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2018-12-28kasan, arm64: adjust shadow size for tag-based modeAndrey Konovalov
Tag-based KASAN uses 1 shadow byte for 16 bytes of kernel memory, so it requires 1/16th of the kernel virtual address space for the shadow memory. This commit sets KASAN_SHADOW_SCALE_SHIFT to 4 when the tag-based KASAN mode is enabled. Link: http://lkml.kernel.org/r/308b6bd49f756bb5e533be93c6f085ba99b30339.1544099024.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-12arm64: enable per-task stack canariesArd Biesheuvel
This enables the use of per-task stack canary values if GCC has support for emitting the stack canary reference relative to the value of sp_el0, which holds the task struct pointer in the arm64 kernel. The $(eval) extends KBUILD_CFLAGS at the moment the make rule is applied, which means asm-offsets.o (which we rely on for the offset value) is built without the arguments, and everything built afterwards has the options set. Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-04arm64: relocatable: fix inconsistencies in linker script and optionsArd Biesheuvel
readelf complains about the section layout of vmlinux when building with CONFIG_RELOCATABLE=y (for KASLR): readelf: Warning: [21]: Link field (0) should index a symtab section. readelf: Warning: [21]: Info field (0) should index a relocatable section. Also, it seems that our use of '-pie -shared' is contradictory, and thus ambiguous. In general, the way KASLR is wired up at the moment is highly tailored to how ld.bfd happens to implement (and conflate) PIE executables and shared libraries, so given the current effort to support other toolchains, let's fix some of these issues as well. - Drop the -pie linker argument and just leave -shared. In ld.bfd, the differences between them are unclear (except for the ELF type of the produced image [0]) but lld chokes on seeing both at the same time. - Rename the .rela output section to .rela.dyn, as is customary for shared libraries and PIE executables, so that it is not misidentified by readelf as a static relocation section (producing the warnings above). - Pass the -z notext and -z norelro options to explicitly instruct the linker to permit text relocations, and to omit the RELRO program header (which requires a certain section layout that we don't adhere to in the kernel). These are the defaults for current versions of ld.bfd. - Discard .eh_frame and .gnu.hash sections to avoid them from being emitted between .head.text and .text, screwing up the section layout. These changes only affect the ELF image, and produce the same binary image. [0] b9dce7f1ba01 ("arm64: kernel: force ET_DYN ELF type for ...") Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Peter Smith <peter.smith@linaro.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-11-03Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull more arm64 updates from Catalin Marinas: - fix W+X page (mark RO) allocated by the arm64 kprobes code - Makefile fix for .i files in out of tree modules * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: kprobe: make page to RO mode when allocate it arm64: kdump: fix small typo arm64: makefile fix build of .i file in external module case
2018-11-02arm64: makefile fix build of .i file in external module caseVictor Kamensky
After 'a66649dab350 arm64: fix vdso-offsets.h dependency' if one will try to build .i file in case of external kernel module, build fails complaining that prepare0 target is missing. This issue came up with SystemTap when it tries to build variety of .i files for its own generated kernel modules trying to figure given kernel features/capabilities. The issue is that prepare0 is defined in top level Makefile only if KBUILD_EXTMOD is not defined. .i file rule depends on prepare and in case KBUILD_EXTMOD defined top level Makefile contains empty rule for prepare. But after mentioned commit arch/arm64/Makefile would introduce dependency on prepare0 through its own prepare target. Fix it to put proper ifdef KBUILD_EXTMOD around code introduced by mentioned commit. It matches what top level Makefile does. Acked-by: Kevin Brodsky <kevin.brodsky@arm.com> Signed-off-by: Victor Kamensky <kamensky@cisco.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-02kbuild: consolidate Devicetree dtb build rulesRob Herring
There is nothing arch specific about building dtb files other than their location under /arch/*/boot/dts/. Keeping each arch aligned is a pain. The dependencies and supported targets are all slightly different. Also, a cross-compiler for each arch is needed, but really the host compiler preprocessor is perfectly fine for building dtbs. Move the build rules to a common location and remove the arch specific ones. This is done in a single step to avoid warnings about overriding rules. The build dependencies had been a mixture of 'scripts' and/or 'prepare'. These pull in several dependencies some of which need a target compiler (specifically devicetable-offsets.h) and aren't needed to build dtbs. All that is really needed is dtc, so adjust the dependencies to only be dtc. This change enables support 'dtbs_install' on some arches which were missing the target. Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Paul Burton <paul.burton@mips.com> Acked-by: Ley Foon Tan <ley.foon.tan@intel.com> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michal Marek <michal.lkml@markovi.net> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: linux-kbuild@vger.kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Cc: uclinux-h8-devel@lists.sourceforge.jp Cc: linux-mips@linux-mips.org Cc: nios2-dev@lists.rocketboards.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-xtensa@linux-xtensa.org Signed-off-by: Rob Herring <robh@kernel.org>
2018-08-24kbuild: rename LDFLAGS to KBUILD_LDFLAGSMasahiro Yamada
Commit a0f97e06a43c ("kbuild: enable 'make CFLAGS=...' to add additional options to CC") renamed CFLAGS to KBUILD_CFLAGS. Commit 222d394d30e7 ("kbuild: enable 'make AFLAGS=...' to add additional options to AS") renamed AFLAGS to KBUILD_AFLAGS. Commit 06c5040cdb13 ("kbuild: enable 'make CPPFLAGS=...' to add additional options to CPP") renamed CPPFLAGS to KBUILD_CPPFLAGS. For some reason, LDFLAGS was not renamed. Using a well-known variable like LDFLAGS may result in accidental override of the variable. Kbuild generally uses KBUILD_ prefixed variables for the internally appended options, so here is one more conversion to sanitize the naming convention. I did not touch Makefiles under tools/ since the tools build system is a different world. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-14Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "A bunch of good stuff in here. Worth noting is that we've pulled in the x86/mm branch from -tip so that we can make use of the core ioremap changes which allow us to put down huge mappings in the vmalloc area without screwing up the TLB. Much of the positive diffstat is because of the rseq selftest for arm64. Summary: - Wire up support for qspinlock, replacing our trusty ticket lock code - Add an IPI to flush_icache_range() to ensure that stale instructions fetched into the pipeline are discarded along with the I-cache lines - Support for the GCC "stackleak" plugin - Support for restartable sequences, plus an arm64 port for the selftest - Kexec/kdump support on systems booting with ACPI - Rewrite of our syscall entry code in C, which allows us to zero the GPRs on entry from userspace - Support for chained PMU counters, allowing 64-bit event counters to be constructed on current CPUs - Ensure scheduler topology information is kept up-to-date with CPU hotplug events - Re-enable support for huge vmalloc/IO mappings now that the core code has the correct hooks to use break-before-make sequences - Miscellaneous, non-critical fixes and cleanups" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (90 commits) arm64: alternative: Use true and false for boolean values arm64: kexec: Add comment to explain use of __flush_icache_range() arm64: sdei: Mark sdei stack helper functions as static arm64, kaslr: export offset in VMCOREINFO ELF notes arm64: perf: Add cap_user_time aarch64 efi/libstub: Only disable stackleak plugin for arm64 arm64: drop unused kernel_neon_begin_partial() macro arm64: kexec: machine_kexec should call __flush_icache_range arm64: svc: Ensure hardirq tracing is updated before return arm64: mm: Export __sync_icache_dcache() for xen-privcmd drivers/perf: arm-ccn: Use devm_ioremap_resource() to map memory arm64: Add support for STACKLEAK gcc plugin arm64: Add stack information to on_accessible_stack drivers/perf: hisi: update the sccl_id/ccl_id when MT is supported arm64: fix ACPI dependencies rseq/selftests: Add support for arm64 arm64: acpi: fix alignment fault in accessing ACPI efi/arm: map UEFI memory map even w/o runtime services enabled efi/arm: preserve early mapping of UEFI memory map longer for BGRT drivers: acpi: add dependency of EFI for arm64 ...
2018-07-23arm64: build with baremetal linker target instead of Linux when availableOlof Johansson
Not all toolchains have the baremetal elf targets, RedHat/Fedora ones in particular. So, probe for whether it's available and use the previous (linux) targets if it isn't. Reported-by: Laura Abbott <labbott@redhat.com> Tested-by: Laura Abbott <labbott@redhat.com> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Paul Kocialkowski <contact@paulk.fr> Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-10Revert "arm64: Use aarch64elf and aarch64elfb emulation mode variants"Laura Abbott
This reverts commit 38fc4248677552ce35efc09902fdcb06b61d7ef9. Distributions such as Fedora and Debian do not package the ELF linker scripts with their toolchains, resulting in kernel build failures such as: | CHK include/generated/compile.h | LD [M] arch/arm64/crypto/sha512-ce.o | aarch64-linux-gnu-ld: cannot open linker script file ldscripts/aarch64elf.xr: No such file or directory | make[1]: *** [scripts/Makefile.build:530: arch/arm64/crypto/sha512-ce.o] Error 1 | make: *** [Makefile:1029: arch/arm64/crypto] Error 2 Revert back to the linux targets for now, adding a comment to the Makefile so we don't accidentally break this in the future. Cc: Paul Kocialkowski <contact@paulk.fr> Cc: <stable@vger.kernel.org> Fixes: 38fc42486775 ("arm64: Use aarch64elf and aarch64elfb emulation mode variants") Tested-by: Kevin Hilman <khilman@baylibre.com> Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-05arm64: remove no-op -p linker flagGreg Hackmann
Linking the ARM64 defconfig kernel with LLVM lld fails with the error: ld.lld: error: unknown argument: -p Makefile:1015: recipe for target 'vmlinux' failed Without this flag, the ARM64 defconfig kernel successfully links with lld and boots on Dragonboard 410c. After digging through binutils source and changelogs, it turns out that -p is only relevant to ancient binutils installations targeting 32-bit ARM. binutils accepts -p for AArch64 too, but it's always been undocumented and silently ignored. A comment in ld/emultempl/aarch64elf.em explains that it's "Only here for backwards compatibility". Since this flag is a no-op on ARM64, we can safely drop it. Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Greg Hackmann <ghackmann@google.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-07-04arm64: add endianness option to LDFLAGS instead of LDMasahiro Yamada
With the recent syntax extension, Kconfig is now able to evaluate the compiler / toolchain capability. However, accumulating flags to 'LD' is not compatible with the way it works; 'LD' must be passed to Kconfig to call $(ld-option,...) from Kconfig files. If you tweak 'LD' in arch Makefile depending on CONFIG_CPU_BIG_ENDIAN, this would end up with circular dependency between Makefile and Kconfig. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-07-04arm64: Use aarch64elf and aarch64elfb emulation mode variantsPaul Kocialkowski
The aarch64linux and aarch64linuxb emulation modes are not supported by bare-metal toolchains and Linux using them forbids building the kernel with these toolchains. Since there is apparently no reason to target these emulation modes, the more generic elf modes are used instead, allowing to build on bare-metal toolchains as well as the already-supported ones. Fixes: 3d6a7b99e3fa ("arm64: ensure the kernel is compiled for LP64") Cc: stable@vger.kernel.org Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Paul Kocialkowski <contact@paulk.fr> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-06-08arm64: move GCC version check for ARCH_SUPPORTS_INT128 to KconfigMasahiro Yamada
This becomes much neater in Kconfig. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Kees Cook <keescook@chromium.org>
2018-06-01kbuild: add machine size to CHECKFLAGSLuc Van Oostenryck
By default, sparse assumes a 64bit machine when compiled on x86-64 and 32bit when compiled on anything else. This can of course create all sort of problems for the other archs, like issuing false warnings ('shift too big (32) for type unsigned long'), or worse, failing to emit legitimate warnings. Fix this by adding the -m32/-m64 flag, depending on CONFIG_64BIT, to CHECKFLAGS in the main Makefile (and so for all archs). Also, remove the now unneeded -m32/-m64 in arch specific Makefiles. Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-04-24arm64: support __int128 with clangJason A. Donenfeld
Commit fb8722735f50 ("arm64: support __int128 on gcc 5+") added support for arm64 __int128 with gcc with a version-conditional, but neglected to enable this for clang, which in fact appears to support aarch64 __int128. This commit therefore enables it if the compiler is clang, using the same type of makefile conditional used elsewhere in the tree. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-09arm64/kernel: don't ban ADRP to work around Cortex-A53 erratum #843419Ard Biesheuvel
Working around Cortex-A53 erratum #843419 involves special handling of ADRP instructions that end up in the last two instruction slots of a 4k page, or whose output register gets overwritten without having been read. (Note that the latter instruction sequence is never emitted by a properly functioning compiler, which is why it is disregarded by the handling of the same erratum in the bfd.ld linker which we rely on for the core kernel) Normally, this gets taken care of by the linker, which can spot such sequences at final link time, and insert a veneer if the ADRP ends up at a vulnerable offset. However, linux kernel modules are partially linked ELF objects, and so there is no 'final link time' other than the runtime loading of the module, at which time all the static relocations are resolved. For this reason, we have implemented the #843419 workaround for modules by avoiding ADRP instructions altogether, by using the large C model, and by passing -mpc-relative-literal-loads to recent versions of GCC that may emit adrp/ldr pairs to perform literal loads. However, this workaround forces us to keep literal data mixed with the instructions in the executable .text segment, and literal data may inadvertently turn into an exploitable speculative gadget depending on the relative offsets of arbitrary symbols. So let's reimplement this workaround in a way that allows us to switch back to the small C model, and to drop the -mpc-relative-literal-loads GCC switch, by patching affected ADRP instructions at runtime: - ADRP instructions that do not appear at 4k relative offset 0xff8 or 0xffc are ignored - ADRP instructions that are within 1 MB of their target symbol are converted into ADR instructions - remaining ADRP instructions are redirected via a veneer that performs the load using an unaffected movn/movk sequence. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: tidied up ADRP -> ADR instruction patching.] [will: use ULL suffix for 64-bit immediate] Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-06kasan, arm64: clean up KASAN_SHADOW_SCALE_SHIFT usageAndrey Konovalov
This is a follow up patch to the series I sent recently that cleans up KASAN_SHADOW_SCALE_SHIFT usage (which value was hardcoded and scattered all over the code). This fixes the one place that I forgot to fix. The change is purely aesthetical, instead of hardcoding the value for KASAN_SHADOW_SCALE_SHIFT in arch/arm64/Makefile, an appropriate variable is declared and used. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-01arm64: ftrace: emit ftrace-mod.o contents through codeArd Biesheuvel
When building the arm64 kernel with both CONFIG_ARM64_MODULE_PLTS and CONFIG_DYNAMIC_FTRACE enabled, the ftrace-mod.o object file is built with the kernel and contains a trampoline that is linked into each module, so that modules can be loaded far away from the kernel and still reach the ftrace entry point in the core kernel with an ordinary relative branch, as is emitted by the compiler instrumentation code dynamic ftrace relies on. In order to be able to build out of tree modules, this object file needs to be included into the linux-headers or linux-devel packages, which is undesirable, as it makes arm64 a special case (although a precedent does exist for 32-bit PPC). Given that the trampoline essentially consists of a PLT entry, let's not bother with a source or object file for it, and simply patch it in whenever the trampoline is being populated, using the existing PLT support routines. Cc: <stable@vger.kernel.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64: support __int128 on gcc 5+Jason A. Donenfeld
Versions of gcc prior to gcc 5 emitted a __multi3 function call when dealing with TI types, resulting in failures when trying to link to libgcc, and more generally, bad performance. However, since gcc 5, the compiler supports actually emitting fast instructions, which means we can at long last enable this option and receive the speedups. The gcc commit that added proper Aarch64 support is: https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=d1ae7bb994f49316f6f63e6173f2931e837a351d This commit appears to be part of the gcc 5 release. There are still a few instructions, __ashlti3 and __ashrti3, which require libgcc, which is fine. Rather than linking to libgcc, we simply provide them ourselves, since they're not that complicated. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-30arm64: prevent regressions in compressed kernel image size when upgrading to ↵Nick Desaulniers
binutils 2.27 Upon upgrading to binutils 2.27, we found that our lz4 and gzip compressed kernel images were significantly larger, resulting is 10ms boot time regressions. As noted by Rahul: "aarch64 binaries uses RELA relocations, where each relocation entry includes an addend value. This is similar to x86_64. On x86_64, the addend values are also stored at the relocation offset for relative relocations. This is an optimization: in the case where code does not need to be relocated, the loader can simply skip processing relative relocations. In binutils-2.25, both bfd and gold linkers did this for x86_64, but only the gold linker did this for aarch64. The kernel build here is using the bfd linker, which stored zeroes at the relocation offsets for relative relocations. Since a set of zeroes compresses better than a set of non-zero addend values, this behavior was resulting in much better lz4 compression. The bfd linker in binutils-2.27 is now storing the actual addend values at the relocation offsets. The behavior is now consistent with what it does for x86_64 and what gold linker does for both architectures. The change happened in this upstream commit: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=1f56df9d0d5ad89806c24e71f296576d82344613 Since a bunch of zeroes got replaced by non-zero addend values, we see the side effect of lz4 compressed image being a bit bigger. To get the old behavior from the bfd linker, "--no-apply-dynamic-relocs" flag can be used: $ LDFLAGS="--no-apply-dynamic-relocs" make With this flag, the compressed image size is back to what it was with binutils-2.25. If the kernel is using ASLR, there aren't additional runtime costs to --no-apply-dynamic-relocs, as the relocations will need to be applied again anyway after the kernel is relocated to a random address. If the kernel is not using ASLR, then presumably the current default behavior of the linker is better. Since the static linker performed the dynamic relocs, and the kernel is not moved to a different address at load time, it can skip applying the relocations all over again." Some measurements: $ ld -v GNU ld (binutils-2.25-f3d35cf6) 2.25.51.20141117 ^ $ ls -l vmlinux -rwxr-x--- 1 ndesaulniers eng 300652760 Oct 26 11:57 vmlinux $ ls -l Image.lz4-dtb -rw-r----- 1 ndesaulniers eng 16932627 Oct 26 11:57 Image.lz4-dtb $ ld -v GNU ld (binutils-2.27-53dd00a1) 2.27.0.20170315 ^ pre patch: $ ls -l vmlinux -rwxr-x--- 1 ndesaulniers eng 300376208 Oct 26 11:43 vmlinux $ ls -l Image.lz4-dtb -rw-r----- 1 ndesaulniers eng 18159474 Oct 26 11:43 Image.lz4-dtb post patch: $ ls -l vmlinux -rwxr-x--- 1 ndesaulniers eng 300376208 Oct 26 12:06 vmlinux $ ls -l Image.lz4-dtb -rw-r----- 1 ndesaulniers eng 16932466 Oct 26 12:06 Image.lz4-dtb By Siqi's measurement w/ gzip: binutils 2.27 with this patch (with --no-apply-dynamic-relocs): Image 41535488 Image.gz 13404067 binutils 2.27 without this patch (without --no-apply-dynamic-relocs): Image 41535488 Image.gz 14125516 Any compression scheme should be able to get better results from the longer runs of zeros, not just GZIP and LZ4. 10ms boot time savings isn't anything to get excited about, but users of arm64+compression+bfd-2.27 should not have to pay a penalty for no runtime improvement. Reported-by: Gopinath Elanchezhian <gelanchezhian@google.com> Reported-by: Sindhuri Pentyala <spentyala@google.com> Reported-by: Wei Wang <wvw@google.com> Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Suggested-by: Rahul Chaudhry <rahulchaudhry@google.com> Suggested-by: Siqi Lin <siqilin@google.com> Suggested-by: Stephen Hines <srhines@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: added comment to Makefile] Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-09-18arm64: ensure the kernel is compiled for LP64Andrew Pinski
The kernel needs to be compiled as a LP64 binary for ARM64, even when using a compiler that defaults to code-generation for the ILP32 ABI. Consequently, we need to explicitly pass '-mabi=lp64' (supported on gcc-4.9 and newer). Signed-off-by: Andrew Pinski <Andrew.Pinski@caviumnetworks.com> Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com> Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com> Signed-off-by: Yury Norov <ynorov@caviumnetworks.com> Reviewed-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-06-26arm64: pass endianness info to sparseLuc Van Oostenryck
ARM64 depends on the macro __AARCH64EB__ being defined or not to correctly select or define endian-specific macros, structures or pieces of code. This macro is predefined by the compiler but sparse knows nothing about it and thus may pre-process files differently from what gcc would. Fix this by passing '-D__AARCH64EL__' or '-D__AARCH64EB__' to sparse depending of the endianness of the kernel, like defined by GCC. Note: In most case it won't change anything since most arm64 use little-endian (but an allyesconfig would use big-endian!). CC: Catalin Marinas <catalin.marinas@arm.com> CC: Will Deacon <will.deacon@arm.com> CC: linux-arm-kernel@lists.infradead.org Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-06-20arm64: pass machine size to sparseLuc Van Oostenryck
When using sparse on the arm64 tree we get many thousands of warnings like 'constant ... is so big it is unsigned long long' or 'shift too big (32) for type unsigned long'. This happens because by default sparse considers the machine as 32bit and defines the size of the types accordingly. Fix this by passing the '-m64' flag to sparse so that sparse can correctly define longs as being 64bit. CC: Catalin Marinas <catalin.marinas@arm.com> CC: Will Deacon <will.deacon@arm.com> CC: linux-arm-kernel@lists.infradead.org Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-06-07arm64: ftrace: add support for far branches to dynamic ftraceArd Biesheuvel
Currently, dynamic ftrace support in the arm64 kernel assumes that all core kernel code is within range of ordinary branch instructions that occur in module code, which is usually the case, but is no longer guaranteed now that we have support for module PLTs and address space randomization. Since on arm64, all patching of branch instructions involves function calls to the same entry point [ftrace_caller()], we can emit the modules with a trampoline that has unlimited range, and patch both the trampoline itself and the branch instruction to redirect the call via the trampoline. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: minor clarification to smp_wmb() comment] Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-05-10Merge tag 'kbuild-misc-v4.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull misc Kbuild updates from Masahiro Yamada: - clean up builddeb script - use full path for KBUILD_IMAGE to fix rpm-pkg build - fix objdiff tool to ignore debug info * tag 'kbuild-misc-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: builddeb: fix typo builddeb: Update a few outdated and hardcoded strings deb-pkg: Remove the KBUILD_IMAGE workaround unicore32: Use full path in KBUILD_IMAGE definition sh: Use full path in KBUILD_IMAGE definition arc: Use full path in KBUILD_IMAGE definition arm: Use full path in KBUILD_IMAGE definition arm64: Use full path in KBUILD_IMAGE definition scripts: objdiff: Ignore debug info when comparing
2017-04-12arm64: Silence spurious kbuild warning on menuconfigMarc Zyngier
Since bbb56c27228d ("arm64: Add detection code for broken .inst support in binutils"), running any make target that doesn't involve the cross compiler results in a spurious warning: $ make ARCH=arm64 menuconfig arch/arm64/Makefile:43: Detected assembler with broken .inst; disassembly will be unreliable while $ make ARCH=arm64 CROSS_COMPILE=aarch64-arm-linux- menuconfig is silent (assuming your compiler is not affected). That's because the code that tests for the workaround is always run, irrespective of the current configuration being available or not. An easy fix is to make the detection conditional on CONFIG_ARM64 being defined, which is only the case when actually building something. Fixes: bbb56c27228d ("arm64: Add detection code for broken .inst support in binutils") Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-03-20arm64: Use full path in KBUILD_IMAGE definitionMichal Marek
The KBUILD_IMAGE variable is used by the rpm and deb-pkg targets, which expect it to point to the image file in the build directory. The builddeb script has a workaround for architectures which only provide the basename, but let's provide a clean interface for packaging tools. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Michal Marek <mmarek@suse.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-12-06arm64: Add detection code for broken .inst support in binutilsMarc Zyngier
Binutils version up to (and including) 2.25 have a pathological behaviour when it comes to mixing .inst directive and arithmetic involving labels. The assembler complains about non-constant expressions and compilation stops pretty quickly. In order to detect this and work around it, let's add a bit of detection code that will set the CONFIG_BROKEN_GAS_INST option should a broken gas be detected. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-10-20arm64: kernel: force ET_DYN ELF type for CONFIG_RELOCATABLE=yArd Biesheuvel
GNU ld used to set the ELF file type to ET_DYN for PIE executables, which is the same file type used for shared libraries. However, this was changed recently, and now PIE executables are emitted as ET_EXEC instead. The distinction is only relevant for ELF loaders, and so there is little reason to care about the difference when building the kernel, which is why the change has gone unnoticed until now. However, debuggers do use the ELF binary, and expect ET_EXEC type files to appear in memory at the exact offset described in the ELF metadata. This means source level debugging is no longer possible when KASLR is in effect or when executing the stub. So add the -shared LD option when building with CONFIG_RELOCATABLE=y. This forces the ELF file type to be set to ET_DYN (which is what you get when building with binutils 2.24 and earlier anyway), and has no other ill effects. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-31arm64: Set UTS_MACHINE in the MakefileMichal Marek
The make rpm target depends on proper UTS_MACHINE definition. Also, use the variable in arch/arm64/kernel/setup.c, so that it's not accidentally removed in the future. Reported-and-tested-by: Fabian Vogt <fvogt@suse.com> Signed-off-by: Michal Marek <mmarek@suse.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-26arm64: errata: Pass --fix-cortex-a53-843419 to ld if workaround enabledWill Deacon
Cortex-A53 erratum 843419 is worked around by the linker, although it is a configure-time option to GCC as to whether ld is actually asked to apply the workaround or not. This patch ensures that we pass --fix-cortex-a53-843419 to the linker when both CONFIG_ARM64_ERRATUM_843419=y and the linker supports the option. Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-06Merge tag 'arm64-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Will Deacon: - fix HugeTLB leak due to CoW and PTE_RDONLY mismatch - avoid accessing unmapped FDT fields when checking validity - correctly account for vDSO AUX entry in ARCH_DLINFO - fix kallsyms with absolute expressions in linker script - kill unnecessary symbol-based relocs in vmlinux * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: Fix copy-on-write referencing in HugeTLB arm64: mm: avoid fdt_check_header() before the FDT is fully mapped arm64: Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO arm64: relocatable: suppress R_AARCH64_ABS64 relocations in vmlinux arm64: vmlinux.lds: make __rela_offset and __dynsym_offset ABSOLUTE
2016-07-29arm64: relocatable: suppress R_AARCH64_ABS64 relocations in vmlinuxArd Biesheuvel
The linker routines that we rely on to produce a relocatable PIE binary treat it as a shared ELF object in some ways, i.e., it emits symbol based R_AARCH64_ABS64 relocations into the final binary since doing so would be appropriate when linking a shared library that is subject to symbol preemption. (This means that an executable can override certain symbols that are exported by a shared library it is linked with, and that the shared library *must* update all its internal references as well, and point them to the version provided by the executable.) Symbol preemption does not occur for OS hosted PIE executables, let alone for vmlinux, and so we would prefer to get rid of these symbol based relocations. This would allow us to simplify the relocation routines, and to strip the .dynsym, .dynstr and .hash sections from the binary. (Note that these are tiny, and are placed in the .init segment, but they clutter up the vmlinux binary.) Note that these R_AARCH64_ABS64 relocations are only emitted for absolute references to symbols defined in the linker script, all other relocatable quantities are covered by anonymous R_AARCH64_RELATIVE relocations that simply list the offsets to all 64-bit values in the binary that need to be fixed up based on the offset between the link time and run time addresses. Fortunately, GNU ld has a -Bsymbolic option, which is intended for shared libraries to allow them to ignore symbol preemption, and unconditionally bind all internal symbol references to its own definitions. So set it for our PIE binary as well, and get rid of the asoociated sections and the relocation code that processes them. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: fixed conflict with __dynsym_offset linker script entry] Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-07-27Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - Kexec support for arm64 - Kprobes support - Expose MIDR_EL1 and REVIDR_EL1 CPU identification registers to sysfs - Trapping of user space cache maintenance operations and emulation in the kernel (CPU errata workaround) - Clean-up of the early page tables creation (kernel linear mapping, EFI run-time maps) to avoid splitting larger blocks (e.g. pmds) into smaller ones (e.g. ptes) - VDSO support for CLOCK_MONOTONIC_RAW in clock_gettime() - ARCH_HAS_KCOV enabled for arm64 - Optimise IP checksum helpers - SWIOTLB optimisation to only allocate/initialise the buffer if the available RAM is beyond the 32-bit mask - Properly handle the "nosmp" command line argument - Fix for the initialisation of the CPU debug state during early boot - vdso-offsets.h build dependency workaround - Build fix when RANDOMIZE_BASE is enabled with MODULES off * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (64 commits) arm64: arm: Fix-up the removal of the arm64 regs_query_register_name() prototype arm64: Only select ARM64_MODULE_PLTS if MODULES=y arm64: mm: run pgtable_page_ctor() on non-swapper translation table pages arm64: mm: make create_mapping_late() non-allocating arm64: Honor nosmp kernel command line option arm64: Fix incorrect per-cpu usage for boot CPU arm64: kprobes: Add KASAN instrumentation around stack accesses arm64: kprobes: Cleanup jprobe_return arm64: kprobes: Fix overflow when saving stack arm64: kprobes: WARN if attempting to step with PSTATE.D=1 arm64: debug: remove unused local_dbg_{enable, disable} macros arm64: debug: remove redundant spsr manipulation arm64: debug: unmask PSTATE.D earlier arm64: localise Image objcopy flags arm64: ptrace: remove extra define for CPSR's E bit kprobes: Add arm64 case in kprobe example module arm64: Add kernel return probes support (kretprobes) arm64: Add trampoline code for kretprobes arm64: kprobes instruction simulation support arm64: Treat all entry code as non-kprobe-able ...
2016-07-19arm64: localise Image objcopy flagsMark Rutland
We currently define OBJCOPYFLAGS in the top-level arm64 Makefile, and thus these flags will be passed to all uses of objcopy, kernel-wide, for which they are not explicitly overridden. The flags we set are intended for converting vmlinux (and ELF) into Image (a raw binary), and thus the flags chosen are problematic for some other uses which do not expect a raw binary result, e.g. the upcoming lkdtm rodata test: http://www.openwall.com/lists/kernel-hardening/2016/06/08/2 This patch localises the objcopy flags such that they are only used for the vmlinux -> Image conversion. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Acked-by: Kees Cook <keescook@chromium.org> Tested-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-07-11arm64: fix vdso-offsets.h dependencyKevin Brodsky
arm64/kernel/{vdso,signal}.c include vdso-offsets.h, as well as any file that includes asm/vdso.h. Therefore, vdso-offsets.h must be generated before these files are compiled. The current rules in arm64/kernel/Makefile do not actually enforce this, because even though $(obj)/vdso is listed as a prerequisite for vdso-offsets.h, this does not result in the intended effect of building the vdso subdirectory (before all the other objects). As a consequence, depending on the order in which the rules are followed, vdso-offsets.h is updated or not before arm64/kernel/{vdso,signal}.o are built. The current rules also impose an unnecessary dependency on vdso-offsets.h for all arm64/kernel/*.o, resulting in unnecessary rebuilds. This is made obvious when using make -j: touch arch/arm64/kernel/vdso/gettimeofday.S && make -j$NCPUS arch/arm64/kernel will sometimes result in none of arm64/kernel/*.o being rebuilt, sometimes all of them, or even just some of them. It is quite difficult to ensure that a header is generated before it is used with recursive Makefiles by using normal rules. Instead, arch-specific generated headers are normally built in the archprepare recipe in the arch Makefile (see for instance arch/ia64/Makefile). Unfortunately, asm-offsets.h is included in gettimeofday.S, and must therefore be generated before vdso-offsets.h, which is not the case if archprepare is used. For this reason, a rule run after archprepare has to be used. This commit adds rules in arm64/Makefile to build vdso-offsets.h during the prepare step, ensuring that vdso-offsets.h is generated before building anything. It also removes the now-unnecessary dependencies on vdso-offsets.h in arm64/kernel/Makefile. Finally, it removes the duplication of asm-offsets.h between arm64/kernel/vdso/ and include/generated/ and makes include/generated/vdso-offsets.h a target in arm64/kernel/vdso/Makefile. Cc: Will Deacon <will.deacon@arm.com> Cc: Michal Marek <mmarek@suse.com> Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-06-21arm64: fix boot image dependencies to not generate invalid imagesMasahiro Yamada
I fixed boot image dependencies for arch/arm in commit 3939f3345050 ("ARM: 8418/1: add boot image dependencies to not generate invalid images"). I see a similar problem for arch/arm64; "make -jN Image Image.gz" would sometimes end up generating bad images where N > 1. Fix the dependency in arch/arm64/Makefile to avoid the race between "make Image" and "make Image.*". Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-06-03arm64: fix alignment when RANDOMIZE_TEXT_OFFSET is enabledMark Rutland
With ARM64_64K_PAGES and RANDOMIZE_TEXT_OFFSET enabled, we hit the following issue on the boot: kernel BUG at arch/arm64/mm/mmu.c:480! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 4.6.0 #310 Hardware name: ARM Juno development board (r2) (DT) task: ffff000008d58a80 ti: ffff000008d30000 task.ti: ffff000008d30000 PC is at map_kernel_segment+0x44/0xb0 LR is at paging_init+0x84/0x5b0 pc : [<ffff000008c450b4>] lr : [<ffff000008c451a4>] pstate: 600002c5 Call trace: [<ffff000008c450b4>] map_kernel_segment+0x44/0xb0 [<ffff000008c451a4>] paging_init+0x84/0x5b0 [<ffff000008c42728>] setup_arch+0x198/0x534 [<ffff000008c40848>] start_kernel+0x70/0x388 [<ffff000008c401bc>] __primary_switched+0x30/0x74 Commit 7eb90f2ff7e3 ("arm64: cover the .head.text section in the .text segment mapping") removed the alignment between the .head.text and .text sections, and used the _text rather than the _stext interval for mapping the .text segment. Prior to this commit _stext was always section aligned and didn't cause any issue even when RANDOMIZE_TEXT_OFFSET was enabled. Since that alignment has been removed and _text is used to map the .text segment, we need ensure _text is always page aligned when RANDOMIZE_TEXT_OFFSET is enabled. This patch adds logic to TEXT_OFFSET fuzzing to ensure that the offset is always aligned to the kernel page size. To ensure this, we rely on the PAGE_SHIFT being available via Kconfig. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reported-by: Sudeep Holla <sudeep.holla@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Fixes: 7eb90f2ff7e3 ("arm64: cover the .head.text section in the .text segment mapping") Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-03-17Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "Here are the main arm64 updates for 4.6. There are some relatively intrusive changes to support KASLR, the reworking of the kernel virtual memory layout and initial page table creation. Summary: - Initial page table creation reworked to avoid breaking large block mappings (huge pages) into smaller ones. The ARM architecture requires break-before-make in such cases to avoid TLB conflicts but that's not always possible on live page tables - Kernel virtual memory layout: the kernel image is no longer linked to the bottom of the linear mapping (PAGE_OFFSET) but at the bottom of the vmalloc space, allowing the kernel to be loaded (nearly) anywhere in physical RAM - Kernel ASLR: position independent kernel Image and modules being randomly mapped in the vmalloc space with the randomness is provided by UEFI (efi_get_random_bytes() patches merged via the arm64 tree, acked by Matt Fleming) - Implement relative exception tables for arm64, required by KASLR (initial code for ARCH_HAS_RELATIVE_EXTABLE added to lib/extable.c but actual x86 conversion to deferred to 4.7 because of the merge dependencies) - Support for the User Access Override feature of ARMv8.2: this allows uaccess functions (get_user etc.) to be implemented using LDTR/STTR instructions. Such instructions, when run by the kernel, perform unprivileged accesses adding an extra level of protection. The set_fs() macro is used to "upgrade" such instruction to privileged accesses via the UAO bit - Half-precision floating point support (part of ARMv8.2) - Optimisations for CPUs with or without a hardware prefetcher (using run-time code patching) - copy_page performance improvement to deal with 128 bytes at a time - Sanity checks on the CPU capabilities (via CPUID) to prevent incompatible secondary CPUs from being brought up (e.g. weird big.LITTLE configurations) - valid_user_regs() reworked for better sanity check of the sigcontext information (restored pstate information) - ACPI parking protocol implementation - CONFIG_DEBUG_RODATA enabled by default - VDSO code marked as read-only - DEBUG_PAGEALLOC support - ARCH_HAS_UBSAN_SANITIZE_ALL enabled - Erratum workaround Cavium ThunderX SoC - set_pte_at() fix for PROT_NONE mappings - Code clean-ups" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (99 commits) arm64: kasan: Fix zero shadow mapping overriding kernel image shadow arm64: kasan: Use actual memory node when populating the kernel image shadow arm64: Update PTE_RDONLY in set_pte_at() for PROT_NONE permission arm64: Fix misspellings in comments. arm64: efi: add missing frame pointer assignment arm64: make mrs_s prefixing implicit in read_cpuid arm64: enable CONFIG_DEBUG_RODATA by default arm64: Rework valid_user_regs arm64: mm: check at build time that PAGE_OFFSET divides the VA space evenly arm64: KVM: Move kvm_call_hyp back to its original localtion arm64: mm: treat memstart_addr as a signed quantity arm64: mm: list kernel sections in order arm64: lse: deal with clobbered IP registers after branch via PLT arm64: mm: dump: Use VA_START directly instead of private LOWEST_ADDR arm64: kconfig: add submenu for 8.2 architectural features arm64: kernel: acpi: fix ioremap in ACPI parking protocol cpu_postboot arm64: Add support for Half precision floating point arm64: Remove fixmap include fragility arm64: Add workaround for Cavium erratum 27456 arm64: mm: Mark .rodata as RO ...
2016-02-24arm64: add support for building vmlinux as a relocatable PIE binaryArd Biesheuvel
This implements CONFIG_RELOCATABLE, which links the final vmlinux image with a dynamic relocation section, allowing the early boot code to perform a relocation to a different virtual address at runtime. This is a prerequisite for KASLR (CONFIG_RANDOMIZE_BASE). Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24arm64: add support for module PLTsArd Biesheuvel
This adds support for emitting PLTs at module load time for relative branches that are out of range. This is a prerequisite for KASLR, which may place the kernel and the modules anywhere in the vmalloc area, making it more likely that branch target offsets exceed the maximum range of +/- 128 MB. In this version, I removed the distinction between relocations against .init executable sections and ordinary executable sections. The reason is that it is hardly worth the trouble, given that .init.text usually does not contain that many far branches, and this version now only reserves PLT entry space for jump and call relocations against undefined symbols (since symbols defined in the same module can be assumed to be within +/- 128 MB) For example, the mac80211.ko module (which is fairly sizable at ~400 KB) built with -mcmodel=large gives the following relocation counts: relocs branches unique !local .text 3925 3347 518 219 .init.text 11 8 7 1 .exit.text 4 4 4 1 .text.unlikely 81 67 36 17 ('unique' means branches to unique type/symbol/addend combos, of which !local is the subset referring to undefined symbols) IOW, we are only emitting a single PLT entry for the .init sections, and we are better off just adding it to the core PLT section instead. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-19arm64: kbuild: make "make install" not depend on vmlinuxMasahiro Yamada
For the same reason as commit 19514fc665ff ("arm, kbuild: make "make install" not depend on vmlinux"), the install targets should never trigger the rebuild of the kernel. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-01-26arm64: errata: Add -mpc-relative-literal-loads to build flagsdann frazier
GCC6 (and Linaro's 2015.12 snapshot of GCC5) has a new default that uses adrp/ldr or adrp/add to address literal pools. When CONFIG_ARM64_ERRATUM_843419 is enabled, modules built with this toolchain fail to load: module libahci: unsupported RELA relocation: 275 This patch fixes the problem by passing '-mpc-relative-literal-loads' to the compiler. Cc: stable@vger.kernel.org Fixes: df057cc7b4fa ("arm64: errata: add module build workaround for erratum #843419") BugLink: http://bugs.launchpad.net/bugs/1533009 Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Suggested-by: Christophe Lyon <christophe.lyon@linaro.org> Signed-off-by: Dann Frazier <dann.frazier@canonical.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-01-26Eliminate the .eh_frame sections from the aarch64 vmlinux and kernel modulesWilliam Cohen
By default the aarch64 gcc generates .eh_frame sections. Unlike .debug_frame sections, the .eh_frame sections are loaded into memory when the associated code is loaded. On an example kernel being built with this default the .eh_frame section in vmlinux used an extra 1.7MB of memory. The x86 disables the creation of the .eh_frame section. The aarch64 should probably do the same to save some memory. Signed-off-by: William Cohen <wcohen@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-11-04Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - "genirq: Introduce generic irq migration for cpu hotunplugged" patch merged from tip/irq/for-arm to allow the arm64-specific part to be upstreamed via the arm64 tree - CPU feature detection reworked to cope with heterogeneous systems where CPUs may not have exactly the same features. The features reported by the kernel via internal data structures or ELF_HWCAP are delayed until all the CPUs are up (and before user space starts) - Support for 16KB pages, with the additional bonus of a 36-bit VA space, though the latter only depending on EXPERT - Implement native {relaxed, acquire, release} atomics for arm64 - New ASID allocation algorithm which avoids IPI on roll-over, together with TLB invalidation optimisations (using local vs global where feasible) - KASan support for arm64 - EFI_STUB clean-up and isolation for the kernel proper (required by KASan) - copy_{to,from,in}_user optimisations (sharing the memcpy template) - perf: moving arm64 to the arm32/64 shared PMU framework - L1_CACHE_BYTES increased to 128 to accommodate Cavium hardware - Support for the contiguous PTE hint on kernel mapping (16 consecutive entries may be able to use a single TLB entry) - Generic CONFIG_HZ now used on arm64 - defconfig updates * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (91 commits) arm64/efi: fix libstub build under CONFIG_MODVERSIONS ARM64: Enable multi-core scheduler support by default arm64/efi: move arm64 specific stub C code to libstub arm64: page-align sections for DEBUG_RODATA arm64: Fix build with CONFIG_ZONE_DMA=n arm64: Fix compat register mappings arm64: Increase the max granular size arm64: remove bogus TASK_SIZE_64 check arm64: make Timer Interrupt Frequency selectable arm64/mm: use PAGE_ALIGNED instead of IS_ALIGNED arm64: cachetype: fix definitions of ICACHEF_* flags arm64: cpufeature: declare enable_cpu_capabilities as static genirq: Make the cpuhotplug migration code less noisy arm64: Constify hwcap name string arrays arm64/kvm: Make use of the system wide safe values arm64/debug: Make use of the system wide safe value arm64: Move FP/ASIMD hwcap handling to common code arm64/HWCAP: Use system wide safe values arm64/capabilities: Make use of system wide safe value arm64: Delay cpu feature capability checks ...
2015-10-12arm64: add KASAN supportAndrey Ryabinin
This patch adds arch specific code for kernel address sanitizer (see Documentation/kasan.txt). 1/8 of kernel addresses reserved for shadow memory. There was no big enough hole for this, so virtual addresses for shadow were stolen from vmalloc area. At early boot stage the whole shadow region populated with just one physical page (kasan_zero_page). Later, this page reused as readonly zero shadow for some memory that KASan currently don't track (vmalloc). After mapping the physical memory, pages for shadow memory are allocated and mapped. Functions like memset/memmove/memcpy do a lot of memory accesses. If bad pointer passed to one of these function it is important to catch this. Compiler's instrumentation cannot do this since these functions are written in assembly. KASan replaces memory functions with manually instrumented variants. Original functions declared as weak symbols so strong definitions in mm/kasan/kasan.c could replace them. Original functions have aliases with '__' prefix in name, so we could call non-instrumented variant if needed. Some files built without kasan instrumentation (e.g. mm/slub.c). Original mem* function replaced (via #define) with prefixed variants to disable memory access checks for such files. Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Tested-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-12arm64: errata: use KBUILD_CFLAGS_MODULE for erratum #843419Will Deacon
Commit df057cc7b4fa ("arm64: errata: add module build workaround for erratum #843419") sets CFLAGS_MODULE to ensure that the large memory model is used by the compiler when building kernel modules. However, CFLAGS_MODULE is an environment variable and intended to be overridden on the command line, which appears to be the case with the Ubuntu kernel packaging system, so use KBUILD_CFLAGS_MODULE instead. Cc: <stable@vger.kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Fixes: df057cc7b4fa ("arm64: errata: add module build workaround for erratum #843419") Reported-by: Dann Frazier <dann.frazier@canonical.com> Tested-by: Dann Frazier <dann.frazier@canonical.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-09-17arm64: errata: add module build workaround for erratum #843419Will Deacon
Cortex-A53 processors <= r0p4 are affected by erratum #843419 which can lead to a memory access using an incorrect address in certain sequences headed by an ADRP instruction. There is a linker fix to generate veneers for ADRP instructions, but this doesn't work for kernel modules which are built as unlinked ELF objects. This patch adds a new config option for the erratum which, when enabled, builds kernel modules with the mcmodel=large flag. This uses absolute addressing for all kernel symbols, thereby removing the use of ADRP as a PC-relative form of addressing. The ADRP relocs are removed from the module loader so that we fail to load any potentially affected modules. Cc: <stable@vger.kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: atomics: patch in lse instructions when supported by the CPUWill Deacon
On CPUs which support the LSE atomic instructions introduced in ARMv8.1, it makes sense to use them in preference to ll/sc sequences. This patch introduces runtime patching of atomic_t and atomic64_t routines so that the call-site for the out-of-line ll/sc sequences is patched with an LSE atomic instruction when we detect that the CPU supports it. If binutils is not recent enough to assemble the LSE instructions, then the ll/sc sequences are inlined as though CONFIG_ARM64_LSE_ATOMICS=n. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>