Re: [Xen-devel] HVM domains crash after upgrade from XEN 4.5.1 to 4.5.2

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 19.11.15 at 00:17, <andrew.cooper3@xxxxxxxxxx> wrote:
> The disassembly of do_IRQ now looks like a plausible function, but the
> consistently faulting address has no plausible way of generating a
> double fault.  I suspect therefore that something has caused memory
> corruption in Xen .text section.

Dump of assembler code for function do_IRQ:
   0xffff82d080176577 <+0>:     push   %rbp
   0xffff82d080176578 <+1>:     mov    %rsp,%rbp
   0xffff82d08017657b <+4>:     push   %r15
   0xffff82d08017657d <+6>:     push   %r14
   0xffff82d08017657f <+8>:     push   %r13
   0xffff82d080176581 <+10>:    push   %r12
   0xffff82d080176583 <+12>:    push   %rbx
   0xffff82d080176584 <+13>:    lea    -0x1058(%rsp),%rsp
   0xffff82d08017658c <+21>:    orq    $0x0,(%rsp)
   0xffff82d080176591 <+26>:    lea    0x1020(%rsp),%rsp

The orq surely has potential for causing a double fault, if %rsp is
near the stack limit. The two LEAs look suspect, presumably a
result of some non-standard option passed to gcc. Removing that
option might already be a step forward.

Jan


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