Messages in this thread | | | Date | Mon, 18 Apr 2022 14:59:49 -0700 | From | Kees Cook <> | Subject | Re: [PATCH RFC 2/8] arm64: stacktrace: Add arch_within_stack_frames |
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On Mon, Apr 18, 2022 at 09:22:11PM +0800, He Zhe wrote: > This function checks if the given address range crosses frame boundary. > It is based on the existing x86 algorithm, but implemented via stacktrace. > This can be tested by USERCOPY_STACK_FRAME_FROM and > USERCOPY_STACK_FRAME_TO in lkdtm.
Hi,
Thanks for doing this implementation! One reason usercopy hardening didn't persue doing a "full" stacktrace was because it seemed relatively expensive. Did you do any usercopy-heavily workload testing to see if there was a noticeable performance impact?
It would be nice to block the exposure of canaries and PAC bits, though, so I'm not opposed, but I'd like to get a better sense of how "heavy" this might be.
Thanks!
-Kees
-- Kees Cook
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