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 PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 26 May 2020 12:31:00 +0800 From: Lai Jiangshan <jiangshanlai+lkml@...il.com> To: Andy Lutomirski <luto@...nel.org> Cc: Lai Jiangshan <laijs@...ux.alibaba.com>, LKML <linux-kernel@...r.kernel.org>, Peter Zijlstra <peterz@...radead.org>, Thomas Gleixner <tglx@...utronix.de>, X86 ML <x86@...nel.org>, Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, "H. Peter Anvin" <hpa@...or.com>, Alexandre Chartre <alexandre.chartre@...cle.com>, Steven Rostedt <rostedt@...dmis.org>, Masami Hiramatsu <mhiramat@...nel.org> Subject: Re: [RFC PATCH V2 4/7] x86/hw_breakpoint: Prevent data breakpoints on user_pcid_flush_mask On Tue, May 26, 2020 at 12:21 PM Andy Lutomirski <luto@...nel.org> wrote: > > On Mon, May 25, 2020 at 6:42 PM Lai Jiangshan <laijs@...ux.alibaba.com> wrote: > > > > The percpu user_pcid_flush_mask is used for CPU entry > > If a data breakpoint on it, it will cause an unwanted #DB. > > Protect the full cpu_tlbstate structure to be sure. > > > > There are some other percpu data used in CPU entry, but they are > > either in already-protected cpu_tss_rw or are safe to trigger #DB > > (espfix_waddr, espfix_stack). > > How hard would it be to rework this to have DECLARE_PERCPU_NODEBUG() > and DEFINE_PERCPU_NODEBUG() or similar? I don't know, but it is an excellent idea. Although the patchset protects only 2 or 3 portions of percpu data, but there is many percpu data used in tracing or kprobe code. They are needed to be protected too. Adds CC: Steven Rostedt <rostedt@...dmis.org> Masami Hiramatsu <mhiramat@...nel.org>
Powered by blists - more mailing lists