BMC/Intel-BMC/linux.git/arch/Kconfig, branch dev-4.18

compiler.h: Allow arch-specific asm/compiler.h

2018-11-04T13:51:49+00:00

[ Upstream commit 04f264d3a8b0eb25d378127bd78c3c9a0261c828 ] We have a need to override the definition of barrier_before_unreachable() for MIPS, which means we either need to add architecture-specific code into linux/compiler-gcc.h or we need to allow the architecture to provide a header that can define the macro before the generic definition. The latter seems like the better approach. A straightforward approach to the per-arch header is to make use of asm-generic to provide a default empty header & adjust architectures which don't need anything specific to make use of that by adding the header to generic-y. Unfortunately this doesn't work so well due to commit 28128c61e08e ("kconfig.h: Include compiler types to avoid missed struct attributes") which caused linux/compiler_types.h to be included in the compilation of every C file via the -include linux/kconfig.h flag in c_flags. Because the -include flag is present for all C files we compile, we need the architecture-provided header to be present before any C files are compiled. If any C files can be compiled prior to the asm-generic header wrappers being generated then we hit a build failure due to missing header. Such cases do exist - one pointed out by the kbuild test robot is the compilation of arch/ia64/kernel/nr-irqs.c, which occurs as part of the archprepare target [1]. This leaves us with a few options: 1) Use generic-y & fix any build failures we find by enforcing ordering such that the asm-generic target occurs before any C compilation, such that linux/compiler_types.h can always include the generated asm-generic wrapper which in turn includes the empty asm-generic header. This would rely on us finding all the problematic cases - I don't know for sure that the ia64 issue is the only one. 2) Add an actual empty header to each architecture, so that we don't need the generated asm-generic wrapper. This seems messy. 3) Give up & add #ifdef CONFIG_MIPS or similar to linux/compiler_types.h. This seems messy too. 4) Include the arch header only when it's actually needed, removing the need for the asm-generic wrapper for all other architectures. This patch allows us to use approach 4, by including an asm/compiler.h header from linux/compiler_types.h after the inclusion of the compiler-specific linux/compiler-*.h header(s). We do this conditionally, only when CONFIG_HAVE_ARCH_COMPILER_H is selected, in order to avoid the need for asm-generic wrappers & the associated build ordering issue described above. The asm/compiler.h header is included after the generic linux/compiler-*.h header(s) for consistency with the way linux/compiler-intel.h & linux/compiler-clang.h are included after the linux/compiler-gcc.h header that they override. [1] https://lists.01.org/pipermail/kbuild-all/2018-August/051175.html Signed-off-by: Paul Burton Reviewed-by: Masahiro Yamada Patchwork: https://patchwork.linux-mips.org/patch/20269/ Cc: Arnd Bergmann Cc: James Hogan Cc: Masahiro Yamada Cc: Ralf Baechle Cc: linux-arch@vger.kernel.org Cc: linux-kbuild@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Sasha Levin

mm/tlb, x86/mm: Support invalidating TLB caches for RCU_TABLE_FREE

2018-09-05T07:29:47+00:00

commit d86564a2f085b79ec046a5cba90188e612352806 upstream. Jann reported that x86 was missing required TLB invalidates when he hit the !*batch slow path in tlb_remove_table(). This is indeed the case; RCU_TABLE_FREE does not provide TLB (cache) invalidates, the PowerPC-hash where this code originated and the Sparc-hash where this was subsequently used did not need that. ARM which later used this put an explicit TLB invalidate in their __p*_free_tlb() functions, and PowerPC-radix followed that example. But when we hooked up x86 we failed to consider this. Fix this by (optionally) hooking tlb_remove_table() into the TLB invalidate code. NOTE: s390 was also needing something like this and might now be able to use the generic code again. [ Modified to be on top of Nick's cleanups, which simplified this patch now that tlb_flush_mmu_tlbonly() really only flushes the TLB - Linus ] Fixes: 9e52fc2b50de ("x86/mm: Enable RCU based page table freeing (CONFIG_HAVE_RCU_TABLE_FREE=y)") Reported-by: Jann Horn Signed-off-by: Peter Zijlstra (Intel) Acked-by: Rik van Riel Cc: Nicholas Piggin Cc: David Miller Cc: Will Deacon Cc: Martin Schwidefsky Cc: Michael Ellerman Cc: stable@kernel.org Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

cpu/hotplug: Provide knobs to control SMT

2018-08-15T15:37:26+00:00

commit 05736e4ac13c08a4a9b1ef2de26dd31a32cbee57 upstream. Provide a command line and a sysfs knob to control SMT. The command line options are: 'nosmt': Enumerate secondary threads, but do not online them 'nosmt=force': Ignore secondary threads completely during enumeration via MP table and ACPI/MADT. The sysfs control file has the following states (read/write): 'on': SMT is enabled. Secondary threads can be freely onlined 'off': SMT is disabled. Secondary threads, even if enumerated cannot be onlined 'forceoff': SMT is permanentely disabled. Writes to the control file are rejected. 'notsupported': SMT is not supported by the CPU The command line option 'nosmt' sets the sysfs control to 'off'. This can be changed to 'on' to reenable SMT during runtime. The command line option 'nosmt=force' sets the sysfs control to 'forceoff'. This cannot be changed during runtime. When SMT is 'on' and the control file is changed to 'off' then all online secondary threads are offlined and attempts to online a secondary thread later on are rejected. When SMT is 'off' and the control file is changed to 'on' then secondary threads can be onlined again. The 'off' -> 'on' transition does not automatically online the secondary threads. When the control file is set to 'forceoff', the behaviour is the same as setting it to 'off', but the operation is irreversible and later writes to the control file are rejected. When the control status is 'notsupported' then writes to the control file are rejected. Signed-off-by: Thomas Gleixner Reviewed-by: Konrad Rzeszutek Wilk Acked-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

docs: Fix some broken references

2018-06-15T21:10:01+00:00

As we move stuff around, some doc references are broken. Fix some of them via this script: ./scripts/documentation-file-ref-check --fix Manually checked if the produced result is valid, removing a few false-positives. Acked-by: Takashi Iwai Acked-by: Masami Hiramatsu Acked-by: Stephen Boyd Acked-by: Charles Keepax Acked-by: Mathieu Poirier Reviewed-by: Coly Li Signed-off-by: Mauro Carvalho Chehab Acked-by: Jonathan Corbet

Kbuild: rename HAVE_CC_STACKPROTECTOR config variable

2018-06-14T22:15:28+00:00

HAVE_CC_STACKPROTECTOR should be selected by architectures with stack canary implementation. It is not about the compiler support. For the consistency with commit 050e9baa9dc9 ("Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables"), remove 'CC_' from the config symbol. I moved the 'select' lines to keep the alphabetical sorting. Signed-off-by: Masahiro Yamada Acked-by: Kees Cook Signed-off-by: Linus Torvalds

Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables

2018-06-14T03:21:18+00:00

The changes to automatically test for working stack protector compiler support in the Kconfig files removed the special STACKPROTECTOR_AUTO option that picked the strongest stack protector that the compiler supported. That was all a nice cleanup - it makes no sense to have the AUTO case now that the Kconfig phase can just determine the compiler support directly. HOWEVER. It also meant that doing "make oldconfig" would now _disable_ the strong stackprotector if you had AUTO enabled, because in a legacy config file, the sane stack protector configuration would look like CONFIG_HAVE_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_NONE is not set # CONFIG_CC_STACKPROTECTOR_REGULAR is not set # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_STACKPROTECTOR_AUTO=y and when you ran this through "make oldconfig" with the Kbuild changes, it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version used to be disabled (because it was really enabled by AUTO), and would disable it in the new config, resulting in: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_HAS_SANE_STACKPROTECTOR=y That's dangerously subtle - people could suddenly find themselves with the weaker stack protector setup without even realizing. The solution here is to just rename not just the old RECULAR stack protector option, but also the strong one. This does that by just removing the CC_ prefix entirely for the user choices, because it really is not about the compiler support (the compiler support now instead automatially impacts _visibility_ of the options to users). This results in "make oldconfig" actually asking the user for their choice, so that we don't have any silent subtle security model changes. The end result would generally look like this: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_STACKPROTECTOR=y CONFIG_STACKPROTECTOR_STRONG=y CONFIG_CC_HAS_SANE_STACKPROTECTOR=y where the "CC_" versions really are about internal compiler infrastructure, not the user selections. Acked-by: Masahiro Yamada Signed-off-by: Linus Torvalds

Merge tag 'kbuild-v4.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2018-06-13T15:40:34+00:00

Pull more Kbuild updates from Masahiro Yamada: - fix some bugs introduced by the recent Kconfig syntax extension - add some symbols about compiler information in Kconfig, such as CC_IS_GCC, CC_IS_CLANG, GCC_VERSION, etc. - test compiler capability for the stack protector in Kconfig, and clean-up Makefile - test compiler capability for GCC-plugins in Kconfig, and clean-up Makefile - allow to enable GCC-plugins for COMPILE_TEST - test compiler capability for KCOV in Kconfig and correct dependency - remove auto-detect mode of the GCOV format, which is now more nicely handled in Kconfig - test compiler capability for mprofile-kernel on PowerPC, and clean-up Makefile - misc cleanups * tag 'kbuild-v4.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: linux/linkage.h: replace VMLINUX_SYMBOL_STR() with __stringify() kconfig: fix localmodconfig sh: remove no-op macro VMLINUX_SYMBOL() powerpc/kbuild: move -mprofile-kernel check to Kconfig Documentation: kconfig: add recommended way to describe compiler support gcc-plugins: disable GCC_PLUGIN_STRUCTLEAK_BYREF_ALL for COMPILE_TEST gcc-plugins: allow to enable GCC_PLUGINS for COMPILE_TEST gcc-plugins: test plugin support in Kconfig and clean up Makefile gcc-plugins: move GCC version check for PowerPC to Kconfig kcov: test compiler capability in Kconfig and correct dependency gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT arm64: move GCC version check for ARCH_SUPPORTS_INT128 to Kconfig kconfig: add CC_IS_CLANG and CLANG_VERSION kconfig: add CC_IS_GCC and GCC_VERSION stack-protector: test compiler capability in Kconfig and drop AUTO mode kbuild: fix endless syncconfig in case arch Makefile sets CROSS_COMPILE

gcc-plugins: disable GCC_PLUGIN_STRUCTLEAK_BYREF_ALL for COMPILE_TEST

2018-06-11T00:16:28+00:00

We have enabled GCC_PLUGINS for COMPILE_TEST, but allmodconfig now produces new warnings. CC [M] drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.o drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c: In function ‘wlc_phy_workarounds_nphy_rev7’: drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c:16563:1: warning: the frame size of 3128 bytes is larger than 2048 bytes [-Wframe-larger-than=] } ^ drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c: In function ‘wlc_phy_workarounds_nphy_rev3’: drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c:16905:1: warning: the frame size of 2800 bytes is larger than 2048 bytes [-Wframe-larger-than=] } ^ drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c: In function ‘wlc_phy_cal_txiqlo_nphy’: drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c:26033:1: warning: the frame size of 2488 bytes is larger than 2048 bytes [-Wframe-larger-than=] } ^ It looks like GCC_PLUGIN_STRUCTLEAK_BYREF_ALL is causing this. Add "depends on !COMPILE_TEST" to not dirturb the compile test. Reported-by: Stephen Rothwell Suggested-by: Kees Cook Signed-off-by: Masahiro Yamada

gcc-plugins: allow to enable GCC_PLUGINS for COMPILE_TEST

2018-06-11T00:16:27+00:00

Now that the compiler's plugin support is checked in Kconfig, all{yes,mod}config will not be bothered. Remove 'depends on !COMPILE_TEST' for GCC_PLUGINS. 'depends on !COMPILE_TEST' for the following three are still kept: GCC_PLUGIN_CYC_COMPLEXITY GCC_PLUGIN_STRUCTLEAK_VERBOSE GCC_PLUGIN_RANDSTRUCT_PERFORMANCE Kees suggested to do so because the first two are too noisy, and the last one would reduce the compile test coverage. I commented the reasons in arch/Kconfig. Signed-off-by: Masahiro Yamada Acked-by: Kees Cook

gcc-plugins: test plugin support in Kconfig and clean up Makefile

2018-06-11T00:16:22+00:00

Run scripts/gcc-plugin.sh from Kconfig so that users can enable GCC_PLUGINS only when the compiler supports building plugins. Kconfig defines a new symbol, PLUGIN_HOSTCC. This will contain the compiler (g++ or gcc) used for building plugins, or empty if the plugin can not be supported at all. This allows us to remove all ugly testing in Makefile.gcc-plugins. Signed-off-by: Masahiro Yamada Acked-by: Kees Cook