Re: [lkp-robot] [x86/asm] f5caf621ee: PANIC:double_fault

[Ingo Molnar]

* kernel test robot <xiaolong.ye@xxxxxxxxx> wrote:

> 
> FYI, we noticed the following commit:
> 
> commit: f5caf621ee357279e759c0911daf6d55c7d36f03 ("x86/asm: Fix inline asm call constraints for Clang")
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
> 
> in testcase: trinity
> with following parameters:
> 
> 	runtime: 300s
> 
> test-description: Trinity is a linux system call fuzz tester.
> test-url: http://codemonkey.org.uk/projects/trinity/
> 
> 
> on test machine: qemu-system-x86_64 -enable-kvm -m 420M
> 
> caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
> 
> 
> +-----------------------------------------+------------+------------+
> |                                         | 0d0970eef3 | f5caf621ee |
> +-----------------------------------------+------------+------------+
> | boot_successes                          | 9          | 4          |
> | boot_failures                           | 0          | 4          |
> | PANIC:double_fault                      | 0          | 4          |
> | Kernel_panic-not_syncing:Machine_halted | 0          | 4          |
> +-----------------------------------------+------------+------------+

I think a key piece of information is that the test is using GCC 4.4:

        export compiler='gcc-4.4'

... which is pretty old compared to what gets tested typically.

GCC 4.4 was released in 2009 (!), the last minor update of 4.4.7 was 5 years ago.

Thanks,

	Ingo