Re: Regression in 2.6.25-rc3: s2ram segfaults before suspending

H. Peter Anvin
2008-02-28T19:32:43Z

Klaus S. Madsen wrote:
>>
>> Typically, when the kernel reflects an error in VM86 mode it will update
>> the structure in memory (in your case, the vm86plus_struct) to reflect
>> the context. Would it be possible for you to read it out?
> Hmm. As far as I can tell, its actually using the vm86old system call?
> That's at least what the comment in libx86 states.
>
> However the contents of struct vm86_struct after the segfault is:
>
> (gdb) print context.vm
> $2 = {regs = {ebx = 0, ecx = 0, edx = 0, esi = 0, edi = 0, ebp = 0,
> eax = 20227, __null_ds = 0, __null_es = 0, __null_fs = -1071579136,
> __null_gs = 0, orig_eax = -1, eip = 6326, cs = 49152, __csh = 0,
> eflags = 209410, esp = 4090, ss = 256, __ssh = 0, es = 0, __esh = 0,
> ds = 64, __dsh = 0, fs = 0, __fsh = 0, gs = 0, __gsh = 0}, flags = 0,
> screen_bitmap = 0, cpu_type = 0, int_revectored = {__map = {0, 0, 0,0, 0,
> 0, 0, 2147483648}}, int21_revectored = {__map = {0, 0, 0, 0, 0, 0, 0,
> 0}}}
>
> My version of glibc does not seem to have vm86old declared, so I haven't
> tried to remove the assembly code.
>
> Should I try to change it to use vm86, instead of vm86old?
>

Yes, that would probably be a good idea. To some degree, I guess it
really has nothing to do with the more fundamental issue, but it's
somewhat odd.

I'll pick apart the state above looking for fishiness as soon as I get
back from lunch.

-hpa