lkml.org 
[lkml]   [2012]   [Mar]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] x86: export 'pcibios_enabled'
On Wed, Mar 14, 2012 at 11:21:37AM +0000, Alan Cox wrote:
> You can use set_memory_x() to mark memory executable (and _nx to set it back).
NO I can't, if I set_memory_x and don't set pcibios_enabled = 1, then
static_protections will still failed because pcibios_enabled == 0,
and I don't want to use set_memory_x, because I don't want to give the user
of uvesafb that feeling "I will lost BIOS NX protection if I choice uvesafb."

> If you really need to know if NX is being used then the check
>
> if (__supported_pte_mask & PTE_NX)
>
> will do the trick and the variable is exported.
I don't understand what do you mean, do you means CONFIG_X86_PAE for 32? Or CONFIG_X86_64?
when NX is being used, the pci bios is NX or not also depend on
ACPI.ACPI on or off all will influnce the code path in pci_arch_init,
decide the set_bios_x have chance to execute or not.See
https://lkml.org/lkml/2011/11/16/84

By the way _PAGE_NX instead of PTE_NX, right?

> I'd suggest however you wrap that in a cpu_has_nx() type macro somewhere
> in the arch headers.
>
The same above.

> If you go poking around pcibios values you are going to get burned if
> someone is ever bored enough to make NX and PCIBIOS work together
> differently.
>
Indeed according to 5bd5a452662bc37c54fb6828db1a3faf87e6511c, who bring me
the trouble, check the pcibios_enabled is the only simple and good way to
resolve the Oops I meet.

If you really don't want it, and if I am not all wrong about your "helper method",
you means you want export the below:
int check_pcibios_enabled()?
See https://lkml.org/lkml/2012/2/26/124

Thanks.



\
 
 \ /
  Last update: 2012-03-22 01:45    [from the cache]
©2003-2011 Jasper Spaans