linux-dev/arch/arm64/kernel/Makefile, branch master

Merge tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2022-10-10T19:00:45Z

Pull Kbuild updates from Masahiro Yamada: - Remove potentially incomplete targets when Kbuid is interrupted by SIGINT etc in case GNU Make may miss to do that when stderr is piped to another program. - Rewrite the single target build so it works more correctly. - Fix rpm-pkg builds with V=1. - List top-level subdirectories in ./Kbuild. - Ignore auto-generated __kstrtab_* and __kstrtabns_* symbols in kallsyms. - Avoid two different modules in lib/zstd/ having shared code, which potentially causes building the common code as build-in and modular back-and-forth. - Unify two modpost invocations to optimize the build process. - Remove head-y syntax in favor of linker scripts for placing particular sections in the head of vmlinux. - Bump the minimal GNU Make version to 3.82. - Clean up misc Makefiles and scripts. * tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits) docs: bump minimal GNU Make version to 3.82 ia64: simplify esi object addition in Makefile Revert "kbuild: Check if linker supports the -X option" kbuild: rebuild .vmlinux.export.o when its prerequisite is updated kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o zstd: Fixing mixed module-builtin objects kallsyms: ignore __kstrtab_* and __kstrtabns_* symbols kallsyms: take the input file instead of reading stdin kallsyms: drop duplicated ignore patterns from kallsyms.c kbuild: reuse mksysmap output for kallsyms mksysmap: update comment about __crc_* kbuild: remove head-y syntax kbuild: use obj-y instead extra-y for objects placed at the head kbuild: hide error checker logs for V=1 builds kbuild: re-run modpost when it is updated kbuild: unify two modpost invocations kbuild: move vmlinux.o rule to the top Makefile kbuild: move .vmlinux.objs rule to Makefile.modpost kbuild: list sub-directories in ./Kbuild Makefile.compiler: replace cc-ifversion with compiler-specific macros ...

kbuild: use obj-y instead extra-y for objects placed at the head

2022-10-02T09:04:05Z

The objects placed at the head of vmlinux need special treatments: - arch/$(SRCARCH)/Makefile adds them to head-y in order to place them before other archives in the linker command line. - arch/$(SRCARCH)/kernel/Makefile adds them to extra-y instead of obj-y to avoid them going into built-in.a. This commit gets rid of the latter. Create vmlinux.a to collect all the objects that are unconditionally linked to vmlinux. The objects listed in head-y are moved to the head of vmlinux.a by using 'ar m'. With this, arch/$(SRCARCH)/kernel/Makefile can consistently use obj-y for builtin objects. There is no *.o that is directly linked to vmlinux. Drop unneeded code in scripts/clang-tools/gen_compile_commands.py. $(AR) mPi needs 'T' to workaround the llvm-ar bug. The fix was suggested by Nathan Chancellor [1]. [1]: https://lore.kernel.org/llvm/YyjjT5gQ2hGMH0ni@dev-arch.thelio-3990X/ Signed-off-by: Masahiro Yamada Tested-by: Nick Desaulniers Reviewed-by: Nicolas Schier

arm64: compat: Implement misalignment fixups for multiword loads

2022-09-06T08:34:53Z

The 32-bit ARM kernel implements fixups on behalf of user space when using LDM/STM or LDRD/STRD instructions on addresses that are not 32-bit aligned. This is not something that is supported by the architecture, but was done anyway to increase compatibility with user space software, which mostly targeted x86 at the time and did not care about aligned accesses. This feature is one of the remaining impediments to being able to switch to 64-bit kernels on 64-bit capable hardware running 32-bit user space, so let's implement it for the arm64 compat layer as well. Note that the intent is to implement the exact same handling of misaligned multi-word loads and stores as the 32-bit kernel does, including what appears to be missing support for user space programs that rely on SETEND to switch to a different byte order and back. Also, like the 32-bit ARM version, we rely on the faulting address reported by the CPU to infer the memory address, instead of decoding the instruction fully to obtain this information. This implementation is taken from the 32-bit ARM tree, with all pieces removed that deal with instructions other than LDRD/STRD and LDM/STM, or that deal with alignment exceptions taken in kernel mode. Cc: debian-arm@lists.debian.org Cc: Vagrant Cascadian Cc: Riku Voipio Cc: Steve McIntyre Signed-off-by: Ard Biesheuvel Reviewed-by: Arnd Bergmann Link: https://lore.kernel.org/r/20220701135322.3025321-1-ardb@kernel.org [catalin.marinas@arm.com: change the option to 'default n'] Signed-off-by: Catalin Marinas

Merge branch 'for-next/boot' into for-next/core

2022-07-25T09:59:15Z

* for-next/boot: (34 commits) arm64: fix KASAN_INLINE arm64: Add an override for ID_AA64SMFR0_EL1.FA64 arm64: Add the arm64.nosve command line option arm64: Add the arm64.nosme command line option arm64: Expose a __check_override primitive for oddball features arm64: Allow the idreg override to deal with variable field width arm64: Factor out checking of a feature against the override into a macro arm64: Allow sticky E2H when entering EL1 arm64: Save state of HCR_EL2.E2H before switch to EL1 arm64: Rename the VHE switch to "finalise_el2" arm64: mm: fix booting with 52-bit address space arm64: head: remove __PHYS_OFFSET arm64: lds: use PROVIDE instead of conditional definitions arm64: setup: drop early FDT pointer helpers arm64: head: avoid relocating the kernel twice for KASLR arm64: kaslr: defer initialization to initcall where permitted arm64: head: record CPU boot mode after enabling the MMU arm64: head: populate kernel page tables with MMU and caches on arm64: head: factor out TTBR1 assignment into a macro arm64: idreg-override: use early FDT mapping in ID map ...

arm64: head: avoid relocating the kernel twice for KASLR

2022-06-24T16:18:11Z

Currently, when KASLR is in effect, we set up the kernel virtual address space twice: the first time, the KASLR seed is looked up in the device tree, and the kernel virtual mapping is torn down and recreated again, after which the relocations are applied a second time. The latter step means that statically initialized global pointer variables will be reset to their initial values, and to ensure that BSS variables are not set to values based on the initial translation, they are cleared again as well. All of this is needed because we need the command line (taken from the DT) to tell us whether or not to randomize the virtual address space before entering the kernel proper. However, this code has expanded little by little and now creates global state unrelated to the virtual randomization of the kernel before the mapping is torn down and set up again, and the BSS cleared for a second time. This has created some issues in the past, and it would be better to avoid this little dance if possible. So instead, let's use the temporary mapping of the device tree, and execute the bare minimum of code to decide whether or not KASLR should be enabled, and what the seed is. Only then, create the virtual kernel mapping, clear BSS, etc and proceed as normal. This avoids the issues around inconsistent global state due to BSS being cleared twice, and is generally more maintainable, as it permits us to defer all the remaining DT parsing and KASLR initialization to a later time. This means the relocation fixup code runs only a single time as well, allowing us to simplify the RELR handling code too, which is not idempotent and was therefore required to keep track of the offset that was applied the first time around. Note that this means we have to clone a pair of FDT library objects, so that we can control how they are built - we need the stack protector and other instrumentation disabled so that the code can tolerate being called this early. Note that only the kernel page tables and the temporary stack are mapped read-write at this point, which ensures that the early code does not modify any global state inadvertently. Signed-off-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20220624150651.1358849-21-ardb@kernel.org Signed-off-by: Will Deacon

arm64: kasan: do not instrument stacktrace.c

2022-06-23T14:57:29Z

Disable KASAN instrumentation of arch/arm64/kernel/stacktrace.c. This speeds up Generic KASAN by 5-20%. As a side-effect, KASAN is now unable to detect bugs in the stack trace collection code. This is taken as an acceptable downside. Also replace READ_ONCE_NOCHECK() with READ_ONCE() in stacktrace.c. As the file is now not instrumented, there is no need to use the NOCHECK version of READ_ONCE(). Suggested-by: Mark Rutland Acked-by: Mark Rutland Signed-off-by: Andrey Konovalov Link: https://lore.kernel.org/r/c4c944a2a905e949760fbeb29258185087171708.1653317461.git.andreyknvl@google.com Signed-off-by: Will Deacon

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

arm64: mte: Dump the MTE tags in the core file

2022-02-15T22:53:29Z

For each vma mapped with PROT_MTE (the VM_MTE flag set), generate a PT_ARM_MEMTAG_MTE segment in the core file and dump the corresponding tags. The in-file size for such segments is 128 bytes per page. For pages in a VM_MTE vma which are not present in the user page tables or don't have the PG_mte_tagged flag set (e.g. execute-only), just write zeros in the core file. An example of program headers for two vmas, one 2-page, the other 4-page long: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align ... LOAD 0x030000 0x0000ffff80034000 0x0000000000000000 0x000000 0x002000 RW 0x1000 LOAD 0x030000 0x0000ffff80036000 0x0000000000000000 0x004000 0x004000 RW 0x1000 ... LOPROC+0x1 0x05b000 0x0000ffff80034000 0x0000000000000000 0x000100 0x002000 0 LOPROC+0x1 0x05b100 0x0000ffff80036000 0x0000000000000000 0x000200 0x004000 0 Signed-off-by: Catalin Marinas Acked-by: Luis Machado Reviewed-by: Mark Brown Link: https://lore.kernel.org/r/20220131165456.2160675-5-catalin.marinas@arm.com Signed-off-by: Will Deacon

kbuild: use more subdir- for visiting subdirectories while cleaning

2021-10-24T04:49:46Z

Documentation/kbuild/makefiles.rst suggests to use "archclean" for cleaning arch/$(SRCARCH)/boot/, but it is not a hard requirement. Since commit d92cc4d51643 ("kbuild: require all architectures to have arch/$(SRCARCH)/Kbuild"), we can use the "subdir- += boot" trick for all 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)

arm64: entry: fix KCOV suppression

2021-07-15T16:37:55Z

We suppress KCOV for entry.o rather than entry-common.o. As entry.o is built from entry.S, this is pointless, and permits instrumentation of entry-common.o, which is built from entry-common.c. Fix the Makefile to suppress KCOV for entry-common.o, as we had intended to begin with. I've verified with objdump that this is working as expected. Fixes: bf6fa2c0dda7 ("arm64: entry: don't instrument entry code with KCOV") Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: James Morse Cc: Marc Zyngier Cc: Will Deacon Link: https://lore.kernel.org/r/20210715123049.9990-1-mark.rutland@arm.com Signed-off-by: Will Deacon