wireguard-linux/scripts, branch jd/unified-crypt-queue

kbuild: add dummy toolchains to enable all cc-option etc. in Kconfig

2020-04-08T15:13:45Z

Staring v4.18, Kconfig evaluates compiler capabilities, and hides CONFIG options your compiler does not support. This works well if you configure and build the kernel on the same host machine. It is inconvenient if you prepare the .config that is carried to a different build environment (typically this happens when you package the kernel for distros) because using a different compiler potentially produces different CONFIG options than the real build environment. So, you probably want to make as many options visible as possible. In other words, you need to create a super-set of CONFIG options that cover any build environment. If some of the CONFIG options turned out to be unsupported on the build machine, they are automatically disabled by the nature of Kconfig. However, it is not feasible to get a full-featured compiler for every arch. This issue was discussed here: https://lkml.org/lkml/2019/12/9/620 Other than distros, savedefconfig is also a problem. Some arch sub-systems periodically resync defconfig files. If you use a less-capable compiler for savedefconfig, options that do not meet 'depends on $(cc-option,...)' will be forcibly disabled. So, 'make defconfig && make savedefconfig' may silently change the behavior. This commit adds a set of dummy toolchains that pretend to support any feature. Most of compiler features are tested by cc-option, which simply checks the exit code of $(CC). The dummy tools are shell scripts that always exit with 0. So, $(cc-option, ...) is evaluated as 'y'. There are more complicated checks such as: scripts/gcc-x86_{32,64}-has-stack-protector.sh scripts/gcc-plugin.sh scripts/tools-support-relr.sh scripts/dummy-tools/gcc passes all checks. From the top directory of the source tree, you can do: $ make CROSS_COMPILE=scripts/dummy-tools/ oldconfig Signed-off-by: Masahiro Yamada Reviewed-by: Philipp Rudo Tested-by: Jeremy Cline

kbuild: link lib-y objects to vmlinux forcibly when CONFIG_MODULES=y

2020-04-08T15:13:45Z

Kbuild supports not only obj-y but also lib-y to list objects linked to vmlinux. The difference between them is that all the objects from obj-y are forcibly linked to vmlinux, whereas the objects from lib-y are linked as needed; if there is no user of a lib-y object, it is not linked. lib-y is intended to list utility functions that may be called from all over the place (and may be unused at all), but it is a problem for EXPORT_SYMBOL(). Even if there is no call-site in the vmlinux, we need to keep exported symbols for the use from loadable modules. Commit 7f2084fa55e6 ("[kbuild] handle exports in lib-y objects reliably") worked around it by linking a dummy object, lib-ksyms.o, which contains references to all the symbols exported from lib.a in that directory. It uses the linker script command, EXTERN. Unfortunately, the meaning of EXTERN of ld.lld is different from that of ld.bfd. Therefore, this does not work with LD=ld.lld (CBL issue #515). Anyway, the build rule of lib-ksyms.o is somewhat tricky. So, I want to get rid of it. At first, I was thinking of accumulating lib-y objects into obj-y (or even replacing lib-y with obj-y entirely), but the lib-y syntax is used beyond the ordinary use in lib/ and arch/*/lib/. Examples: - drivers/firmware/efi/libstub/Makefile builds lib.a, which is linked into vmlinux in the own way (arm64), or linked to the decompressor (arm, x86). - arch/alpha/lib/Makefile builds lib.a which is linked not only to vmlinux, but also to bootloaders in arch/alpha/boot/Makefile. - arch/xtensa/boot/lib/Makefile builds lib.a for use from arch/xtensa/boot/boot-redboot/Makefile. One more thing, adding everything to obj-y would increase the vmlinux size of allnoconfig (or tinyconfig). For less impact, I tweaked the destination of lib.a at the top Makefile; when CONFIG_MODULES=y, lib.a goes to KBUILD_VMLINUX_OBJS, which is forcibly linked to vmlinux, otherwise lib.a goes to KBUILD_VMLINUX_LIBS as before. The size impact for normal usecases is quite small since at lease one symbol in every lib-y object is eventually called by someone. In case you are intrested, here are the figures. x86_64_defconfig: text data bss dec hex filename 19566602 5422072 1589328 26578002 1958c52 vmlinux.before 19566932 5422104 1589328 26578364 1958dbc vmlinux.after The case with the biggest impact is allnoconfig + CONFIG_MODULES=y. ARCH=x86 allnoconfig + CONFIG_MODULES=y: text data bss dec hex filename 1175162 254740 1220608 2650510 28718e vmlinux.before 1177974 254836 1220608 2653418 287cea vmlinux.after Hopefully this is still not a big deal. The per-file trimming with the static library is not so effective after all. If fine-grained optimization is desired, some architectures support CONFIG_LD_DEAD_CODE_DATA_ELIMINATION, which trims dead code per-symbol basis. When LTO is supported in mainline, even better optimization will be possible. Link: https://github.com/ClangBuiltLinux/linux/issues/515 Signed-off-by: Masahiro Yamada Reported-by: kbuild test robot Reviewed-by: Nick Desaulniers

kbuild: remove -I$(srctree)/tools/include from scripts/Makefile

2020-04-08T15:13:45Z

I do not like to add an extra include path for every tool with no good reason. This should be specified per file. This line was added by commit 6520fe5564ac ("x86, realmode: 16-bit real-mode code support for relocs tool"), which did not touch anything else in scripts/. I see no reason to add this. Also, remove the comment about kallsyms because we do not have any for the rest of programs. Signed-off-by: Masahiro Yamada

kbuild: mkcompile_h: Include $LD version in /proc/version

2020-04-08T15:13:45Z

When doing Clang builds of the kernel, it is possible to link with either ld.bfd (binutils) or ld.lld (LLVM), but it is not possible to discover this from a running kernel. Add the "$LD -v" output to /proc/version. Signed-off-by: Kees Cook Reviewed-by: Nick Desaulniers Tested-by: Nick Desaulniers Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor Reviewed-by: Fangrui Song Reviewed-by: Sedat Dilek Tested-by: Sedat Dilek Signed-off-by: Masahiro Yamada

kconfig: qconf: Fix a few alignment issues

2020-04-08T15:13:45Z

There are a few items with wrong alignments. Solve them. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Masahiro Yamada

kconfig: qconf: remove some old bogus TODOs

2020-04-08T15:13:45Z

The items described on those TODOs are already solved. So, remove the comments. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Masahiro Yamada

kconfig: qconf: fix support for the split view mode

2020-04-08T15:13:45Z

At least on my tests (building against Qt5.13), it seems to me that, since Kernel 3.14, the split view mode is broken. Maybe it was not a top priority during the conversion time. Anyway, this patch changes the logic in order to properly support the split view mode and the single view mode. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Masahiro Yamada

kconfig: qconf: fix the content of the main widget

2020-04-08T15:13:45Z

The port to Qt5 tried to preserve the same way as it used to work with Qt3 and Qt4. However, at least with newer versions of Qt5 (5.13), this doesn't work properly. Change the schema by adding a vertical layout, in order for it to start working properly again. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Masahiro Yamada

kconfig: qconf: Change title for the item window

2020-04-08T15:13:45Z

Both main config window and the item window have "Option" name. That sounds weird, and makes harder to debug issues of a window appearing at the wrong place. So, change the title to reflect the contents of each window. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Masahiro Yamada

kconfig: qconf: clean deprecated warnings

2020-04-08T15:13:45Z

The recommended way to initialize a null string is with QString(). This is there at least since Qt5.5, with is when qconf was ported to Qt5. Fix those warnings: scripts/kconfig/qconf.cc: In member function ‘void ConfigItem::updateMenu()’: scripts/kconfig/qconf.cc:158:31: warning: ‘QString::null’ is deprecated: use QString() [-Wdeprecated-declarations] 158 | setText(noColIdx, QString::null); | ^~~~ In file included from /usr/include/qt5/QtCore/qobject.h:47, from /usr/include/qt5/QtWidgets/qwidget.h:45, from /usr/include/qt5/QtWidgets/qmainwindow.h:44, from /usr/include/qt5/QtWidgets/QMainWindow:1, from scripts/kconfig/qconf.cc:9: Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Masahiro Yamada