Changes in Makefile

eb13a1ff271b0d180687eebb30611b0b276d5193 - random: vDSO: avoid call to memset() when zeroing reserved parameter

Fri, 25 Sep 2026 23:46:32 +0200

random: vDSO: avoid call to memset() when zeroing reserved parameterAfter a recent change in LLVM [1], builds with the random vDSOimplementation, such as PowerPC and RISC-V, fail when checking the vDSO: arch/powerpc/kernel/vdso/vdso32.so.dbg: dynamic relocations are not supported arch/riscv/kernel/vdso/vdso.so.dbg: dynamic relocations are not supportedmemset() is now generated when zeroing params->reserved for some buildsbecause LLVM has an optimization (now run in more instances) that canrecognize at compile time when it is assigning a static value to acontiguous area of memory and turn that into a call to memset(). Bothclang and GCC assume memset() is always available [2].Clang has an internal fiddly hook, -max-store-memset, which we can setto a high number, to disable generating out of line memset calls [3].Similarly, GCC has -finline-stringops=memset to do the same [4], shouldthis issue ever hit future version of GCC. While these options wouldn'tmake sense for normal kernel code, it is fine for the extremely limitedand intentionally compact vDSO code.Link: https://github.com/llvm/llvm-project/commit/90cebef1411617fc3eedd359bdf00cb44b1c2439 [1]Link: https://gcc.gnu.org/onlinedocs/gcc-16.2.0/gcc/Standards.html#index-ffreestanding [2]Link: https://github.com/llvm/llvm-project/commit/b28eeb28bea39148738dc375e8a97072a1907e64 [3]Link: https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html#index-finline-stringops [4]Closes: https://github.com/ClangBuiltLinux/linux/issues/2183Cc: stable@vger.kernel.org # v6.12+Signed-off-by: Nathan Chancellor Signed-off-by: Jason A. Donenfeld List of files: /linux/arch/riscv/kernel/vdso/Makefile

9cfff2edcc5ef84bdbf91892b7e127a41b9db35f - riscv: vdso: Simplify cflags remove logic

Sat, 08 Aug 2026 03:24:30 +0200

riscv: vdso: Simplify cflags remove logicListing all flags for each object file is tedious and error-prone.Replace it with a simpler solution.Link: https://lore.kernel.org/all/20260630135316-f26f0e0f-c08c-4d4d-9963-10f9985a7689@linutronix.de/Signed-off-by: Thomas Weißschuh Link: https://patch.msgid.link/20260701-riscv-vdso-lto-v1-2-89db0cd82077@linutronix.deSigned-off-by: Paul Walmsley List of files: /linux/arch/riscv/kernel/vdso/Makefile

ad6dcfa023762e37962f77ee48e752b7570e9440 - riscv: vdso: Do not use LTO for the vDSO

Wed, 01 Jul 2026 11:21:22 +0200

riscv: vdso: Do not use LTO for the vDSOWith LTO enabled the compiler assumes that the vDSO functions are notused and optimizes them away completely. Currently this happens to__vdso_clock_getres(), __vdso_clock_gettime(), __vdso_getrandom(),__vdso_gettimeofday() and __vdso_riscv_hwprobe().Disable LTO for the vDSO, as these functions are hand-optimized anyways.Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202606301855.WvkSC4kD-lkp@intel.com/Fixes: 021d23428bdb ("RISC-V: build: Allow LTO to be selected")Cc: stable@vger.kernel.orgSigned-off-by: Thomas Weißschuh Link: https://patch.msgid.link/20260701-riscv-vdso-lto-v1-1-89db0cd82077@linutronix.deSigned-off-by: Paul Walmsley List of files: /linux/arch/riscv/kernel/vdso/Makefile

ccad8c1336b6511e3c7ca5c02f797b1fd2cf67e1 - arch/riscv: add dual vdso creation logic and select vdso based on hw

Mon, 26 Jan 2026 05:09:56 +0100

arch/riscv: add dual vdso creation logic and select vdso based on hwShadow stack instructions are taken from the Zimop ISA extension,which is mandated on RVA23. Any userspace with shadow stackinstructions in it will fault on hardware that doesn't have supportfor Zimop. Thus, a shadow stack-enabled userspace can't be run onhardware that doesn't support Zimop.It's not known how Linux userspace providers will respond to this kindof binary fragmentation. In order to keep kernel portable acrossdifferent hardware, 'arch/riscv/kernel/vdso_cfi' is created which hasMakefile logic to compile 'arch/riscv/kernel/vdso' sources with CFIflags, and 'arch/riscv/kernel/vdso.c' is modified to select theappropriate vdso depending on whether the underlying CPU implementsthe Zimop extension. Since the offset of vdso symbols will change dueto having two different vdso binaries, there is added logic to includea new generated vdso offset header and dynamically select the offset(like for rt_sigreturn).Signed-off-by: Deepak Gupta Acked-by: Charles Mirabile Tested-by: Andreas Korb # QEMU, custom CVA6Tested-by: Valentin Haudiquet Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-24-b55691eacf4f@rivosinc.com[pjw@kernel.org: cleaned up patch description]Signed-off-by: Paul Walmsley List of files: /linux/arch/riscv/kernel/vdso/Makefile

37f57bd3faeac92e898c3381355f4fd2b6a80901 - arch/riscv: compile vdso with landing pad and shadow stack note

Mon, 26 Jan 2026 05:09:56 +0100

arch/riscv: compile vdso with landing pad and shadow stack noteUser mode tasks compiled with Zicfilp may call indirectly into thevdso (like hwprobe indirect calls). Add support for compiling landingpads into the vdso. Landing pad instructions in the vdso will beno-ops for tasks which have not enabled landing pads. Furthermore, addsupport for the C sources of the vdso to be compiled with shadow stackand landing pads enabled as well.Landing pad and shadow stack instructions are emitted only when theVDSO_CFI cflags option is defined during compile.Signed-off-by: Jim Shu Reviewed-by: Zong Li Signed-off-by: Deepak Gupta Tested-by: Andreas Korb # QEMU, custom CVA6Tested-by: Valentin Haudiquet Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-23-b55691eacf4f@rivosinc.com[pjw@kernel.org: cleaned up patch description, issues reported by checkpatch]Signed-off-by: Paul Walmsley List of files: /linux/arch/riscv/kernel/vdso/Makefile

2670a39b1ea68fb0b9175e26e299f3fe974e0332 - Merge tag 'riscv-mw2-6.16-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/alexghiti/linux into for-next

Thu, 05 Jun 2025 20:23:07 +0200

Merge tag 'riscv-mw2-6.16-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/alexghiti/linux into for-nextriscv patches for 6.16-rc1, part 2* Performance improvements - Add support for vdso getrandom - Implement raid6 calculations using vectors - Introduce svinval tlb invalidation* Cleanup - A bunch of deduplication of the macros we use for manipulating instructions* Misc - Introduce a kunit test for kprobes - Add support for mseal as riscv fits the requirements (thanks to Lorenzo for making sure of that :))[Palmer: There was a rebase between part 1 and part 2, so I've had to dosome more git surgery here... at least two rounds of surgery...]* alex-pr-2: (866 commits) RISC-V: vDSO: Wire up getrandom() vDSO implementation riscv: enable mseal sysmap for RV64 raid6: Add RISC-V SIMD syndrome and recovery calculations riscv: mm: Add support for Svinval extension riscv: Add kprobes KUnit test riscv: kprobes: Remove duplication of RV_EXTRACT_ITYPE_IMM riscv: kprobes: Remove duplication of RV_EXTRACT_UTYPE_IMM riscv: kprobes: Remove duplication of RV_EXTRACT_RD_REG riscv: kprobes: Remove duplication of RVC_EXTRACT_BTYPE_IMM riscv: kprobes: Remove duplication of RVC_EXTRACT_C2_RS1_REG riscv: kproves: Remove duplication of RVC_EXTRACT_JTYPE_IMM riscv: kprobes: Remove duplication of RV_EXTRACT_BTYPE_IMM riscv: kprobes: Remove duplication of RV_EXTRACT_RS1_REG riscv: kprobes: Remove duplication of RV_EXTRACT_JTYPE_IMM riscv: kprobes: Move branch_funct3 to insn.h riscv: kprobes: Move branch_rs2_idx to insn.h Linux 6.15-rc6 Input: xpad - fix xpad_device sorting Input: xpad - add support for several more controllers Input: xpad - fix Share button on Xbox One controllers ... List of files: /linux/arch/riscv/kernel/vdso/Makefile

ee0d03053e7009a3a3532fb37f6c94bfa0a8cca3 - RISC-V: vDSO: Wire up getrandom() vDSO implementation

Fri, 11 Apr 2025 04:46:00 +0200

RISC-V: vDSO: Wire up getrandom() vDSO implementationHook up the generic vDSO implementation to the generic vDSO getrandomimplementation by providing the required __arch_chacha20_blocks_nostackand getrandom_syscall implementations. Also wire up the selftests.The benchmark result: vdso: 25000000 times in 2.466341333 seconds libc: 25000000 times in 41.447720005 seconds syscall: 25000000 times in 41.043926672 seconds vdso: 25000000 x 256 times in 162.286219353 seconds libc: 25000000 x 256 times in 2953.855018685 seconds syscall: 25000000 x 256 times in 2796.268546000 seconds[ alex: - Fix dynamic relocation - Squash Nathan's fix https://lore.kernel.org/all/20250423-riscv-fix-compat_vdso-lld-v2-1-b7bbbc244501@kernel.org/ - Add comment from Loongarch ]Signed-off-by: Xi Ruoyao Link: https://lore.kernel.org/r/20250411024600.16045-1-xry111@xry111.siteTested-by: Alexandre Ghiti Signed-off-by: Alexandre Ghiti Signed-off-by: Palmer Dabbelt List of files: /linux/arch/riscv/kernel/vdso/Makefile

2f956db8b3b02256b21da4d1f26fedc63782adff - Revert "RISC-V: vDSO: Wire up getrandom() vDSO implementation"

Mon, 02 Jun 2025 19:33:15 +0200

Revert "RISC-V: vDSO: Wire up getrandom() vDSO implementation"This has been on -next for a bit, but it's broken and there's already av2. So I'm reverting it to avoid more rebasing.This reverts commit 89079520cef65d6da1e864eab4464effe5396e23.Link: https://lore.kernel.org/r/20250602173315.20228-1-palmer@dabbelt.comSigned-off-by: Palmer Dabbelt List of files: /linux/arch/riscv/kernel/vdso/Makefile

2940954c1ac527386e5203d4be8263d704491fbe - riscv: vDSO: Remove --hash-style=both

Mon, 24 Feb 2025 12:20:40 +0100

riscv: vDSO: Remove --hash-style=bothWhen RISC-V borned, DT_GNU_HASH had already became the de-factostandard so DT_HASH is just wasting storage space. Remove the explicit--hash-style=both setting and rely on the distro toolchain default,which is most likely "gnu" (i.e. generating only DT_GNU_HASH, noDT_HASH).Following the logic of commit 48f6430505c0("arm64/vdso: Remove --hash-style=sysv").Signed-off-by: Xi Ruoyao Link: https://lore.kernel.org/r/20250224112042.60282-2-xry111@xry111.siteSigned-off-by: Palmer Dabbelt List of files: /linux/arch/riscv/kernel/vdso/Makefile

89079520cef65d6da1e864eab4464effe5396e23 - RISC-V: vDSO: Wire up getrandom() vDSO implementation

Fri, 11 Apr 2025 04:46:00 +0200

RISC-V: vDSO: Wire up getrandom() vDSO implementationHook up the generic vDSO implementation to the generic vDSO getrandomimplementation by providing the required __arch_chacha20_blocks_nostackand getrandom_syscall implementations. Also wire up the selftests.The benchmark result: vdso: 25000000 times in 2.466341333 seconds libc: 25000000 times in 41.447720005 seconds syscall: 25000000 times in 41.043926672 seconds vdso: 25000000 x 256 times in 162.286219353 seconds libc: 25000000 x 256 times in 2953.855018685 seconds syscall: 25000000 x 256 times in 2796.268546000 secondsSigned-off-by: Xi Ruoyao Link: https://lore.kernel.org/r/20250411024600.16045-1-xry111@xry111.siteSigned-off-by: Palmer Dabbelt List of files: /linux/arch/riscv/kernel/vdso/Makefile

127b0e05c1669d240426719b3b9db8a8366eed50 - vdso: Rename included Makefile

Tue, 04 Feb 2025 13:05:36 +0100

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/arch/riscv/kernel/vdso/Makefile

c6898d66fd198cd458734da40e414361f295de6a - riscv: Check that vdso does not contain any dynamic relocations

Wed, 16 Oct 2024 10:36:25 +0200

riscv: Check that vdso does not contain any dynamic relocationsLike other architectures, use the common cmd_vdso_check to make sure ofthat.Reviewed-by: Björn Töpel Tested-by: Vladimir Isaev Signed-off-by: Alexandre Ghiti Reviewed-by: Guo Ren Link: https://lore.kernel.org/r/20241016083625.136311-3-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt List of files: /linux/arch/riscv/kernel/vdso/Makefile

bf40167d54d55d4b54d0103713d86a8638fb9290 - riscv: vdso: Prevent the compiler from inserting calls to memset()

Wed, 16 Oct 2024 10:36:24 +0200

riscv: vdso: Prevent the compiler from inserting calls to memset()The compiler is smart enough to insert a call to memset() inriscv_vdso_get_cpus(), which generates a dynamic relocation.So prevent this by using -fno-builtin option.Fixes: e2c0cdfba7f6 ("RISC-V: User-facing API")Cc: stable@vger.kernel.orgSigned-off-by: Alexandre Ghiti Reviewed-by: Guo Ren Link: https://lore.kernel.org/r/20241016083625.136311-2-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt List of files: /linux/arch/riscv/kernel/vdso/Makefile

7587a3602bf2f12e798ea955b17521948ddb56a5 - riscv: vdso: do not strip debugging info for vdso.so.dbg

Tue, 11 Jun 2024 06:09:47 +0200

riscv: vdso: do not strip debugging info for vdso.so.dbgThe vdso.so.dbg is a debug version of vdso and could be used for debuggingpurpose. For example, perf-annotate requires debugging info to show sourcelines. So let's keep its debugging info.Signed-off-by: Changbin Du Reviewed-by: Cyril Bur Reviewed-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20240611040947.3024710-1-changbin.du@huawei.comSigned-off-by: Palmer Dabbelt List of files: /linux/arch/riscv/kernel/vdso/Makefile

7f7f6f7ad654b326897c9f54438a06f03454bd0d - Makefile: remove redundant tool coverage variables

Mon, 06 May 2024 15:35:43 +0200

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/arch/riscv/kernel/vdso/Makefile

b1992c3772e69a6fd0e3fc81cd4d2820c8b6eca0 - kbuild: use $(src) instead of $(srctree)/$(src) for source directory

Sat, 27 Apr 2024 16:55:02 +0200

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/arch/riscv/kernel/vdso/Makefile

ad14f7ca9f0d9fdf73d1fd61aaf8248d46ffc849 - riscv: hwprobe: do not produce frtace relocation

Wed, 13 Mar 2024 08:35:46 +0100

riscv: hwprobe: do not produce frtace relocationSuch relocation causes crash of android linker similar to onedescribed in commit e05d57dcb8c7("riscv: Fixup __vdso_gettimeofday broke dynamic ftrace").Looks like this relocation is added by CONFIG_DYNAMIC_FTRACE which isdisabled in the default android kernel.Before:readelf -rW arch/riscv/kernel/vdso/vdso.so:Relocation section '.rela.dyn' at offset 0xd00 contains 1 entry: Offset Info Type0000000000000d20 0000000000000003 R_RISCV_RELATIVEobjdump:0000000000000c86 <__vdso_riscv_hwprobe@@LINUX_4.15>: c86: 0001 nop c88: 0001 nop c8a: 0001 nop c8c: 0001 nop c8e: e211 bnez a2,c92 <__vdso_riscv_hwprobe...After:readelf -rW arch/riscv/kernel/vdso/vdso.so:There are no relocations in this file.objdump:0000000000000c86 <__vdso_riscv_hwprobe@@LINUX_4.15>: c86: e211 bnez a2,c8a <__vdso_riscv_hwprobe... c88: c6b9 beqz a3,cd6 <__vdso_riscv_hwprobe... c8a: e739 bnez a4,cd8 <__vdso_riscv_hwprobe... c8c: ffffd797 auipc a5,0xffffdAlso disable SCS since it also should not be available in vdso.Fixes: aa5af0aa90ba ("RISC-V: Add hwprobe vDSO function and data")Signed-off-by: Roman Artemev Signed-off-by: Vladimir Isaev Reviewed-by: Alexandre Ghiti Reviewed-by: Guo Ren Link: https://lore.kernel.org/r/20240313085843.17661-1-vladimir.isaev@syntacore.comSigned-off-by: Palmer Dabbelt List of files: /linux/arch/riscv/kernel/vdso/Makefile

d46392bbf5c6ce594669f00b8177f0b34e983f90 - Merge tag 'riscv-for-linus-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Wed, 08 Nov 2023 18:21:18 +0100

Merge tag 'riscv-for-linus-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linuxPull RISC-V updates from Palmer Dabbelt: - Support for cbo.zero in userspace - Support for CBOs on ACPI-based systems - A handful of improvements for the T-Head cache flushing ops - Support for software shadow call stacks - Various cleanups and fixes* tag 'riscv-for-linus-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (31 commits) RISC-V: hwprobe: Fix vDSO SIGSEGV riscv: configs: defconfig: Enable configs required for RZ/Five SoC riscv: errata: prefix T-Head mnemonics with th. riscv: put interrupt entries into .irqentry.text riscv: mm: Update the comment of CONFIG_PAGE_OFFSET riscv: Using TOOLCHAIN_HAS_ZIHINTPAUSE marco replace zihintpause riscv/mm: Fix the comment for swap pte format RISC-V: clarify the QEMU workaround in ISA parser riscv: correct pt_level name via pgtable_l5/4_enabled RISC-V: Provide pgtable_l5_enabled on rv32 clocksource: timer-riscv: Increase rating of clock_event_device for Sstc clocksource: timer-riscv: Don't enable/disable timer interrupt lkdtm: Fix CFI_BACKWARD on RISC-V riscv: Use separate IRQ shadow call stacks riscv: Implement Shadow Call Stack riscv: Move global pointer loading to a macro riscv: Deduplicate IRQ stack switching riscv: VMAP_STACK overflow detection thread-safe RISC-V: cacheflush: Initialize CBO variables on ACPI systems RISC-V: ACPI: RHCT: Add function to get CBO block sizes ... List of files: /linux/arch/riscv/kernel/vdso/Makefile

56769ba4b297a629148eb24d554aef72d1ddfd9e - kbuild: unify vdso_install rules

Sat, 14 Oct 2023 12:54:35 +0200

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/arch/riscv/kernel/vdso/Makefile

d1584d791a297aa8ed93503382a682a6ecfc4218 - riscv: Implement Shadow Call Stack

Thu, 28 Sep 2023 00:48:02 +0200

riscv: Implement Shadow Call StackImplement CONFIG_SHADOW_CALL_STACK for RISC-V. When enabled, thecompiler injects instructions to all non-leaf C functions tostore the return address to the shadow stack and unconditionallyload it again before returning, which makes it harder to corruptthe return address through a stack overflow, for example.The active shadow call stack pointer is stored in the gpregister, which makes SCS incompatible with gp relaxation. Use--no-relax-gp to ensure gp relaxation is disabled and disableglobal pointer loading. Add SCS pointers to struct thread_info,implement SCS initialization, and task switchingSigned-off-by: Sami Tolvanen Tested-by: Nathan Chancellor Link: https://lore.kernel.org/r/20230927224757.1154247-12-samitolvanen@google.comSigned-off-by: Palmer Dabbelt List of files: /linux/arch/riscv/kernel/vdso/Makefile