Messages in this thread | | | Date | Sat, 30 Nov 2013 00:24:57 +0100 (CET) | From | Jiri Kosina <> | Subject | Re: [PATCH] Add a text_poke syscall v2 |
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On Fri, 29 Nov 2013, Oleg Nesterov wrote:
> > > Andi, et al. I am going to discuss the things I do not really > > > understand, probably this can't make any sense, but... > > > > I think it's enough to set the dirty bit in the underlying > > struct page, no need to play games with the PTE. > > Ah, sorry for confusion, I guess you misunderstood. > > I meant, perhaps sys_text_poke() doesn't the in-kernel text_poke > machinery altogether? > > Can't we invalidate pte (so that any user will stuck in page fault), > update the page(s), restore the pte and drop the locks?
Do you think this'd be faster than the int3-based aproach?
We have moved from using stop_machine() to int3-based patching exactly because it's much more lightweight.
> This way sys_text_poke() won't be x86-specific, and it will be per-mm.
Good point, it'd be really nice to have this as an alternative on archs where breakpoint-based patching wouldn't be possible for some reason.
-- Jiri Kosina SUSE Labs
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