Commit 5bc048a1 authored by Xiongfeng Wang's avatar Xiongfeng Wang Committed by Zheng Zengkai
Browse files

sdei_watchdog: refresh 'last_timestamp' when enabling nmi_watchdog 



hulk inclusion
category: feature
bugzilla: 48046
CVE: NA

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

The trigger period of secure time is set by firmware. We need to check
the time_stamp every time the secure time fires to make sure the
hardlockup detection is not executed too soon. We need to refresh
'last_timestamp' to the current time when we enable the nmi_watchdog.
Otherwise, false hardlockup may be detected when the secure timer fires
the first time.

Signed-off-by: default avatarXiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: default avatarHanjun Guo <guohanjun@huawei.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: default avatarXiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent cc19c0b3

arch/arm64/kernel/watchdog_sdei.c

+2 −0
Original line number Diff line number Diff line
@@ -30,6 +30,8 @@ int watchdog_nmi_enable(unsigned int cpu) 
	if (!sdei_watchdog_registered)

		return -EINVAL;



	refresh_hld_last_timestamp();



	ret = sdei_api_event_enable(sdei_watchdog_event_num);

	if (ret) {

		pr_err("Enable NMI Watchdog failed on cpu%d\n",

include/linux/nmi.h

+1 −0
Original line number Diff line number Diff line
@@ -206,6 +206,7 @@ u64 hw_nmi_get_sample_period(int watchdog_thresh); 
#if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \

    defined(CONFIG_HARDLOCKUP_DETECTOR)

void watchdog_update_hrtimer_threshold(u64 period);

void refresh_hld_last_timestamp(void);

#else

static inline void watchdog_update_hrtimer_threshold(u64 period) { }

#endif

kernel/watchdog_hld.c

+9 −0
Original line number Diff line number Diff line
@@ -89,6 +89,15 @@ static bool watchdog_check_timestamp(void) 
	__this_cpu_write(last_timestamp, now);

	return true;

}



void refresh_hld_last_timestamp(void)

{

	ktime_t now;



	now = ktime_get_mono_fast_ns();

	__this_cpu_write(last_timestamp, now);



}

#else

static inline bool watchdog_check_timestamp(void)

{