Re: [Xen-devel] [PATCH v5 2/4] x86/ldt: Make modify_ldt synchronous

[Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>]

On 07/30/2015 03:25 PM, Andy Lutomirski wrote:
> On Thu, Jul 30, 2015 at 11:35 AM, Boris Ostrovsky
> <boris.ostrovsky@xxxxxxxxxx> wrote:
> > [OK]    LDT entry 0 has AR 0x0040F200 and limit 0x00000000
> > [OK]    LDT entry 0 is invalid
> > [RUN]   Cross-CPU LDT invalidation
> > Segmentation fault (core dumped)
> That's not good.
>
> Can you backtrace it?  (I.e. compite ldt_gdt_32 with -g and load the
> core dumb in gdb?)  My best guesses are either a signal delivery
> failure (although that shouldn't be a problem for 32-bit userspace on
> any kernel) or an actual LDT access fault, and the latter would be
> interesting.
>
> I haven't been able to reproduce this.
This looks like a userspace bug. Breaks on F18, works fine in F22.

Possibly something about signal handling --- I noticed on F18 I'd get 
two SEGV's in a row whereas we should only get one.
Anyway, this is not an issue as far as this thread is concerned.

-boris

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel