465bfd9c44
When building pseries_defconfig, building vdso32 errors out:
error: unknown target ABI 'elfv1'
This happens because -m32 in clang changes the target to 32-bit,
which does not allow the ABI to be changed.
Commit 4dc831aa8813 ("powerpc: Fix compiling a BE kernel with a
powerpc64le toolchain") added these flags to fix building big endian
kernels with a little endian GCC.
Clang doesn't need -mabi because the target triple controls the
default value. -mlittle-endian and -mbig-endian manipulate the triple
into either powerpc64-* or powerpc64le-*, which properly sets the
default ABI.
Adding a debug print out in the PPC64TargetInfo constructor after line
383 above shows this:
$ echo | ./clang -E --target=powerpc64-linux -mbig-endian -o /dev/null -
Default ABI: elfv1
$ echo | ./clang -E --target=powerpc64-linux -mlittle-endian -o /dev/null -
Default ABI: elfv2
$ echo | ./clang -E --target=powerpc64le-linux -mbig-endian -o /dev/null -
Default ABI: elfv1
$ echo | ./clang -E --target=powerpc64le-linux -mlittle-endian -o /dev/null -
Default ABI: elfv2
Don't specify -mabi when building with clang to avoid the build error
with -m32 and not change any code generation.
-mcall-aixdesc is not an implemented flag in clang so it can be safely
excluded as well, see commit 238abecde8ad ("powerpc: Don't use gcc
specific options on clang").
pseries_defconfig successfully builds after this patch and
powernv_defconfig and ppc44x_defconfig don't regress.
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
[mpe: Trim clang links in change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191119045712.39633-2-natechancellor@gmail.com
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.