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2019-10-05x86/retpolines: Fix up backport of a9d57ef15cbeNathan Chancellor
Commit a9d57ef15cbe ("x86/retpolines: Disable switch jump tables when retpolines are enabled") added -fno-jump-tables to workaround a GCC issue while deliberately avoiding adding this flag when CONFIG_CC_IS_CLANG is set, which is defined by the kconfig system when CC=clang is provided. However, this symbol was added in 4.18 in commit 469cb7376c06 ("kconfig: add CC_IS_CLANG and CLANG_VERSION") so it is always undefined in 4.14, meaning -fno-jump-tables gets added when using Clang. Fix this up by using the equivalent $(cc-name) comparison, which matches what upstream did until commit 076f421da5d4 ("kbuild: replace cc-name test with CONFIG_CC_IS_CLANG"). Fixes: e28951100515 ("x86/retpolines: Disable switch jump tables when retpolines are enabled") Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-19x86/build: Add -Wnoaddress-of-packed-member to REALMODE_CFLAGS, to silence ↵Linus Torvalds
GCC9 build warning commit 42e0e95474fc6076b5cd68cab8fa0340a1797a72 upstream. One of the very few warnings I have in the current build comes from arch/x86/boot/edd.c, where I get the following with a gcc9 build: arch/x86/boot/edd.c: In function ‘query_edd’: arch/x86/boot/edd.c:148:11: warning: taking address of packed member of ‘struct boot_params’ may result in an unaligned pointer value [-Waddress-of-packed-member] 148 | mbrptr = boot_params.edd_mbr_sig_buffer; | ^~~~~~~~~~~ This warning triggers because we throw away all the CFLAGS and then make a new set for REALMODE_CFLAGS, so the -Wno-address-of-packed-member we added in the following commit is not present: 6f303d60534c ("gcc-9: silence 'address-of-packed-member' warning") The simplest solution for now is to adjust the warning for this version of CFLAGS as well, but it would definitely make sense to examine whether REALMODE_CFLAGS could be derived from CFLAGS, so that it picks up changes in the compiler flags environment automatically. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Borislav Petkov <bp@alien8.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-31x86/build: Keep local relocations with ld.lldKees Cook
[ Upstream commit 7c21383f3429dd70da39c0c7f1efa12377a47ab6 ] The LLVM linker (ld.lld) defaults to removing local relocations, which causes KASLR boot failures. ld.bfd and ld.gold already handle this correctly. This adds the explicit instruction "--discard-none" during the link phase. There is no change in output for ld.bfd and ld.gold, but ld.lld now produces an image with all the needed relocations. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: clang-built-linux@googlegroups.com Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190404214027.GA7324@beast Link: https://github.com/ClangBuiltLinux/linux/issues/404 Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-02x86/retpolines: Disable switch jump tables when retpolines are enabledDaniel Borkmann
commit a9d57ef15cbe327fe54416dd194ee0ea66ae53a4 upstream. Commit ce02ef06fcf7 ("x86, retpolines: Raise limit for generating indirect calls from switch-case") raised the limit under retpolines to 20 switch cases where gcc would only then start to emit jump tables, and therefore effectively disabling the emission of slow indirect calls in this area. After this has been brought to attention to gcc folks [0], Martin Liska has then fixed gcc to align with clang by avoiding to generate switch jump tables entirely under retpolines. This is taking effect in gcc starting from stable version 8.4.0. Given kernel supports compilation with older versions of gcc where the fix is not being available or backported anymore, we need to keep the extra KBUILD_CFLAGS around for some time and generally set the -fno-jump-tables to align with what more recent gcc is doing automatically today. More than 20 switch cases are not expected to be fast-path critical, but it would still be good to align with gcc behavior for versions < 8.4.0 in order to have consistency across supported gcc versions. vmlinux size is slightly growing by 0.27% for older gcc. This flag is only set to work around affected gcc, no change for clang. [0] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86952 Suggested-by: Martin Liska <mliska@suse.cz> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Björn Töpel<bjorn.topel@intel.com> Cc: Magnus Karlsson <magnus.karlsson@intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: David S. Miller <davem@davemloft.net> Link: https://lkml.kernel.org/r/20190325135620.14882-1-daniel@iogearbox.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-02x86, retpolines: Raise limit for generating indirect calls from switch-caseDaniel Borkmann
commit ce02ef06fcf7a399a6276adb83f37373d10cbbe1 upstream. From networking side, there are numerous attempts to get rid of indirect calls in fast-path wherever feasible in order to avoid the cost of retpolines, for example, just to name a few: * 283c16a2dfd3 ("indirect call wrappers: helpers to speed-up indirect calls of builtin") * aaa5d90b395a ("net: use indirect call wrappers at GRO network layer") * 028e0a476684 ("net: use indirect call wrappers at GRO transport layer") * 356da6d0cde3 ("dma-mapping: bypass indirect calls for dma-direct") * 09772d92cd5a ("bpf: avoid retpoline for lookup/update/delete calls on maps") * 10870dd89e95 ("netfilter: nf_tables: add direct calls for all builtin expressions") [...] Recent work on XDP from Björn and Magnus additionally found that manually transforming the XDP return code switch statement with more than 5 cases into if-else combination would result in a considerable speedup in XDP layer due to avoidance of indirect calls in CONFIG_RETPOLINE enabled builds. On i40e driver with XDP prog attached, a 20-26% speedup has been observed [0]. Aside from XDP, there are many other places later in the networking stack's critical path with similar switch-case processing. Rather than fixing every XDP-enabled driver and locations in stack by hand, it would be good to instead raise the limit where gcc would emit expensive indirect calls from the switch under retpolines and stick with the default as-is in case of !retpoline configured kernels. This would also have the advantage that for archs where this is not necessary, we let compiler select the underlying target optimization for these constructs and avoid potential slow-downs by if-else hand-rewrite. In case of gcc, this setting is controlled by case-values-threshold which has an architecture global default that selects 4 or 5 (latter if target does not have a case insn that compares the bounds) where some arch back ends like arm64 or s390 override it with their own target hooks, for example, in gcc commit db7a90aa0de5 ("S/390: Disable prediction of indirect branches") the threshold pretty much disables jump tables by limit of 20 under retpoline builds. Comparing gcc's and clang's default code generation on x86-64 under O2 level with retpoline build results in the following outcome for 5 switch cases: * gcc with -mindirect-branch=thunk-inline -mindirect-branch-register: # gdb -batch -ex 'disassemble dispatch' ./c-switch Dump of assembler code for function dispatch: 0x0000000000400be0 <+0>: cmp $0x4,%edi 0x0000000000400be3 <+3>: ja 0x400c35 <dispatch+85> 0x0000000000400be5 <+5>: lea 0x915f8(%rip),%rdx # 0x4921e4 0x0000000000400bec <+12>: mov %edi,%edi 0x0000000000400bee <+14>: movslq (%rdx,%rdi,4),%rax 0x0000000000400bf2 <+18>: add %rdx,%rax 0x0000000000400bf5 <+21>: callq 0x400c01 <dispatch+33> 0x0000000000400bfa <+26>: pause 0x0000000000400bfc <+28>: lfence 0x0000000000400bff <+31>: jmp 0x400bfa <dispatch+26> 0x0000000000400c01 <+33>: mov %rax,(%rsp) 0x0000000000400c05 <+37>: retq 0x0000000000400c06 <+38>: nopw %cs:0x0(%rax,%rax,1) 0x0000000000400c10 <+48>: jmpq 0x400c90 <fn_3> 0x0000000000400c15 <+53>: nopl (%rax) 0x0000000000400c18 <+56>: jmpq 0x400c70 <fn_2> 0x0000000000400c1d <+61>: nopl (%rax) 0x0000000000400c20 <+64>: jmpq 0x400c50 <fn_1> 0x0000000000400c25 <+69>: nopl (%rax) 0x0000000000400c28 <+72>: jmpq 0x400c40 <fn_0> 0x0000000000400c2d <+77>: nopl (%rax) 0x0000000000400c30 <+80>: jmpq 0x400cb0 <fn_4> 0x0000000000400c35 <+85>: push %rax 0x0000000000400c36 <+86>: callq 0x40dd80 <abort> End of assembler dump. * clang with -mretpoline emitting search tree: # gdb -batch -ex 'disassemble dispatch' ./c-switch Dump of assembler code for function dispatch: 0x0000000000400b30 <+0>: cmp $0x1,%edi 0x0000000000400b33 <+3>: jle 0x400b44 <dispatch+20> 0x0000000000400b35 <+5>: cmp $0x2,%edi 0x0000000000400b38 <+8>: je 0x400b4d <dispatch+29> 0x0000000000400b3a <+10>: cmp $0x3,%edi 0x0000000000400b3d <+13>: jne 0x400b52 <dispatch+34> 0x0000000000400b3f <+15>: jmpq 0x400c50 <fn_3> 0x0000000000400b44 <+20>: test %edi,%edi 0x0000000000400b46 <+22>: jne 0x400b5c <dispatch+44> 0x0000000000400b48 <+24>: jmpq 0x400c20 <fn_0> 0x0000000000400b4d <+29>: jmpq 0x400c40 <fn_2> 0x0000000000400b52 <+34>: cmp $0x4,%edi 0x0000000000400b55 <+37>: jne 0x400b66 <dispatch+54> 0x0000000000400b57 <+39>: jmpq 0x400c60 <fn_4> 0x0000000000400b5c <+44>: cmp $0x1,%edi 0x0000000000400b5f <+47>: jne 0x400b66 <dispatch+54> 0x0000000000400b61 <+49>: jmpq 0x400c30 <fn_1> 0x0000000000400b66 <+54>: push %rax 0x0000000000400b67 <+55>: callq 0x40dd20 <abort> End of assembler dump. For sake of comparison, clang without -mretpoline: # gdb -batch -ex 'disassemble dispatch' ./c-switch Dump of assembler code for function dispatch: 0x0000000000400b30 <+0>: cmp $0x4,%edi 0x0000000000400b33 <+3>: ja 0x400b57 <dispatch+39> 0x0000000000400b35 <+5>: mov %edi,%eax 0x0000000000400b37 <+7>: jmpq *0x492148(,%rax,8) 0x0000000000400b3e <+14>: jmpq 0x400bf0 <fn_0> 0x0000000000400b43 <+19>: jmpq 0x400c30 <fn_4> 0x0000000000400b48 <+24>: jmpq 0x400c10 <fn_2> 0x0000000000400b4d <+29>: jmpq 0x400c20 <fn_3> 0x0000000000400b52 <+34>: jmpq 0x400c00 <fn_1> 0x0000000000400b57 <+39>: push %rax 0x0000000000400b58 <+40>: callq 0x40dcf0 <abort> End of assembler dump. Raising the cases to a high number (e.g. 100) will still result in similar code generation pattern with clang and gcc as above, in other words clang generally turns off jump table emission by having an extra expansion pass under retpoline build to turn indirectbr instructions from their IR into switch instructions as a built-in -mno-jump-table lowering of a switch (in this case, even if IR input already contained an indirect branch). For gcc, adding --param=case-values-threshold=20 as in similar fashion as s390 in order to raise the limit for x86 retpoline enabled builds results in a small vmlinux size increase of only 0.13% (before=18,027,528 after=18,051,192). For clang this option is ignored due to i) not being needed as mentioned and ii) not having above cmdline parameter. Non-retpoline-enabled builds with gcc continue to use the default case-values-threshold setting, so nothing changes here. [0] https://lore.kernel.org/netdev/20190129095754.9390-1-bjorn.topel@gmail.com/ and "The Path to DPDK Speeds for AF_XDP", LPC 2018, networking track: - http://vger.kernel.org/lpc_net2018_talks/lpc18_pres_af_xdp_perf-v3.pdf - http://vger.kernel.org/lpc_net2018_talks/lpc18_paper_af_xdp_perf-v2.pdf Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Björn Töpel <bjorn.topel@intel.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: netdev@vger.kernel.org Cc: David S. Miller <davem@davemloft.net> Cc: Magnus Karlsson <magnus.karlsson@intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Link: https://lkml.kernel.org/r/20190221221941.29358-1-daniel@iogearbox.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-21x86/build: Fix compiler support check for CONFIG_RETPOLINEMasahiro Yamada
commit 25896d073d8a0403b07e6dec56f58e6c33678207 upstream. It is troublesome to add a diagnostic like this to the Makefile parse stage because the top-level Makefile could be parsed with a stale include/config/auto.conf. Once you are hit by the error about non-retpoline compiler, the compilation still breaks even after disabling CONFIG_RETPOLINE. The easiest fix is to move this check to the "archprepare" like this commit did: 829fe4aa9ac1 ("x86: Allow generating user-space headers without a compiler") Reported-by: Meelis Roos <mroos@linux.ee> Tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com> Fixes: 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support") Link: http://lkml.kernel.org/r/1543991239-18476-1-git-send-email-yamada.masahiro@socionext.com Link: https://lkml.org/lkml/2018/12/4/206 Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Cc: Gi-Oh Kim <gi-oh.kim@cloud.ionos.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05x86/retpoline: Make CONFIG_RETPOLINE depend on compiler supportZhenzhong Duan
commit 4cd24de3a0980bf3100c9dcb08ef65ca7c31af48 upstream Since retpoline capable compilers are widely available, make CONFIG_RETPOLINE hard depend on the compiler capability. Break the build when CONFIG_RETPOLINE is enabled and the compiler does not support it. Emit an error message in that case: "arch/x86/Makefile:226: *** You are building kernel with non-retpoline compiler, please update your compiler.. Stop." [dwmw: Fail the build with non-retpoline compiler] Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Borislav Petkov <bp@suse.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michal Marek <michal.lkml@markovi.net> Cc: <srinivas.eeda@oracle.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/cca0cb20-f9e2-4094-840b-fb0f8810cd34@default Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-28x86/build/64: Force the linker to use 2MB page sizeH.J. Lu
commit e3d03598e8ae7d195af5d3d049596dec336f569f upstream. Binutils 2.31 will enable -z separate-code by default for x86 to avoid mixing code pages with data to improve cache performance as well as security. To reduce x86-64 executable and shared object sizes, the maximum page size is reduced from 2MB to 4KB. But x86-64 kernel must be aligned to 2MB. Pass -z max-page-size=0x200000 to linker to force 2MB page size regardless of the default page size used by linker. Tested with Linux kernel 4.15.6 on x86-64. Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.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/CAMe9rOp4_%3D_8twdpTyAP2DhONOCeaTOsniJLoppzhoNptL8xzA@mail.gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-15objtool, retpolines: Integrate objtool with retpoline support more closelyPeter Zijlstra
commit d5028ba8ee5a18c9d0bb926d883c28b370f89009 upstream. Disable retpoline validation in objtool if your compiler sucks, and otherwise select the validation stuff for CONFIG_RETPOLINE=y (most builds would already have it set due to ORC). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-15x86/retpoline: Support retpoline builds with ClangDavid Woodhouse
commit 87358710c1fb4f1bf96bbe2349975ff9953fc9b2 upstream. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: arjan.van.de.ven@intel.com Cc: bp@alien8.de Cc: dave.hansen@intel.com Cc: jmattson@google.com Cc: karahmed@amazon.de Cc: kvm@vger.kernel.org Cc: pbonzini@redhat.com Cc: rkrcmar@redhat.com Link: http://lkml.kernel.org/r/1519037457-7643-5-git-send-email-dwmw@amazon.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-22kmemcheck: remove annotationsLevin, Alexander (Sasha Levin)
commit 4950276672fce5c241857540f8561c440663673d upstream. Patch series "kmemcheck: kill kmemcheck", v2. As discussed at LSF/MM, kill kmemcheck. KASan is a replacement that is able to work without the limitation of kmemcheck (single CPU, slow). KASan is already upstream. We are also not aware of any users of kmemcheck (or users who don't consider KASan as a suitable replacement). The only objection was that since KASAN wasn't supported by all GCC versions provided by distros at that time we should hold off for 2 years, and try again. Now that 2 years have passed, and all distros provide gcc that supports KASAN, kill kmemcheck again for the very same reasons. This patch (of 4): Remove kmemcheck annotations, and calls to kmemcheck from the kernel. [alexander.levin@verizon.com: correctly remove kmemcheck call from dma_map_sg_attrs] Link: http://lkml.kernel.org/r/20171012192151.26531-1-alexander.levin@verizon.com Link: http://lkml.kernel.org/r/20171007030159.22241-2-alexander.levin@verizon.com Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Cc: Alexander Potapenko <glider@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tim Hansen <devtimhansen@gmail.com> Cc: Vegard Nossum <vegardno@ifi.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17x86/retpoline: Remove compile time warningThomas Gleixner
commit b8b9ce4b5aec8de9e23cabb0a26b78641f9ab1d6 upstream. Remove the compile time warning when CONFIG_RETPOLINE=y and the compiler does not have retpoline support. Linus rationale for this is: It's wrong because it will just make people turn off RETPOLINE, and the asm updates - and return stack clearing - that are independent of the compiler are likely the most important parts because they are likely the ones easiest to target. And it's annoying because most people won't be able to do anything about it. The number of people building their own compiler? Very small. So if their distro hasn't got a compiler yet (and pretty much nobody does), the warning is just annoying crap. It is already properly reported as part of the sysfs interface. The compile-time warning only encourages bad things. Fixes: 76b043848fd2 ("x86/retpoline: Add initial retpoline support") Requested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: gnomes@lxorguk.ukuu.org.uk Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: thomas.lendacky@amd.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Link: https://lkml.kernel.org/r/CA+55aFzWgquv4i6Mab6bASqYXg3ErV3XDFEYf=GEcCDQg5uAtw@mail.gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17x86/retpoline: Add initial retpoline supportDavid Woodhouse
commit 76b043848fd22dbf7f8bf3a1452f8c70d557b860 upstream. Enable the use of -mindirect-branch=thunk-extern in newer GCC, and provide the corresponding thunks. Provide assembler macros for invoking the thunks in the same way that GCC does, from native and inline assembler. This adds X86_FEATURE_RETPOLINE and sets it by default on all CPUs. In some circumstances, IBRS microcode features may be used instead, and the retpoline can be disabled. On AMD CPUs if lfence is serialising, the retpoline can be dramatically simplified to a simple "lfence; jmp *\reg". A future patch, after it has been verified that lfence really is serialising in all circumstances, can enable this by setting the X86_FEATURE_RETPOLINE_AMD feature bit in addition to X86_FEATURE_RETPOLINE. Do not align the retpoline in the altinstr section, because there is no guarantee that it stays aligned when it's copied over the oldinstr during alternative patching. [ Andi Kleen: Rename the macros, add CONFIG_RETPOLINE option, export thunks] [ tglx: Put actual function CALL/JMP in front of the macros, convert to symbolic labels ] [ dwmw2: Convert back to numeric labels, merge objtool fixes ] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: gnomes@lxorguk.ukuu.org.uk Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: thomas.lendacky@amd.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: https://lkml.kernel.org/r/1515707194-20531-4-git-send-email-dwmw@amazon.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-21x86/build: Use cc-option to validate stack alignment parameterMatthias Kaehlcke
With the following commit: 8f91869766c0 ("x86/build: Fix stack alignment for CLang") cc-option is only used to determine the name of the stack alignment option supported by the compiler, but not to verify that the actual parameter <option>=N is valid in combination with the other CFLAGS. This causes problems (as reported by the kbuild robot) with older GCC versions which only support stack alignment on a boundary of 16 bytes or higher. Also use (__)cc_option to add the stack alignment option to CFLAGS to make sure only valid options are added. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bernhard.Rosenkranzer@linaro.org Cc: Greg Hackmann <ghackmann@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michael Davidson <md@google.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hines <srhines@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dianders@chromium.org Fixes: 8f91869766c0 ("x86/build: Fix stack alignment for CLang") Link: http://lkml.kernel.org/r/20170817182047.176752-1-mka@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-17x86/build: Fix stack alignment for CLangMatthias Kaehlcke
Commit: d77698df39a5 ("x86/build: Specify stack alignment for clang") intended to use the same stack alignment for clang as with gcc. The two compilers use different options to configure the stack alignment (gcc: -mpreferred-stack-boundary=n, clang: -mstack-alignment=n). The above commit assumes that the clang option uses the same parameter type as gcc, i.e. that the alignment is specified as 2^n. However clang interprets the value of this option literally to use an alignment of n, in consequence the stack remains misaligned. Change the values used with -mstack-alignment to be the actual alignment instead of a power of two. cc-option isn't used here with the typical pattern of KBUILD_CFLAGS += $(call cc-option ...). The reason is that older gcc versions don't support the -mpreferred-stack-boundary option, since cc-option doesn't verify whether the alternative option is valid it would incorrectly select the clang option -mstack-alignment.. Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bernhard.Rosenkranzer@linaro.org Cc: Greg Hackmann <ghackmann@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michael Davidson <md@google.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hines <srhines@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dianders@chromium.org Link: http://lkml.kernel.org/r/20170817004740.170588-1-mka@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-10x86/build: Drop unused mflags-yCao jin
Subarchitecture support (mflags-y) was removed from x86 in this commit: 6bda2c8b32fe ("x86: remove subarchitecture support") So drop the mflags-y usage from the Makefile. Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.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/1502105384-23214-1-git-send-email-caoj.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-07Merge tag 'kbuild-v4.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild 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
2017-06-25x86/build: Specify stack alignment for clangMatthias Kaehlcke
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 <mka@chromium.org> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-06-25x86/build: Use __cc-option for boot code compiler optionsMatthias Kaehlcke
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 <mka@chromium.org> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-06-14x86/mce: Merge mce_amd_inj into mce-injectBorislav Petkov
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 <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Yazen Ghannam <yazen.ghannam@amd.com> Cc: Borislav Petkov <bp@alien8.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/20170613162835.30750-4-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-24x86/build: Permit building with old make versionsJan Kiszka
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>
2017-05-09x86/build: Don't add -maccumulate-outgoing-args w/o compiler supportNick Desaulniers
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>
2017-05-01Merge branch 'x86-build-for-linus' of ↵Linus Torvalds
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}
2017-04-19x86/build: convert function graph '-Os' error to warningJosh Poimboeuf
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>
2017-04-17x86/kbuild: Use cc-option to enable -falign-{jumps/loops}Matthias Kaehlcke
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>
2017-03-30x86/build: Mostly disable '-maccumulate-outgoing-args'Josh Poimboeuf
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>
2016-09-21lib/raid6: Add AVX512 optimized gen_syndrome functionsGayatri Kammela
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>
2016-07-26kbuild: abort build on bad stack protector flagKees Cook
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>
2016-04-22x86/init: Rename EBDA code fileLuis R. Rodriguez
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>
2016-04-22x86/rtc: Replace paravirt rtc check with platform legacy quirkLuis R. Rodriguez
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>
2015-11-04Merge branch 'linus' of ↵Linus Torvalds
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 ...
2015-10-09x86/asm: Re-add parts of the manual CFI infrastructureAndy Lutomirski
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>
2015-09-21crypto: x86/sha - Add build support for Intel SHA Extensions optimized SHA1 ↵tim
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>
2015-09-01Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds
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' ...
2015-08-13x86/ras: Move AMD MCE injector to arch/x86/ras/Borislav Petkov
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>
2015-07-22x86/build: Fix detection of GCC -mpreferred-stack-boundary supportAndy Lutomirski
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>
2015-06-04x86/asm/entry: Move the arch/x86/syscalls/ definitions to ↵Ingo Molnar
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>
2015-06-03x86/asm/entry, x86/vdso: Move the vDSO code to arch/x86/entry/vdso/Ingo Molnar
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>
2015-06-02x86/debug: Remove perpetually broken, unmaintainable dwarf annotationsIngo Molnar
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>
2015-05-17x86: Pack loops tightly as wellIngo Molnar
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>
2015-05-15x86: Align jump targets to 1-byte boundariesIngo Molnar
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>
2015-05-08Merge branch 'linus' into x86/asm, before applying dependent patchIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-06x86/asm: Use -mskip-rax-setup if supportedH.J. Lu
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>
2015-04-02kbuild: use relative path more to include MakefileMasahiro Yamada
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>
2015-02-04x86/raid6: correctly check for assembler capabilitiesJan Beulich
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>
2014-10-13Merge branch 'x86-build-for-linus' of ↵Linus Torvalds
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
2014-10-07Merge tag 'tiny/for-3.18' of ↵Linus Torvalds
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
2014-09-22Merge branches 'tiny/bloat-o-meter-no-SyS', 'tiny/more-procless', ↵Josh Triplett
'tiny/no-advice', 'tiny/tinyconfig' and 'tiny/x86-boot-compressed-use-yn' into tiny/next
2014-09-16x86/kbuild: Eliminate duplicate command line optionsRasmus Villemoes
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>
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