Re: + makefile-fix-build-with-make-380-again.patch added to -mm tree

From: Kees Cook
Date: Fri Feb 21 2014 - 15:09:58 EST


On Fri, Feb 21, 2014 at 12:07 PM, <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> Subject: + makefile-fix-build-with-make-380-again.patch added to -mm tree
> To: JBeulich@xxxxxxxx,jbeulich@xxxxxxxx,keescook@xxxxxxxxxxxx,mingo@xxxxxxxxxx,mmarek@xxxxxxx
> From: akpm@xxxxxxxxxxxxxxxxxxxx
> Date: Fri, 21 Feb 2014 12:07:52 -0800
>
>
> The patch titled
> Subject: Makefile: fix build with make 3.80 again
> has been added to the -mm tree. Its filename is
> makefile-fix-build-with-make-380-again.patch
>
> This patch should soon appear at
> http://ozlabs.org/~akpm/mmots/broken-out/makefile-fix-build-with-make-380-again.patch
> and later at
> http://ozlabs.org/~akpm/mmotm/broken-out/makefile-fix-build-with-make-380-again.patch
>
> Before you just go and hit "reply", please:
> a) Consider who else should be cc'ed
> b) Prefer to cc a suitable mailing list as well
> c) Ideally: find the original patch on the mailing list and do a
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>
> *** Remember to use Documentation/SubmitChecklist when testing your code ***
>
> The -mm tree is included into linux-next and is updated
> there every 3-4 working days
>
> ------------------------------------------------------
> From: "Jan Beulich" <JBeulich@xxxxxxxx>
> Subject: Makefile: fix build with make 3.80 again
>
> According to Documentation/Changes, make 3.80 is still being supported for
> building the kernel, hence make files must not make (unconditional) use of
> features introduced only in newer versions. Commit 8779657d
> ("stackprotector: Introduce CONFIG_CC_STACKPROTECTOR_STRONG") however
> introduced an "else ifdef" construct which make 3.80 doesn't understand.
>
> Also correct a warning message still referencing the old config option
> name.
>
> Apart from that I question the use of "ifdef" here (but it was used that
> way already prior to said commit): ifeq (,y) would seem more to the point.
>
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Michal Marek <mmarek@xxxxxxx>
> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> ---
>
> Makefile | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff -puN Makefile~makefile-fix-build-with-make-380-again Makefile
> --- a/Makefile~makefile-fix-build-with-make-380-again
> +++ a/Makefile
> @@ -605,7 +605,7 @@ endif
> ifdef CONFIG_CC_STACKPROTECTOR_REGULAR
> stackp-flag := -fstack-protector
> ifeq ($(call cc-option, $(stackp-flag)),)
> - $(warning Cannot use CONFIG_CC_STACKPROTECTOR: \
> + $(warning Cannot use CONFIG_CC_STACKPROTECTOR_REGULAR: \
> -fstack-protector not supported by compiler)
> endif
> else ifdef CONFIG_CC_STACKPROTECTOR_STRONG
> @@ -618,6 +618,7 @@ else
> # Force off for distro compilers that enable stack protector by default.
> stackp-flag := $(call cc-option, -fno-stack-protector)
> endif
> +endif
> KBUILD_CFLAGS += $(stackp-flag)
>
> # This warning generated too much noise in a regular build.
> _
>
> Patches currently in -mm which might be from JBeulich@xxxxxxxx are
>
> makefile-fix-build-with-make-380-again.patch
>

This appears to be missing the:

-else ifdef CONFIG_CC_STACKPROTECTOR_STRONG
+else
+ifdef CONFIG_CC_STACKPROTECTOR_STRONG

chunk?

--
Kees Cook
Chrome OS Security
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