[lkml]   [2013]   [Jul]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [tip:x86/urgent] x86: Make sure IDT is page aligned
On Tue, Jul 16, 2013 at 3:33 PM, tip-bot for Kees Cook <> wrote:
> Commit-ID: 4df05f361937ee86e5a8c9ead8aeb6a19ea9b7d7
> Gitweb:
> Author: Kees Cook <>
> AuthorDate: Tue, 16 Jul 2013 11:34:41 -0700
> Committer: H. Peter Anvin <>
> CommitDate: Tue, 16 Jul 2013 15:14:48 -0700
> x86: Make sure IDT is page aligned
> Since the IDT is referenced from a fixmap, make sure it is page aligned.
> Merge with 32-bit one, since it was already aligned to deal with F00F
> bug. Since bss is cleared before IDT setup, it can live there. This also
> moves the other *_idt_table variables into common locations.
> This avoids the risk of the IDT ever being moved in the bss and having
> the mapping be offset, resulting in calling incorrect handlers. In the
> current upstream kernel this is not a manifested bug, but heavily patched
> kernels (such as those using the PaX patch series) did encounter this bug.
> The tables other than idt_table technically do not need to be page
> aligned, at least not at the current time, but using a common
> declaration avoids mistakes. On 64 bits the table is exactly one page
> long, anyway.
> Signed-off-by: Kees Cook <>
> Link:
> Reported-by: PaX Team <>
> Signed-off-by: H. Peter Anvin <>

Hi, Peter,

Any reason for why following changelog get dropped?

- add comments to all IDTs about alignment reasoning, suggested by Linus
- rework using __page_aligned_bss, suggested by Yinghai LU
- move all the other IDT variables as well, suggested by HPA
- merge 32-bit and 64-bit idt_table definition
- 32-bit was already aligned

That at least would help us to check if you apply the right version.


 \ /
  Last update: 2013-07-17 22:01    [W:0.122 / U:4.464 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site