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

This commit is contained in:

Peter Zijlstra

2020-11-20 11:50:35 +01:00

parent 43be4388e9

commit 58c644ba51

23 changed files with 64 additions and 38 deletions

									
										arch/riscv/kernel/process.c
									
		+1
		-1
	
												View File
												
				@@ -36,7 +36,7 @@ extern asmlinkage void ret_from_kernel_thread(void);

				void arch_cpu_idle(void)

				{

					wait_for_interrupt();

					local_irq_enable();

					raw_local_irq_enable();

				}

				void show_regs(struct pt_regs *regs)