Messages in this thread | | | From | Andi Kleen <> | Subject | Re: [PATCH] Add a text_poke syscall | Date | Wed, 20 Nov 2013 09:25:31 -0800 |
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"H. Peter Anvin" <hpa@zytor.com> writes: > > We're talking user space here, which has different requirement (COW, > memory protection, ...) which means it is not really the same code. You > can't take a page fault while patching the kernel.
The syscall pins the page, then it calls the kernel code. There are no page faults during patching.
> I'm referring to if some thread actually stumbles over INT 3, which is > indeed not very long for one patch site (as long as you don't end up > with page faults.) However, for tracing, you may want to do tens of > thousands of patches, and you really want to batch them.
For tens of thousand of patches you very likely don't want live patching, but a stop everything approach.
-Andi
-- ak@linux.intel.com -- Speaking for myself only
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