Commit 5e3e94b1 authored by Li Zhengyu's avatar Li Zhengyu Committed by Liao Chen
Browse files

arm64: Add non nmi ipi backtrace support 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8PRY6


CVE: NA

--------------------------------

Use non nmi ipi to support backtrace on arm64 with nmi
unsupported.
It has been tested on qemu.

Signed-off-by: default avatarLi Zhengyu <lizhengyu3@huawei.com>
Signed-off-by: default avatarLiao Chen <liaochen4@huawei.com>
parent 49f3cbc2

arch/arm64/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -2242,6 +2242,14 @@ config ARM64_DEBUG_PRIORITY_MASKING 
	  If unsure, say N

endif # ARM64_PSEUDO_NMI



config NON_NMI_IPI_BACKTRACE

	bool "Support non nmi ipi backtrace"

	depends on ARM64_PSEUDO_NMI

	default n

	help

	  This adds support for non nmi ipi backtrace, which allows hungtask_monitor

	  to print stack trace when recovering from a hung task.



config RELOCATABLE

	bool "Build a relocatable kernel image" if EXPERT

	select ARCH_HAS_RELR

arch/arm64/configs/openeuler_defconfig

+1 −0
Original line number Diff line number Diff line
@@ -536,6 +536,7 @@ CONFIG_ARM64_SVE=y 
CONFIG_ARM64_SME=y

CONFIG_ARM64_PSEUDO_NMI=y

# CONFIG_ARM64_DEBUG_PRIORITY_MASKING is not set

CONFIG_NON_NMI_IPI_BACKTRACE=y

CONFIG_RELOCATABLE=y

CONFIG_RANDOMIZE_BASE=y

CONFIG_KASLR_SKIP_MEM_RANGE=y

arch/arm64/kernel/ipi_nmi.c

+35 −4
Original line number Diff line number Diff line
@@ -33,12 +33,43 @@ void arm64_send_nmi(cpumask_t *mask) 
	__ipi_send_mask(ipi_nmi_desc, mask);

}



bool arch_trigger_cpumask_backtrace(const cpumask_t *mask, int exclude_cpu)

#ifdef CONFIG_NON_NMI_IPI_BACKTRACE

static void ipi_cpu_backtrace(void *info)

{

	if (!ipi_nmi_desc)

		return false;

	__printk_safe_enter();

	nmi_cpu_backtrace(get_irq_regs());

	__printk_safe_exit();

}



static DEFINE_PER_CPU(call_single_data_t, cpu_backtrace_csd) =

	CSD_INIT(ipi_cpu_backtrace, NULL);



static void arm64_send_ipi(cpumask_t *mask)

{

	call_single_data_t *csd;

	int this_cpu = raw_smp_processor_id();

	int cpu;

	int ret;



	for_each_online_cpu(cpu) {

		if (cpu == this_cpu)

			continue;

		csd = &per_cpu(cpu_backtrace_csd, cpu);

		ret = smp_call_function_single_async(cpu, csd);

		if (ret)

			pr_info("Sending IPI failed to CPU %d\n", cpu);

	}

}

#endif



bool arch_trigger_cpumask_backtrace(const cpumask_t *mask, int exclude_cpu)

{

	if (ipi_nmi_desc)

		nmi_trigger_cpumask_backtrace(mask, exclude_cpu, arm64_send_nmi);

#ifdef CONFIG_NON_NMI_IPI_BACKTRACE

	else

		nmi_trigger_cpumask_backtrace(mask, exclude_cpu, arm64_send_ipi);

#endif



	return true;

}