Messages in this thread | | | From | Andy Lutomirski <> | Date | Fri, 9 Feb 2018 17:43:55 +0000 | Subject | Re: [PATCH 09/31] x86/entry/32: Leave the kernel via trampoline stack |
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On Fri, Feb 9, 2018 at 5:05 PM, Linus Torvalds <torvalds@linux-foundation.org> wrote: > On Fri, Feb 9, 2018 at 1:25 AM, Joerg Roedel <joro@8bytes.org> wrote: >> + >> + /* Copy over the stack-frame */ >> + cld >> + rep movsb > > Ugh. This is going to be horrendous. Maybe not noticeable on modern > CPU's, but the whole 32-bit code is kind of pointless on a modern CPU. > > At least use "rep movsl". If the kernel stack isn't 4-byte aligned, > you have issues. >
The 64-bit code mostly uses a bunch of push instructions for this.
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