kernel/linux.git/init/Kconfig, branch v4.19.248

kbuild: add CONFIG_LD_IS_LLD

2022-03-11T09:15:12+00:00

commit b744b43f79cc758127042e71f9ad7b1afda30f84 upstream. Similarly to the CC_IS_CLANG config, add LD_IS_LLD to avoid GNU ld specific logic such as ld-version or ld-ifversion and gain the ability to select potential features that depend on the linker at configuration time such as LTO. Signed-off-by: Sami Tolvanen Acked-by: Masahiro Yamada [nc: Reword commit message] Signed-off-by: Nathan Chancellor Tested-by: Sedat Dilek Reviewed-by: Sedat Dilek Signed-off-by: Thomas Bogendoerfer Signed-off-by: Greg Kroah-Hartman

bpf: Add kconfig knob for disabling unpriv bpf by default

2022-02-16T11:51:45+00:00

commit 08389d888287c3823f80b0216766b71e17f0aba5 upstream. Add a kconfig knob which allows for unprivileged bpf to be disabled by default. If set, the knob sets /proc/sys/kernel/unprivileged_bpf_disabled to value of 2. This still allows a transition of 2 -> {0,1} through an admin. Similarly, this also still keeps 1 -> {1} behavior intact, so that once set to permanently disabled, it cannot be undone aside from a reboot. We've also added extra2 with max of 2 for the procfs handler, so that an admin still has a chance to toggle between 0 <-> 2. Either way, as an additional alternative, applications can make use of CAP_BPF that we added a while ago. Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/74ec548079189e4e4dffaeb42b8987bb3c852eee.1620765074.git.daniel@iogearbox.net [fllinden@amazon.com: backported to 4.19] Signed-off-by: Frank van der Linden Signed-off-by: Greg Kroah-Hartman

init/Kconfig: make COMPILE_TEST depend on HAS_IOMEM

2021-04-10T11:21:19+00:00

commit ea29b20a828511de3348334e529a3d046a180416 upstream. I read the commit log of the following two: - bc083a64b6c0 ("init/Kconfig: make COMPILE_TEST depend on !UML") - 334ef6ed06fa ("init/Kconfig: make COMPILE_TEST depend on !S390") Both are talking about HAS_IOMEM dependency missing in many drivers. So, 'depends on HAS_IOMEM' seems the direct, sensible solution to me. This does not change the behavior of UML. UML still cannot enable COMPILE_TEST because it does not provide HAS_IOMEM. The current dependency for S390 is too strong. Under the condition of CONFIG_PCI=y, S390 provides HAS_IOMEM, hence can enable COMPILE_TEST. I also removed the meaningless 'default n'. Link: https://lkml.kernel.org/r/20210224140809.1067582-1-masahiroy@kernel.org Signed-off-by: Masahiro Yamada Cc: Heiko Carstens Cc: Guenter Roeck Cc: Arnd Bergmann Cc: Kees Cook Cc: Daniel Borkmann Cc: Johannes Weiner Cc: KP Singh Cc: Nathan Chancellor Cc: Nick Terrell Cc: Quentin Perret Cc: Valentin Schneider Cc: "Enrico Weigelt, metux IT consult" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

init/Kconfig: make COMPILE_TEST depend on !S390

2021-04-10T11:21:19+00:00

commit 334ef6ed06fa1a54e35296b77b693bcf6d63ee9e upstream. While allmodconfig and allyesconfig build for s390 there are also various bots running compile tests with randconfig, where PCI is disabled. This reveals that a lot of drivers should actually depend on HAS_IOMEM. Adding this to each device driver would be a never ending story, therefore just disable COMPILE_TEST for s390. The reasoning is more or less the same as described in commit bc083a64b6c0 ("init/Kconfig: make COMPILE_TEST depend on !UML"). Reported-by: kernel test robot Suggested-by: Arnd Bergmann Signed-off-by: Heiko Carstens Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

printk: reduce LOG_BUF_SHIFT range for H8300

2020-11-05T10:08:41+00:00

[ Upstream commit 550c10d28d21bd82a8bb48debbb27e6ed53262f6 ] The .bss section for the h8300 is relatively small. A value of CONFIG_LOG_BUF_SHIFT that is larger than 19 will create a static printk ringbuffer that is too large. Limit the range appropriately for the H8300. Reported-by: kernel test robot Signed-off-by: John Ogness Reviewed-by: Sergey Senozhatsky Acked-by: Steven Rostedt (VMware) Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20200812073122.25412-1-john.ogness@linutronix.de Signed-off-by: Sasha Levin

Stop the ad-hoc games with -Wno-maybe-initialized

2020-05-20T06:18:45+00:00

commit 78a5255ffb6a1af189a83e493d916ba1c54d8c75 upstream. We have some rather random rules about when we accept the "maybe-initialized" warnings, and when we don't. For example, we consider it unreliable for gcc versions < 4.9, but also if -O3 is enabled, or if optimizing for size. And then various kernel config options disabled it, because they know that they trigger that warning by confusing gcc sufficiently (ie PROFILE_ALL_BRANCHES). And now gcc-10 seems to be introducing a lot of those warnings too, so it falls under the same heading as 4.9 did. At the same time, we have a very straightforward way to _enable_ that warning when wanted: use "W=2" to enable more warnings. So stop playing these ad-hoc games, and just disable that warning by default, with the known and straight-forward "if you want to work on the extra compiler warnings, use W=123". Would it be great to have code that is always so obvious that it never confuses the compiler whether a variable is used initialized or not? Yes, it would. In a perfect world, the compilers would be smarter, and our source code would be simpler. That's currently not the world we live in, though. Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

kbuild: compute false-positive -Wmaybe-uninitialized cases in Kconfig

2020-05-20T06:18:45+00:00

commit b303c6df80c9f8f13785aa83a0471fca7e38b24d upstream. Since -Wmaybe-uninitialized was introduced by GCC 4.7, we have patched various false positives: - commit e74fc973b6e5 ("Turn off -Wmaybe-uninitialized when building with -Os") turned off this option for -Os. - commit 815eb71e7149 ("Kbuild: disable 'maybe-uninitialized' warning for CONFIG_PROFILE_ALL_BRANCHES") turned off this option for CONFIG_PROFILE_ALL_BRANCHES - commit a76bcf557ef4 ("Kbuild: enable -Wmaybe-uninitialized warning for "make W=1"") turned off this option for GCC < 4.9 Arnd provided more explanation in https://lkml.org/lkml/2017/3/14/903 I think this looks better by shifting the logic from Makefile to Kconfig. Link: https://github.com/ClangBuiltLinux/linux/issues/350 Signed-off-by: Masahiro Yamada Reviewed-by: Nathan Chancellor Tested-by: Nick Desaulniers Signed-off-by: Greg Kroah-Hartman

jump_label: move 'asm goto' support test to Kconfig

2019-06-04T06:02:34+00:00

commit e9666d10a5677a494260d60d1fa0b73cc7646eb3 upstream. Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by: Masahiro Yamada Acked-by: Michael Ellerman (powerpc) Tested-by: Sedat Dilek [nc: Fix trivial conflicts in 4.19 arch/xtensa/kernel/jump_label.c doesn't exist yet Ensured CC_HAVE_ASM_GOTO and HAVE_JUMP_LABEL were sufficiently eliminated] Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

kbuild: Disable LD_DEAD_CODE_DATA_ELIMINATION with ftrace & GCC <= 4.7

2019-01-22T20:40:34+00:00

commit 16fd20aa98080c2fa666dc384036ec08c80af710 upstream. When building using GCC 4.7 or older, -ffunction-sections & the -pg flag used by ftrace are incompatible. This causes warnings or build failures (where -Werror applies) such as the following: arch/mips/generic/init.c: error: -ffunction-sections disabled; it makes profiling impossible This used to be taken into account by the ordering of calls to cc-option from within the top-level Makefile, which was introduced by commit 90ad4052e85c ("kbuild: avoid conflict between -ffunction-sections and -pg on gcc-4.7"). Unfortunately this was broken when the CONFIG_LD_DEAD_CODE_DATA_ELIMINATION cc-option check was moved to Kconfig in commit e85d1d65cd8a ("kbuild: test dead code/data elimination support in Kconfig"), because the flags used by this check no longer include -pg. Fix this by not allowing CONFIG_LD_DEAD_CODE_DATA_ELIMINATION to be enabled at the same time as ftrace/CONFIG_FUNCTION_TRACER when building using GCC 4.7 or older. Signed-off-by: Paul Burton Fixes: e85d1d65cd8a ("kbuild: test dead code/data elimination support in Kconfig") Reported-by: Geert Uytterhoeven Cc: Nicholas Piggin Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Masahiro Yamada Signed-off-by: Greg Kroah-Hartman

sched/pelt: Fix warning and clean up IRQ PELT config

2018-12-19T18:19:49+00:00

Commit 11d4afd4ff667f9b6178ee8c142c36cb78bd84db upstream. Create a config for enabling irq load tracking in the scheduler. irq load tracking is useful only when irq or paravirtual time is accounted but it's only possible with SMP for now. Also use __maybe_unused to remove the compilation warning in update_rq_clock_task() that has been introduced by: 2e62c4743adc ("sched/fair: Remove #ifdefs from scale_rt_capacity()") Suggested-by: Ingo Molnar Reported-by: Dou Liyang Reported-by: Miguel Ojeda Signed-off-by: Vincent Guittot Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: bp@alien8.de Cc: dou_liyang@163.com Fixes: 2e62c4743adc ("sched/fair: Remove #ifdefs from scale_rt_capacity()") Link: http://lkml.kernel.org/r/1537867062-27285-1-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin