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Date: Mon, 14 Sep 2015 10:54:25 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Baoquan He <bhe@redhat.com>, Denys Vlasenko <dvlasenk@redhat.com>,
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Subject: Re: [llvmlinux] percpu | bitmap issue? (Cannot boot on bare metal
 due to a kernel NULL pointer dereference)
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On Mon, Sep 14, 2015 at 09:35:04AM +0200, Sedat Dilek wrote:
> > /me goes back to ignoring LLVM for the time being.

> The issue was reported as LLVM PR #9457 [1] and the bug-history [2] says...
> 
>    Reported: 2011-03-11 07:27 CST by PaX Team
> 
> ...so it is a known and old issue.

> Beyond "fixing" or implementing missing (GCC) features on the LLVM-Clang-side...
> People there have some discussion and ideas on a "workaround" or fix
> it on the Linux-kernel-side.

Barring LLVM implementing the relevant function call attributes, you
could look at either generating the required thunks (as mentioned
earlier as a work-around) or at the very least validating that all
required thunks are present.

> I invite you to join the discussion at LLVMLinux...
> As I know... "YES, you can." Linux x86/x86_64 (assembler) Kung-Fu.
> ( I admit I have not these skillz. )

Its a matter of time for me; I simply do not have enough time as it is
so I have to make choices.