From: Michael Ellerman <mpe@ellerman.id.au>
To: Darren Hart <dvhart@infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: linux-kselftest@vger.kernel.org, bamvor.zhangjian@huawei.com,
        Shuah Khan <shuah@kernel.org>, stable@vger.kernel.org
Subject: Re: [PATCH] selftests/futex: Fix build error with OUTPUT variable
In-Reply-To: <20170324161854.GA6958@fury>
References: <20170324161854.GA6958@fury>
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Date: Tue, 28 Mar 2017 11:19:25 +1100
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Darren Hart <dvhart@infradead.org> writes:

> The use of $$OUTPUT in the target shell commands resulted in an empty
> string followed by an absolute path for which mkdir failed:
>
> $ make -C tools/testing/selftests/futex
> make: Entering directory '/home/dvhart/source/linux/linux-pdx86/tools/testing/selftests/futex'
> Makefile:36: warning: overriding recipe for target 'clean'
> ../lib.mk:55: warning: ignoring old recipe for target 'clean'
> for DIR in functional; do		\
> 	BUILD_TARGET=$OUTPUT/$DIR;	\
> 	mkdir $BUILD_TARGET  -p;	\
> 	make OUTPUT=$BUILD_TARGET -C $DIR all;\
> done
> mkdir: cannot create directory ‘/functional’: Permission denied
>
> Replace $$OUTPUT with $(OUTPUT) when referring to the Makefile OUTPUT
> variable. The above make command now completes successfully.
>
> Fixes: a8ba798bc8ec ("selftests: enable O and KBUILD_OUTPUT")
> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
> Cc: linux-kselftest@vger.kernel.org
> Cc: bamvor.zhangjian@huawei.com
> Cc: Shuah Khan <shuah@kernel.org>
> Cc: <stable@vger.kernel.org> # 4.10.x-

The OUTPUT support only went into v4.11-rc1, so I don't see why you need
a stable tag?

Change looks good though.

cheers