Messages in this thread | | | From | Linus Torvalds <> | Date | Wed, 7 Feb 2018 11:01:29 -0800 | Subject | Re: [linus:master] BUILD REGRESSION a2e5790d841658485d642196dbb0927303d6c22f |
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On Wed, Feb 7, 2018 at 10:38 AM, Randy Dunlap <rdunlap@infradead.org> wrote: > On 02/07/2018 10:13 AM, Linus Torvalds wrote: >> >> That said, intel only _documents_ UD2 (0f 0b). > > Intel Order Number: 325383-064US, October 2017, documents UD0, UD1, and UD2. > Section A.2.5, Table A-1, says:
Ahh, I had an older version.
Looking at the latest one I can find (325462-065US), it does specify that it has a modrm byte:
0F FF /r UD0 1 r32, r/m32
so I think that our opcode maps are wrong, and it's a bit dangerous to put random constants right after the UD0.
Maybe we should make our use of UD0 have a third byte: add a harmless modrm byte before the warning constants?
But yes, at least my objdump just thinks it's a bad 2-byte sequence, and doesn't look at any modrm bytes at all.
Linus
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