Re: [PATCH 00/15] net: taint when the device driver firmware crashes
From: Shannon Nelson <hidden>
Date: 2020-05-10 02:20:02
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On 5/9/20 6:58 PM, Andrew Lunn wrote:
On Sat, May 09, 2020 at 06:01:51PM -0700, Shannon Nelson wrote:quoted
On 5/8/20 9:35 PM, Luis Chamberlain wrote:quoted
Device driver firmware can crash, and sometimes, this can leave your system in a state which makes the device or subsystem completely useless. Detecting this by inspecting /proc/sys/kernel/tainted instead of scraping some magical words from the kernel log, which is driver specific, is much easier. So instead this series provides a helper which lets drivers annotate this and shows how to use this on networking drivers.If the driver is able to detect that the device firmware has come back alive, through user intervention or whatever, should there be a way to "untaint" the kernel? Or would you expect it to remain tainted?Hi Shannon In general, you don't want to be able to untained. Say a non-GPL licenced module is loaded, which taints the kernel. It might then try to untaint the kernel to hide its.
Yeah, obviously we don't want this to be abuseable. I was just wondering about reversing this particular status if the broken device could get itself fixed.
As for firmware, how much damage can the firmware do as it crashed? If it is a DMA master, it could of splattered stuff through memory. Restarting the firmware is not going to reverse the damage it has done.
True, and tho' the driver might get the thing restarted, it wouldn't necessarily know what kind of damage had ensued. Carry on, sln