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: Tue, 25 Aug 2020 14:04:00 -0700 From: "Yu, Yu-cheng" <yu-cheng.yu@...el.com> To: Dave Hansen <dave.hansen@...el.com>, Andy Lutomirski <luto@...nel.org> Cc: X86 ML <x86@...nel.org>, "H. Peter Anvin" <hpa@...or.com>, Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, LKML <linux-kernel@...r.kernel.org>, "open list:DOCUMENTATION" <linux-doc@...r.kernel.org>, Linux-MM <linux-mm@...ck.org>, linux-arch <linux-arch@...r.kernel.org>, Linux API <linux-api@...r.kernel.org>, Arnd Bergmann <arnd@...db.de>, Balbir Singh <bsingharora@...il.com>, Borislav Petkov <bp@...en8.de>, Cyrill Gorcunov <gorcunov@...il.com>, Dave Hansen <dave.hansen@...ux.intel.com>, Eugene Syromiatnikov <esyr@...hat.com>, Florian Weimer <fweimer@...hat.com>, "H.J. Lu" <hjl.tools@...il.com>, Jann Horn <jannh@...gle.com>, Jonathan Corbet <corbet@....net>, Kees Cook <keescook@...omium.org>, Mike Kravetz <mike.kravetz@...cle.com>, Nadav Amit <nadav.amit@...il.com>, Oleg Nesterov <oleg@...hat.com>, Pavel Machek <pavel@....cz>, Peter Zijlstra <peterz@...radead.org>, Randy Dunlap <rdunlap@...radead.org>, "Ravi V. Shankar" <ravi.v.shankar@...el.com>, Vedvyas Shanbhogue <vedvyas.shanbhogue@...el.com>, Dave Martin <Dave.Martin@....com>, Weijiang Yang <weijiang.yang@...el.com> Subject: Re: [PATCH v11 25/25] x86/cet/shstk: Add arch_prctl functions for shadow stack On 8/25/2020 12:19 PM, Dave Hansen wrote: > On 8/25/20 11:43 AM, Yu, Yu-cheng wrote: >>>> arch_prctl(ARCH_X86_CET_MMAP_SHSTK, u64 *args) >>>> Allocate a new shadow stack. >>>> >>>> The parameter 'args' is a pointer to a user buffer. >>>> >>>> *args = desired size >>>> *(args + 1) = MAP_32BIT or MAP_POPULATE >>>> >>>> On returning, *args is the allocated shadow stack address. >>> >>> This is hideous. Would this be better as a new syscall? >> >> Could you point out why this is hideous, so that I can modify the >> arch_prctl? > > Passing values in memory is hideous when we don't have to. A syscall > would let you have separate arguments for size and flags and would also > let you have a nice return value instead of needing to do that in memory > too. That is a good justification. > >> I think this is more arch-specific. Even if it becomes a new syscall, >> we still need to pass the same parameters. > > Right, but without the copying in and out of memory. > Linux-api is already on the Cc list. Do we need to add more people to get some agreements for the syscall?
Powered by blists - more mailing lists