Changes in Makefile

127b0e05 - vdso: Rename included Makefile

Tue, 04 Feb 2025 12:05:36 +0000

vdso: Rename included MakefileAs the Makefile is included into other Makefiles it can not be used todefine objects to be built from the current source directory.However the generic datastore will introduce such a local source file.Rename the included Makefile so it is clear how it is to be used and tomake room for a regular Makefile in lib/vdso/.Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-4-13a4669dfc8c@linutronix.de List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

712676ea - arm64: vDSO: Wire up getrandom() vDSO implementation

Tue, 03 Sep 2024 12:09:17 +0000

arm64: vDSO: Wire up getrandom() vDSO implementationHook up the generic vDSO implementation to the aarch64 vDSO data page.The _vdso_rng_data required data is placed within the _vdso_data vvarpage, by using a offset larger than the vdso_data.The vDSO function requires a ChaCha20 implementation that does not writeto the stack, and that can do an entire ChaCha20 permutation. The oneprovided uses NEON on the permute operation, with a fallback to thesyscall for chips that do not support AdvSIMD.This also passes the vdso_test_chacha test along withvdso_test_getrandom. The vdso_test_getrandom bench-single result onNeoverse-N1 shows: vdso: 25000000 times in 0.783884250 seconds libc: 25000000 times in 8.780275399 secondssyscall: 25000000 times in 8.786581518 secondsA small fixup to arch/arm64/include/asm/mman.h was required to avoidpulling kernel code into the vDSO, similar to what's already done inarch/arm64/include/asm/rwonce.h.Signed-off-by: Adhemerval Zanella Reviewed-by: Ard Biesheuvel Acked-by: Will Deacon Signed-off-by: Jason A. Donenfeld List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

48f64305 - arm64/vdso: Remove --hash-style=sysv

Thu, 18 Jul 2024 17:34:23 +0000

arm64/vdso: Remove --hash-style=sysvglibc added support for .gnu.hash in 2006 and .hash has been obsoletedfor more than one decade in many Linux distributions. Using--hash-style=sysv might imply unaddressed issues and confuse readers.Just drop the option and rely on the linker default, which is likely"both", or "gnu" when the distribution really wants to eliminate sysvhash overhead.Similar to commit 6b7e26547fad ("x86/vdso: Emit a GNU hash").Signed-off-by: Fangrui Song Link: https://lore.kernel.org/r/20240718173423.1574395-1-maskray@google.comSigned-off-by: Will Deacon List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

7f7f6f7a - Makefile: remove redundant tool coverage variables

Mon, 06 May 2024 13:35:43 +0000

Makefile: remove redundant tool coverage variablesNow Kbuild provides reasonable defaults for objtool, sanitizers, andprofilers.Remove redundant variables.Note:This commit changes the coverage for some objects: - include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV - include arch/sparc/vdso/vdso-image-*.o into UBSAN - include arch/sparc/vdso/vma.o into UBSAN - include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vma.o into GCOV, KCOV - include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOVI believe these are positive effects because all of them are kernelspace objects.Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook Tested-by: Roberto Sassu List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

b1992c37 - kbuild: use $(src) instead of $(srctree)/$(src) for source directory

Sat, 27 Apr 2024 14:55:02 +0000

kbuild: use $(src) instead of $(srctree)/$(src) for source directoryKbuild conventionally uses $(obj)/ for generated files, and $(src)/ forchecked-in source files. It is merely a convention without any functionaldifference. In fact, $(obj) and $(src) are exactly the same, as definedin scripts/Makefile.build: src := $(obj)When the kernel is built in a separate output directory, $(src) doesnot accurately reflect the source directory location. While Kbuildresolves this discrepancy by specifying VPATH=$(srctree) to search forsource files, it does not cover all cases. For example, when adding aheader search path for local headers, -I$(srctree)/$(src) is typicallypassed to the compiler.This introduces inconsistency between upstream and downstream Makefilesbecause $(src) is used instead of $(srctree)/$(src) for the latter.To address this inconsistency, this commit changes the semantics of$(src) so that it always points to the directory in the source tree.Going forward, the variables used in Makefiles will have the followingmeanings: $(obj) - directory in the object tree $(src) - directory in the source tree (changed by this commit) $(objtree) - the top of the kernel object tree $(srctree) - the top of the kernel source treeConsequently, $(srctree)/$(src) in upstream Makefiles need to be replacedwith $(src).Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

56769ba4 - kbuild: unify vdso_install rules

Sat, 14 Oct 2023 10:54:35 +0000

kbuild: unify vdso_install rulesCurrently, there is no standard implementation for vdso_install,leading to various issues: 1. Code duplication Many architectures duplicate similar code just for copying files to the install destination. Some architectures (arm, sparc, x86) create build-id symlinks, introducing more code duplication. 2. Unintended updates of in-tree build artifacts The vdso_install rule depends on the vdso files to install. It may update in-tree build artifacts. This can be problematic, as explained in commit 19514fc665ff ("arm, kbuild: make "make install" not depend on vmlinux"). 3. Broken code in some architectures Makefile code is often copied from one architecture to another without proper adaptation. 'make vdso_install' for parisc does not work. 'make vdso_install' for s390 installs vdso64, but not vdso32.To address these problems, this commit introduces a generic vdso_installrule.Architectures that support vdso_install need to define vdso-install-yin arch/*/Makefile. vdso-install-y lists the files to install.For example, arch/x86/Makefile looks like this: vdso-install-$(CONFIG_X86_64) += arch/x86/entry/vdso/vdso64.so.dbg vdso-install-$(CONFIG_X86_X32_ABI) += arch/x86/entry/vdso/vdsox32.so.dbg vdso-install-$(CONFIG_X86_32) += arch/x86/entry/vdso/vdso32.so.dbg vdso-install-$(CONFIG_IA32_EMULATION) += arch/x86/entry/vdso/vdso32.so.dbgThese files will be installed to $(MODLIB)/vdso/ with the .dbg suffix,if exists, stripped away.vdso-install-y can optionally take the second field after the colonseparator. This is needed because some architectures install a vdsofile as a different base name.The following is a snippet from arch/arm64/Makefile. vdso-install-$(CONFIG_COMPAT_VDSO) += arch/arm64/kernel/vdso32/vdso.so.dbg:vdso32.soThis will rename vdso.so.dbg to vdso32.so during installation. If sucharchitectures change their implementation so that the base names match,this workaround will go away.Signed-off-by: Masahiro Yamada Acked-by: Sven Schnelle # s390Reviewed-by: Nicolas Schier Reviewed-by: Guo Ren Acked-by: Helge Deller # pariscAcked-by: Catalin Marinas Acked-by: Russell King (Oracle) List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

aff69273 - vdso: Improve cmd_vdso_check to check all dynamic relocations

Fri, 10 Mar 2023 19:07:50 +0000

vdso: Improve cmd_vdso_check to check all dynamic relocationsThe actual intention is that no dynamic relocation exists in the VDSO. Forthis the VDSO build validates that the resulting .so file does not have anyrelocations which are specified via $(ARCH_REL_TYPE_ABS) per architecture,which is fragile as e.g. ARM64 lacks an entry for R_AARCH64_RELATIVE. Asideof that ARCH_REL_TYPE_ABS is a misnomer as it checks for relativerelocations too.However, some GNU ld ports produce unneeded R_*_NONE relocation entries. Ifa port fails to determine the exact .rel[a].dyn size, the trailing zerosbecome R_*_NONE relocations. E.g. ld's powerpc port recently fixedhttps://sourceware.org/bugzilla/show_bug.cgi?id=29540). R_*_NONE aregenerally a no-op in the dynamic loaders. So just ignore them.Remove the ARCH_REL_TYPE_ABS defines and just validate that the resulting.so file does not contain any R_* relocation entries except R_*_NONE.Signed-off-by: Fangrui Song Signed-off-by: Thomas Gleixner Tested-by: Vincenzo Frascino # for aarch64Reviewed-by: Christophe Leroy Reviewed-by: Vincenzo Frascino # for vDSO, aarch64Acked-by: Michael Ellerman (powerpc)Link: https://lore.kernel.org/r/20230310190750.3323802-1-maskray@google.com List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

e1789d7c - kbuild: upgrade the orphan section warning to an error if CONFIG_WERROR is set

Tue, 25 Oct 2022 07:30:23 +0000

kbuild: upgrade the orphan section warning to an error if CONFIG_WERROR is setAndrew Cooper suggested upgrading the orphan section warning to a hard linkerror. However Nathan Chancellor said outright turning the warning into anerror with no escape hatch might be too aggressive, as we have had thesewarnings triggered by new compiler generated sections, and suggested turningorphan sections into an error only if CONFIG_WERROR is set. Kees Cook echoedand emphasized that the mandate from Linus is that we should avoid breakingbuilds. It wrecks bisection, it causes problems across compiler versions, etc.Thus upgrade the orphan section warning to a hard link error only ifCONFIG_WERROR is set.Suggested-by: Andrew Cooper Suggested-by: Nathan Chancellor Signed-off-by: Xin Li Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20221025073023.16137-2-xin3.li@intel.com List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

f143ff39 - treewide: Filter out CC_FLAGS_CFI

Thu, 08 Sep 2022 21:54:43 +0000

treewide: Filter out CC_FLAGS_CFIIn preparation for removing CC_FLAGS_CFI from CC_FLAGS_LTO, explicitlyfilter out CC_FLAGS_CFI in all the makefiles where we currently filterout CC_FLAGS_LTO.Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Tested-by: Kees Cook Tested-by: Nathan Chancellor Acked-by: Peter Zijlstra (Intel) Tested-by: Peter Zijlstra (Intel) Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220908215504.3686827-2-samitolvanen@google.com List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

e0ab20b2 - arm64: vdso: enable orphan handling for VDSO

Tue, 10 May 2022 09:58:32 +0000

arm64: vdso: enable orphan handling for VDSOLike vmlinux, enable orphan-handling for the VDSO. This can catchsubtle errors that might arise from unexpected sections being included.Signed-off-by: Joey Gouly Cc: Catalin Marinas Cc: Will Deacon Cc: Masahiro Yamada Cc: Vincenzo Frascino Cc: Kees Cook Reviewed-by: Kees Cook Reviewed-by: Vincenzo Frascino Link: https://lore.kernel.org/r/20220510095834.32394-3-joey.gouly@arm.comSigned-off-by: Will Deacon List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

205f3991 - arm64: vdso: fix makefile dependency on vdso.so

Tue, 10 May 2022 10:27:21 +0000

arm64: vdso: fix makefile dependency on vdso.soThere is currently no dependency for vdso*-wrap.S on vdso*.so, which means thatyou can get a build that uses a stale vdso*-wrap.o.In commit a5b8ca97fbf8, the file that includes the vdso.so was moved and renamedfrom arch/arm64/kernel/vdso/vdso.S to arch/arm64/kernel/vdso-wrap.S, when thishappened the Makefile was not updated to force the dependcy on vdso.so.Fixes: a5b8ca97fbf8 ("arm64: do not descend to vdso directories twice")Signed-off-by: Joey Gouly Cc: Masahiro Yamada Cc: Vincenzo Frascino Cc: Catalin Marinas Cc: Will Deacon Link: https://lore.kernel.org/r/20220510102721.50811-1-joey.gouly@arm.comSigned-off-by: Will Deacon List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

613f4b3e - randstruct: Split randstruct Makefile and CFLAGS

Tue, 03 May 2022 20:55:01 +0000

randstruct: Split randstruct Makefile and CFLAGSTo enable the new Clang randstruct implementation[1], moverandstruct into its own Makefile and split the CFLAGS fromGCC_PLUGINS_CFLAGS into RANDSTRUCT_CFLAGS.[1] https://reviews.llvm.org/D121556Cc: linux-hardening@vger.kernel.orgSigned-off-by: Kees Cook Link: https://lore.kernel.org/r/20220503205503.3054173-5-keescook@chromium.org List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

58cd4a08 - arm64: vdso: Fix "no previous prototype" warning

Fri, 21 Jan 2022 12:12:34 +0000

arm64: vdso: Fix "no previous prototype" warningIf compiling the arm64 kernel with W=1 the following warning is produced:| arch/arm64/kernel/vdso/vgettimeofday.c:9:5: error: no previous prototype for ‘__kernel_clock_gettime’ [-Werror=missing-prototypes]| 9 | int __kernel_clock_gettime(clockid_t clock,| | ^~~~~~~~~~~~~~~~~~~~~~| arch/arm64/kernel/vdso/vgettimeofday.c:15:5: error: no previous prototype for ‘__kernel_gettimeofday’ [-Werror=missing-prototypes]| 15 | int __kernel_gettimeofday(struct __kernel_old_timeval *tv,| | ^~~~~~~~~~~~~~~~~~~~~| arch/arm64/kernel/vdso/vgettimeofday.c:21:5: error: no previous prototype for ‘__kernel_clock_getres’ [-Werror=missing-prototypes]| 21 | int __kernel_clock_getres(clockid_t clock_id,| | ^~~~~~~~~~~~~~~~~~~~~This patch removes "-Wmissing-prototypes" and "-Wmissing-declarations" compilersflags from the compilation of vgettimeofday.c to make possible to build thekernel with CONFIG_WERROR enabled.Cc: Will Deacon Reported-by: Marc Kleine-Budde Signed-off-by: Vincenzo Frascino Tested-by: Marc Kleine-Budde Link: https://lore.kernel.org/r/20220121121234.47273-1-vincenzo.frascino@arm.comSigned-off-by: Catalin Marinas List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

dd03762a - arm64: Enable KCSAN

Sat, 11 Dec 2021 13:17:34 +0000

arm64: Enable KCSANThis patch enables KCSAN for arm64, with updates to build rulesto not use KCSAN for several incompatible compilation units.Recent GCC version(at least GCC10) made outline-atomics as thedefault option(unlike Clang), which will cause linker errorsfor kernel/kcsan/core.o. Disables the out-of-line atomics byno-outline-atomics to fix the linker errors.Meanwhile, as Mark said[1], some latent issues are needed to befixed which isn't just a KCSAN problem, we make the KCSAN dependson EXPERT for now.Tested selftest and kcsan_test(built with GCC11 and Clang 13),and all passed.[1] https://lkml.kernel.org/r/YadiUPpJ0gADbiHQ@FVFF77S0Q05NAcked-by: Marco Elver # kernel/kcsanTested-by: Joey Gouly Signed-off-by: Kefeng Wang Link: https://lore.kernel.org/r/20211211131734.126874-1-wangkefeng.wang@huawei.com[catalin.marinas@arm.com: added comment to justify EXPERT]Signed-off-by: Catalin Marinas List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

34688c76 - arm64: vdso: remove -nostdlib compiler flag

Sun, 07 Nov 2021 16:18:02 +0000

arm64: vdso: remove -nostdlib compiler flagThe -nostdlib option requests the compiler to not use the standardsystem startup files or libraries when linking. It is effective onlywhen $(CC) is used as a linker driver.Since commit 691efbedc60d ("arm64: vdso: use $(LD) instead of $(CC)to link VDSO"), $(LD) is directly used, hence -nostdlib is unneeded.Signed-off-by: Masahiro Yamada Link: https://lore.kernel.org/r/20211107161802.323125-1-masahiroy@kernel.orgSigned-off-by: Will Deacon List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

a5b8ca97 - arm64: do not descend to vdso directories twice

Fri, 18 Dec 2020 02:45:40 +0000

arm64: do not descend to vdso directories twicearm64 descends into each vdso directory twice; first in vdso_prepare,second during the ordinary build process.PPC mimicked it and uncovered a problem [1]. In the first descend,Kbuild directly visits the vdso directories, therefore it does notinherit subdir-ccflags-y from upper directories.This means the command line parameters may differ between the two.If it happens, the offset values in the generated headers might bedifferent from real offsets of vdso.so in the kernel.This potential danger should be avoided. The vdso directories arebuilt in the vdso_prepare stage, so the second descend is unneeded.[1]: https://lore.kernel.org/linux-kbuild/CAK7LNARAkJ3_-4gX0VA2UkapbOftuzfSTVMBbgbw=HD8n7N+7w@mail.gmail.com/T/#ma10dcb961fda13f36d42d58fa6cb2da988b7e73aSigned-off-by: Masahiro Yamada Link: https://lore.kernel.org/r/20201218024540.1102650-1-masahiroy@kernel.orgSigned-off-by: Will Deacon List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

004d53f8 - arm64: vdso: disable LTO

Fri, 11 Dec 2020 18:46:31 +0000

arm64: vdso: disable LTODisable LTO for the vDSO by filtering out CC_FLAGS_LTO, as there's nopoint in using link-time optimization for the small amount of C code.Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Acked-by: Will Deacon Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20201211184633.3213045-15-samitolvanen@google.com List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

e2bba5f9 - arm64: vdso: disable .eh_frame_hdr via /DISCARD/ instead of --no-eh-frame-hdr

Wed, 30 Dec 2020 22:19:54 +0000

arm64: vdso: disable .eh_frame_hdr via /DISCARD/ instead of --no-eh-frame-hdrCurrently with ld.lld we emit an empty .eh_frame_hdr section (and acorresponding program header) into the vDSO. With ld.bfd the sectionis not emitted but the program header is, with p_vaddr set to 0. Thiscan lead to unwinders attempting to interpret the data at whicheverlocation the program header happens to point to as an unwind infoheader. This happens to be mostly harmless as long as the byte atthat location (interpreted as a version number) has a value otherthan 1, causing both libgcc and LLVM libunwind to ignore the section(in libunwind's case, after printing an error message to stderr),but it could lead to worse problems if the byte happened to be 1 orthe program header points to non-readable memory (e.g. if the emptysection was placed at a page boundary).Instead of disabling .eh_frame_hdr via --no-eh-frame-hdr (whichalso has the downside of being unsupported by older versions of GNUbinutils), disable it by discarding the section, and stop emittingthe program header that points to it.I understand that we intend to emit valid unwind info for the vDSOat some point. Once that happens this patch can be reverted.Signed-off-by: Peter Collingbourne Acked-by: Ard Biesheuvel Acked-by: Vincenzo Frascino Link: https://linux-review.googlesource.com/id/If745fd9cadcb31b4010acbf5693727fe111b0863Link: https://lore.kernel.org/r/20201230221954.2007257-1-pcc@google.comSigned-off-by: Catalin Marinas List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

e35123d8 - arm64: lto: Strengthen READ_ONCE() to acquire when CONFIG_LTO=y

Tue, 30 Jun 2020 13:02:48 +0000

arm64: lto: Strengthen READ_ONCE() to acquire when CONFIG_LTO=yWhen building with LTO, there is an increased risk of the compilerconverting an address dependency headed by a READ_ONCE() invocationinto a control dependency and consequently allowing for harmfulreordering by the CPU.Ensure that such transformations are harmless by overriding the genericREAD_ONCE() definition with one that provides acquire semantics whenbuilding with LTO.Acked-by: Peter Zijlstra (Intel) Acked-by: Mark Rutland Signed-off-by: Will Deacon List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile

0f6372e5 - treewide: remove DISABLE_LTO

Tue, 13 Oct 2020 00:31:45 +0000

treewide: remove DISABLE_LTOThis change removes all instances of DISABLE_LTO fromMakefiles, as they are currently unused, and the preferredmethod of disabling LTO is to filter out the flags instead.Note added by Masahiro Yamada:DISABLE_LTO was added as preparation for GCC LTO, but GCC LTO wasnot pulled into the mainline. (https://lkml.org/lkml/2014/4/8/272)Suggested-by: Kees Cook Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Signed-off-by: Masahiro Yamada List of files: /linux-6.15/arch/arm64/kernel/vdso/Makefile