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2020-11-02kbuild: remove unused OBJSIZEVasily Gorbik1-3/+2
The "size" tool has been solely used by s390 to enforce .bss section usage restrictions in early startup code. Since commit 980d5f9ab36b ("s390/boot: enable .bss section for compressed kernel") and commit 2e83e0eb85ca ("s390: clean .bss before running uncompressed kernel") these restrictions have been lifted for the decompressor and uncompressed kernel and the size tool is now unused. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-10-12Merge tag 'docs-5.10' of git://git.lwn.net/linuxLinus Torvalds1-0/+4
Pull documentation updates from Jonathan Corbet: "As hoped, things calmed down for docs this cycle; fewer changes and almost no conflicts at all. This includes: - A reworked and expanded user-mode Linux document - Some simplifications and improvements for submitting-patches.rst - An emergency fix for (some) problems with Sphinx 3.x - Some welcome automarkup improvements to automatically generate cross-references to struct definitions and other documents - The usual collection of translation updates, typo fixes, etc" * tag 'docs-5.10' of git://git.lwn.net/linux: (81 commits) gpiolib: Update indentation in driver.rst for code excerpts Documentation/admin-guide: tainted-kernels: Fix typo occured Documentation: better locations for sysfs-pci, sysfs-tagging docs: programming-languages: refresh blurb on clang support Documentation: kvm: fix a typo Documentation: Chinese translation of Documentation/arm64/amu.rst doc: zh_CN: index files in arm64 subdirectory mailmap: add entry for <mstarovoitov@marvell.com> doc: seq_file: clarify role of *pos in ->next() docs: trace: ring-buffer-design.rst: use the new SPDX tag Documentation: kernel-parameters: clarify "module." parameters Fix references to nommu-mmap.rst docs: rewrite admin-guide/sysctl/abi.rst docs: fb: Remove vesafb scrollback boot option docs: fb: Remove sstfb scrollback boot option docs: fb: Remove matroxfb scrollback boot option docs: fb: Remove framebuffer scrollback boot option docs: replace the old User Mode Linux HowTo with a new one Documentation/admin-guide: blockdev/ramdisk: remove use of "rdev" Documentation/admin-guide: README & svga: remove use of "rdev" ...
2020-09-26Documentation/llvm: Fix clang target examplesFlorian Fainelli1-2/+2
clang --target=<triple> is how we can specify a particular toolchain triple to be use, fix the two occurences in the documentation. Fixes: fcf1b6a35c16 ("Documentation/llvm: add documentation on building w/ Clang/LLVM") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-08-31Documentation: add minimum clang/llvm versionNick Desaulniers1-0/+4
Based on a vote at the LLVM BoF at Plumbers 2020, we decided to start small, supporting just one formal upstream release of LLVM for now. We can probably widen the support window of supported versions over time. Also, note that LLVM's release process is different than GCC's. GCC tends to have 1 major release per year while releasing minor updates to the past 3 major versions. LLVM tends to support one major release and one minor release every six months. Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Gustavo A. R. Silva <gustavoars@kernel.org> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200826191555.3350406-1-ndesaulniers@google.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-08-31Documentation/llvm: Improve formatting of commands, variables, and argumentsNathan Chancellor1-13/+13
While reviewing a separate patch, I noticed that the formatting of the commands, variables, and arguments was not in a monospaced font like the rest of the Kbuild documentation (see kbuild/kconfig.rst for an example). This is due to a lack of "::" before indented command blocks and single backticks instead of double backticks for inline formatting. Add those so that the document looks nicer in an HTML format, while not ruining the look in plain text. As a result of this, we can remove the escaped backslashes in the last code block and move them to single backslashes. Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-08-10kbuild: Replace HTTP links with HTTPS onesAlexander A. Klimov1-1/+1
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-04-09kbuild: support LLVM=1 to switch the default tools to Clang/LLVMMasahiro Yamada1-2/+6
As Documentation/kbuild/llvm.rst implies, building the kernel with a full set of LLVM tools gets very verbose and unwieldy. Provide a single switch LLVM=1 to use Clang and LLVM tools instead of GCC and Binutils. You can pass it from the command line or as an environment variable. Please note LLVM=1 does not turn on the integrated assembler. You need to pass LLVM_IAS=1 to use it. When the upstream kernel is ready for the integrated assembler, I think we can make it default. We discussed what we need, and we agreed to go with a simple boolean flag that switches both target and host tools: https://lkml.org/lkml/2020/3/28/494 https://lkml.org/lkml/2020/4/3/43 Some items discussed, but not adopted: - LLVM_DIR When multiple versions of LLVM are installed, I just thought supporting LLVM_DIR=/path/to/my/llvm/bin/ might be useful. CC = $(LLVM_DIR)clang LD = $(LLVM_DIR)ld.lld ... However, we can handle this by modifying PATH. So, we decided to not do this. - LLVM_SUFFIX Some distributions (e.g. Debian) package specific versions of LLVM with naming conventions that use the version as a suffix. CC = clang$(LLVM_SUFFIX) LD = ld.lld(LLVM_SUFFIX) ... will allow a user to pass LLVM_SUFFIX=-11 to use clang-11 etc., but the suffixed versions in /usr/bin/ are symlinks to binaries in /usr/lib/llvm-#/bin/, so this can also be handled by PATH. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> # build Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-04-09kbuild: replace AS=clang with LLVM_IAS=1Masahiro Yamada1-1/+4
The 'AS' variable is unused for building the kernel. Only the remaining usage is to turn on the integrated assembler. A boolean flag is a better fit for this purpose. AS=clang was added for experts. So, I replaced it with LLVM_IAS=1, breaking the backward compatibility. Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-04-09Documentation/llvm: fix the name of llvm-sizeFangrui Song1-1/+1
The tool is called llvm-size, not llvm-objsize. Fixes: fcf1b6a35c16 ("Documentation/llvm: add documentation on building w/ Clang/LLVM") Signed-off-by: Fangrui Song <maskray@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-03-03Documentation/llvm: add documentation on building w/ Clang/LLVMNick Desaulniers1-0/+80
Added to kbuild documentation. Provides more official info on building kernels with Clang and LLVM than our wiki. Suggested-by: Kees Cook <keescook@chromium.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>