Re: possible deadlock in __perf_event_task_sched_out

[Peter Zijlstra]

On Mon, Sep 13, 2021 at 10:39:10AM +0800, Hao Sun wrote:
> Hello,
> 
> When using Healer to fuzz the latest Linux kernel, the following crash
> was triggered.
> 
> HEAD commit: 4b93c544e90e-thunderbolt: test: split up test cases
> git tree: upstream
> console output:
> https://drive.google.com/file/d/1Gy99NMo9JxZF6dHPdxnnb91n_jPJUQnA/view?usp=sharing
> kernel config: https://drive.google.com/file/d/1c0u2EeRDhRO-ZCxr9MP2VvAtJd6kfg-p/view?usp=sharing
> 
> Sorry, I don't have a reproducer for this crash, hope the symbolized
> report can help.
> If you fix this issue, please add the following tag to the commit:

This reads like a very badly configured VM, in part because the console
output is partial. That first Call trace: is ex_handler_wrmsr_unsafe,
but it is truncated, also the pr_warn_once() went missing.

Please take more care in configuring your VM before sending out more
bogus messages like this.