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From:   Sedat Dilek <sedat.dilek@gmail.com>
Date:   Tue, 22 May 2018 09:39:31 +0200
Message-ID: <CA+icZUVsV=5jvTcXVWqMs6ROhT3mv+7zBOoJ0JkUy5Mf+a4GNw@mail.gmail.com>
Subject: Re: Clang patch stacks for LTS kernels (v4.4 and v4.9) and status update
To:     Nick Desaulniers <nick.desaulniers@gmail.com>
Cc:     Matthias Kaehlcke <mka@chromium.org>,
        lkml <linux-kernel@vger.kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Manoj Gupta <manojgupta@chromium.org>,
        AlistairStrachan <astrachan@google.com>,
        "Steven Rostedt (VMware)" <rostedt@goodmis.org>
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On Sat, May 19, 2018 at 12:54 AM, Nick Desaulniers
<nick.desaulniers@gmail.com> wrote:
> Sedat,
> Thanks for the report.  We have a fix ready in
> https://bugs.llvm.org/show_bug.cgi?id=37512.  Can you report what
> version of clang you were using and if earlier versions of clang have
> this issue?
> Thanks,

Can you give some advices on how to implement
"attribute((no_stack_protector))" for Clang?

I looked on how this is done for GCC...

[ include/linux/compiler-gcc.h ]

#if GCC_VERSION >= 40400
#define __optimize(level)       __attribute__((__optimize__(level)))
#define __nostackprotector      __optimize("no-stack-protector")
#endif /* GCC_VERSION >= 40400 */

[ include/linux/compiler_types.h ]

#ifndef __nostackprotector
# define __nostackprotector
#endif

LLVM-bug #37512 says:

"GCC option for this is: attribute((optimize("no-stack-protector")))
and the equivalent clang syntax would be: attribute((no_stack_protector))"

So, there should be a define in "include/linux/compiler-clang.h" for this?

[ include/linux/compiler-clang.h ]

#define __nostackprotector attribute((no_stack_protector))

Looks that good to you?

- Sedat -