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    SubjectRe: [PATCH] x86/Makefile: make -stack-alignment conditional on LLD < 13.0.0
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    Hi Nathan,

    On 10.06.21 16:42, Nathan Chancellor wrote:
    > Hi Tor,
    >
    > On 6/10/2021 2:28 AM, torvic9@mailbox.org wrote:
    >> Since LLVM commit 3787ee4, the '-stack-alignment' flag has been
    >> dropped [1],
    >> leading to the following error message when building a LTO kernel with
    >> Clang-13 and LLD-13:
    >>
    >>      ld.lld: error: -plugin-opt=-: ld.lld: Unknown command line argument
    >>      '-stack-alignment=8'.  Try 'ld.lld --help'
    >>      ld.lld: Did you mean '--stackrealign=8'?
    >>
    >> It also appears that the '-code-model' flag is not necessary anymore
    >> starting
    >> with LLVM-9 [2].
    >>
    >> Drop '-code-model' and make '-stack-alignment' conditional on LLD <
    >> 13.0.0.
    >>
    >> This is for linux-stable 5.12.
    >> Another patch will be submitted for 5.13 shortly (unless there are
    >> objections).
    >
    > This patch needs to be accepted into mainline first before it can go to
    > stable so this line needs to be removed. The rest of the description
    > looks good to me, good job on being descriptive!
    >

    Thank you for explaining this.
    I wasn't exactly sure how the procedure for stable was.
    Does this mean that the patch should be based on 5.13?
    I usually use Linus' tree mirrored at GitHub.

    >> Discussion: https://github.com/ClangBuiltLinux/linux/issues/1377
    >> [1]: https://reviews.llvm.org/D103048
    >> [2]: https://reviews.llvm.org/D52322
    >
    > As Greg's auto-response points out, there needs to be an actual
    >
    > Cc: stable@vger.kernel.org
    >
    > here in the patch, rather than just cc'ing stable@vger.kernel.org
    > through email.
    >

    Yes I misinterpreted this in the sense of "put stable mail in CC".
    So if I get this right, I should NOT put stable email in CC, but only
    add the "Cc: stable@vger.kernel.org" tag above the "Signed-off-by"?

    >> Signed-off-by: Tor Vic <torvic9@mailbox.org>
    >
    > The actual patch itself looks good and I have verified that it fixes the
    > build error. On the resend with the above fixed, please feel free to add:
    >
    > Reviewed-by: Nathan Chancellor <nathan@kernel.org>
    > Tested-by: Nathan Chancellor <nathan@kernel.org>
    >
    >> ---
    >>   arch/x86/Makefile | 5 +++--
    >>   1 file changed, 3 insertions(+), 2 deletions(-)
    >>
    >> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
    >> index 1f2e5bf..2855a1a 100644
    >> --- a/arch/x86/Makefile
    >> +++ b/arch/x86/Makefile
    >> @@ -192,8 +192,9 @@ endif
    >>   KBUILD_LDFLAGS += -m elf_$(UTS_MACHINE)
    >>     ifdef CONFIG_LTO_CLANG
    >> -KBUILD_LDFLAGS    += -plugin-opt=-code-model=kernel \
    >> -           -plugin-opt=-stack-alignment=$(if $(CONFIG_X86_32),4,8)
    >> +ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
    >> +KBUILD_LDFLAGS    += -plugin-opt=-stack-alignment=$(if
    >> $(CONFIG_X86_32),4,8)
    >> +endif
    >>   endif
    >>     ifdef CONFIG_X86_NEED_RELOCS
    >>
    >
    > Cheers,
    > Nathan

    Thanks for your help!
    Tor

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