Messages in this thread | | | From | Andy Lutomirski <> | Date | Mon, 18 Jan 2016 10:29:24 -0800 | Subject | Re: [PATCH] x86: static_cpu_has_safe: discard dynamic check after init |
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On Mon, Jan 18, 2016 at 10:14 AM, Borislav Petkov <bp@suse.de> wrote: > On Mon, Jan 18, 2016 at 11:52:34AM -0500, Brian Gerst wrote: >> It is due to page alignment padding. It was not enough to lose a >> whole page from .text in your case. > > So nothing more got freed. > >> The size command includes any section that is marked executable in the >> text count, including init text. If you use readelf -S vmlinux.o >> instead you will notice that .text is the same size or smaller, and >> .static_cpu_has (which is freed after boot) is the difference. > > So we're talking about less than a page here? > > [19] .static_cpu_has PROGBITS ffffffff81d335d3 011335d3 > 00000000000002df 0000000000000000 AX 0 0 1 > > That's 479 bytes. Meh, it doesn't look like it is worth the trouble. >
I think that, if we can make static_cpu_has be unconditionally safe as a result and get rid of warn_pre_alternatives, then it is worth the trouble.
--Andy
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