Commit abde6b94 authored by Wei Li's avatar Wei Li Committed by Zheng Zengkai
Browse files

stop_machine: mask pseudo nmi before running the callback 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4JBQ8



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

Kprobes use 'stop_machine' to modify code which could be ran in the
pseudo nmi context at the same time. This patch mask pseudo nmi before
running the stop_machine callback to avoid this race condition.

Signed-off-by: default avatarWei Li <liwei391@huawei.com>
Reviewed-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: default avatarCheng Jian <cj.chengjian@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent da6731e7

arch/arm64/include/asm/arch_gicv3.h

+11 −0
Original line number Diff line number Diff line
@@ -184,5 +184,16 @@ static inline void gic_arch_enable_irqs(void) 
	asm volatile ("msr daifclr, #2" : : : "memory");

}



static inline void gic_arch_disable_irqs(void)

{

	asm volatile ("msr daifset, #2" : : : "memory");

}



static inline void gic_arch_restore_irqs(unsigned long flags)

{

	if (gic_supports_nmi())

		asm volatile ("msr	daif, %0" : : "r" (flags >> 32)

					: "memory");

}

#endif /* __ASSEMBLY__ */

#endif /* __ASM_ARCH_GICV3_H */

kernel/stop_machine.c

+3 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 


#ifdef CONFIG_ARM64

#include <linux/arm_sdei.h>

#include <asm/arch_gicv3.h>

#endif



/*
@@ -223,6 +224,7 @@ static int multi_cpu_stop(void *data) 
				local_irq_disable();

				hard_irq_disable();

#ifdef CONFIG_ARM64

				gic_arch_disable_irqs();

				sdei_mask_local_cpu();

#endif

				break;
@@ -247,6 +249,7 @@ static int multi_cpu_stop(void *data) 


#ifdef CONFIG_ARM64

	sdei_unmask_local_cpu();

	gic_arch_restore_irqs(flags);

#endif

	local_irq_restore(flags);

	return err;