Re: [PATCH 12/27] x86/msr: Restrict MSR access when the kernel is locked down

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

 



On Fri, Oct 20, 2017 at 09:48:16PM +0100, David Howells wrote:
> Alan Cox <gnomes@xxxxxxxxxxxxxxxxxxx> wrote:
> 
> > There are a load of standard tools that use this so I think you are going
> > to need a whitelist. Can you at least log *which* MSR in the failing case
> > so a whitelist can be built over time ?
> 
[...snip]
> 
> And do you know where wrmsr_safe_regs() might be found?  I can see things
> using it and exporting it, but no implementation, so I'm guessing it's
> macroised somewhere.

Looks the definition is in 

arch/x86/lib/msr-reg.S

#ifdef CONFIG_X86_64
/*
 * int {rdmsr,wrmsr}_safe_regs(u32 gprs[8]);
 *
 * reg layout: u32 gprs[eax, ecx, edx, ebx, esp, ebp, esi, edi]
 *
 */
.macro op_safe_regs op
ENTRY(\op\()_safe_regs)
        pushq %rbx
        pushq %r12
...

Regards
Joey Lee
--
To unsubscribe from this list: send the line "unsubscribe linux-efi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux