Reviewed-by: Xiongfeng Wang wangxiongfeng2@huawei.com
-------------------------------------------------- 汪雄峰 Wang Xiongfeng Mobile: +86-15267087487tel:+86-15267087487 Email: wangxiongfeng2@huawei.commailto:wangxiongfeng2@huawei.com 发件人：sangyan sangyan@huawei.com 收件人：Xiexiuqi xiexiuqi@huawei.com;kernel kernel@openeuler.org;wangxiongfeng (C) wangxiongfeng2@huawei.com;Zhengzengkai zhengzengkai@huawei.com 抄 送：zhuling (C) zhuling8@huawei.com;luanjianhai luanjianhai@huawei.com;luolongjun luolongjun@huawei.com;lixiaoguang (D) lixiaoguang2@huawei.com;hewenliang (C) hewenliang4@huawei.com;sangyan sangyan@huawei.com;jingxiangfeng jingxiangfeng@huawei.com;snoweay snoweay@163.com;Luchunhua luchunhua@huawei.com 时 间：2021-03-12 19:13:04 主 题：[PATCH openEuler-21.03 v1] arm64: Uninstall cpu park after cpu up
From: Sang Yan < sangyan@huawei.commailto:sangyan@huawei.com>
hulk inclusion category: feature bugzilla: 48159 CVE: N/A
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One cpu in PARK state could not come up in this case: CPU 0 | CPU 1 boot_secondary(cpu 1) | --> write_park_exit(cpu 1) | | cpu uping from PARK | ... uninstall_cpu_park() | --> memset to 0 park text | | ... | Exception in memory !! wait for cpu up |
Cpu 1 uping from PARK may trap into exception while cpu 0 clear cpu 1's park text memory.
This uninstall_cpu_park should be after waiting for cpu up.
Signed-off-by: Sang Yan < sangyan@huawei.commailto:sangyan@huawei.com> --- arch/arm64/kernel/smp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index d7b750a..fb6007d 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -300,15 +300,15 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) return ret; }
-#ifdef CONFIG_ARM64_CPU_PARK - uninstall_cpu_park(cpu); -#endif /* * CPU was successfully started, wait for it to come online or * time out. */ wait_for_completion_timeout(&cpu_running, msecs_to_jiffies(5000)); +#ifdef CONFIG_ARM64_CPU_PARK + uninstall_cpu_park(cpu); +#endif if (cpu_online(cpu)) return 0;
-- 2.9.5