lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 29 Dec 2017 12:34:42 -0800 From: Linus Torvalds <torvalds@...ux-foundation.org> To: Alexander Tsoy <alexander@...y.me> Cc: Dave Hansen <dave.hansen@...el.com>, Greg KH <greg@...ah.com>, Andy Lutomirski <luto@...nel.org>, Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...nel.org>, Borislav Petkov <bp@...e.de>, Boris Ostrovsky <boris.ostrovsky@...cle.com>, Borislav Petkov <bp@...en8.de>, Borislav Petkov <bpetkov@...e.de>, Brian Gerst <brgerst@...il.com>, Dave Hansen <dave.hansen@...ux.intel.com>, David Laight <David.Laight@...lab.com>, Denys Vlasenko <dvlasenk@...hat.com>, Eduardo Valentin <eduval@...zon.com>, Greg KH <gregkh@...uxfoundation.org>, "H. Peter Anvin" <hpa@...or.com>, Josh Poimboeuf <jpoimboe@...hat.com>, Juergen Gross <jgross@...e.com>, Peter Zijlstra <peterz@...radead.org>, Rik van Riel <riel@...hat.com>, Will Deacon <will.deacon@....com>, "Liguori, Anthony" <aliguori@...zon.com>, Daniel Gruss <daniel.gruss@...k.tugraz.at>, Hugh Dickins <hughd@...gle.com>, Kees Cook <keescook@...gle.com>, Kernel Mailing List <linux-kernel@...r.kernel.org>, stable <stable@...r.kernel.org> Subject: Re: 4.14.9 with CONFIG_MCORE2 fails to boot On Fri, Dec 29, 2017 at 12:22 PM, Alexander Tsoy <alexander@...y.me> wrote: >> But double-checking that "-march=core2" case is definitely worth >> looking into. Especially since there are clear indications that it's >> gcc version-dependent anyway. Alexander? > > Yes, the change suggested by Dave makes the problem go away. Ok, that's good information. It doesn't really explain *why* that commit 7f2590a110b8 ("x86/entry/64: Use a per-CPU trampoline stack for IDT entries") ends up being sensitive to that compiler option, though. So it narrows the cause down, but it doesn't really root-cause the problem. It tends to be almost impossible to find differences in code generation, because they are generally all over. Ho humm. What happens if you change the "-march=core2" to "-mtune=core2"? Does it still boot? Because maybe the actual differences that "-march=core2" generates might be easier to see when compared to "-mtune=core2". Linus
Powered by blists - more mailing lists