Re: [PATCH v3 1/4] kasan, arm64: Add KASAN light mode
From: Andrey Konovalov <hidden>
Date: 2021-01-16 17:13:02
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On Sat, Jan 16, 2021 at 2:43 PM Vincenzo Frascino [off-list ref] wrote:
On 1/15/21 3:08 PM, Mark Rutland wrote:quoted
On Fri, Jan 15, 2021 at 12:00:40PM +0000, Vincenzo Frascino wrote:quoted
Architectures supported by KASAN HW can provide a light mode of execution. On an MTE enabled arm64 hw for example this can be identified with the asynch mode of execution. In this mode, if a tag check fault occurs, the TFSR_EL1 register is updated asynchronously. The kernel checks the corresponding bits periodically.What's the expected usage of this relative to prod, given that this has to be chosen at boot time? When/where is this expected to be used relative to prod mode?
Hi Mark, Sync + no panic (what is called prod right now) + logging is for the initial MTE integration stage as causing panics is risky. There's no way to know how often MTE-detected bugs will happen during normal usage as the kernel is buggy. Eventually, we're hoping to switch to sync + panic to allow MTE to act as a security mitigation. For devices where the slowdown caused by sync is untolerable, there'll be an option to use async, which is significantly faster. The exact perf numbers are yet to be measured properly, I'll share them with one of the future patches. Thanks! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel