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: Wed, 1 Nov 2017 18:56:42 +0100 From: Borislav Petkov <bp@...e.de> To: Ricardo Neri <ricardo.neri-calderon@...ux.intel.com> Cc: Ingo Molnar <mingo@...hat.com>, Thomas Gleixner <tglx@...utronix.de>, "H. Peter Anvin" <hpa@...or.com>, Andy Lutomirski <luto@...nel.org>, Peter Zijlstra <peterz@...radead.org>, Andrew Morton <akpm@...ux-foundation.org>, Brian Gerst <brgerst@...il.com>, Chris Metcalf <cmetcalf@...lanox.com>, Dave Hansen <dave.hansen@...ux.intel.com>, Paolo Bonzini <pbonzini@...hat.com>, Masami Hiramatsu <mhiramat@...nel.org>, Huang Rui <ray.huang@....com>, Jiri Slaby <jslaby@...e.cz>, Jonathan Corbet <corbet@....net>, "Michael S. Tsirkin" <mst@...hat.com>, Paul Gortmaker <paul.gortmaker@...driver.com>, Vlastimil Babka <vbabka@...e.cz>, Chen Yucong <slaoub@...il.com>, "Ravi V. Shankar" <ravi.v.shankar@...el.com>, Shuah Khan <shuah@...nel.org>, linux-kernel@...r.kernel.org, x86@...nel.org, ricardo.neri@...el.com, Adam Buchbinder <adam.buchbinder@...il.com>, Colin Ian King <colin.king@...onical.com>, Lorenzo Stoakes <lstoakes@...il.com>, Qiaowei Ren <qiaowei.ren@...el.com>, Arnaldo Carvalho de Melo <acme@...hat.com>, Adrian Hunter <adrian.hunter@...el.com>, Kees Cook <keescook@...omium.org>, Thomas Garnier <thgarnie@...gle.com>, Dmitry Vyukov <dvyukov@...gle.com> Subject: Re: [PATCH v10 18/18] x86/insn-eval: Incorporate segment base in linear address computation On Fri, Oct 27, 2017 at 01:25:45PM -0700, Ricardo Neri wrote: > insn_get_addr_ref() returns the effective address as defined by the > section 3.7.5.1 Vol 1 of the Intel 64 and IA-32 Architectures Software > Developer's Manual. In order to compute the linear address, we must add > to the effective address the segment base address as set in the segment > descriptor. The segment descriptor to use depends on the register used as > operand and segment override prefixes, if any. > > In most cases, the segment base address will be 0 if the USER_DS/USER32_DS > segment is used or if segmentation is not used. However, the base address > is not necessarily zero if a user programs defines its own segments. This > is possible by using a local descriptor table. > > Since the effective address is a signed quantity, the unsigned segment > base address is saved in a separate variable and added to the final, > unsigned, effective address. > > Cc: Dave Hansen <dave.hansen@...ux.intel.com> > Cc: Adam Buchbinder <adam.buchbinder@...il.com> > Cc: Colin Ian King <colin.king@...onical.com> > Cc: Lorenzo Stoakes <lstoakes@...il.com> > Cc: Qiaowei Ren <qiaowei.ren@...el.com> > Cc: Arnaldo Carvalho de Melo <acme@...hat.com> > Cc: Masami Hiramatsu <mhiramat@...nel.org> > Cc: Adrian Hunter <adrian.hunter@...el.com> > Cc: Kees Cook <keescook@...omium.org> > Cc: Thomas Garnier <thgarnie@...gle.com> > Cc: Peter Zijlstra <peterz@...radead.org> > Cc: Borislav Petkov <bp@...e.de> > Cc: Dmitry Vyukov <dvyukov@...gle.com> > Cc: Ravi V. Shankar <ravi.v.shankar@...el.com> > Cc: x86@...nel.org > Signed-off-by: Ricardo Neri <ricardo.neri-calderon@...ux.intel.com> > --- > arch/x86/lib/insn-eval.c | 55 +++++++++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 52 insertions(+), 3 deletions(-) Reviewed-by: Borislav Petkov <bp@...e.de> -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --
Powered by blists - more mailing lists