mirror of https://github.com/torvalds/linux.git
When doing non-clean builds and switching between CONFIG_LTO=n and CONFIG_LTO=y, the build system (correctly) didn't notice that assembly and LTO-excluded C object files were rewritten in place by objtool (to add the .orc_unwind* sections), since their build command lines were the same between CONFIG_LTO=y and CONFIG_LTO=n. The objtool step would fail: vmlinux.o: warning: objtool: file already has .orc_unwind section, skipping make: *** [Makefile:1194: vmlinux] Error 255 Avoid this by making sure the build will see a difference between an LTO and non-LTO build (by including "-fno-lto" in KBUILD_*FLAGS). This will get ignored when CC_FLAGS_LTO is present, and will not be included at all when CONFIG_LTO=n. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> |
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.