Commit d9b81574 authored by Zheng Zengkai's avatar Zheng Zengkai
Browse files

sdei_watchdog: Avoid exception during sdei handler 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I82QPR



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

On Kunpeng920 platform, when firmware triggers SDEI event too soon,
A WARN_ON() will be called in sdei_watchdog_callback(), this leads
to warning "sdei: unsafe: exception during handler" being reported
in _sdei_handler().

As the comments for the warning mentioned,
We took a synchronous exception from the SDEI handler.
This could deadlock, and if you interrupt KVM it will
hyp-panic instead.

Remove the WARN_ON() to avoid potential issue and warning.

Fixes: 0fa83fd0 ("sdei_watchdog: avoid possible false hardlockup")
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 9905568f

arch/arm64/kernel/watchdog_sdei.c

+0 −1
Original line number Diff line number Diff line
@@ -78,7 +78,6 @@ static int sdei_watchdog_callback(u32 event, 
	if (delta < watchdog_thresh * (u64)NSEC_PER_SEC * 4 / 5) {

		pr_err(FW_BUG "SDEI Watchdog event triggered too soon, "

			"time to last check:%lld ns\n", delta);

		WARN_ON(1);

		return 0;

	}