Changes in Kbuild

2cbb20b0 - tracing: Disable branch profiling in noinstr code

Fri, 21 Mar 2025 19:53:32 +0000

tracing: Disable branch profiling in noinstr codeCONFIG_TRACE_BRANCH_PROFILING inserts a call to ftrace_likely_update()for each use of likely() or unlikely(). That breaks noinstr rules ifthe affected function is annotated as noinstr.Disable branch profiling for files with noinstr functions. In additionto some individual files, this also includes the entire arch/x86subtree, as well as the kernel/entry, drivers/cpuidle, and drivers/idledirectories, all of which are noinstr-heavy.Due to the nature of how sched binaries are built by combining multiple.c files into one, branch profiling is disabled more broadly across thesched code than would otherwise be needed.This fixes many warnings like the following: vmlinux.o: warning: objtool: do_syscall_64+0x40: call to ftrace_likely_update() leaves .noinstr.text section vmlinux.o: warning: objtool: __rdgsbase_inactive+0x33: call to ftrace_likely_update() leaves .noinstr.text section vmlinux.o: warning: objtool: handle_bug.isra.0+0x198: call to ftrace_likely_update() leaves .noinstr.text section ...Reported-by: Ingo Molnar Suggested-by: Steven Rostedt Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Acked-by: Thomas Gleixner Cc: Linus Torvalds Link: https://lore.kernel.org/r/fb94fc9303d48a5ed370498f54500cc4c338eb6d.1742586676.git.jpoimboe@kernel.org List of files: /linux-6.15/arch/x86/Kbuild

3f1a9bc5 - x86/build: Use obj-y to descend into arch/x86/virt/

Sat, 30 Mar 2024 06:05:54 +0000

x86/build: Use obj-y to descend into arch/x86/virt/Commit c33621b4c5ad ("x86/virt/tdx: Wire up basic SEAMCALL functions")introduced a new instance of core-y instead of the standardized obj-ysyntax.X86 Makefiles descend into subdirectories of arch/x86/virt inconsistently;into arch/x86/virt/ via core-y defined in arch/x86/Makefile, but intoarch/x86/virt/svm/ via obj-y defined in arch/x86/Kbuild.This is problematic when you build a single object in parallel becausemultiple threads attempt to build the same file. $ make -j$(nproc) arch/x86/virt/vmx/tdx/seamcall.o [ snip ] AS arch/x86/virt/vmx/tdx/seamcall.o AS arch/x86/virt/vmx/tdx/seamcall.o fixdep: error opening file: arch/x86/virt/vmx/tdx/.seamcall.o.d: No such file or directory make[4]: *** [scripts/Makefile.build:362: arch/x86/virt/vmx/tdx/seamcall.o] Error 2Use the obj-y syntax, as it works correctly.Signed-off-by: Masahiro Yamada Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20240330060554.18524-1-masahiroy@kernel.org List of files: /linux-6.15/arch/x86/Kbuild

216d106c - x86/sev: Add SEV-SNP host initialization support

Fri, 26 Jan 2024 04:11:04 +0000

x86/sev: Add SEV-SNP host initialization supportThe memory integrity guarantees of SEV-SNP are enforced through a newstructure called the Reverse Map Table (RMP). The RMP is a single datastructure shared across the system that contains one entry for every 4Kpage of DRAM that may be used by SEV-SNP VMs. The APM Volume 2 sectionon Secure Nested Paging (SEV-SNP) details a number of steps needed todetect/enable SEV-SNP and RMP table support on the host: - Detect SEV-SNP support based on CPUID bit - Initialize the RMP table memory reported by the RMP base/end MSR registers and configure IOMMU to be compatible with RMP access restrictions - Set the MtrrFixDramModEn bit in SYSCFG MSR - Set the SecureNestedPagingEn and VMPLEn bits in the SYSCFG MSR - Configure IOMMURMP table entry format is non-architectural and it can vary byprocessor. It is defined by the PPR document for each respective CPUfamily. Restrict SNP support to CPU models/families which are compatiblewith the current RMP table entry format to guard against any undefinedbehavior when running on other system types. Future models/support willhandle this through an architectural mechanism to allow for broadercompatibility.SNP host code depends on CONFIG_KVM_AMD_SEV config flag which may beenabled even when CONFIG_AMD_MEM_ENCRYPT isn't set, so update theSNP-specific IOMMU helpers used here to rely on CONFIG_KVM_AMD_SEVinstead of CONFIG_AMD_MEM_ENCRYPT.Signed-off-by: Brijesh Singh Co-developed-by: Ashish Kalra Signed-off-by: Ashish Kalra Co-developed-by: Tom Lendacky Signed-off-by: Tom Lendacky Co-developed-by: Borislav Petkov (AMD) Signed-off-by: Borislav Petkov (AMD) Co-developed-by: Michael Roth Signed-off-by: Michael Roth Link: https://lore.kernel.org/r/20240126041126.1927228-5-michael.roth@amd.com List of files: /linux-6.15/arch/x86/Kbuild

61983110 - x86/cc: Move arch/x86/{kernel/cc_platform.c => coco/core.c}

Tue, 22 Feb 2022 18:57:38 +0000

x86/cc: Move arch/x86/{kernel/cc_platform.c => coco/core.c}Move cc_platform.c to arch/x86/coco/. The directory is going to be thehome space for code related to confidential computing.Intel TDX code will land here. AMD SEV code will also eventually bemoved there.No functional changes.Signed-off-by: Kirill A. Shutemov Signed-off-by: Borislav Petkov Reviewed-by: Tom Lendacky Link: https://lore.kernel.org/r/20220222185740.26228-3-kirill.shutemov@linux.intel.com List of files: /linux-6.15/arch/x86/Kbuild

8212f898 - kbuild: use more subdir- for visiting subdirectories while cleaning

Wed, 13 Oct 2021 06:36:22 +0000

kbuild: use more subdir- for visiting subdirectories while cleaningDocumentation/kbuild/makefiles.rst suggests to use "archclean" forcleaning arch/$(SRCARCH)/boot/, but it is not a hard requirement.Since commit d92cc4d51643 ("kbuild: require all architectures to havearch/$(SRCARCH)/Kbuild"), we can use the "subdir- += boot" trick forall architectures. This can take advantage of the parallel option (-j)for "make clean".I also cleaned up the comments in arch/$(SRCARCH)/Makefile. The "archdep"target no longer exists.Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook Acked-by: Geert Uytterhoeven Acked-by: Michael Ellerman (powerpc) List of files: /linux-6.15/arch/x86/Kbuild

96ac6d43 - treewide: Add SPDX license identifier - Kbuild

Thu, 30 May 2019 12:03:44 +0000

treewide: Add SPDX license identifier - KbuildAdd SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any formThese files fall under the project license, GPL v2 only. The resulting SPDXlicense identifier is: GPL-2.0Reported-by: Masahiro Yamada Signed-off-by: Greg Kroah-Hartman Reviewed-by: Kate Stewart Signed-off-by: Greg Kroah-Hartman List of files: /linux-6.15/arch/x86/Kbuild

716ff017 - KVM: x86: Allow Qemu/KVM to use PVH entry point

Mon, 10 Dec 2018 19:09:35 +0000

KVM: x86: Allow Qemu/KVM to use PVH entry pointFor certain applications it is desirable to rapidly boot a KVM virtualmachine. In cases where legacy hardware and software support within theguest is not needed, Qemu should be able to boot directly into theuncompressed Linux kernel binary without the need to run firmware.There already exists an ABI to allow this for Xen PVH guests and the ABIis supported by Linux and FreeBSD: https://xenbits.xen.org/docs/unstable/misc/pvh.htmlThis patch enables Qemu to use that same entry point for booting KVMguests.Signed-off-by: Maran Wilson Suggested-by: Konrad Rzeszutek Wilk Suggested-by: Boris Ostrovsky Tested-by: Boris Ostrovsky Reviewed-by: Juergen Gross Signed-off-by: Boris Ostrovsky List of files: /linux-6.15/arch/x86/Kbuild

fcd47476 - xen/pvh: Move PVH entry code out of Xen specific tree

Mon, 10 Dec 2018 19:07:55 +0000

xen/pvh: Move PVH entry code out of Xen specific treeOnce hypervisors other than Xen start using the PVH entry point forstarting VMs, we would like the option of being able to compile PVH entrycapable kernels without enabling CONFIG_XEN and all the code that comesalong with that. To allow that, we are moving the PVH code out of Xen andinto files sitting at a higher level in the tree.This patch is not introducing any code or functional changes, just movingfiles from one location to another.Signed-off-by: Maran Wilson Reviewed-by: Konrad Rzeszutek Wilk Reviewed-by: Juergen Gross Signed-off-by: Boris Ostrovsky List of files: /linux-6.15/arch/x86/Kbuild

ecda85e7 - x86/lguest: Remove lguest support

Wed, 16 Aug 2017 17:31:57 +0000

x86/lguest: Remove lguest supportLguest seems to be rather unused these days. It has seen only patchesensuring it still builds the last two years and its official state is"Odd Fixes".Remove it in order to be able to clean up the paravirt code.Signed-off-by: Juergen Gross Acked-by: Rusty Russell Acked-by: Thomas Gleixner Cc: Linus Torvalds Cc: Peter Zijlstra Cc: boris.ostrovsky@oracle.comCc: lguest@lists.ozlabs.orgCc: rusty@rustcorp.com.auCc: xen-devel@lists.xenproject.orgLink: http://lkml.kernel.org/r/20170816173157.8633-3-jgross@suse.comSigned-off-by: Ingo Molnar List of files: /linux-6.15/arch/x86/Kbuild

79cadff2 - x86/hyper-v: Include hyperv/ only when CONFIG_HYPERV is set

Wed, 02 Aug 2017 16:09:13 +0000

x86/hyper-v: Include hyperv/ only when CONFIG_HYPERV is setCode is arch/x86/hyperv/ is only needed when CONFIG_HYPERV is set, the'basic' support and detection lives in arch/x86/kernel/cpu/mshyperv.cwhich is included when CONFIG_HYPERVISOR_GUEST is set.Signed-off-by: Vitaly Kuznetsov Reviewed-by: Andy Shevchenko Reviewed-by: Stephen Hemminger Cc: Andy Lutomirski Cc: Haiyang Zhang Cc: Jork Loeser Cc: K. Y. Srinivasan Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Simon Xiao Cc: Steven Rostedt Cc: Thomas Gleixner Cc: devel@linuxdriverproject.orgLink: http://lkml.kernel.org/r/20170802160921.21791-2-vkuznets@redhat.comSigned-off-by: Ingo Molnar List of files: /linux-6.15/arch/x86/Kbuild

91c17449 - Revert "x86/hyper-v: include hyperv/ only when CONFIG_HYPERV is set"

Thu, 20 Jul 2017 09:12:33 +0000

Revert "x86/hyper-v: include hyperv/ only when CONFIG_HYPERV is set"This reverts commit 2e252fbf777d3b1250b63a5bf45e2ac1932687d3 as it isobviously not correct.And it should have gone in through the x86 tree :(Reported-by: Colin King Reported-by: Ingo Molnar Reported-by: Stephen Rothwell Cc: Vitaly Kuznetsov Cc: Andy Shevchenko Cc: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman List of files: /linux-6.15/arch/x86/Kbuild

2e252fbf - x86/hyper-v: include hyperv/ only when CONFIG_HYPERV is set

Sun, 25 Jun 2017 17:06:40 +0000

x86/hyper-v: include hyperv/ only when CONFIG_HYPERV is setCode is arch/x86/hyperv/ is only needed when CONFIG_HYPERV is set, the'basic' support and detection lives in arch/x86/kernel/cpu/mshyperv.cwhich is included when CONFIG_HYPERVISOR_GUEST is set.Signed-off-by: Vitaly Kuznetsov Reviewed-by: Andy Shevchenko Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman List of files: /linux-6.15/arch/x86/Kbuild

8730046c - Drivers: hv vmbus: Move Hypercall page setup out of common code

Wed, 18 Jan 2017 23:45:02 +0000

Drivers: hv vmbus: Move Hypercall page setup out of common codeAs part of the effort to separate out architecture specific code, move thehypercall page setup to an architecture specific file.Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman List of files: /linux-6.15/arch/x86/Kbuild

fa9cbf32 - perf/x86: Move perf_event.c ............... => x86/events/core.c

Mon, 08 Feb 2016 16:09:04 +0000

perf/x86: Move perf_event.c ............... => x86/events/core.cAlso, keep the churn at minimum by adjusting the include "perf_event.h"when each file gets moved.Signed-off-by: Borislav Petkov Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Link: http://lkml.kernel.org/r/1454947748-28629-2-git-send-email-bp@alien8.deSigned-off-by: Ingo Molnar List of files: /linux-6.15/arch/x86/Kbuild

d603c8e1 - x86/asm/entry, x86/vdso: Move the vDSO code to arch/x86/entry/vdso/

Wed, 03 Jun 2015 16:05:44 +0000

x86/asm/entry, x86/vdso: Move the vDSO code to arch/x86/entry/vdso/Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Thomas Gleixner Cc: Andy Lutomirski Cc: Denys Vlasenko Cc: Brian Gerst Cc: Peter Zijlstra Cc: linux-kernel@vger.kernel.orgSigned-off-by: Ingo Molnar List of files: /linux-6.15/arch/x86/Kbuild

905a36a2 - x86/asm/entry: Move entry_64.S and entry_32.S to arch/x86/entry/

Wed, 03 Jun 2015 11:37:36 +0000

x86/asm/entry: Move entry_64.S and entry_32.S to arch/x86/entry/Create a new directory hierarchy for the low level x86 entry code: arch/x86/entry/*This will host all the low level glue that is currently scatteredall across arch/x86/.Start with entry_64.S and entry_32.S.Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Thomas Gleixner Cc: Andy Lutomirski Cc: Denys Vlasenko Cc: Brian Gerst Cc: Peter Zijlstra Cc: linux-kernel@vger.kernel.orgSigned-off-by: Ingo Molnar List of files: /linux-6.15/arch/x86/Kbuild

74ca317c - kexec: create a new config option CONFIG_KEXEC_FILE for new syscall

Fri, 29 Aug 2014 22:18:46 +0000

kexec: create a new config option CONFIG_KEXEC_FILE for new syscallCurrently new system call kexec_file_load() and all the associated codecompiles if CONFIG_KEXEC=y. But new syscall also compiles purgatorycode which currently uses gcc option -mcmodel=large. This option seemsto be available only gcc 4.4 onwards.Hiding new functionality behind a new config option will not breakexisting users of old gcc. Those who wish to enable new functionalitywill require new gcc. Having said that, I am trying to figure out howcan I move away from using -mcmodel=large but that can take a while.I think there are other advantages of introducing this new configoption. As this option will be enabled only on x86_64, other archesdon't have to compile generic kexec code which will never be used. Thisnew code selects CRYPTO=y and CRYPTO_SHA256=y. And all other arches hadto do this for CONFIG_KEXEC. Now with introduction of new configoption, we can remove crypto dependency from other arches.Now CONFIG_KEXEC_FILE is available only on x86_64. So whereever I hadCONFIG_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 notrecursive.Signed-off-by: Vivek Goyal Cc: Eric Biederman Cc: H. Peter Anvin Tested-by: Shaun Ruffell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/x86/Kbuild

8fc5b4d4 - purgatory: core purgatory functionality

Fri, 08 Aug 2014 21:26:02 +0000

purgatory: core purgatory functionalityCreate a stand alone relocatable object purgatory which runs between twokernels. This name, concept and some code has been taken fromkexec-tools. Idea is that this code runs after a crash and it runs inminimal environment. So keep it separate from rest of the kernel and inlong term we will have to practically do no maintenance of this code.This code also has the logic to do verify sha256 hashes of varioussegments which have been loaded into memory. So first we verify that thekernel we are jumping to is fine and has not been corrupted and makeprogress 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 Cc: Borislav Petkov Cc: Michael Kerrisk Cc: Yinghai Lu Cc: Eric Biederman Cc: H. Peter Anvin Cc: Matthew Garrett Cc: Greg Kroah-Hartman Cc: Dave Young Cc: WANG Chao Cc: Baoquan He Cc: Andy Lutomirski Signed-off-by: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/x86/Kbuild

b3266bd6 - x86, realmode: realmode.bin infrastructure

Tue, 08 May 2012 18:22:25 +0000

x86, realmode: realmode.bin infrastructureCreate realmode.bin and realmode.relocs files. Piggypack them into relocatable object that will be includedinto .init.data section of the main kernel image.The first file includes binary image of the real-mode code.The latter file includes all relocations. The layout of thebinary image is specified in realmode.lds.S. The makefilegenerates pa_ prefixed symbols for each exported global.These are used in 32-bit code and in realmode header todefine symbols that need to be relocated.Signed-off-by: Jarkko Sakkinen Link: http://lkml.kernel.org/r/1336501366-28617-3-git-send-email-jarkko.sakkinen@intel.comOriginally-by: H. Peter Anvin Signed-off-by: H. Peter Anvin List of files: /linux-6.15/arch/x86/Kbuild

0a14842f - net: filter: Just In Time compiler for x86-64

Wed, 20 Apr 2011 09:27:32 +0000

net: filter: Just In Time compiler for x86-64In order to speedup packet filtering, here is an implementation of aJIT compiler for x86_64It is disabled by default, and must be enabled by the admin.echo 1 >/proc/sys/net/core/bpf_jit_enableIt uses module_alloc() and module_free() to get memory in the 2GB textkernel range since we call helpers functions from the generated code.EAX : BPF A accumulatorEBX : BPF X accumulatorRDI : pointer to skb (first argument given to JIT function)RBP : frame pointer (even if CONFIG_FRAME_POINTER=n)r9d : skb->len - skb->data_len (headlen)r8 : skb->dataTo get a trace of generated code, use :echo 2 >/proc/sys/net/core/bpf_jit_enableExample of generated code :# tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24flen=18 proglen=147 pass=3 image=ffffffffa00b5000JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 beJIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31JIT code: ffffffffa00b5090: c0 c9 c3BPF program is 144 bytes long, so native program is almost same size ;)(000) ldh [12](001) jeq #0x800 jt 2 jf 8(002) ld [26](003) and #0xffffff00(004) jeq #0xc0a81400 jt 16 jf 5(005) ld [30](006) and #0xffffff00(007) jeq #0xc0a81400 jt 16 jf 17(008) jeq #0x806 jt 10 jf 9(009) jeq #0x8035 jt 10 jf 17(010) ld [28](011) and #0xffffff00(012) jeq #0xc0a81400 jt 16 jf 13(013) ld [38](014) and #0xffffff00(015) jeq #0xc0a81400 jt 16 jf 17(016) ret #65535(017) ret #0Signed-off-by: Eric Dumazet Cc: Arnaldo Carvalho de Melo Cc: Ben Hutchings Cc: Hagen Paul Pfeifer Signed-off-by: David S. Miller List of files: /linux-6.15/arch/x86/Kbuild