Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5bb9efe3 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf_counter: fix print debug irq disable 



inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
bash/15802 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (sysrq_key_table_lock){?.....},

Don't unconditionally enable interrupts in the perf_counter_print_debug()
path.

[ Impact: fix potential deadlock pointed out by lockdep ]

LKML-Reference: <new-submission>
Reported-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
parent e758a33d

arch/x86/kernel/cpu/perf_counter.c

+3 −2
Original line number Diff line number Diff line
@@ -621,12 +621,13 @@ void perf_counter_print_debug(void) 
{

	u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;

	struct cpu_hw_counters *cpuc;

	unsigned long flags;

	int cpu, idx;



	if (!x86_pmu.num_counters)

		return;



	local_irq_disable();

	local_irq_save(flags);



	cpu = smp_processor_id();

	cpuc = &per_cpu(cpu_hw_counters, cpu);
@@ -664,7 +665,7 @@ void perf_counter_print_debug(void) 
		pr_info("CPU#%d: fixed-PMC%d count: %016llx\n",

			cpu, idx, pmc_count);

	}

	local_irq_enable();

	local_irq_restore(flags);

}



static void x86_pmu_disable(struct perf_counter *counter)