Re: general protection fault, probably for non-canonical address in pick_next_task_fair()

[Thomas Gleixner]

On Thu, Feb 29 2024 at 07:55, Breno Leitao wrote:
> I've been running some stress test using stress-ng with a kernel with some
> debug options enabled, such as KASAN and friends (See the config below).
>
> I saw it in rc4 and the decode instructions are a bit off (as it is here
> also - search for mavabs in dmesg below and you will find something as `(bad)`,
> so I though it was a machine issue. But now I see it again, and I am sharing
> for awareness.

The (bad) is after the faulting instruction, but gives an hint:

  2e:	0f 84 67 ff ff ff    	je     0xffffffffffffff9b
  34:	48 89 ef             	mov    %rbp,%rdi
  37:	e8 cf 70 76 00       	call   0x76710b
  3c:	e9                   	.byte 0xe9

That's an invalid opcode, which means that memory is corrupted.

Thanks,

        tglx