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Valentin ObstandGreg Kroah-Hartman
b48efc18de
[ Upstream commitd4e6fbd245] Align the behavior for gcc and clang builds by interpreting unset `ARCH` and `CROSS_COMPILE` variables in `LLVM` builds as a sign that the user wants to build for the host architecture. This patch preserves the properties that setting the `ARCH` variable to an unknown value will trigger an error that complains about insufficient information, and that a set `CROSS_COMPILE` variable will override the target triple that is determined based on presence/absence of `ARCH`. When compiling with clang, i.e., `LLVM` is set, an unset `ARCH` variable in combination with an unset `CROSS_COMPILE` variable, i.e., compiling for the host architecture, leads to compilation failures since `lib.mk` can not determine the clang target triple. In this case, the following error message is displayed for each subsystem that does not set `ARCH` in its own Makefile before including `lib.mk` (lines wrapped at 75 chrs): make[1]: Entering directory '/mnt/build/linux/tools/testing/selftests/ sysctl' ../lib.mk:33: *** Specify CROSS_COMPILE or add '--target=' option to lib.mk. Stop. make[1]: Leaving directory '/mnt/build/linux/tools/testing/selftests/ sysctl' In the same scenario a gcc build would default to the host architecture, i.e., it would use plain `gcc`. Fixes:795285ef24("selftests: Fix clang cross compilation") Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.