linux/arch/csky/kernel/process.c
Peter Zijlstra 58c644ba51 sched/idle: Fix arch_cpu_idle() vs tracing
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
2020-11-24 16:47:35 +01:00

108 lines
2.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
#include <linux/module.h>
#include <linux/version.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/sched/debug.h>
#include <linux/delay.h>
#include <linux/kallsyms.h>
#include <linux/uaccess.h>
#include <linux/ptrace.h>
#include <asm/elf.h>
#include <abi/reg_ops.h>
struct cpuinfo_csky cpu_data[NR_CPUS];
#ifdef CONFIG_STACKPROTECTOR
#include <linux/stackprotector.h>
unsigned long __stack_chk_guard __read_mostly;
EXPORT_SYMBOL(__stack_chk_guard);
#endif
asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);
/*
* Some archs flush debug and FPU info here
*/
void flush_thread(void){}
int copy_thread(unsigned long clone_flags,
unsigned long usp,
unsigned long kthread_arg,
struct task_struct *p,
unsigned long tls)
{
struct switch_stack *childstack;
struct pt_regs *childregs = task_pt_regs(p);
#ifdef CONFIG_CPU_HAS_FPU
save_to_user_fp(&p->thread.user_fp);
#endif
childstack = ((struct switch_stack *) childregs) - 1;
memset(childstack, 0, sizeof(struct switch_stack));
/* setup thread.sp for switch_to !!! */
p->thread.sp = (unsigned long)childstack;
if (unlikely(p->flags & PF_KTHREAD)) {
memset(childregs, 0, sizeof(struct pt_regs));
childstack->r15 = (unsigned long) ret_from_kernel_thread;
childstack->r10 = kthread_arg;
childstack->r9 = usp;
childregs->sr = mfcr("psr");
} else {
*childregs = *(current_pt_regs());
if (usp)
childregs->usp = usp;
if (clone_flags & CLONE_SETTLS)
task_thread_info(p)->tp_value = childregs->tls
= tls;
childregs->a0 = 0;
childstack->r15 = (unsigned long) ret_from_fork;
}
return 0;
}
/* Fill in the fpu structure for a core dump. */
int dump_fpu(struct pt_regs *regs, struct user_fp *fpu)
{
memcpy(fpu, &current->thread.user_fp, sizeof(*fpu));
return 1;
}
EXPORT_SYMBOL(dump_fpu);
int dump_task_regs(struct task_struct *tsk, elf_gregset_t *pr_regs)
{
struct pt_regs *regs = task_pt_regs(tsk);
/* NOTE: usp is error value. */
ELF_CORE_COPY_REGS((*pr_regs), regs)
return 1;
}
#ifndef CONFIG_CPU_PM_NONE
void arch_cpu_idle(void)
{
#ifdef CONFIG_CPU_PM_WAIT
asm volatile("wait\n");
#endif
#ifdef CONFIG_CPU_PM_DOZE
asm volatile("doze\n");
#endif
#ifdef CONFIG_CPU_PM_STOP
asm volatile("stop\n");
#endif
raw_local_irq_enable();
}
#endif