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2019-02-06Linux 4.20.7v4.20.7Greg Kroah-Hartman
2019-01-31Linux 4.20.6v4.20.6Greg Kroah-Hartman
2019-01-26Linux 4.20.5v4.20.5Greg Kroah-Hartman
2019-01-26kbuild: let fixdep directly write to .*.cmd filesMasahiro Yamada
[ Upstream commit 392885ee82d35d515ba2af7b72c5e357c3002113 ] Currently, fixdep writes dependencies to .*.tmp, which is renamed to .*.cmd after everything succeeds. This is a very safe way to avoid corrupted .*.cmd files. The if_changed_dep has carried this safety mechanism since it was added in 2002. If fixdep fails for some reasons or a user terminates the build while fixdep is running, the incomplete output from the fixdep could be troublesome. This is my insight about some bad scenarios: [1] If the compiler succeeds to generate *.o file, but fixdep fails to write necessary dependencies to .*.cmd file, Make will miss to rebuild the object when headers or CONFIG options are changed. In this case, fixdep should not generate .*.cmd file at all so that 'arg-check' will surely trigger the rebuild of the object. [2] A partially constructed .*.cmd file may not be a syntactically correct makefile. The next time Make runs, it would include it, then fail to parse it. Once this happens, 'make clean' is be the only way to fix it. In fact, [1] is no longer a problem since commit 9c2af1c7377a ("kbuild: add .DELETE_ON_ERROR special target"). Make deletes a target file on any failure in its recipe. Because fixdep is a part of the recipe of *.o target, if it fails, the *.o is deleted anyway. However, I am a bit worried about the slight possibility of [2]. So, here is a solution. Let fixdep directly write to a .*.cmd file, but allow makefiles to include it only when its corresponding target exists. This effectively reverts commit 2982c953570b ("kbuild: remove redundant $(wildcard ...) for cmd_files calculation"), and commit 00d78ab2ba75 ("kbuild: remove dead code in cmd_files calculation in top Makefile") because now we must check the presence of targets. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-22Linux 4.20.4v4.20.4Greg Kroah-Hartman
2019-01-22kbuild: mark prepare0 as PHONY to fix external module buildMasahiro Yamada
commit e00d8880481497474792d28c14479a9fb6752046 upstream. Commit c3ff2a5193fa ("powerpc/32: add stack protector support") caused kernel panic on PowerPC when an external module is used with CONFIG_STACKPROTECTOR because the 'prepare' target was not executed for the external module build. Commit e07db28eea38 ("kbuild: fix single target build for external module") turned it into a build error because the 'prepare' target is now executed but the 'prepare0' target is missing for the external module build. External module on arm/arm64 with CONFIG_STACKPROTECTOR_PER_TASK is also broken in the same way. Move 'PHONY += prepare0' to the common place. GNU Make is fine with missing rule for phony targets. I also removed the comment which is wrong irrespective of this commit. I minimize the change so it can be easily backported to 4.20.x To fix v4.20, please backport e07db28eea38 ("kbuild: fix single target build for external module"), and then this commit. Link: https://bugzilla.kernel.org/show_bug.cgi?id=201891 Fixes: e07db28eea38 ("kbuild: fix single target build for external module") Fixes: c3ff2a5193fa ("powerpc/32: add stack protector support") Fixes: 189af4657186 ("ARM: smp: add support for per-task stack canaries") Fixes: 0a1213fa7432 ("arm64: enable per-task stack canaries") Cc: linux-stable <stable@vger.kernel.org> # v4.20 Reported-by: Samuel Holland <samuel@sholland.org> Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-22kbuild: fix single target build for external moduleMasahiro Yamada
commit e07db28eea38ed4e332b3a89f3995c86b713cb5b upstream. Building a single target in an external module fails due to missing .tmp_versions directory. For example, $ make -C /lib/modules/$(uname -r)/build M=$PWD foo.o will fail in the following way: CC [M] /home/masahiro/foo/foo.o /bin/sh: 1: cannot create /home/masahiro/foo/.tmp_versions/foo.mod: Directory nonexistent This is because $(cmd_crmodverdir) is executed only before building /, %/, %.ko single targets of external modules. Create .tmp_versions in the 'prepare' target. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16Linux 4.20.3v4.20.3Greg Kroah-Hartman
2019-01-13Linux 4.20.2v4.20.2Greg Kroah-Hartman
2019-01-09Linux 4.20.1v4.20.1Greg Kroah-Hartman
2018-12-23Linux 4.20v4.20Linus Torvalds
2018-12-21Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "The biggest part is a series of reverts for the macro based GCC inlining workarounds. It caused regressions in distro build and other kernel tooling environments, and the GCC project was very receptive to fixing the underlying inliner weaknesses - so as time ran out we decided to do a reasonably straightforward revert of the patches. The plan is to rely on the 'asm inline' GCC 9 feature, which might be backported to GCC 8 and could thus become reasonably widely available on modern distros. Other than those reverts, there's misc fixes from all around the place. I wish our final x86 pull request for v4.20 was smaller..." * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Revert "kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs" Revert "x86/objtool: Use asm macros to work around GCC inlining bugs" Revert "x86/refcount: Work around GCC inlining bug" Revert "x86/alternatives: Macrofy lock prefixes to work around GCC inlining bugs" Revert "x86/bug: Macrofy the BUG table section handling, to work around GCC inlining bugs" Revert "x86/paravirt: Work around GCC inlining bugs when compiling paravirt ops" Revert "x86/extable: Macrofy inline assembly code to work around GCC inlining bugs" Revert "x86/cpufeature: Macrofy inline assembly code to work around GCC inlining bugs" Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs" x86/mtrr: Don't copy uninitialized gentry fields back to userspace x86/fsgsbase/64: Fix the base write helper functions x86/mm/cpa: Fix cpa_flush_array() TLB invalidation x86/vdso: Pass --eh-frame-hdr to the linker x86/mm: Fix decoy address handling vs 32-bit builds x86/intel_rdt: Ensure a CPU remains online for the region's pseudo-locking sequence x86/dump_pagetables: Fix LDT remap address marker x86/mm: Fix guard hole handling
2018-12-20Merge tag 'kbuild-fixes-v4.20-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fix from Masahiro Yamada: "Fix false positive warning/error about missing library for objtool" * tag 'kbuild-fixes-v4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: fix false positive warning/error about missing libelf
2018-12-20kbuild: fix false positive warning/error about missing libelfMasahiro Yamada
For the same reason as commit 25896d073d8a ("x86/build: Fix compiler support check for CONFIG_RETPOLINE"), you cannot put this $(error ...) into the parse stage of the top Makefile. Perhaps I'd propose a more sophisticated solution later, but this is the best I can do for now. Link: https://lkml.org/lkml/2017/12/25/211 Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com> Reported-by: Bernd Edlinger <bernd.edlinger@hotmail.de> Reported-by: Qian Cai <cai@lca.pw> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Qian Cai <cai@lca.pw>
2018-12-19Revert "kbuild/Makefile: Prepare for using macros in inline assembly code to ↵Ingo Molnar
work around asm() related GCC inlining bugs" This reverts commit 77b0bf55bc675233d22cd5df97605d516d64525e. See this commit for details about the revert: e769742d3584 ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"") Conflicts: arch/x86/Makefile Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Borislav Petkov <bp@alien8.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Juergen Gross <jgross@suse.com> Cc: Richard Biener <rguenther@suse.de> Cc: Kees Cook <keescook@chromium.org> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Nadav Amit <namit@vmware.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-16Linux 4.20-rc7v4.20-rc7Linus Torvalds
2018-12-09Linux 4.20-rc6v4.20-rc6Linus Torvalds
2018-12-02Linux 4.20-rc5v4.20-rc5Linus Torvalds
2018-11-25Linux 4.20-rc4v4.20-rc4Linus Torvalds
2018-11-18Linux 4.20-rc3v4.20-rc3Linus Torvalds
2018-11-11Linux 4.20-rc2v4.20-rc2Linus Torvalds
2018-11-04Linux 4.20-rc1v4.20-rc1Linus Torvalds
2018-11-02kbuild: remove cc-name variableMasahiro Yamada
There is one more user of $(cc-name) in the top Makefile. It is supposed to detect Clang before invoking Kconfig, so it should still be there in the $(shell ...) form. All the other users of $(cc-name) have been replaced with $(CONFIG_CC_IS_CLANG). Hence, scripts/Kbuild.include does not need to define cc-name any more. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-11-02kbuild: replace cc-name test with CONFIG_CC_IS_CLANGMasahiro Yamada
Evaluating cc-name invokes the compiler every time even when you are not compiling anything, like 'make help'. This is not efficient. The compiler type has been already detected in the Kconfig stage. Use CONFIG_CC_IS_CLANG, instead. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Paul Burton <paul.burton@mips.com> (MIPS) Acked-by: Joel Stanley <joel@jms.id.au>
2018-10-28Merge tag 'vla-v4.20-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull VLA removal from Kees Cook: "Globally warn on VLA use. This turns on "-Wvla" globally now that the last few trees with their VLA removals have landed (crypto, block, net, and powerpc). Arnd mentioned that there may be a couple more VLAs hiding in hard-to-find randconfigs, but nothing big has shaken out in the last month or so in linux-next. We should be basically VLA-free now! Wheee. :) Summary: - Remove unused fallback for BUILD_BUG_ON (which technically contains a VLA) - Lift -Wvla to the top-level Makefile" * tag 'vla-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: Makefile: Globally enable VLA warning compiler.h: give up __compiletime_assert_fallback()
2018-10-28Merge tag 'kbuild-v4.20' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - optimize kallsyms slightly - remove check for old CFLAGS usage - add some compiler flags unconditionally instead of evaluating $(call cc-option,...) - fix variable shadowing in host tools - refactor scripts/mkmakefile - refactor various makefiles * tag 'kbuild-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: modpost: Create macro to avoid variable shadowing ASN.1: Remove unnecessary shadowed local variable kbuild: use 'else ifeq' for checksrc to improve readability kbuild: remove unneeded link_multi_deps kbuild: add -Wno-unused-but-set-variable flag unconditionally kbuild: add -Wdeclaration-after-statement flag unconditionally kbuild: add -Wno-pointer-sign flag unconditionally modpost: remove leftover symbol prefix handling for module device table kbuild: simplify command line creation in scripts/mkmakefile kbuild: do not pass $(objtree) to scripts/mkmakefile kbuild: remove user ID check in scripts/mkmakefile kbuild: remove VERSION and PATCHLEVEL from $(objtree)/Makefile kbuild: add --include-dir flag only for out-of-tree build kbuild: remove dead code in cmd_files calculation in top Makefile kbuild: hide most of targets when running config or mixed targets kbuild: remove old check for CFLAGS use kbuild: prefix Makefile.dtbinst path with $(srctree) unconditionally kallsyms: remove left-over Blackfin code kallsyms: reduce size a little on 64-bit
2018-10-26Merge tag 'devicetree-for-4.20' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux Pull Devicetree updates from Rob Herring: "A bit bigger than normal as I've been busy this cycle. There's a few things with dependencies and a few things subsystem maintainers didn't pick up, so I'm taking them thru my tree. The fixes from Johan didn't get into linux-next, but they've been waiting for some time now and they are what's left of what subsystem maintainers didn't pick up. Summary: - Sync dtc with upstream version v1.4.7-14-gc86da84d30e4 - Work to get rid of direct accesses to struct device_node name and type pointers in preparation for removing them. New helpers for parsing DT cpu nodes and conversions to use the helpers. printk conversions to %pOFn for printing DT node names. Most went thru subystem trees, so this is the remainder. - Fixes to DT child node lookups to actually be restricted to child nodes instead of treewide. - Refactoring of dtb targets out of arch code. This makes the support more uniform and enables building all dtbs on c6x, microblaze, and powerpc. - Various DT binding updates for Renesas r8a7744 SoC - Vendor prefixes for Facebook, OLPC - Restructuring of some ARM binding docs moving some peripheral bindings out of board/SoC binding files - New "secure-chosen" binding for secure world settings on ARM - Dual licensing of 2 DT IRQ binding headers" * tag 'devicetree-for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (78 commits) ARM: dt: relicense two DT binding IRQ headers power: supply: twl4030-charger: fix OF sibling-node lookup NFC: nfcmrvl_uart: fix OF child-node lookup net: stmmac: dwmac-sun8i: fix OF child-node lookup net: bcmgenet: fix OF child-node lookup drm/msm: fix OF child-node lookup drm/mediatek: fix OF sibling-node lookup of: Add missing exports of node name compare functions dt-bindings: Add OLPC vendor prefix dt-bindings: misc: bk4: Add device tree binding for Liebherr's BK4 SPI bus dt-bindings: thermal: samsung: Add SPDX license identifier dt-bindings: clock: samsung: Add SPDX license identifiers dt-bindings: timer: ostm: Add R7S9210 support dt-bindings: phy: rcar-gen2: Add r8a7744 support dt-bindings: can: rcar_can: Add r8a7744 support dt-bindings: timer: renesas, cmt: Document r8a7744 CMT support dt-bindings: watchdog: renesas-wdt: Document r8a7744 support dt-bindings: thermal: rcar: Add device tree support for r8a7744 Documentation: dt: Add binding for /secure-chosen/stdout-path dt-bindings: arm: zte: Move sysctrl bindings to their own doc ...
2018-10-23Merge branch 'locking-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking and misc x86 updates from Ingo Molnar: "Lots of changes in this cycle - in part because locking/core attracted a number of related x86 low level work which was easier to handle in a single tree: - Linux Kernel Memory Consistency Model updates (Alan Stern, Paul E. McKenney, Andrea Parri) - lockdep scalability improvements and micro-optimizations (Waiman Long) - rwsem improvements (Waiman Long) - spinlock micro-optimization (Matthew Wilcox) - qspinlocks: Provide a liveness guarantee (more fairness) on x86. (Peter Zijlstra) - Add support for relative references in jump tables on arm64, x86 and s390 to optimize jump labels (Ard Biesheuvel, Heiko Carstens) - Be a lot less permissive on weird (kernel address) uaccess faults on x86: BUG() when uaccess helpers fault on kernel addresses (Jann Horn) - macrofy x86 asm statements to un-confuse the GCC inliner. (Nadav Amit) - ... and a handful of other smaller changes as well" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits) locking/lockdep: Make global debug_locks* variables read-mostly locking/lockdep: Fix debug_locks off performance problem locking/pvqspinlock: Extend node size when pvqspinlock is configured locking/qspinlock_stat: Count instances of nested lock slowpaths locking/qspinlock, x86: Provide liveness guarantee x86/asm: 'Simplify' GEN_*_RMWcc() macros locking/qspinlock: Rework some comments locking/qspinlock: Re-order code locking/lockdep: Remove duplicated 'lock_class_ops' percpu array x86/defconfig: Enable CONFIG_USB_XHCI_HCD=y futex: Replace spin_is_locked() with lockdep locking/lockdep: Make class->ops a percpu counter and move it under CONFIG_DEBUG_LOCKDEP=y x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs x86/cpufeature: Macrofy inline assembly code to work around GCC inlining bugs x86/extable: Macrofy inline assembly code to work around GCC inlining bugs x86/paravirt: Work around GCC inlining bugs when compiling paravirt ops x86/bug: Macrofy the BUG table section handling, to work around GCC inlining bugs x86/alternatives: Macrofy lock prefixes to work around GCC inlining bugs x86/refcount: Work around GCC inlining bug x86/objtool: Use asm macros to work around GCC inlining bugs ...
2018-10-22Linux 4.19v4.19Greg Kroah-Hartman
2018-10-19kbuild: add -Wno-unused-but-set-variable flag unconditionallyMasahiro Yamada
We have raised the compiler requirement from time to time. With commit cafa0010cd51 ("Raise the minimum required gcc version to 4.6"), the minimum for GCC is 4.6 now. This flag was added by GCC 4.6, and it is recognized by ICC as well. It is true that Clang does not support this flag but this commit is just touching the else part of the "ifeq ($(cc-name),clang)" check. Hence, Clang build is not affected. Let's rip off the cc-disable-warning switch, and see if somebody complains about it. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2018-10-19kbuild: add -Wdeclaration-after-statement flag unconditionallyMasahiro Yamada
We have raised the compiler requirement from time to time. With commit cafa0010cd51 ("Raise the minimum required gcc version to 4.6"), the minimum for GCC is 4.6 now. This flag has been here since the pre-git era. It is documented in the GCC 4.6 manual, and it is recognized by Clang and ICC as well. Let's rip off the cc-option switch, and see if somebody complains about it. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com>
2018-10-19kbuild: add -Wno-pointer-sign flag unconditionallyMasahiro Yamada
We have raised the compiler requirement from time to time. With commit cafa0010cd51 ("Raise the minimum required gcc version to 4.6"), the minimum for GCC is 4.6 now. The -Wno-pointer-sign has been here since the pre-git era. It is documented in the GCC 4.6 manual, and it is recognized by Clang and ICC as well. Let's rip off the cc-disable-warning switch, and see if somebody complains about it. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com>
2018-10-15Linux 4.19-rc8v4.19-rc8Greg Kroah-Hartman
2018-10-11Merge tag 'kbuild-fixes-v4.19-2' of ↵Greg Kroah-Hartman
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Masahiro writes: "Kbuild fixes for v4.19 (2nd) - Fix warnings from recordmcount.pl when building with Clang - Allow Clang to use GNU toolchains correctly - Disable CONFIG_SAMPLES for UML to avoid build error" * tag 'kbuild-fixes-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: samples: disable CONFIG_SAMPLES for UML kbuild: allow to use GCC toolchain not in Clang search path ftrace: Build with CPPFLAGS to get -Qunused-arguments
2018-10-11Makefile: Globally enable VLA warningKees Cook
Now that Variable Length Arrays (VLAs) have been entirely removed[1] from the kernel, enable the VLA warning globally. The only exceptions to this are the KASan an UBSan tests which are explicitly checking that VLAs trigger their respective tests. [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Airlie <airlied@linux.ie> Cc: linux-kbuild@vger.kernel.org Cc: intel-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org Signed-off-by: Kees Cook <keescook@chromium.org>
2018-10-07Linux 4.19-rc7v4.19-rc7Greg Kroah-Hartman
2018-10-04kbuild: do not pass $(objtree) to scripts/mkmakefileMasahiro Yamada
Since $(objtree) is always '.', it is not useful to pass it to scripts/mkmakefile. I assume nobody wants to run this script directly. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-10-04kbuild: remove VERSION and PATCHLEVEL from $(objtree)/MakefileMasahiro Yamada
Neither VERSION nor PATCHLEVEL is used in any useful way. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-10-04kbuild: add --include-dir flag only for out-of-tree buildMasahiro Yamada
The --include-dir flag is used to include check-in Makefiles from $(objtree) without $(srctree)/ prefix. Obviously, this is unneeded for in-tree build. Add the flag just before changing the working directory. This becomes effective after invoking sub-make. Add a little bit comments about it. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-10-04kbuild/Makefile: Prepare for using macros in inline assembly code to work ↵Nadav Amit
around asm() related GCC inlining bugs Using macros in inline assembly allows us to work around bugs in GCC's inlining decisions. Compile macros.S and use it to assemble all C files. Currently only x86 will use it. Background: The inlining pass of GCC doesn't include an assembler, so it's not aware of basic properties of the generated code, such as its size in bytes, or that there are such things as discontiuous blocks of code and data due to the newfangled linker feature called 'sections' ... Instead GCC uses a lazy and fragile heuristic: it does a linear count of certain syntactic and whitespace elements in inlined assembly block source code, such as a count of new-lines and semicolons (!), as a poor substitute for "code size and complexity". Unsurprisingly this heuristic falls over and breaks its neck whith certain common types of kernel code that use inline assembly, such as the frequent practice of putting useful information into alternative sections. As a result of this fresh, 20+ years old GCC bug, GCC's inlining decisions are effectively disabled for inlined functions that make use of such asm() blocks, because GCC thinks those sections of code are "large" - when in reality they are often result in just a very low number of machine instructions. This absolute lack of inlining provess when GCC comes across such asm() blocks both increases generated kernel code size and causes performance overhead, which is particularly noticeable on paravirt kernels, which make frequent use of these inlining facilities in attempt to stay out of the way when running on baremetal hardware. Instead of fixing the compiler we use a workaround: we set an assembly macro and call it from the inlined assembly block. As a result GCC considers the inline assembly block as a single instruction. (Which it often isn't but I digress.) This uglifies and bloats the source code - for example just the refcount related changes have this impact: Makefile | 9 +++++++-- arch/x86/Makefile | 7 +++++++ arch/x86/kernel/macros.S | 7 +++++++ scripts/Kbuild.include | 4 +++- scripts/mod/Makefile | 2 ++ 5 files changed, 26 insertions(+), 3 deletions(-) Yay readability and maintainability, it's not like assembly code is hard to read and maintain ... We also hope that GCC will eventually get fixed, but we are not holding our breath for that. Yet we are optimistic, it might still happen, any decade now. [ mingo: Wrote new changelog describing the background. ] Tested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Nadav Amit <namit@vmware.com> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <michal.lkml@markovi.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kbuild@vger.kernel.org Link: http://lkml.kernel.org/r/20181003213100.189959-3-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-02kbuild: consolidate Devicetree dtb build rulesRob Herring
There is nothing arch specific about building dtb files other than their location under /arch/*/boot/dts/. Keeping each arch aligned is a pain. The dependencies and supported targets are all slightly different. Also, a cross-compiler for each arch is needed, but really the host compiler preprocessor is perfectly fine for building dtbs. Move the build rules to a common location and remove the arch specific ones. This is done in a single step to avoid warnings about overriding rules. The build dependencies had been a mixture of 'scripts' and/or 'prepare'. These pull in several dependencies some of which need a target compiler (specifically devicetable-offsets.h) and aren't needed to build dtbs. All that is really needed is dtc, so adjust the dependencies to only be dtc. This change enables support 'dtbs_install' on some arches which were missing the target. Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Paul Burton <paul.burton@mips.com> Acked-by: Ley Foon Tan <ley.foon.tan@intel.com> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michal Marek <michal.lkml@markovi.net> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: linux-kbuild@vger.kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Cc: uclinux-h8-devel@lists.sourceforge.jp Cc: linux-mips@linux-mips.org Cc: nios2-dev@lists.rocketboards.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-xtensa@linux-xtensa.org Signed-off-by: Rob Herring <robh@kernel.org>
2018-09-30Linux 4.19-rc6v4.19-rc6Greg Kroah-Hartman
2018-09-23Linux 4.19-rc5v4.19-rc5Greg Kroah-Hartman
2018-09-19kbuild: allow to use GCC toolchain not in Clang search pathStefan Agner
When using a GCC cross toolchain which is not in a compiled in Clang search path, Clang reverts to the system assembler and linker. This leads to assembler or linker errors, depending on which tool is first used for a given architecture. It seems that Clang is not searching $PATH for a matching assembler or linker. Make sure that Clang picks up the correct assembler or linker by passing the cross compilers bin directory as search path. This allows to use Clang provided by distributions with GCC toolchains not in /usr/bin. Link: https://github.com/ClangBuiltLinux/linux/issues/78 Signed-off-by: Stefan Agner <stefan@agner.ch> Reviewed-and-tested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-09-17Merge tag 'linux-kselftest-4.19-rc5' of ↵Greg Kroah-Hartman
git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest Pulled kselftest fixes from Shuah: "This Kselftest fixes update for 4.9-rc5 consists of: -- fixes to build failures -- fixes to add missing config files to increase test coverage -- fixes to cgroup test and a new cgroup test for memory.oom.group"
2018-09-16Linux 4.19-rc4v4.19-rc4Linus Torvalds
2018-09-14kbuild: remove dead code in cmd_files calculation in top MakefileMasahiro Yamada
Nobody sets 'targets' in the top-level Makefile or arch/*/Makefile, hence $(targets) is empty. $(wildcard .*.cmd) will do for including the .vmlinux.cmd file. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-09-14kbuild: hide most of targets when running config or mixed targetsMasahiro Yamada
When mixed/config targets are being processed, the top Makefile does not need to parse the rest of targets. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-09-12tracing/Makefile: Fix handling redefinition of CC_FLAGS_FTRACEPaulo Zanoni
As a Kernel developer, I make heavy use of "make targz-pkg" in order to locally compile and remotely install my development Kernels. The nice feature I rely on is that after a normal "make", "make targz-pkg" only generates the tarball without having to recompile everything. That was true until commit f28bc3c32c05 ("tracing: Handle CC_FLAGS_FTRACE more accurately"). After it, running "make targz-pkg" after "make" will recompile the whole Kernel tree, making my development workflow much slower. The Kernel is choosing to recompile everything because it claims the command line has changed. A diff of the .cmd files show a repeated -mfentry in one of the files. That is because "make targz-pkg" calls "make modules_install" and the environment is already populated with the exported variables, CC_FLAGS_FTRACE being one of them. Then, -mfentry gets duplicated because it is not protected behind an ifndef block, like -pg. To complicate the problem a little bit more, architectures can define their own version CC_FLAGS_FTRACE, so our code not only has to consider recursive Makefiles, but also architecture overrides. So in this patch we move CC_FLAGS_FTRACE up and unconditionally define it to -pg. Then we let the architecture Makefiles possibly override it, and finally append the extra options later. This ensures the variable is always fully redefined at each invocation so recursive Makefiles don't keep appending, and hopefully it maintains the intended behavior on how architectures can override the defaults.. Thanks Steven Rostedt and Vasily Gorbik for the help on this regression. Cc: Michal Marek <michal.lkml@markovi.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: linux-kbuild@vger.kernel.org Fixes: commit f28bc3c32c05 ("tracing: Handle CC_FLAGS_FTRACE more accurately") Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-09-09Linux 4.19-rc3v4.19-rc3Linus Torvalds