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
| ||
|
Message-ID: <20230720001852.GA572618@google.com> Date: Wed, 19 Jul 2023 17:18:52 -0700 From: Sami Tolvanen <samitolvanen@...gle.com> To: Deepak Gupta <debug@...osinc.com> Cc: palmer@...belt.com, linux-kernel@...r.kernel.org, linux-riscv@...ts.infradead.org, Guo Ren <guoren@...nel.org>, Jisheng Zhang <jszhang@...nel.org> Subject: Re: [PATCH v2] riscv: VMAP_STACK overflow detection thread-safe Hi Deepak, On Thu, Nov 24, 2022 at 01:48:45AM -0800, Deepak Gupta wrote: > commit 31da94c25aea ("riscv: add VMAP_STACK overflow detection") added > support for CONFIG_VMAP_STACK. If overflow is detected, CPU switches to > `shadow_stack` temporarily before switching finally to per-cpu > `overflow_stack`. > > If two CPUs/harts are racing and end up in over flowing kernel stack, one > or both will end up corrupting each other state because `shadow_stack` is > not per-cpu. This patch optimizes per-cpu overflow stack switch by > directly picking per-cpu `overflow_stack` and gets rid of `shadow_stack`. Are you planning on resending this patch? I see it didn't gain much traction last time, but this looks like a much cleaner solution for selecting the overflow stack than having a `shadow_stack` and calling to C to compute the per-CPU offset. The asm_per_cpu macro also would come in handy when implementing CONFIG_SHADOW_CALL_STACK, which we'd like to have on RISC-V too. Sami
Powered by blists - more mailing lists