wireguard-linux/arch/arm64/kernel/vdso/Makefile, branch update-toolchain

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

2024-07-23T14:28:23Z

glibc added support for .gnu.hash in 2006 and .hash has been obsoleted for 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 sysv hash 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.com Signed-off-by: Will Deacon

Makefile: remove redundant tool coverage variables

2024-05-14T14:35:48Z

Now Kbuild provides reasonable defaults for objtool, sanitizers, and profilers. 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, KCOV I believe these are positive effects because all of them are kernel space objects. Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook Tested-by: Roberto Sassu

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

2024-05-09T19:34:52Z

Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for checked-in source files. It is merely a convention without any functional difference. In fact, $(obj) and $(src) are exactly the same, as defined in scripts/Makefile.build: src := $(obj) When the kernel is built in a separate output directory, $(src) does not accurately reflect the source directory location. While Kbuild resolves this discrepancy by specifying VPATH=$(srctree) to search for source files, it does not cover all cases. For example, when adding a header search path for local headers, -I$(srctree)/$(src) is typically passed to the compiler. This introduces inconsistency between upstream and downstream Makefiles because $(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 following meanings: $(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 tree Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced with $(src). Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier

kbuild: unify vdso_install rules

2023-10-28T12:09:02Z

Currently, 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_install rule. Architectures that support vdso_install need to define vdso-install-y in 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.dbg These files will be installed to $(MODLIB)/vdso/ with the .dbg suffix, if exists, stripped away. vdso-install-y can optionally take the second field after the colon separator. This is needed because some architectures install a vdso file as a different base name. The following is a snippet from arch/arm64/Makefile. vdso-install-$(CONFIG_COMPAT_VDSO) += arch/arm64/kernel/vdso32/vdso.so.dbg:vdso32.so This will rename vdso.so.dbg to vdso32.so during installation. If such architectures change their implementation so that the base names match, this workaround will go away. Signed-off-by: Masahiro Yamada Acked-by: Sven Schnelle # s390 Reviewed-by: Nicolas Schier Reviewed-by: Guo Ren Acked-by: Helge Deller # parisc Acked-by: Catalin Marinas Acked-by: Russell King (Oracle)

vdso: Improve cmd_vdso_check to check all dynamic relocations

2023-03-21T20:15:34Z

The actual intention is that no dynamic relocation exists in the VDSO. For this the VDSO build validates that the resulting .so file does not have any relocations which are specified via $(ARCH_REL_TYPE_ABS) per architecture, which is fragile as e.g. ARM64 lacks an entry for R_AARCH64_RELATIVE. Aside of that ARCH_REL_TYPE_ABS is a misnomer as it checks for relative relocations too. However, some GNU ld ports produce unneeded R_*_NONE relocation entries. If a port fails to determine the exact .rel[a].dyn size, the trailing zeros become R_*_NONE relocations. E.g. ld's powerpc port recently fixed https://sourceware.org/bugzilla/show_bug.cgi?id=29540). R_*_NONE are generally 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 aarch64 Reviewed-by: Christophe Leroy Reviewed-by: Vincenzo Frascino # for vDSO, aarch64 Acked-by: Michael Ellerman (powerpc) Link: https://lore.kernel.org/r/20230310190750.3323802-1-maskray@google.com

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

2022-11-01T17:04:52Z

Andrew Cooper suggested upgrading the orphan section warning to a hard link error. However Nathan Chancellor said outright turning the warning into an error with no escape hatch might be too aggressive, as we have had these warnings triggered by new compiler generated sections, and suggested turning orphan sections into an error only if CONFIG_WERROR is set. Kees Cook echoed and emphasized that the mandate from Linus is that we should avoid breaking builds. It wrecks bisection, it causes problems across compiler versions, etc. Thus upgrade the orphan section warning to a hard link error only if CONFIG_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

treewide: Filter out CC_FLAGS_CFI

2022-09-26T17:13:12Z

In preparation for removing CC_FLAGS_CFI from CC_FLAGS_LTO, explicitly filter out CC_FLAGS_CFI in all the makefiles where we currently filter out 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

arm64: vdso: enable orphan handling for VDSO

2022-06-23T14:34:59Z

Like vmlinux, enable orphan-handling for the VDSO. This can catch subtle 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.com Signed-off-by: Will Deacon

Merge tag 'kernel-hardening-v5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2022-05-24T19:27:09Z

Pull kernel hardening updates from Kees Cook: - usercopy hardening expanded to check other allocation types (Matthew Wilcox, Yuanzheng Song) - arm64 stackleak behavioral improvements (Mark Rutland) - arm64 CFI code gen improvement (Sami Tolvanen) - LoadPin LSM block dev API adjustment (Christoph Hellwig) - Clang randstruct support (Bill Wendling, Kees Cook) * tag 'kernel-hardening-v5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (34 commits) loadpin: stop using bdevname mm: usercopy: move the virt_addr_valid() below the is_vmalloc_addr() gcc-plugins: randstruct: Remove cast exception handling af_unix: Silence randstruct GCC plugin warning niu: Silence randstruct warnings big_keys: Use struct for internal payload gcc-plugins: Change all version strings match kernel randomize_kstack: Improve docs on requirements/rationale lkdtm/stackleak: fix CONFIG_GCC_PLUGIN_STACKLEAK=n arm64: entry: use stackleak_erase_on_task_stack() stackleak: add on/off stack variants lkdtm/stackleak: check stack boundaries lkdtm/stackleak: prevent unexpected stack usage lkdtm/stackleak: rework boundary management lkdtm/stackleak: avoid spurious failure stackleak: rework poison scanning stackleak: rework stack high bound handling stackleak: clarify variable names stackleak: rework stack low bound handling stackleak: remove redundant check ...

arm64: vdso: fix makefile dependency on vdso.so

2022-05-10T11:08:40Z

There is currently no dependency for vdso*-wrap.S on vdso*.so, which means that you can get a build that uses a stale vdso*-wrap.o. In commit a5b8ca97fbf8, the file that includes the vdso.so was moved and renamed from arch/arm64/kernel/vdso/vdso.S to arch/arm64/kernel/vdso-wrap.S, when this happened 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.com Signed-off-by: Will Deacon