117acf5c29
Back in 2004 we added logic to arch/ppc64/Makefile to pass the --synthetic option to nm, if it was supported by nm. Then in 2005 when arch/ppc64 and arch/ppc were merged, the logic to add --synthetic was moved inside an #ifdef CONFIG_PPC64 block within arch/powerpc/Makefile, and has remained there since. That was fine, though crufty, until recently when a change to init/Kconfig added a config time check that uses $(NM). On powerpc that leads to an infinite loop because Kconfig uses $(NM) to calculate some values, then the powerpc Makefile changes $(NM), which Kconfig notices and restarts. The original commit that added --synthetic simply said: On new toolchains we need to use nm --synthetic or we miss code symbols. And the nm man page says that the --synthetic option causes nm to: Include synthetic symbols in the output. These are special symbols created by the linker for various purposes. So it seems safe to always pass --synthetic if nm supports it, ie. on 32-bit and 64-bit, it just means 32-bit kernels might have more symbols reported (and in practice I see no extra symbols). Making it unconditional avoids the #ifdef CONFIG_PPC64, which in turn avoids the infinite loop. Debugged-by: Peter Collingbourne <pcc@google.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Will Deacon <will@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.