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/s390/kernel/vdso64/Makefile

27939d6c - s390/Kconfig: Select VMAP_STACK unconditionally

Mon, 02 Dec 2024 11:56:38 +0000

s390/Kconfig: Select VMAP_STACK unconditionallyThere is no point in supporting !VMAP_STACK kernel builds. VMAP_STACK hasproven to work since many years. Also, since KASAN_VMALLOC is supported,kernels built with !VMAP_STACK are completely untested.Therefore select VMAP_STACK unconditionally and remove all config optionsand code required for !VMAP_STACK builds.Acked-by: Christian Borntraeger Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev List of files: /linux-6.15/arch/s390/kernel/vdso64/Makefile

b920aa77 - s390/vdso: Wire up getrandom() vdso implementation

Fri, 13 Sep 2024 13:05:43 +0000

s390/vdso: Wire up getrandom() vdso implementationProvide the s390 specific vdso getrandom() architecture backend._vdso_rng_data required data is placed within the _vdso_data vvar page,by using a hardcoded offset larger than vdso_data.As required the chacha20 implementation does not write to the stack.The implementation follows more or less the arm64 implementations andmakes use of vector instructions. It has a fallback to the getrandom()system call for machines where the vector facility is not installed.The check if the vector facility is installed, as well as anoptimization for machines with the vector-enhancements facility 2, isimplemented with alternatives, avoiding runtime checks.Note that __kernel_getrandom() is implemented without the vdso userwrapper which would setup a stack frame for odd cases (aka very oldglibc variants) where the caller has not done that. All callers of__kernel_getrandom() are required to setup a stack frame, like the C ABIrequires it.The vdso testcases vdso_test_getrandom and vdso_test_chacha pass.Benchmark on a z16: $ ./vdso_test_getrandom bench-single vdso: 25000000 times in 0.493703559 seconds syscall: 25000000 times in 6.584025337 secondsSigned-off-by: Heiko Carstens Reviewed-by: Harald Freudenberger Signed-off-by: Jason A. Donenfeld List of files: /linux-6.15/arch/s390/kernel/vdso64/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/s390/kernel/vdso64/Makefile

185445c7 - s390/vdso: Use standard stack frame layout

Mon, 29 Apr 2024 12:28:43 +0000

s390/vdso: Use standard stack frame layoutBy default user space is compiled with standard stack frame layout and notwith the packed stack layout. The vdso code however inherited the-mpacked-stack compiler option from the kernel. Remove this option to makesure the vdso is compiled with standard stack frame layout.This makes sure that the stack frame backchain location for vdso generatedstack frames is the same like for calling code (if compiled with defaultoptions). This allows to manually walk stack frames without DWARFinformation, like the kernel is doing it e.g. with arch_stack_walk_user().Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO")Reviewed-by: Jens Remus Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev List of files: /linux-6.15/arch/s390/kernel/vdso64/Makefile

10f70525 - s390/vdso: Generate unwind information for C modules

Mon, 29 Apr 2024 15:02:52 +0000

s390/vdso: Generate unwind information for C modulesGDB fails to unwind vDSO functions with error message "PC not saved",for instance when stepping through gettimeofday().Add -fasynchronous-unwind-tables to CFLAGS to generate .eh_frameDWARF unwind information for the vDSO C modules.Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO")Signed-off-by: Jens Remus Signed-off-by: Alexander Gordeev List of files: /linux-6.15/arch/s390/kernel/vdso64/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/s390/kernel/vdso64/Makefile

b957df3b - arch: use $(obj)/ instead of $(src)/ for preprocessed linker scripts

Sat, 27 Apr 2024 14:54:59 +0000

arch: use $(obj)/ instead of $(src)/ for preprocessed linker scriptsThese are generated files. Prefix them with $(obj)/ instead of $(src)/.Signed-off-by: Masahiro Yamada Acked-by: Helge Deller Reviewed-by: Nicolas Schier List of files: /linux-6.15/arch/s390/kernel/vdso64/Makefile

8192a1b3 - s390/vdso64: filter out munaligned-symbols flag for vdso

Mon, 19 Feb 2024 13:27:31 +0000

s390/vdso64: filter out munaligned-symbols flag for vdsoGcc recently implemented an optimization [1] for loading symbols withoutexplicit alignment, aligning with the IBM Z ELF ABI. This ABI mandatessymbols to reside on a 2-byte boundary, enabling the use of the larlinstruction. However, kernel linker scripts may still generate unalignedsymbols. To address this, a new -munaligned-symbols option has beenintroduced [2] in recent gcc versions.[1] https://gcc.gnu.org/pipermail/gcc-patches/2023-June/622872.html[2] https://gcc.gnu.org/pipermail/gcc-patches/2023-August/625986.htmlHowever, when -munaligned-symbols is used in vdso code, it leads to thefollowing compilation error:`.data.rel.ro.local' referenced in section `.text' ofarch/s390/kernel/vdso64/vdso64_generic.o: defined in discarded section`.data.rel.ro.local' of arch/s390/kernel/vdso64/vdso64_generic.ovdso linker script discards .data section to make it lightweight.However, -munaligned-symbols in vdso object files references literalpool and accesses _vdso_data. Hence, compile vdso code without-munaligned-symbols. This means in the future, vdso code should dealwith alignment of newly introduced unaligned linker symbols.Acked-by: Vasily Gorbik Signed-off-by: Sumanth Korikkar Link: https://lore.kernel.org/r/20240219132734.22881-2-sumanthk@linux.ibm.comSigned-off-by: Heiko Carstens List of files: /linux-6.15/arch/s390/kernel/vdso64/Makefile

0628c039 - s390/vdso: drop '-fPIC' from LDFLAGS

Wed, 31 Jan 2024 03:14:28 +0000

s390/vdso: drop '-fPIC' from LDFLAGS'-fPIC' as an option to the linker does not do what it seems like itshould. With ld.bfd, it is treated as '-f PIC', which does not makesense based on the meaning of '-f': -f SHLIB, --auxiliary SHLIB Auxiliary filter for shared object symbol tableWhen building with ld.lld (currently under review in a GitHub pullrequest), it just errors out because '-f' means nothing and neither does'-fPIC': ld.lld: error: unknown argument '-fPIC''-fPIC' was blindly copied from CFLAGS when the vDSO stopped beinglinked with '$(CC)', it should not be needed. Remove it to clear up thebuild failure with ld.lld.Fixes: 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO")Link: https://github.com/llvm/llvm-project/pull/75643Signed-off-by: Nathan Chancellor Reviewed-by: Fangrui Song Link: https://lore.kernel.org/r/20240130-s390-vdso-drop-fpic-from-ldflags-v1-1-094ad104fc55@kernel.orgSigned-off-by: Heiko Carstens List of files: /linux-6.15/arch/s390/kernel/vdso64/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/s390/kernel/vdso64/Makefile

d15e4314 - s390/vdso: filter out mno-pic-data-is-text-relative cflag

Fri, 23 Jun 2023 13:12:05 +0000

s390/vdso: filter out mno-pic-data-is-text-relative cflagcmd_vdso_check checks if there are any dynamic relocations invdso64.so.dbg. When kernel is compiled with-mno-pic-data-is-text-relative, R_390_RELATIVE relocs are generated andthis results in kernel build error.kpatch uses -mno-pic-data-is-text-relative option when building thekernel to prevent relative addressing between code and data. The flagavoids relocation error when klp text and data are too far apartkpatch does not patch vdso code and hence themno-pic-data-is-text-relative flag is not essential.Signed-off-by: Sumanth Korikkar Acked-by: Ilya Leoshkevich Signed-off-by: Alexander Gordeev List of files: /linux-6.15/arch/s390/kernel/vdso64/Makefile

0dd0bbc2 - s390/vdso: check for undefined symbols after build

Wed, 21 Jun 2023 07:18:52 +0000

s390/vdso: check for undefined symbols after buildWhen adding an undefined symbol the build still succeeds, butuserspace is crashing trying to execute vdso because theundefined symbol is not resolved. Add the check for undefinedsymbols to prevent this.Signed-off-by: Sven Schnelle Acked-by: Heiko Carstens Signed-off-by: Alexander Gordeev List of files: /linux-6.15/arch/s390/kernel/vdso64/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/s390/kernel/vdso64/Makefile

fd8589dc - s390/vdso: Drop '-shared' from KBUILD_CFLAGS_64

Thu, 12 Jan 2023 03:05:07 +0000

s390/vdso: Drop '-shared' from KBUILD_CFLAGS_64When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, itpoints out that there is a linking phase flag added to CFLAGS, whichwill only be used for compiling clang-16: error: argument unused during compilation: '-shared' [-Werror,-Wunused-command-line-argument]'-shared' is already present in ldflags-y so it can just be dropped.Fixes: 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO")Signed-off-by: Nathan Chancellor Acked-by: Heiko Carstens Reviewed-by: Sven Schnelle Tested-by: Linux Kernel Functional Testing Tested-by: Anders Roxell Signed-off-by: Masahiro Yamada List of files: /linux-6.15/arch/s390/kernel/vdso64/Makefile

f8210229 - s390/vdso: Drop unused '-s' flag from KBUILD_AFLAGS_64

Thu, 12 Jan 2023 03:05:06 +0000

s390/vdso: Drop unused '-s' flag from KBUILD_AFLAGS_64When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, itwarns: clang-16: error: argument unused during compilation: '-s' [-Werror,-Wunused-command-line-argument]The compiler's '-s' flag is a linking option (it is passed along to thelinker directly), which means it does nothing when the linker is notinvoked by the compiler. The kernel builds all .o files with '-c', whichstops the compilation pipeline before linking, so '-s' can be safelydropped from KBUILD_AFLAGS_64.Signed-off-by: Nathan Chancellor Acked-by: Heiko Carstens Reviewed-by: Sven Schnelle Tested-by: Linux Kernel Functional Testing Tested-by: Anders Roxell Signed-off-by: Masahiro Yamada List of files: /linux-6.15/arch/s390/kernel/vdso64/Makefile

00b55eaf - s390/vdso: filter out -mstack-guard and -mstack-size

Thu, 11 Nov 2021 09:58:26 +0000

s390/vdso: filter out -mstack-guard and -mstack-sizeWhen CONFIG_VMAP_STACK is disabled, the user can enable CONFIG_STACK_CHECK,which adds a stack overflow check to each C function in the kernel. This isalso done for functions in the vdso page. These functions are run in usercontext and user stack sizes are usually different to what the kernel uses.This might trigger the stack check although the stack size is valid.Therefore filter the -mstack-guard and -mstack-size flags when compilingvdso C files.Cc: stable@kernel.org # 5.10+Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO")Reported-by: Janosch Frank Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Heiko Carstens List of files: /linux-6.15/arch/s390/kernel/vdso64/Makefile

7b737adc - s390/vdso: remove -nostdlib compiler flag

Sun, 07 Nov 2021 16:21:11 +0000

s390/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 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) tolink vDSO"), $(LD) is directly used, hence -nostdlib is unneeded.Signed-off-by: Masahiro Yamada Link: https://lore.kernel.org/r/20211107162111.323701-1-masahiroy@kernel.orgSigned-off-by: Heiko Carstens List of files: /linux-6.15/arch/s390/kernel/vdso64/Makefile

e37b3dd0 - s390: enable KCSAN

Wed, 28 Jul 2021 11:59:04 +0000

s390: enable KCSANs390x GCC and SystemZ Clang have ThreadSanitizer support now [1] [2],so enable KCSAN for s390.[1] https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=ea22954e7c58[2] https://reviews.llvm.org/D105629Signed-off-by: Ilya Leoshkevich Signed-off-by: Heiko Carstens List of files: /linux-6.15/arch/s390/kernel/vdso64/Makefile

779df224 - s390/vdso: add minimal compat vdso

Fri, 25 Jun 2021 12:50:08 +0000

s390/vdso: add minimal compat vdsoAdd a small vdso for 31 bit compat application that providestrampolines for calls to sigreturn,rt_sigreturn,syscall_restart.This is requird for moving these syscalls away from the signalframe to the vdso. Note that this patch effectively disablesCONFIG_COMPAT when using clang to compile the kernel. clangdoesn't support 31 bit mode.We want to redirect sigreturn and restart_syscall to the vdso. However,the kernel cannot parse the ELF vdso file, so we need to generate headerfiles which contain the offsets of the syscall instructions in the vdsopage.Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik List of files: /linux-6.15/arch/s390/kernel/vdso64/Makefile