Messages in this thread | | | Date | Wed, 30 Mar 2016 15:52:46 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH 10/11] perf tools: Add probing for udev86 library |
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* Arnaldo Carvalho de Melo <acme@redhat.com> wrote:
> Em Wed, Mar 30, 2016 at 12:43:27PM +0200, Ingo Molnar escreveu: > > > From: Andi Kleen <ak@linux.intel.com> > > > > Add autoprobing for the udev86 disassembler library. > > > So the typo in the title is confusing, what is 'udev86'? > > > Also, this library does not seem to be available on stock Ubuntu. We should not be > > adding library dependencies that cannot be resolved on major distros: > > Ok, I'll remove, I thought it would be ok because I fired up: > > # dnf install udis86-devel > > On fedora and it installed straight away, but after I started trying to > update my docker images I couldn't find it on debian > experimental/unstable:
> Nor even in OpenSuSE:
> Or even Mageia:
Yeah, so udis86 also seems to be a pretty old, relatively stale library with no support for new instructions AFAICS.
So I'd rather encourage librarizing one of the x86 instruction decoders in arch/x86/, and adding pretty-printing functionality to it. The code can already see instruction boundaries, which is the hardest part.
That would also be better supported on non-x86 architectures in the long run:
triton:~/tip> find arch/ -name insn.c | xargs ls -l -rw-rw-r-- 1 mingo mingo 30244 Mar 29 11:24 arch/arm64/kernel/insn.c -rw-rw-r-- 1 mingo mingo 1347 Dec 8 06:27 arch/arm/kernel/insn.c -rw-rw-r-- 1 mingo mingo 15123 Mar 30 12:31 arch/x86/lib/insn.c
Such an in-kernel-repo library could also be used by live kernel debuggers such as kgdb/kdb, oops/crash-time disassembly printout, etc.
... so how about that direction instead?
Thank,
Ingo
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