Re: Disabling x86 System Management Mode

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



John <[email protected]> writes:

Please use a full real name for posting.

> AFAIU, even a hard real-time OS is "defenseless" against SMIs that
> kick the CPU into SMM.

There are usually chipset specific bits that can be set to disable SMMs.
See the datasheet if you can get them. Unfortunately most chipset vendors
don't give out data sheets easily.

> .globl foo
> foo:
>    push %ebx
>    push %esi
>    cpuid
>    rdtsc

At least some SMM implementations restore the old TSC value. Sad but true.
Besides RDTSC can be speculated around on some CPUs which also adds errors.

-Andi
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux