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* x86/build: Permit building with old make versionsJan Kiszka2017-05-241-1/+1
| | | | | | | | | | | | | | | | 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 <jan.kiszka@siemens.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1944fcd8-e3df-d1f7-c0e4-60aeb1917a24@siemens.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/build: Don't add -maccumulate-outgoing-args w/o compiler supportNick Desaulniers2017-05-091-1/+2
| | | | | | | | | | | | | | | 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 <nick.desaulniers@gmail.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170509032946.20444-1-nick.desaulniers@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'x86-build-for-linus' of ↵Linus Torvalds2017-05-011-2/+2
|\ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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/kbuild: Use cc-option to enable -falign-{jumps/loops}Matthias Kaehlcke2017-04-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | clang currently does not support these optimizations, only enable them when they are available. Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Cc: Greg Hackmann <ghackmann@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michael Davidson <md@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: grundler@chromium.org Link: http://lkml.kernel.org/r/20170413172609.118122-1-mka@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | x86/build: convert function graph '-Os' error to warningJosh Poimboeuf2017-04-191-0/+8
|/ | | | | | | | | | | | | | | | | | | | | | | | 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 <andi@firstfloor.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kbuild test robot <fengguang.wu@intel.com> Cc: kbuild-all@01.org Link: http://lkml.kernel.org/r/20170418214429.o7fbwbmf4nqosezy@treble Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/build: Mostly disable '-maccumulate-outgoing-args'Josh Poimboeuf2017-03-301-4/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <jpoimboe@redhat.com> Cc: Andrew Lutomirski <luto@kernel.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: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170316193133.zrj6gug53766m6nn@treble Signed-off-by: Ingo Molnar <mingo@kernel.org>
* lib/raid6: Add AVX512 optimized gen_syndrome functionsGayatri Kammela2016-09-211-2/+3
| | | | | | | | | | | | | | | | | | | Optimize RAID6 gen_syndrom functions to take advantage of the 512-bit ZMM integer instructions introduced in AVX512. AVX512 optimized gen_syndrom functions, which is simply based on avx2.c written by Yuanhan Liu and sse2.c written by hpa. The patch was tested and benchmarked before submission on a hardware that has AVX512 flags to support such instructions Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jim Kukunas <james.t.kukunas@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Megha Dey <megha.dey@linux.intel.com> Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Shaohua Li <shli@fb.com>
* kbuild: abort build on bad stack protector flagKees Cook2016-07-261-8/+0
| | | | | | | | | | | | | | | | | | | | | Before, the stack protector flag was sanity checked before .config had been reprocessed. This meant the build couldn't be aborted early, and only a warning could be emitted followed later by the compiler blowing up with an unknown flag. This has caused a lot of confusion over time, so this splits the flag selection from sanity checking and performs the sanity checking after the make has been restarted from a reprocessed .config, so builds can be aborted as early as possible now. Additionally moves the x86-specific sanity check to the same location, since it suffered from the same warn-then-wait-for-compiler-failure problem. Link: http://lkml.kernel.org/r/20160712223043.GA11664@www.outflux.net Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Michal Marek <mmarek@suse.com> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86/init: Rename EBDA code fileLuis R. Rodriguez2016-04-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This makes it clearer what this is. Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.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: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: andrew.cooper3@citrix.com Cc: andriy.shevchenko@linux.intel.com Cc: bigeasy@linutronix.de Cc: boris.ostrovsky@oracle.com Cc: david.vrabel@citrix.com Cc: ffainelli@freebox.fr Cc: george.dunlap@citrix.com Cc: glin@suse.com Cc: jgross@suse.com Cc: jlee@suse.com Cc: josh@joshtriplett.org Cc: julien.grall@linaro.org Cc: konrad.wilk@oracle.com Cc: kozerkov@parallels.com Cc: lenb@kernel.org Cc: lguest@lists.ozlabs.org Cc: linux-acpi@vger.kernel.org Cc: lv.zheng@intel.com Cc: matt@codeblueprint.co.uk Cc: mbizon@freebox.fr Cc: rjw@rjwysocki.net Cc: robert.moore@intel.com Cc: rusty@rustcorp.com.au Cc: tiwai@suse.de Cc: toshi.kani@hp.com Cc: xen-devel@lists.xensource.com Link: http://lkml.kernel.org/r/1460592286-300-14-git-send-email-mcgrof@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/rtc: Replace paravirt rtc check with platform legacy quirkLuis R. Rodriguez2016-04-221-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have 4 types of x86 platforms that disable RTC: * Intel MID * Lguest - uses paravirt * Xen dom-U - uses paravirt * x86 on legacy systems annotated with an ACPI legacy flag We can consolidate all of these into a platform specific legacy quirk set early in boot through i386_start_kernel() and through x86_64_start_reservations(). This deals with the RTC quirks which we can rely on through the hardware subarch, the ACPI check can be dealt with separately. For Xen things are bit more complex given that the @X86_SUBARCH_XEN x86_hardware_subarch is shared on for Xen which uses the PV path for both domU and dom0. Since the semantics for differentiating between the two are Xen specific we provide a platform helper to help override default legacy features -- x86_platform.set_legacy_features(). Use of this helper is highly discouraged, its only purpose should be to account for the lack of semantics available within your given x86_hardware_subarch. As per 0-day, this bumps the vmlinux size using i386-tinyconfig as follows: TOTAL TEXT init.text x86_early_init_platform_quirks() +70 +62 +62 +43 Only 8 bytes overhead total, as the main increase in size is all removed via __init. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Reviewed-by: Juergen Gross <jgross@suse.com> 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: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: andrew.cooper3@citrix.com Cc: andriy.shevchenko@linux.intel.com Cc: bigeasy@linutronix.de Cc: boris.ostrovsky@oracle.com Cc: david.vrabel@citrix.com Cc: ffainelli@freebox.fr Cc: george.dunlap@citrix.com Cc: glin@suse.com Cc: jlee@suse.com Cc: josh@joshtriplett.org Cc: julien.grall@linaro.org Cc: konrad.wilk@oracle.com Cc: kozerkov@parallels.com Cc: lenb@kernel.org Cc: lguest@lists.ozlabs.org Cc: linux-acpi@vger.kernel.org Cc: lv.zheng@intel.com Cc: matt@codeblueprint.co.uk Cc: mbizon@freebox.fr Cc: rjw@rjwysocki.net Cc: robert.moore@intel.com Cc: rusty@rustcorp.com.au Cc: tiwai@suse.de Cc: toshi.kani@hp.com Cc: xen-devel@lists.xensource.com Link: http://lkml.kernel.org/r/1460592286-300-5-git-send-email-mcgrof@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'linus' of ↵Linus Torvalds2015-11-041-2/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto update from Herbert Xu: "API: - Add support for cipher output IVs in testmgr - Add missing crypto_ahash_blocksize helper - Mark authenc and des ciphers as not allowed under FIPS. Algorithms: - Add CRC support to 842 compression - Add keywrap algorithm - A number of changes to the akcipher interface: + Separate functions for setting public/private keys. + Use SG lists. Drivers: - Add Intel SHA Extension optimised SHA1 and SHA256 - Use dma_map_sg instead of custom functions in crypto drivers - Add support for STM32 RNG - Add support for ST RNG - Add Device Tree support to exynos RNG driver - Add support for mxs-dcp crypto device on MX6SL - Add xts(aes) support to caam - Add ctr(aes) and xts(aes) support to qat - A large set of fixes from Russell King for the marvell/cesa driver" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (115 commits) crypto: asymmetric_keys - Fix unaligned access in x509_get_sig_params() crypto: akcipher - Don't #include crypto/public_key.h as the contents aren't used hwrng: exynos - Add Device Tree support hwrng: exynos - Fix missing configuration after suspend to RAM hwrng: exynos - Add timeout for waiting on init done dt-bindings: rng: Describe Exynos4 PRNG bindings crypto: marvell/cesa - use __le32 for hardware descriptors crypto: marvell/cesa - fix missing cpu_to_le32() in mv_cesa_dma_add_op() crypto: marvell/cesa - use memcpy_fromio()/memcpy_toio() crypto: marvell/cesa - use gfp_t for gfp flags crypto: marvell/cesa - use dma_addr_t for cur_dma crypto: marvell/cesa - use readl_relaxed()/writel_relaxed() crypto: caam - fix indentation of close braces crypto: caam - only export the state we really need to export crypto: caam - fix non-block aligned hash calculation crypto: caam - avoid needlessly saving and restoring caam_hash_ctx crypto: caam - print errno code when hash registration fails crypto: marvell/cesa - fix memory leak crypto: marvell/cesa - fix first-fragment handling in mv_cesa_ahash_dma_last_req() crypto: marvell/cesa - rearrange handling for sw padded hashes ...
| * crypto: x86/sha - Add build support for Intel SHA Extensions optimized SHA1 ↵tim2015-09-211-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | and SHA256 This patch provides the configuration and build support to include and build the optimized SHA1 and SHA256 update transforms for the kernel's crypto library. Originally-by: Chandramouli Narayanan <mouli_7982@yahoo.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* | x86/asm: Re-add parts of the manual CFI infrastructureAndy Lutomirski2015-10-091-2/+8
|/ | | | | | | | | | | | | | | | | | | | | | | | Commit: 131484c8da97 ("x86/debug: Remove perpetually broken, unmaintainable dwarf annotations") removed all the manual DWARF annotations outside the vDSO. It also removed the macros we used for the manual annotations. Re-add these macros so that we can clean up the vDSO annotations. Signed-off-by: Andy Lutomirski <luto@kernel.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: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/4c70bb98a8b773c8ccfaabf6745e569ff43e7f65.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds2015-09-011-3/+10
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm changes from Ingo Molnar: "The biggest changes in this cycle were: - Revamp, simplify (and in some cases fix) Time Stamp Counter (TSC) primitives. (Andy Lutomirski) - Add new, comprehensible entry and exit handlers written in C. (Andy Lutomirski) - vm86 mode cleanups and fixes. (Brian Gerst) - 32-bit compat code cleanups. (Brian Gerst) The amount of simplification in low level assembly code is already palpable: arch/x86/entry/entry_32.S | 130 +---- arch/x86/entry/entry_64.S | 197 ++----- but more simplifications are planned. There's also the usual laudry mix of low level changes - see the changelog for details" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (83 commits) x86/asm: Drop repeated macro of X86_EFLAGS_AC definition x86/asm/msr: Make wrmsrl() a function x86/asm/delay: Introduce an MWAITX-based delay with a configurable timer x86/asm: Add MONITORX/MWAITX instruction support x86/traps: Weaken context tracking entry assertions x86/asm/tsc: Add rdtscll() merge helper selftests/x86: Add syscall_nt selftest selftests/x86: Disable sigreturn_64 x86/vdso: Emit a GNU hash x86/entry: Remove do_notify_resume(), syscall_trace_leave(), and their TIF masks x86/entry/32: Migrate to C exit path x86/entry/32: Remove 32-bit syscall audit optimizations x86/vm86: Rename vm86->v86flags and v86mask x86/vm86: Rename vm86->vm86_info to user_vm86 x86/vm86: Clean up vm86.h includes x86/vm86: Move the vm86 IRQ definitions to vm86.h x86/vm86: Use the normal pt_regs area for vm86 x86/vm86: Eliminate 'struct kernel_vm86_struct' x86/vm86: Move fields from 'struct kernel_vm86_struct' to 'struct vm86' x86/vm86: Move vm86 fields out of 'thread_struct' ...
| * x86/build: Fix detection of GCC -mpreferred-stack-boundary supportAndy Lutomirski2015-07-221-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As per: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383 GCC only allows -mpreferred-stack-boundary=3 on x86_64 if -mno-sse is set. That means that cc-option will not detect -mpreferred-stack-boundary=3 support, because we test for it before setting -mno-sse. Fix it by reordering the Makefile bits. Compile-tested only. This should help avoid code generation issues such as the one that was worked around in: b96fecbfa8c8 ("x86/fpu: Fix boot crash in the early FPU code") I'm a bit concerned that we could still have problems on older GCC versions given that our asm code does not respect GCC's idea of the ABI-required stack alignment. Signed-off-by: Andy Lutomirski <luto@kernel.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: Jan Kara <jack@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/f5297c192969adfa0d28b84cf8a22d59573db26d.1436126872.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | x86/ras: Move AMD MCE injector to arch/x86/ras/Borislav Petkov2015-08-131-0/+2
|/ | | | | | | | | | | | | | This is an x86-specific module and would benefit from being closer to the arch code. Move it there. Update copyright while at it. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/1439396985-12812-14-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm/entry: Move the arch/x86/syscalls/ definitions to ↵Ingo Molnar2015-06-041-1/+1
| | | | | | | | | | | | | | | | | | arch/x86/entry/syscalls/ The build time generated syscall definitions are entry code related, move them into the arch/x86/entry/ directory. Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm/entry, x86/vdso: Move the vDSO code to arch/x86/entry/vdso/Ingo Molnar2015-06-031-1/+1
| | | | | | | | | | | | | Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/debug: Remove perpetually broken, unmaintainable dwarf annotationsIngo Molnar2015-06-021-8/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So the dwarf2 annotations in low level assembly code have become an increasing hindrance: unreadable, messy macros mixed into some of the most security sensitive code paths of the Linux kernel. These debug info annotations don't even buy the upstream kernel anything: dwarf driven stack unwinding has caused problems in the past so it's out of tree, and the upstream kernel only uses the much more robust framepointers based stack unwinding method. In addition to that there's a steady, slow bitrot going on with these annotations, requiring frequent fixups. There's no tooling and no functionality upstream that keeps it correct. So burn down the sick forest, allowing new, healthier growth: 27 files changed, 350 insertions(+), 1101 deletions(-) Someone who has the willingness and time to do this properly can attempt to reintroduce dwarf debuginfo in x86 assembly code plus dwarf unwinding from first principles, with the following conditions: - it should be maximally readable, and maximally low-key to 'ordinary' code reading and maintenance. - find a build time method to insert dwarf annotations automatically in the most common cases, for pop/push instructions that manipulate the stack pointer. This could be done for example via a preprocessing step that just looks for common patterns - plus special annotations for the few cases where we want to depart from the default. We have hundreds of CFI annotations, so automating most of that makes sense. - it should come with build tooling checks that ensure that CFI annotations are sensible. We've seen such efforts from the framepointer side, and there's no reason it couldn't be done on the dwarf side. 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: Frédéric Weisbecker <fweisbec@gmail.com Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jan Beulich <JBeulich@suse.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86: Pack loops tightly as wellIngo Molnar2015-05-171-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Packing loops tightly (-falign-loops=1) is beneficial to code size: text data bss dec filename 12566391 1617840 1089536 15273767 vmlinux.align.16-byte 12224951 1617840 1089536 14932327 vmlinux.align.1-byte 11976567 1617840 1089536 14683943 vmlinux.align.1-byte.funcs-1-byte 11903735 1617840 1089536 14611111 vmlinux.align.1-byte.funcs-1-byte.loops-1-byte Which reduces the size of the kernel by another 0.6%, so the the total combined size reduction of the alignment-packing patches is ~5.5%. The x86 decoder bandwidth and caching arguments laid out in: be6cb02779ca ("x86: Align jump targets to 1-byte boundaries") apply to loop alignment as well. Furtermore, modern CPU uarchs have a loop cache/buffer that is a L0 cache before even any uop cache, covering a few dozen most recently executed instructions. This loop cache generally does not have the 16-byte alignment restrictions of the uop cache. Now loop alignment can still be beneficial if: - a loop is cache-hot and its surroundings are not. - if the loop is so cache hot that the instruction flow becomes x86 decoder bandwidth limited But loop alignment is harmful if: - a loop is cache-cold - a loop's surroundings are cache-hot as well - two cache-hot loops are close to each other - if the loop fits into the loop cache - if the code flow is not decoder bandwidth limited and I'd argue that the latter five scenarios are much more common in the kernel, as our hottest loops are typically: - pointer chasing: this should fit into the loop cache in most cases and is typically data cache and address generation limited - generic memory ops (memset, memcpy, etc.): these generally fit into the loop cache as well, and are likewise data cache limited. So this patch packs loop addresses tightly as well. Acked-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jason Low <jason.low2@hp.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Link: http://lkml.kernel.org/r/20150410123017.GB19918@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86: Align jump targets to 1-byte boundariesIngo Molnar2015-05-151-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following NOP in a hot function caught my attention: > 5a: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) That's a dead NOP that bloats the function a bit, added for the default 16-byte alignment that GCC applies for jump targets. I realize that x86 CPU manufacturers recommend 16-byte jump target alignments (it's in the Intel optimization manual), to help their relatively narrow decoder prefetch alignment and uop cache constraints, but the cost of that is very significant: text data bss dec filename 12566391 1617840 1089536 15273767 vmlinux.align.16-byte 12224951 1617840 1089536 14932327 vmlinux.align.1-byte By using 1-byte jump target alignment (i.e. no alignment at all) we get an almost 3% reduction in kernel size (!) - and a probably similar reduction in I$ footprint. Now, the usual justification for jump target alignment is the following: - modern decoders tend to have 16-byte (effective) decoder prefetch windows. (AMD documents it higher but measurements suggest the effective prefetch window on curretn uarchs is still around 16 bytes) - on Intel there's also the uop-cache with cachelines that have 16-byte granularity and limited associativity. - older x86 uarchs had a penalty for decoder fetches that crossed 16-byte boundaries. These limits are mostly gone from recent uarchs. So if a forward jump target is aligned to cacheline boundary then prefetches will start from a new prefetch-cacheline and there's higher chance for decoding in fewer steps and packing tightly. But I think that argument is flawed for typical optimized kernel code flows: forward jumps often go to 'cold' (uncommon) pieces of code, and aligning cold code to cache lines does not bring a lot of advantages (they are uncommon), while it causes collateral damage: - their alignment 'spreads out' the cache footprint, it shifts followup hot code further out - plus it slows down even 'cold' code that immediately follows 'hot' code (like in the above case), which could have benefited from the partial cacheline that comes off the end of hot code. But even in the cache-hot case the 16 byte alignment brings disadvantages: - it spreads out the cache footprint, possibly making the code fall out of the L1 I$. - On Intel CPUs, recent microarchitectures have plenty of uop cache (typically doubling every 3 years) - while the size of the L1 cache grows much less aggressively. So workloads are rarely uop cache limited. The only situation where alignment might matter are tight loops that could fit into a single 16 byte chunk - but those are pretty rare in the kernel: if they exist they tend to be pointer chasing or generic memory ops, which both tend to be cache miss (or cache allocation) intensive and are not decoder bandwidth limited. So the balance of arguments strongly favors packing kernel instructions tightly versus maximizing for decoder bandwidth: this patch changes the jump target alignment from 16 bytes to 1 byte (tightly packed, unaligned). Acked-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jason Low <jason.low2@hp.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Link: http://lkml.kernel.org/r/20150410120846.GA17101@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'linus' into x86/asm, before applying dependent patchIngo Molnar2015-05-081-1/+1
|\ | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * kbuild: use relative path more to include MakefileMasahiro Yamada2015-04-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Prior to this commit, it was impossible to use relative path to include Makefiles from the top level Makefile because the option "--include-dir=$(srctree)" becomes effective when Make enters into sub Makefiles. To use relative path in any places, this commit moves the option above the "sub-make" target. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
* | x86/asm: Use -mskip-rax-setup if supportedH.J. Lu2015-05-061-0/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GCC 5 added a compiler option, -mskip-rax-setup, for x86-64. It skips setting up the RAX register when SSE is disabled and there are no variable arguments passed in vector registers. (According to the x86_64 ABI, %al is used as a hidden register containing the number of vector registers used). Since the kernel doesn't pass vector registers to functions with variable arguments, this option can be used to optimize the x86-64 kernel. This GCC feature was suggested by Rasmus Villemoes <linux@rasmusvillemoes.dk>. This is the corresponding kernel change using it. For kernel v3.17: text data bss dec filename 11455921 2204048 5853184 19513153 vmlinux #with -mskip-rax-setup 11480079 2204048 5853184 19537311 vmlinux For Kernel v4.0+ - custom config: text data bss dec filename 10231778 3479800 16617472 30329050 vmlinux-gcc5+-mskip-rax-setup 10268797 3547448 16621568 30437813 vmlinux Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> 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: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/raid6: correctly check for assembler capabilitiesJan Beulich2015-02-041-0/+1
| | | | | | | | | | Just like for AVX2 (which simply needs an #if -> #ifdef conversion), SSSE3 assembler support should be checked for before using it. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Jim Kukunas <james.t.kukunas@linux.intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NeilBrown <neilb@suse.de>
* Merge branch 'x86-build-for-linus' of ↵Linus Torvalds2014-10-131-6/+2
|\ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 build update from Ingo Molnar: "A single commit that simplifies the no-FPU-ops build options" * 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kbuild: Eliminate duplicate command line options
| * x86/kbuild: Eliminate duplicate command line optionsRasmus Villemoes2014-09-161-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The options -mno-mmx and -mno-sse are unconditionally added to KBUILD_CFLAGS in both branches of an ifeq and through a $(cc-option) further down. We can safely remove the first instances. In fact, since the -mno-mmx and -mno-sse options were introduced simultaneous with the other two options in the $(cc-option) [according to http://www.gnu.org/software/gcc/gcc-3.1/changes.html], and since the former were unconditionally used, one can deduce that only gcc versions knowing about all four are supported. So also eliminate the $(cc-option) wrap. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Peter Foley <pefoley2@pefoley.com> Link: http://lkml.kernel.org/r/1410365139-24440-1-git-send-email-linux@rasmusvillemoes.dk Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge tag 'tiny/for-3.18' of ↵Linus Torvalds2014-10-071-7/+0
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/josh/linux Pull "tinification" patches from Josh Triplett. Work on making smaller kernels. * tag 'tiny/for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/josh/linux: bloat-o-meter: Ignore syscall aliases SyS_ and compat_SyS_ mm: Support compiling out madvise and fadvise x86: Support compiling out human-friendly processor feature names x86: Drop support for /proc files when !CONFIG_PROC_FS x86, boot: Don't compile early_serial_console.c when !CONFIG_EARLY_PRINTK x86, boot: Don't compile aslr.c when !CONFIG_RANDOMIZE_BASE x86, boot: Use the usual -y -n mechanism for objects in vmlinux x86: Add "make tinyconfig" to configure the tiniest possible kernel x86, platform, kconfig: move kvmconfig functionality to a helper
| * Merge branches 'tiny/bloat-o-meter-no-SyS', 'tiny/more-procless', ↵Josh Triplett2014-09-221-7/+0
| |\ | | | | | | | | | 'tiny/no-advice', 'tiny/tinyconfig' and 'tiny/x86-boot-compressed-use-yn' into tiny/next
| | * x86, platform, kconfig: move kvmconfig functionality to a helperJosh Triplett2014-08-081-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new mergeconfig helper makes it easier to add other partial configurations similar to kvmconfig. Architecture-independent portions of those partial configurations should go in kernel/configs/${name}.config, and architecture-dependent portions should go in arch/${arch}/configs/${name}.config. Based on a patch by Luis R. Rodriguez <mcgrof@suse.com>. Originally-Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Modified to make the helper name more general than just virtualization, support architecture-dependent and architecture-independent partial configurations, move the helper and kvmconfig to scripts/kconfig/Makefile, and factor out more of the common file path. Signed-off-by: Josh Triplett <josh@joshtriplett.org>
* | | kexec: purgatory: add clean-up for purgatory directoryMichael Welling2014-08-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Without this patch the kexec-purgatory.c and purgatory.ro files are not removed after make mrproper. Signed-off-by: Michael Welling <mwelling@ieee.org> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | kexec: create a new config option CONFIG_KEXEC_FILE for new syscallVivek Goyal2014-08-291-4/+1
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently new system call kexec_file_load() and all the associated code compiles if CONFIG_KEXEC=y. But new syscall also compiles purgatory code which currently uses gcc option -mcmodel=large. This option seems to be available only gcc 4.4 onwards. Hiding new functionality behind a new config option will not break existing users of old gcc. Those who wish to enable new functionality will require new gcc. Having said that, I am trying to figure out how can I move away from using -mcmodel=large but that can take a while. I think there are other advantages of introducing this new config option. As this option will be enabled only on x86_64, other arches don't have to compile generic kexec code which will never be used. This new code selects CRYPTO=y and CRYPTO_SHA256=y. And all other arches had to do this for CONFIG_KEXEC. Now with introduction of new config option, we can remove crypto dependency from other arches. Now CONFIG_KEXEC_FILE is available only on x86_64. So whereever I had CONFIG_X86_64 defined, I got rid of that. For CONFIG_KEXEC_FILE, instead of doing select CRYPTO=y, I changed it to "depends on CRYPTO=y". This should be safer as "select" is not recursive. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* / purgatory: core purgatory functionalityVivek Goyal2014-08-081-0/+8
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Create a stand alone relocatable object purgatory which runs between two kernels. This name, concept and some code has been taken from kexec-tools. Idea is that this code runs after a crash and it runs in minimal environment. So keep it separate from rest of the kernel and in long term we will have to practically do no maintenance of this code. This code also has the logic to do verify sha256 hashes of various segments which have been loaded into memory. So first we verify that the kernel we are jumping to is fine and has not been corrupted and make progress only if checsums are verified. This code also takes care of copying some memory contents to backup region. [sfr@canb.auug.org.au: run host built programs from objtree] Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branches 'x86-build-for-linus', 'x86-cleanups-for-linus' and ↵Linus Torvalds2014-08-041-6/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 build/cleanup/debug updates from Ingo Molnar: "Robustify the build process with a quirk to avoid GCC reordering related bugs. Two code cleanups. Simplify entry_64.S CFI annotations, by Jan Beulich" * 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, build: Change code16gcc.h from a C header to an assembly header * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Simplify __HAVE_ARCH_CMPXCHG tests x86/tsc: Get rid of custom DIV_ROUND() macro * 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/debug: Drop several unnecessary CFI annotations
| * x86, build: Change code16gcc.h from a C header to an assembly headerH. Peter Anvin2014-06-041-6/+3
| | | | | | | | | | | | | | | | | | | | | | | | By changing code16gcc.h from a C header to an assembly header and use the -Wa,... option to gcc to force it to be added to the assembly input, we can avoid the problems with gcc reordering code bits on us. If we have -m16, we still use it, of course. Suggested-by: Kevin O'Connor <kevin@koconnor.net> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/n/tip-xw8ibgdemucl9fz3i1bymu6w@git.kernel.org
* | x86-64, build: Fix stack protector Makefile breakage with 32-bit userlandGeorge Spelvin2014-05-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If you are using a 64-bit kernel with 32-bit userland, then scripts/gcc-x86_64-has-stack-protector.sh invokes 32-bit gcc with -mcmodel=kernel, which produces: <stdin>:1:0: error: code model 'kernel' not supported in the 32 bit mode and trips the "broken compiler" test at arch/x86/Makefile:120. There are several places a fix is possible, but the following seems cleanest. (But it's minimal; it would also be possible to factor out a bunch of stuff from the two branches of the if.) Signed-off-by: George Spelvin <linux@horizon.com> Link: http://lkml.kernel.org/r/20140507210552.7581.qmail@ns.horizon.com Cc: <stable@vger.kernel.org> # v3.14 Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* | x86: LLVMLinux: Wrap -mno-80387 with cc-optionBehan Webster2014-04-221-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | Wrap -mno-80387 gcc options with cc-option so they don't break clang. Signed-off-by: Behan Webster <behanw@converseincode.com> Cc: torvalds@linux-foundation.org Cc: dwmw2@infradead.org Cc: pageexec@freemail.hu Link: http://lkml.kernel.org/r/1398145227-25053-1-git-send-email-behanw@converseincode.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2014-04-161-2/+2
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Various fixes: - reboot regression fix - build message spam fix - GPU quirk fix - 'make kvmconfig' fix plus the wire-up of the renameat2() system call on i386" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Remove the PCI reboot method from the default chain x86/build: Supress "Nothing to be done for ..." messages x86/gpu: Fix sign extension issue in Intel graphics stolen memory quirks x86/platform: Fix "make O=dir kvmconfig" i386: Wire up the renameat2() syscall
| * x86/platform: Fix "make O=dir kvmconfig"Antonio Borneo2014-04-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Running: make O=dir x86_64_defconfig make O=dir kvmconfig the second command dirties the source tree with file ".config", symlink "source" and objects in folder "scripts". Fixed by using properly prefixed paths in the arch Makefile. Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com> Acked-by: Borislav Petkov <bp@suse.de> Cc: Pekka Enberg <penberg@kernel.org> Link: http://lkml.kernel.org/r/1397377568-8375-1-git-send-email-borneo.antonio@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | x86 kbuild: LLVMLinux: More cc-options added for clangJan-Simon Möller2014-04-091-1/+1
|/ | | | | | | | | | | Protect more options for x86 with cc-option so that we don't get errors when using clang instead of gcc. Add more or different options when using clang as well. Also need to enforce that SSE is off for clang and the stack is 8-byte aligned. Signed-off-by: Jan-Simon Möller <dl9pf@gmx.de> Signed-off-by: Behan Webster <behanw@converseincode.com> Signed-off-by: Mark Charlebois <charlebm@gmail.com>
* Merge branch 'x86-hash-for-linus' of ↵Linus Torvalds2014-03-311-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 hashing changes from Ingo Molnar: "Small fixes and cleanups to the librarized arch_fast_hash() methods, used by the net/openvswitch code" * 'x86-hash-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, hash: Simplify switch, add __init annotation x86, hash: Swap arguments passed to crc32_u32() x86, hash: Fix build failure with older binutils
| * x86, hash: Fix build failure with older binutilsJan Beulich2014-03-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Just like for other ISA extension instruction uses we should check whether the assembler actually supports them. The fallback here simply is to encode an instruction with fixed operands (%eax and %ecx). [ hpa: tagging for -stable as a build fix ] Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/530F0996020000780011FBE7@nat28.tlf.novell.com Cc: Francesco Fusco <ffusco@redhat.com> Cc: Thomas Graf <tgraf@redhat.com> Cc: David S. Miller <davem@davemloft.net> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: <stable@vger.kernel.org> # v3.14
* | x86: Disable generation of traditional x87 instructionsBorislav Petkov2014-02-041-2/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | We recently had the case where wrongly used floating-constant 'E' caused the generation of traditional x87 instructions in kernel code and wreaking all kinds of havoc. Disable the generation of those too. This will save people a lot of time when trying to debug such issues by erroring out of the build instead of let them manifest themselves in very spectacular and happy-crappy ways at runtime. We're using -mno-fp-ret-in-387 in addition to -mno-80387 (which is == -msoft-float) because, as the gcc manpage says: On machines where a function returns floating-point results in the 80387 register stack, some floating-point opcodes may be emitted even if -msoft-float is used. so we want to turn off *all* non-integer instructions involving any architectural FPU state, unless it is absolutely necessary (and those cases need special handling anyway). Cc: Jiri Kosina <jkosina@suse.cz> Cc: Michael Matz <matz@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1391561711-3023-1-git-send-email-bp@alien8.de Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* x86, build: Build 16-bit code with -m16 where possibleDavid Woodhouse2014-01-301-4/+12
| | | | | | | | | | | | Both clang 3.5 and GCC 4.9 will support this (as of r199754 and r207196 respectively). Both have been tested to produce booting kernels when the 16-bit code is built with -m16. (Modulo LLVM PR3997, at least.) [ hpa: folded test for -m16 into M16_CFLAGS ] Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Link: http://lkml.kernel.org/r/1390997807.20153.133.camel@i7.infradead.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* Merge commit 'f4bcd8ccddb02833340652e9f46f5127828eb79d' into x86/buildH. Peter Anvin2014-01-291-5/+3
|\ | | | | | | | | | | Bring in upstream merge of x86/kaslr for future patches. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * stackprotector: Unify the HAVE_CC_STACKPROTECTOR logic between architecturesKees Cook2013-12-201-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of duplicating the CC_STACKPROTECTOR Kconfig and Makefile logic in each architecture, switch to using HAVE_CC_STACKPROTECTOR and keep everything in one place. This retains the x86-specific bug verification scripts. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Michal Marek <mmarek@suse.cz> Cc: Russell King <linux@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: James Hogan <james.hogan@imgtec.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@linux-mips.org Cc: linux-arch@vger.kernel.org Link: http://lkml.kernel.org/r/1387481759-14535-2-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | x86: Remove duplication of 16-bit CFLAGSDavid Woodhouse2014-01-221-0/+14
|/ | | | | | | | Define them once in arch/x86/Makefile instead of twice. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Link: http://lkml.kernel.org/r/1389180083-23249-1-git-send-email-David.Woodhouse@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* x86, build: Pass in additional -mno-mmx, -mno-sse optionsH. Peter Anvin2013-12-091-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | In checkin 5551a34e5aea x86-64, build: Always pass in -mno-sse we unconditionally added -mno-sse to the main build, to keep newer compilers from generating SSE instructions from autovectorization. However, this did not extend to the special environments (arch/x86/boot, arch/x86/boot/compressed, and arch/x86/realmode/rm). Add -mno-sse to the compiler command line for these environments, and add -mno-mmx to all the environments as well, as we don't want a compiler to generate MMX code either. This patch also removes a $(cc-option) call for -m32, since we have long since stopped supporting compilers too old for the -m32 option, and in fact hardcode it in other places in the Makefiles. Reported-by: Kevin B. Smith <kevin.b.smith@intel.com> Cc: Sunil K. Pandey <sunil.k.pandey@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: H. J. Lu <hjl.tools@gmail.com> Link: http://lkml.kernel.org/n/tip-j21wzqv790q834n7yc6g80j1@git.kernel.org Cc: <stable@vger.kernel.org> # build fix only
* x86-64, build: Always pass in -mno-sseH. Peter Anvin2013-12-031-1/+7
| | | | | | | | | | | | | | | | Always pass in the -mno-sse argument, regardless if -preferred-stack-boundary is supported. We never want to generate SSE instructions in the kernel unless we *really* know what we're doing. According to H. J. Lu, any version of gcc new enough that we support it at all should handle the -mno-sse option, so just add it unconditionally. Reported-by: Kevin B. Smith <kevin.b.smith@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: H. J. Lu <hjl.tools@gmail.com> Link: http://lkml.kernel.org/n/tip-j21wzqv790q834n7yc6g80j1@git.kernel.org Cc: <stable@vger.kernel.org> # build fix only
* x86, relocs: Move ELF relocation handling to CKees Cook2013-08-071-4/+4
| | | | | | | | | | | | | | | Moves the relocation handling into C, after decompression. This requires that the decompressed size is passed to the decompression routine as well so that relocations can be found. Only kernels that need relocation support will use the code (currently just x86_32), but this is laying the ground work for 64-bit using it in support of KASLR. Based on work by Neill Clift and Michael Davidson. Signed-off-by: Kees Cook <keescook@chromium.org> Link: http://lkml.kernel.org/r/20130708161517.GA4832@www.outflux.net Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>