Messages in this thread | | | From | Linus Torvalds <> | Date | Tue, 6 Feb 2018 12:58:27 -0800 | Subject | Re: [PATCH v4 07/10] x86: narrow out of bounds syscalls to sys_read under speculation |
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On Tue, Feb 6, 2018 at 12:49 PM, Andy Lutomirski <luto@kernel.org> wrote: > > Can you use @cc to make an asm statement that outputs both the masked > array index and the "if" condition? I can never remember the syntax, > but something like:
Yes. Although I'd actually suggest just using an "asm goto" if we really want to optimize this. Give the "index_mask_nospec()" a third argument that is the label to jump to for overflow.
Then you can just decide how to implement it best for any particular architecture (and compiler limitation).
Linus
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