Petersen <mkp at mkp.net>
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* Copyright (C) 2000 John Marvin <jsm at parisc-linux.org>
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* Copyright (C) 2000 David Huggins-Daines <dhd with pobox.org>
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* Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
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* Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org>
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* Copyright (C) 2000 David Kennedy <dkennedy with linuxcare.com>
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* Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
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* Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
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* Copyright (C) 2001 Alan Modra <amodra at parisc-linux.org>
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* Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
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* Copyright (C) 2001-2014 Helge Deller <deller@gmx.de>
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* Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
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*/
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#include <stdarg.h>
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#include <linux/elf.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/cpu.h>
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#include <linux/module.h>
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#include <linux/personality.h>
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#include <linux/ptrace.h>
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#include <linux/sched.h>
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#include <linux/sched/debug.h>
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#include <linux/sched/task.h>
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#include <linux/sched/task_stack.h>
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#include <linux/slab.h>
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#include <linux/stddef.h>
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#include <linux/unistd.h>
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#include <linux/kallsyms.h>
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#include <linux/uaccess.h>
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#include <linux/rcupdate.h>
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#include <linux/random.h>
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#include <linux/nmi.h>
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#include <asm/io.h>
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#include <asm/asm-offsets.h>
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#include <asm/assembly.h>
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#include <asm/pdc.h>
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#include <asm/pdc_chassis.h>
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#include <asm/unwind.h>
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#include <asm/sections.h>
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#define COMMAND_GLOBAL F_EXTEND(0xfffe0030)
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#define CMD_RESET 5 /* reset any module */
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/*
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** The Wright Brothers and Gecko systems have a H/W problem
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** (Lasi...'nuf said) may cause a broadcast reset to lockup
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** the system. An HVERSION dependent PDC call was developed
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** to perform a "safe", platform specific broadcast reset instead
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** of kludging up all the code.
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**
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** Older machines which do not implement PDC_BROADCAST_RESET will
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** return (with an error) and the regular broadcast reset can be
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** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
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** the PDC call will not return (the system will be reset).
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*/
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void machine_restart(char *cmd)
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{
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#ifdef FASTBOOT_SELFTEST_SUPPORT
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/*
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** If user has modified the Firmware Selftest Bitmap,
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** run the tests specified in the bitmap after the
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** system is rebooted w/PDC_DO_RESET.
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**
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** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
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**
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** Using "directed resets" at each processor with the MEM_TOC
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** vector cleared will also avoid running destructive
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** memory self tests. (Not implemented yet)
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*/
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if (ftc_bitmap) {
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pdc_do_firm_test_reset(ftc_bitmap);
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}
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#endif
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/* set up a new led state on systems shipped with a LED State panel */
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pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
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/* "Normal" system reset */
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pdc_do_reset();
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/* Nope...box should reset with just CMD_RESET now */
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gsc_writel(CMD_RESET, COMMAND_GLOBAL);
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/* Wait for RESET to lay us to rest. */
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while (1) ;
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}
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void (*chassis_power_off)(void);
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/*
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* This routine is called from sys_reboot to actually turn off the
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* machine
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*/
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void machine_power_off(void)
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{
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/* If there is a registered power off handler, call it. */
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if (chassis_power_off)
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chassis_power_off();
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/* Put the soft power button back under hardware control.
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* If the user had already pressed the power button, the
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* following call will immediately power off. */
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pdc_soft_power_button(0);
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pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
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/* ipmi_poweroff may have been installed. */
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if (pm_power_off)
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pm_power_off();
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/* It seems we have no way to power the system off via
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* software. The user has to press the button himself. */
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printk(KERN_EMERG "System shut down completed.\n"
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"Please power this system off now.");
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/* prevent soft lockup/stalled CPU messages for endless loop. */
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rcu_sysrq_start();
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lockup_detector_soft_poweroff();
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for (;;);
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}
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void (*pm_power_off)(void);
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EXPORT_SYMBOL(pm_power_off);
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void machine_halt(void)
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{
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machine_power_off();
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}
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void flush_thread(void)
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{
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/* Only needs to handle fpu stuff or perf monitors.
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** REVISIT: several arches implement a "lazy fpu state".
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*/
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}
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void release_thread(struct task_struct *dead_task)
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{
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}
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/*
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* Idle thread support
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*
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* Detect when running on QEMU with SeaBIOS PDC Firmware and let
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* QEMU idle the host too.
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*/
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int running_on_qemu __ro_after_init;
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EXPORT_SYMBOL(running_on_qemu);
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void __cpuidle arch_cpu_idle_dead(void)
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{
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/* nop on real hardware, qemu will offline CPU. */
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asm volatile("or %%r31,%%r31,%%r31\n":::);
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}
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void __cpuidle arch_cpu_idle(void)
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{
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raw_local_irq_enable();
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/* nop on real hardware, qemu will idle sleep. */
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asm volatile("or %%r10,%%r10,%%r10\n":::);
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}
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static int __init parisc_idle_init(void)
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{
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if (!running_on_qemu)
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cpu_idle_poll_ctrl(1);
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return 0;
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}
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arch_initcall(parisc_idle_init);
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/*
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* Copy architecture-specific thread state
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*/
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int
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copy_thread(unsigned long clone_flags, unsigned long usp,
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unsigned long kthread_arg, struct task_struct *p, unsigned long tls)
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{
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struct pt_regs *cregs = &(p->thread.regs);
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void *stack = task_stack_page(p);
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/* We have to use void * instead of a function pointer, because
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* function pointers aren't a pointer to the function on 64-bit.
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* Make them const so the compiler knows they live in .text */
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extern void * const ret_from_kernel_thread;
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extern void * const child_return;
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if (unlikely(p->flags & PF_KTHREAD)) {
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/* kernel thread */
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memset(cregs, 0, sizeof(struct pt_regs));
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if (!usp) /* idle thread */
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return 0;
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/* Must exit via ret_from_kernel_thread in order
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* to call schedule_tail()
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*/
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cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
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cregs->kpc = (unsigned long) &ret_from_kernel_thread;
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/*
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* Copy function and argument to be called from
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* ret_from_kernel_thread.
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*/
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#ifdef CONFIG_64BIT
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cregs->gr[27] = ((unsigned long *)usp)[3];
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cregs->gr[26] = ((unsigned long *)usp)[2];
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#else
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cregs->gr[26] = usp;
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#endif
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cregs->gr[25] = kthread_arg;
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} else {
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/* user thread */
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/* usp must be word aligned. This also prevents users from
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* passing in the value 1 (which is the signal for a special
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* return for a kernel thread) */
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if (usp) {
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usp = ALIGN(usp, 4);
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if (likely(usp))
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cregs->gr[30] = usp;
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}
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cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
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cregs->kpc = (unsigned long) &child_return;
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/* Setup thread TLS area */
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if (clone_flags & CLONE_SETTLS)
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cregs->cr27 = tls;
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}
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return 0;
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}
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unsigned long
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get_wchan(struct task_struct *p)
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{
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struct unwind_frame_info info;
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unsigned long ip;
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int count = 0;
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if (!p || p == current || p->state == TASK_RUNNING)
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return 0;
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/*
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* These bracket the sleeping functions..
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*/
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unwind_frame_init_from_blocked_task(&info, p);
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do {
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if (unwind_once(&info) < 0)
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return 0;
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ip = info.ip;
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if (!in_sched_functions(ip))
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return ip;
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} while (count++ < MAX_UNWIND_ENTRIES);
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return 0;
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}
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#ifdef CONFIG_64BIT
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void *dereference_function_descriptor(void *ptr)
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{
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Elf64_Fdesc *desc = ptr;
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void *p;
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if (!get_kernel_nofault(p, (void *)&desc->addr))
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ptr = p;
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return ptr;
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}
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void *dereference_kernel_function_descriptor(void *ptr)
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{
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if (ptr < (void *)__start_opd ||
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ptr >= (void *)__end_opd)
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return ptr;
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return dereference_function_descriptor(ptr);
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}
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#endif
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static inline unsigned long brk_rnd(void)
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{
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return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
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}
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unsigned long arch_randomize_brk(struct mm_struct *mm)
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{
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unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd());
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if (ret < mm->brk)
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return mm->brk;
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return ret;
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}
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