Re: kernel 9.0 crash on amd64

[maya%NetBSD.org@localhost]

On Sun, Apr 19, 2020 at 05:29:40PM +0200, tlaronde%polynum.com@localhost wrote:
> Hello,
> 
> Mainly in order to be able to test wine, I'm compiling a NetBSD kernel
> from netbsd-9-0-RELEASE sources on an amd64 (Intel bicore).
> 
> My config has very minimal changes from NetBSD 8.* config, the only important
> modification being USER_LDT (and I'm not putting option SVS).
> 
> When it crashes, keyboard is unavailable and the information repeated is:
> 
> prevented execution of 0x18 (SMEP)
> fatal page fault in supervisor mode
> trap type 6 code 0x10 rip 0x18 cs 0x8 rflags 0x10246 cr2 0x18 ilevel 0x8
> rsp 0xffffcc00ae0cbb40
> 
> The last bit registered and shown by dmesg (when rebooting with the 8.0
> kernel) is about enumerating ahcisata0.
> 
> Does this ring some bell to somebody?
> 
> TIA,

SMEP is a hardware method to stop execution user-memory.
It tried to execute a function pointer that isn't initialized, most
likely.

It would be interesting to see what the backtrace is
sysctl -w ddb.onpanic=2 will print the backtrace and reboot, which
should make it visible in the back of the dmesg.

Also, if a kernel core dump is done, it should be in /var/crash, gunzip
and crash -M netbsd.12 -N netbsd.12.core
crash> bt

should print a backtrace.