Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1468143
| From | "H. Peter Anvin" <hpa@zytor.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 5/8] x86/head: remove useless zeroed word |
| Date | 2016-08-23 01:20 +0200 |
| Message-ID | <s96Fz-4mL-5@gated-at.bofh.it> (permalink) |
| References | <s7Bkt-3Yh-9@gated-at.bofh.it> <s7Bkt-3Yh-7@gated-at.bofh.it> <s95gt-3lP-11@gated-at.bofh.it> <s95Tb-3OC-13@gated-at.bofh.it> <s96md-40p-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On August 22, 2016 3:47:48 PM PDT, Brian Gerst <brgerst@gmail.com> wrote: >On Mon, Aug 22, 2016 at 6:23 PM, H. Peter Anvin <hpa@zytor.com> wrote: >> On August 22, 2016 2:48:46 PM PDT, Andi Kleen <andi@firstfloor.org> >wrote: >>>Josh Poimboeuf <jpoimboe@redhat.com> writes: >>> >>>> This zeroed word has no apparent purpose, so remove it. >>>> >>>> Brian Gerst says: >>>> >>>> "FYI the word used to be the SS segment selector for the LSS >>>> instruction, which isn't needed in 64-bit mode." >>>> >>> >>>Seems dangerous. It wouldn't surprise me if some CPUs or x86 >emulations >>>load it anyways and trigger page faults if there is really nothing >>>there. >>> >>>-Andi >> >> Yes, seems pointlessly risky. > >It was added in commit 9cf4f298e29abba25c16679fe7be70898223167e, >copied from 32-bit but never used. It doesn't look like we ever used >LSS on 64-bit. > >-- >Brian Gerst Ah, ok. Wasn't in front of a computer. -- Sent from my Android device with K-9 Mail. Please excuse brevity and formatting.
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH 5/8] x86/head: remove useless zeroed word Josh Poimboeuf <jpoimboe@redhat.com> - 2016-08-18 21:40 +0200
Re: [PATCH 5/8] x86/head: remove useless zeroed word Andi Kleen <andi@firstfloor.org> - 2016-08-22 23:50 +0200
Re: [PATCH 5/8] x86/head: remove useless zeroed word "H. Peter Anvin" <hpa@zytor.com> - 2016-08-23 00:30 +0200
Re: [PATCH 5/8] x86/head: remove useless zeroed word Brian Gerst <brgerst@gmail.com> - 2016-08-23 01:00 +0200
Re: [PATCH 5/8] x86/head: remove useless zeroed word "H. Peter Anvin" <hpa@zytor.com> - 2016-08-23 01:20 +0200
Re: [PATCH 5/8] x86/head: remove useless zeroed word Linus Torvalds <torvalds@linux-foundation.org> - 2016-08-23 01:10 +0200
csiph-web