kernel.git/arch/x86/Makefile, branch linux-4.13.y

Merge tag 'kbuild-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2017-07-07T21:09:24Z

Pull Kbuild updates from Masahiro Yamada: - Clean up Makefiles and scripts - Improve clang support - Remove unneeded genhdr-y syntax - Remove unneeded cc-option-align macro - Introduce __cc-option macro and use it to fix x86 boot code compiler flags * tag 'kbuild-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: improve comments on KBUILD_SRC x86/build: Specify stack alignment for clang x86/build: Use __cc-option for boot code compiler options kbuild: Add __cc-option macro kbuild: remove cc-option-align kbuild: replace genhdr-y with generated-y kbuild: clang: Disable 'address-of-packed-member' warning kbuild: remove duplicated arch/*/include/generated/uapi include path kbuild: speed up checksyscalls.sh kbuild: simplify silent build (-s) detection

x86/build: Specify stack alignment for clang

2017-06-25T03:56:52Z

For gcc stack alignment is configured with -mpreferred-stack-boundary=N, clang has the option -mstack-alignment=N for that purpose. Use the same alignment as with gcc. If the alignment is not specified clang assumes an alignment of 16 bytes, as required by the standard ABI. However as mentioned in d9b0cde91c60 ("x86-64, gcc: Use -mpreferred-stack-boundary=3 if supported") the standard kernel entry on x86-64 leaves the stack on an 8-byte boundary, as a consequence clang will keep the stack misaligned. Signed-off-by: Matthias Kaehlcke Acked-by: Ingo Molnar Signed-off-by: Masahiro Yamada

x86/build: Use __cc-option for boot code compiler options

2017-06-25T03:48:39Z

cc-option is used to enable compiler options for the boot code if they are available. The macro uses KBUILD_CFLAGS and KBUILD_CPPFLAGS for the check, however these flags aren't used to build the boot code, in consequence cc-option can yield wrong results. For example -mpreferred-stack-boundary=2 is never set with a 64-bit compiler, since the setting is only valid for 16 and 32-bit binaries. This is also the case for 32-bit kernel builds, because the option -m32 is added to KBUILD_CFLAGS after the assignment of REALMODE_CFLAGS. Use __cc-option instead of cc-option for the boot mode options. The macro receives the compiler options as parameter instead of using KBUILD_C*FLAGS, for the boot code we pass REALMODE_CFLAGS. Also use separate statements for the __cc-option checks instead of performing them in the initial assignment of REALMODE_CFLAGS since the variable is an input of the macro. Signed-off-by: Matthias Kaehlcke Acked-by: Ingo Molnar Signed-off-by: Masahiro Yamada

x86/mce: Merge mce_amd_inj into mce-inject

2017-06-14T05:32:07Z

Reuse mce_amd_inj's debugfs interface so that mce-inject can benefit from it too. The old functionality is still preserved under CONFIG_X86_MCELOG_LEGACY. Tested-by: Yazen Ghannam Signed-off-by: Borislav Petkov Acked-by: Yazen Ghannam Cc: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tony Luck Link: http://lkml.kernel.org/r/20170613162835.30750-4-bp@alien8.de Signed-off-by: Ingo Molnar

x86/build: Permit building with old make versions

2017-05-24T07:05:17Z

At least Make 3.82 dislikes the tab in front of the $(warning) function: arch/x86/Makefile:162: *** recipe commences before first target. Stop. Let's be gentle. Signed-off-by: Jan Kiszka Acked-by: Thomas Gleixner Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1944fcd8-e3df-d1f7-c0e4-60aeb1917a24@siemens.com Signed-off-by: Ingo Molnar

x86/build: Don't add -maccumulate-outgoing-args w/o compiler support

2017-05-09T06:16:45Z

Clang does not support this machine dependent option. Older versions of GCC (pre 3.0) may not support this option, added in 2000, but it's unlikely they can still compile a working kernel. Signed-off-by: Nick Desaulniers Reviewed-by: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20170509032946.20444-1-nick.desaulniers@gmail.com Signed-off-by: Ingo Molnar

Merge branch 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-05-02T05:33:43Z

Pull x86 build update from Ingo Molnar: "A single CLang support related fix" * 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kbuild: Use cc-option to enable -falign-{jumps/loops}

x86/build: convert function graph '-Os' error to warning

2017-04-19T07:57:23Z

For pre-4.6.0 versions of GCC, which don't have '-mfentry', the '-maccumulate-outgoing-args' option is required for function graph tracing in order to avoid GCC bug 42109. However, GCC ignores '-maccumulate-outgoing-args' when '-Os' is also set. Currently we force a build error to prevent that scenario, but that breaks randconfigs. So change the error to a warning which also disables CONFIG_CC_OPTIMIZE_FOR_SIZE. Reported-by: Andi Kleen Signed-off-by: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Cc: kbuild test robot Cc: kbuild-all@01.org Link: http://lkml.kernel.org/r/20170418214429.o7fbwbmf4nqosezy@treble Signed-off-by: Ingo Molnar

x86/kbuild: Use cc-option to enable -falign-{jumps/loops}

2017-04-17T10:39:37Z

clang currently does not support these optimizations, only enable them when they are available. Signed-off-by: Matthias Kaehlcke Cc: Greg Hackmann Cc: Linus Torvalds Cc: Masahiro Yamada Cc: Michael Davidson Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: grundler@chromium.org Link: http://lkml.kernel.org/r/20170413172609.118122-1-mka@chromium.org Signed-off-by: Ingo Molnar

x86/build: Mostly disable '-maccumulate-outgoing-args'

2017-03-30T09:53:04Z

The GCC '-maccumulate-outgoing-args' flag is enabled for most configs, mostly because of issues which are no longer relevant. For most configs, and with most recent versions of GCC, it's no longer needed. Clarify which cases need it, and only enable it for those cases. Also produce a compile-time error for the ftrace graph + mcount + '-Os' case, which will otherwise cause runtime failures. The main benefit of '-maccumulate-outgoing-args' is that it prevents an ugly prologue for functions which have aligned stacks. But removing the option also has some benefits: more readable argument saves, smaller text size, and (presumably) slightly improved performance. Here are the object size savings for 32-bit and 64-bit defconfig kernels: text data bss dec hex filename 10006710 3543328 1773568 15323606 e9d1d6 vmlinux.x86-32.before 9706358 3547424 1773568 15027350 e54c96 vmlinux.x86-32.after text data bss dec hex filename 10652105 4537576 843776 16033457 f4a6b1 vmlinux.x86-64.before 10639629 4537576 843776 16020981 f475f5 vmlinux.x86-64.after That comes out to a 3% text size improvement on x86-32 and a 0.1% text size improvement on x86-64. Signed-off-by: Josh Poimboeuf Cc: Andrew Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Linus Torvalds Cc: Pavel Machek Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20170316193133.zrj6gug53766m6nn@treble Signed-off-by: Ingo Molnar