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724a75ac |
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20-Oct-2023 |
Jamie Cunliffe <Jamie.Cunliffe@arm.com> |
arm64: rust: Enable Rust support for AArch64 This commit provides the build flags for Rust for AArch64. The core Rust support already in the kernel does the rest. This enables the PAC ret and BTI options in the Rust build flags to match the options that are used when building C. The Rust samples have been tested with this commit. Signed-off-by: Jamie Cunliffe <Jamie.Cunliffe@arm.com> Acked-by: Will Deacon <will@kernel.org> Tested-by: Dirk Behme <dirk.behme@de.bosch.com> Tested-by: Boqun Feng <boqun.feng@gmail.com> Acked-by: Miguel Ojeda <ojeda@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Alice Ryhl <aliceryhl@google.com> Tested-by: Fabien Parent <fabien.parent@linaro.org> Link: https://lore.kernel.org/r/20231020155056.3495121-3-Jamie.Cunliffe@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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c7767f5c |
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29-Jan-2024 |
Kevin Brodsky <kevin.brodsky@arm.com> |
arm64: vdso32: Remove unused vdso32-offsets.h Commit 2d071968a405 ("arm64: compat: Remove 32-bit sigreturn code from the vDSO") removed all VDSO_* symbols in the compat vDSO. As a result, vdso32-offsets.h is now empty and therefore unused. Time to remove it. Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Link: https://lore.kernel.org/r/20240129154748.1727759-1-kevin.brodsky@arm.com Signed-off-by: Will Deacon <will@kernel.org>
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a099bec7 |
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17-Nov-2023 |
Masahiro Yamada <masahiroy@kernel.org> |
arm64: vdso32: rename 32-bit debug vdso to vdso32.so.dbg 'make vdso_install' renames arch/arm64/kernel/vdso32/vdso.so.dbg to vdso32.so during installation, which allows 64-bit and 32-bit vdso files to be installed in the same directory. However, arm64 is the only architecture that requires this renaming. To simplify the vdso_install logic, rename the in-tree vdso file so its base name matches the installed file name. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20231117125620.1058300-1-masahiroy@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
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c0a85742 |
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18-Nov-2023 |
Masahiro Yamada <masahiroy@kernel.org> |
arm64: add dependency between vmlinuz.efi and Image A common issue in Makefile is a race in parallel building. You need to be careful to prevent multiple threads from writing to the same file simultaneously. Commit 3939f3345050 ("ARM: 8418/1: add boot image dependencies to not generate invalid images") addressed such a bad scenario. A similar symptom occurs with the following command: $ make -j$(nproc) ARCH=arm64 Image vmlinuz.efi [ snip ] SORTTAB vmlinux OBJCOPY arch/arm64/boot/Image OBJCOPY arch/arm64/boot/Image AS arch/arm64/boot/zboot-header.o PAD arch/arm64/boot/vmlinux.bin GZIP arch/arm64/boot/vmlinuz OBJCOPY arch/arm64/boot/vmlinuz.o LD arch/arm64/boot/vmlinuz.efi.elf OBJCOPY arch/arm64/boot/vmlinuz.efi The log "OBJCOPY arch/arm64/boot/Image" is displayed twice. It indicates that two threads simultaneously enter arch/arm64/boot/ and write to arch/arm64/boot/Image. It occasionally leads to a build failure: $ make -j$(nproc) ARCH=arm64 Image vmlinuz.efi [ snip ] SORTTAB vmlinux OBJCOPY arch/arm64/boot/Image PAD arch/arm64/boot/vmlinux.bin truncate: Invalid number: 'arch/arm64/boot/vmlinux.bin' make[2]: *** [drivers/firmware/efi/libstub/Makefile.zboot:13: arch/arm64/boot/vmlinux.bin] Error 1 make[2]: *** Deleting file 'arch/arm64/boot/vmlinux.bin' make[1]: *** [arch/arm64/Makefile:163: vmlinuz.efi] Error 2 make[1]: *** Waiting for unfinished jobs.... make: *** [Makefile:234: __sub-make] Error 2 vmlinuz.efi depends on Image, but such a dependency is not specified in arch/arm64/Makefile. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: SImon Glass <sjg@chromium.org> Link: https://lore.kernel.org/r/20231119053234.2367621-1-masahiroy@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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56769ba4 |
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14-Oct-2023 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: unify vdso_install rules 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 <masahiroy@kernel.org> Acked-by: Sven Schnelle <svens@linux.ibm.com> # s390 Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> Reviewed-by: Guo Ren <guoren@kernel.org> Acked-by: Helge Deller <deller@gmx.de> # parisc Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
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c6cd63f5 |
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10-Feb-2023 |
Mark Brown <broonie@kernel.org> |
arm64: configs: Add virtconfig Provide a slimline configuration intended to be booted on virtual machines, with the goal of providing a light configuration which will boot on and enable features available in mach-virt. This is defined in terms of the standard defconfig, with an additional virt.config fragment which disables options unneeded in a virtual configuration. As a first step we just disable all the ARCH_ configuration options, disabling the build of all the SoC specific drivers. This results in a kernel that builds about 25% faster in my testing, if this approach works for people we can add further options. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20230203-arm64-defconfigs-v1-3-cd0694a05f13@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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c68cf528 |
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31-Jan-2023 |
Mark Rutland <mark.rutland@arm.com> |
arm64: pauth: don't sign leaf functions Currently, when CONFIG_ARM64_PTR_AUTH_KERNEL=y (and CONFIG_UNWIND_PATCH_PAC_INTO_SCS=n), we enable pointer authentication for all functions, including leaf functions. This isn't necessary, and is unfortunate for a few reasons: * Any PACIASP instruction is implicitly a `BTI C` landing pad, and forcing the addition of a PACIASP in every function introduces a larger set of BTI gadgets than is necessary. * The PACIASP and AUTIASP instructions make leaf functions larger than necessary, bloating the kernel Image. For a defconfig v6.2-rc3 kernel, this appears to add ~64KiB relative to not signing leaf functions, which is unfortunate but not entirely onerous. * The PACIASP and AUTIASP instructions potentially make leaf functions more expensive in terms of performance and/or power. For many trivial leaf functions, this is clearly unnecessary, e.g. | <arch_local_save_flags>: | d503233f paciasp | d53b4220 mrs x0, daif | d50323bf autiasp | d65f03c0 ret | <calibration_delay_done>: | d503233f paciasp | d50323bf autiasp | d65f03c0 ret | d503201f nop * When CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y we disable pointer authentication for leaf functions, so clearly this is not functionally necessary, indicates we have an inconsistent threat model, and convolutes the Makefile logic. We've used pointer authentication in leaf functions since the introduction of in-kernel pointer authentication in commit: 74afda4016a7437e ("arm64: compile the kernel with ptrauth return address signing") ... but at the time we had no rationale for signing leaf functions. Subsequently, we considered avoiding signing leaf functions: https://lore.kernel.org/linux-arm-kernel/1586856741-26839-1-git-send-email-amit.kachhap@arm.com/ https://lore.kernel.org/linux-arm-kernel/1588149371-20310-1-git-send-email-amit.kachhap@arm.com/ ... however at the time we didn't have an abundance of reasons to avoid signing leaf functions as above (e.g. the BTI case), we had no hardware to make performance measurements, and it was reasoned that this gave some level of protection against a limited set of code-reuse gadgets which would fall through to a RET. We documented this in commit: 717b938e22f8dbf0 ("arm64: Document why we enable PAC support for leaf functions") Notably, this was before we supported any forward-edge CFI scheme (e.g. Arm BTI, or Clang CFI/kCFI), which would prevent jumping into the middle of a function. In addition, even with signing forced for leaf functions, AUTIASP may be placed before a number of instructions which might constitute such a gadget, e.g. | <user_regs_reset_single_step>: | f9400022 ldr x2, [x1] | d503233f paciasp | d50323bf autiasp | f9408401 ldr x1, [x0, #264] | 720b005f tst w2, #0x200000 | b26b0022 orr x2, x1, #0x200000 | 926af821 and x1, x1, #0xffffffffffdfffff | 9a820021 csel x1, x1, x2, eq // eq = none | f9008401 str x1, [x0, #264] | d65f03c0 ret | <fpsimd_cpu_dead>: | 2a0003e3 mov w3, w0 | 9000ff42 adrp x2, ffff800009ffd000 <xen_dynamic_chip+0x48> | 9120e042 add x2, x2, #0x838 | 52800000 mov w0, #0x0 // #0 | d503233f paciasp | f000d041 adrp x1, ffff800009a20000 <this_cpu_vector> | d50323bf autiasp | 9102c021 add x1, x1, #0xb0 | f8635842 ldr x2, [x2, w3, uxtw #3] | f821685f str xzr, [x2, x1] | d65f03c0 ret | d503201f nop So generally, trying to use AUTIASP to detect such gadgetization is not robust, and this is dealt with far better by forward-edge CFI (which is designed to prevent such cases). We should bite the bullet and stop pretending that AUTIASP is a mitigation for such forward-edge gadgetization. For the above reasons, this patch has the kernel consistently sign non-leaf functions and avoid signing leaf functions. Considering a defconfig v6.2-rc3 kernel built with LLVM 15.0.6: * The vmlinux is ~43KiB smaller: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 338547808 Jan 25 17:17 vmlinux-after | -rwxr-xr-x 1 mark mark 338591472 Jan 25 17:22 vmlinux-before * The resulting Image is 64KiB smaller: | [mark@lakrids:~/src/linux]% ls -al Image-* | -rwxr-xr-x 1 mark mark 32702976 Jan 25 17:17 Image-after | -rwxr-xr-x 1 mark mark 32768512 Jan 25 17:22 Image-before * There are ~400 fewer BTI gadgets: | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-before 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 1219 bti c | 61982 paciasp | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-after 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 10099 bti c | 52699 paciasp Which is +8880 BTIs, and -9283 PACIASPs, for -403 unnecessary BTI gadgets. While this is small relative to the total, distinguishing the two cases will make it easier to analyse and reduce this set further in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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1e249c41 |
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31-Jan-2023 |
Mark Rutland <mark.rutland@arm.com> |
arm64: unify asm-arch manipulation Assemblers will reject instructions not supported by a target architecture version, and so we must explicitly tell the assembler the latest architecture version for which we want to assemble instructions from. We've added a few AS_HAS_ARMV8_<N> definitions for this, in addition to an inconsistently named AS_HAS_PAC definition, from which arm64's top-level Makefile determines the architecture version that we intend to target, and generates the `asm-arch` variable. To make this a bit clearer and easier to maintain, this patch reworks the Makefile to determine asm-arch in a single if-else-endif chain. AS_HAS_PAC, which is defined when the assembler supports `-march=armv8.3-a`, is renamed to AS_HAS_ARMV8_3. As the logic for armv8.3-a is lifted out of the block handling pointer authentication, `asm-arch` may now be set to armv8.3-a regardless of whether support for pointer authentication is selected. This means that it will be possible to assemble armv8.3-a instructions even if we didn't intend to, but this is consistent with our handling of other architecture versions, and the compiler won't generate armv8.3-a instructions regardless. For the moment there's no need for an CONFIG_AS_HAS_ARMV8_1, as the code for LSE atomics and LDAPR use individual `.arch_extension` entries and do not require the baseline asm arch to be bumped to armv8.1-a. The other armv8.1-a features (e.g. PAN) do not require assembler support. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-2-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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baaf553d |
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23-Jan-2023 |
Mark Rutland <mark.rutland@arm.com> |
arm64: Implement HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS This patch enables support for DYNAMIC_FTRACE_WITH_CALL_OPS on arm64. This allows each ftrace callsite to provide an ftrace_ops to the common ftrace trampoline, allowing each callsite to invoke distinct tracer functions without the need to fall back to list processing or to allocate custom trampolines for each callsite. This significantly speeds up cases where multiple distinct trace functions are used and callsites are mostly traced by a single tracer. The main idea is to place a pointer to the ftrace_ops as a literal at a fixed offset from the function entry point, which can be recovered by the common ftrace trampoline. Using a 64-bit literal avoids branch range limitations, and permits the ops to be swapped atomically without special considerations that apply to code-patching. In future this will also allow for the implementation of DYNAMIC_FTRACE_WITH_DIRECT_CALLS without branch range limitations by using additional fields in struct ftrace_ops. As noted in the core patch adding support for DYNAMIC_FTRACE_WITH_CALL_OPS, this approach allows for directly invoking ftrace_ops::func even for ftrace_ops which are dynamically-allocated (or part of a module), without going via ftrace_ops_list_func. Currently, this approach is not compatible with CLANG_CFI, as the presence/absence of pre-function NOPs changes the offset of the pre-function type hash, and there's no existing mechanism to ensure a consistent offset for instrumented and uninstrumented functions. When CLANG_CFI is enabled, the existing scheme with a global ops->func pointer is used, and there should be no functional change. I am currently working with others to allow the two to work together in future (though this will liekly require updated compiler support). I've benchamrked this with the ftrace_ops sample module [1], which is not currently upstream, but available at: https://lore.kernel.org/lkml/20230103124912.2948963-1-mark.rutland@arm.com git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git ftrace-ops-sample-20230109 Using that module I measured the total time taken for 100,000 calls to a trivial instrumented function, with a number of tracers enabled with relevant filters (which would apply to the instrumented function) and a number of tracers enabled with irrelevant filters (which would not apply to the instrumented function). I tested on an M1 MacBook Pro, running under a HVF-accelerated QEMU VM (i.e. on real hardware). Before this patch: Number of tracers || Total time | Per-call average time (ns) Relevant | Irrelevant || (ns) | Total | Overhead =========+============++=============+==============+============ 0 | 0 || 94,583 | 0.95 | - 0 | 1 || 93,709 | 0.94 | - 0 | 2 || 93,666 | 0.94 | - 0 | 10 || 93,709 | 0.94 | - 0 | 100 || 93,792 | 0.94 | - ---------+------------++-------------+--------------+------------ 1 | 1 || 6,467,833 | 64.68 | 63.73 1 | 2 || 7,509,708 | 75.10 | 74.15 1 | 10 || 23,786,792 | 237.87 | 236.92 1 | 100 || 106,432,500 | 1,064.43 | 1063.38 ---------+------------++-------------+--------------+------------ 1 | 0 || 1,431,875 | 14.32 | 13.37 2 | 0 || 6,456,334 | 64.56 | 63.62 10 | 0 || 22,717,000 | 227.17 | 226.22 100 | 0 || 103,293,667 | 1032.94 | 1031.99 ---------+------------++-------------+--------------+-------------- Note: per-call overhead is estimated relative to the baseline case with 0 relevant tracers and 0 irrelevant tracers. After this patch Number of tracers || Total time | Per-call average time (ns) Relevant | Irrelevant || (ns) | Total | Overhead =========+============++=============+==============+============ 0 | 0 || 94,541 | 0.95 | - 0 | 1 || 93,666 | 0.94 | - 0 | 2 || 93,709 | 0.94 | - 0 | 10 || 93,667 | 0.94 | - 0 | 100 || 93,792 | 0.94 | - ---------+------------++-------------+--------------+------------ 1 | 1 || 281,000 | 2.81 | 1.86 1 | 2 || 281,042 | 2.81 | 1.87 1 | 10 || 280,958 | 2.81 | 1.86 1 | 100 || 281,250 | 2.81 | 1.87 ---------+------------++-------------+--------------+------------ 1 | 0 || 280,959 | 2.81 | 1.86 2 | 0 || 6,502,708 | 65.03 | 64.08 10 | 0 || 18,681,209 | 186.81 | 185.87 100 | 0 || 103,550,458 | 1,035.50 | 1034.56 ---------+------------++-------------+--------------+------------ Note: per-call overhead is estimated relative to the baseline case with 0 relevant tracers and 0 irrelevant tracers. As can be seen from the above: a) Whenever there is a single relevant tracer function associated with a tracee, the overhead of invoking the tracer is constant, and does not scale with the number of tracers which are *not* associated with that tracee. b) The overhead for a single relevant tracer has dropped to ~1/7 of the overhead prior to this series (from 13.37ns to 1.86ns). This is largely due to permitting calls to dynamically-allocated ftrace_ops without going through ftrace_ops_list_func. I've run the ftrace selftests from v6.2-rc3, which reports: | # of passed: 110 | # of failed: 0 | # of unresolved: 3 | # of untested: 0 | # of unsupported: 0 | # of xfailed: 1 | # of undefined(test bug): 0 ... where the unresolved entries were the tests for DIRECT functions (which are not supported), and the checkbashisms selftest (which is irrelevant here): | [8] Test ftrace direct functions against tracers [UNRESOLVED] | [9] Test ftrace direct functions against kprobes [UNRESOLVED] | [62] Meta-selftest: Checkbashisms [UNRESOLVED] ... with all other tests passing (or failing as expected). Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Florent Revest <revest@chromium.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230123134603.1064407-9-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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26299b3f |
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03-Nov-2022 |
Mark Rutland <mark.rutland@arm.com> |
ftrace: arm64: move from REGS to ARGS This commit replaces arm64's support for FTRACE_WITH_REGS with support for FTRACE_WITH_ARGS. This removes some overhead and complexity, and removes some latent issues with inconsistent presentation of struct pt_regs (which can only be reliably saved/restored at exception boundaries). FTRACE_WITH_REGS has been supported on arm64 since commit: 3b23e4991fb66f6d ("arm64: implement ftrace with regs") As noted in the commit message, the major reasons for implementing FTRACE_WITH_REGS were: (1) To make it possible to use the ftrace graph tracer with pointer authentication, where it's necessary to snapshot/manipulate the LR before it is signed by the instrumented function. (2) To make it possible to implement LIVEPATCH in future, where we need to hook function entry before an instrumented function manipulates the stack or argument registers. Practically speaking, we need to preserve the argument/return registers, PC, LR, and SP. Neither of these need a struct pt_regs, and only require the set of registers which are live at function call/return boundaries. Our calling convention is defined by "Procedure Call Standard for the ArmĀ® 64-bit Architecture (AArch64)" (AKA "AAPCS64"), which can currently be found at: https://github.com/ARM-software/abi-aa/blob/main/aapcs64/aapcs64.rst Per AAPCS64, all function call argument and return values are held in the following GPRs: * X0 - X7 : parameter / result registers * X8 : indirect result location register * SP : stack pointer (AKA SP) Additionally, ad function call boundaries, the following GPRs hold context/return information: * X29 : frame pointer (AKA FP) * X30 : link register (AKA LR) ... and for ftrace we need to capture the instrumented address: * PC : program counter No other GPRs are relevant, as none of the other arguments hold parameters or return values: * X9 - X17 : temporaries, may be clobbered * X18 : shadow call stack pointer (or temorary) * X19 - X28 : callee saved This patch implements FTRACE_WITH_ARGS for arm64, only saving/restoring the minimal set of registers necessary. This is always sufficient to manipulate control flow (e.g. for live-patching) or to manipulate function arguments and return values. This reduces the necessary stack usage from 336 bytes for pt_regs down to 112 bytes for ftrace_regs + 32 bytes for two frame records, freeing up 188 bytes. This could be reduced further with changes to the unwinder. As there is no longer a need to save different sets of registers for different features, we no longer need distinct `ftrace_caller` and `ftrace_regs_caller` trampolines. This allows the trampoline assembly to be simpler, and simplifies code which previously had to handle the two trampolines. I've tested this with the ftrace selftests, where there are no unexpected failures. Co-developed-by: Florent Revest <revest@chromium.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Florent Revest <revest@chromium.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Deacon <will@kernel.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20221103170520.931305-5-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
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3b619e22 |
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27-Oct-2022 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: implement dynamic shadow call stack for Clang Implement dynamic shadow call stack support on Clang, by parsing the unwind tables at init time to locate all occurrences of PACIASP/AUTIASP instructions, and replacing them with the shadow call stack push and pop instructions, respectively. This is useful because the overhead of the shadow call stack is difficult to justify on hardware that implements pointer authentication (PAC), and given that the PAC instructions are executed as NOPs on hardware that doesn't, we can just replace them without breaking anything. As PACIASP/AUTIASP are guaranteed to be paired with respect to manipulations of the return address, replacing them 1:1 with shadow call stack pushes and pops is guaranteed to result in the desired behavior. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20221027155908.1940624-4-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
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68c76ad4 |
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27-Oct-2022 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: unwind: add asynchronous unwind tables to kernel and modules Enable asynchronous unwind table generation for both the core kernel as well as modules, and emit the resulting .eh_frame sections as init code so we can use the unwind directives for code patching at boot or module load time. This will be used by dynamic shadow call stack support, which will rely on code patching rather than compiler codegen to emit the shadow call stack push and pop instructions. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20221027155908.1940624-2-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
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ce697cce |
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24-Sep-2022 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: remove head-y syntax Kbuild puts the objects listed in head-y at the head of vmlinux. Conventionally, we do this for head*.S, which contains the kernel entry point. A counter approach is to control the section order by the linker script. Actually, the code marked as __HEAD goes into the ".head.text" section, which is placed before the normal ".text" section. I do not know if both of them are needed. From the build system perspective, head-y is not mandatory. If you can achieve the proper code placement by the linker script only, it would be cleaner. I collected the current head-y objects into head-object-list.txt. It is a whitelist. My hope is it will be reduced in the long run. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
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c37b830f |
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01-May-2022 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: efi: enable generic EFI compressed boot Wire up the generic EFI zboot support for arm64. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
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f774f5bb |
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02-May-2022 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: factor out the common installation code into scripts/install.sh Many architectures have similar install.sh scripts. The first half is really generic; it verifies that the kernel image and System.map exist, then executes ~/bin/${INSTALLKERNEL} or /sbin/${INSTALLKERNEL} if available. The second half is kind of arch-specific; it copies the kernel image and System.map to the destination, but the code is slightly different. Factor out the generic part into scripts/install.sh. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
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2c54b423 |
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13-Dec-2021 |
Ard Biesheuvel <ardb@kernel.org> |
arm64/xor: use EOR3 instructions when available Use the EOR3 instruction to implement xor_blocks() if the instruction is available, which is the case if the CPU implements the SHA-3 extension. This is about 20% faster on Apple M1 when using the 5-way version. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20211213140252.2856053-1-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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8212f898 |
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13-Oct-2021 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: use more subdir- for visiting subdirectories while cleaning 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 <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
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70a4039b |
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29-Jul-2021 |
Masahiro Yamada <masahiroy@kernel.org> |
arm64: move the (z)install rules to arch/arm64/Makefile Currently, the (z)install targets in arch/arm64/Makefile descend into arch/arm64/boot/Makefile to invoke the shell script, but there is no good reason to do so. arch/arm64/Makefile can run the shell script directly. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20210729140527.443116-1-masahiroy@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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017f5fb9 |
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10-Aug-2021 |
Andrew Delgadillo <adelg@google.com> |
arm64: clean vdso & vdso32 files commit a5b8ca97fbf8 ("arm64: do not descend to vdso directories twice") changes the cleaning behavior of arm64's vdso files, in that vdso.lds, vdso.so, and vdso.so.dbg are not removed upon a 'make clean/mrproper': $ make defconfig ARCH=arm64 $ make ARCH=arm64 $ make mrproper ARCH=arm64 $ git clean -nxdf Would remove arch/arm64/kernel/vdso/vdso.lds Would remove arch/arm64/kernel/vdso/vdso.so Would remove arch/arm64/kernel/vdso/vdso.so.dbg To remedy this, manually descend into arch/arm64/kernel/vdso upon cleaning. After this commit: $ make defconfig ARCH=arm64 $ make ARCH=arm64 $ make mrproper ARCH=arm64 $ git clean -nxdf <empty> Similar results are obtained for the vdso32 equivalent. Signed-off-by: Andrew Delgadillo <adelg@google.com> Cc: stable@vger.kernel.org Fixes: a5b8ca97fbf8 ("arm64: do not descend to vdso directories twice") Link: https://lore.kernel.org/r/20210810231755.1743524-1-adelg@google.com Signed-off-by: Will Deacon <will@kernel.org>
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64ee84c7 |
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31-Jul-2021 |
Masahiro Yamada <masahiroy@kernel.org> |
arm64: move warning about toolchains to archprepare Commit 987fdfec2410 ("arm64: move --fix-cortex-a53-843419 linker test to Kconfig") fixed the false-positive warning in the installation step. Yet, there are some cases where this false-positive is shown. For example, you can see it when you cross 987fdfec2410 during git-bisect. $ git checkout 987fdfec2410^ [ snip ] $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig all [ snip ] $ git checkout v5.13 [ snip] $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig all [ snip ] arch/arm64/Makefile:25: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum In the stale include/config/auto.config, CONFIG_ARM64_ERRATUM_843419=y is set without CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419, so the warning is displayed while parsing the Makefiles. Make will restart with the updated include/config/auto.config, hence CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419 will be set eventually, but this warning is a surprise for users. Commit 25896d073d8a ("x86/build: Fix compiler support check for CONFIG_RETPOLINE") addressed a similar issue. Move $(warning ...) out of the parse stage of Makefiles. The same applies to CONFIG_ARM64_USE_LSE_ATOMICS. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20210801053525.105235-1-masahiroy@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
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d92cc4d5 |
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12-May-2021 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: require all architectures to have arch/$(SRCARCH)/Kbuild arch/$(SRCARCH)/Kbuild is useful for Makefile cleanups because you can use the obj-y syntax. Add an empty file if it is missing in arch/$(SRCARCH)/. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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b27a9f41 |
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13-Jun-2021 |
Daniel Kiss <daniel.kiss@arm.com> |
arm64: Add ARM64_PTR_AUTH_KERNEL config option This patch add the ARM64_PTR_AUTH_KERNEL config and deals with the build aspect of it. Userspace support has no dependency on the toolchain therefore all toolchain checks and build flags are controlled the new config option. The default config behavior will not be changed. Signed-off-by: Daniel Kiss <daniel.kiss@arm.com> Acked-by: Will Deacon <will@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210613092632.93591-2-daniel.kiss@arm.com Signed-off-by: Will Deacon <will@kernel.org>
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0c6c2d36 |
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28-Apr-2021 |
Mark Brown <broonie@kernel.org> |
arm64: Generate cpucaps.h The arm64 code allocates an internal constant to every CPU feature it can detect, distinct from the public hwcap numbers we use to expose some features to userspace. Currently this is maintained manually which is an irritating source of conflicts when working on new features, to avoid this replace the header with a simple text file listing the names we've assigned and sort it to minimise conflicts. As part of doing this we also do the Kbuild hookup required to hook up an arch tools directory and to generate header files in there. This will result in a renumbering and reordering of the existing constants, since they are all internal only the values should not be important. The reordering will impact the order in which some steps in enumeration handle features but the algorithm is not intended to depend on this and I haven't seen any issues when testing. Due to the UAO cpucap having been removed in the past we end up with ARM64_NCAPS being 1 smaller than it was before. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20210428121231.11219-1-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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987fdfec |
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24-Mar-2021 |
Masahiro Yamada <masahiroy@kernel.org> |
arm64: move --fix-cortex-a53-843419 linker test to Kconfig Since commit 805b2e1d427a ("kbuild: include Makefile.compiler only when compiler is needed"), "make ARCH=arm64 (modules_)install" shows a false positive warning. Move the ld-option test to Kconfig, so that the result can be stored in the .config file, avoiding multiple-time evaluations in the build and installation time. Reported-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Will Deacon <will@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org>
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a5b8ca97 |
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17-Dec-2020 |
Masahiro Yamada <masahiroy@kernel.org> |
arm64: do not descend to vdso directories twice arm64 descends into each vdso directory twice; first in vdso_prepare, second during the ordinary build process. PPC mimicked it and uncovered a problem [1]. In the first descend, Kbuild directly visits the vdso directories, therefore it does not inherit subdir-ccflags-y from upper directories. This means the command line parameters may differ between the two. If it happens, the offset values in the generated headers might be different from real offsets of vdso.so in the kernel. This potential danger should be avoided. The vdso directories are built in the vdso_prepare stage, so the second descend is unneeded. [1]: https://lore.kernel.org/linux-kbuild/CAK7LNARAkJ3_-4gX0VA2UkapbOftuzfSTVMBbgbw=HD8n7N+7w@mail.gmail.com/T/#ma10dcb961fda13f36d42d58fa6cb2da988b7e73a Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20201218024540.1102650-1-masahiroy@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
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311bea3c |
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17-Dec-2020 |
Nick Desaulniers <ndesaulniers@google.com> |
arm64: link with -z norelro for LLD or aarch64-elf With GNU binutils 2.35+, linking with BFD produces warnings for vmlinux: aarch64-linux-gnu-ld: warning: -z norelro ignored BFD can produce this warning when the target emulation mode does not support RELRO program headers, and -z relro or -z norelro is passed. Alan Modra clarifies: The default linker emulation for an aarch64-linux ld.bfd is -maarch64linux, the default for an aarch64-elf linker is -maarch64elf. They are not equivalent. If you choose -maarch64elf you get an emulation that doesn't support -z relro. The ARCH=arm64 kernel prefers -maarch64elf, but may fall back to -maarch64linux based on the toolchain configuration. LLD will always create RELRO program header regardless of target emulation. To avoid the above warning when linking with BFD, pass -z norelro only when linking with LLD or with -maarch64linux. Fixes: 3b92fa7485eb ("arm64: link with -z norelro regardless of CONFIG_RELOCATABLE") Fixes: 3bbd3db86470 ("arm64: relocatable: fix inconsistencies in linker script and options") Cc: <stable@vger.kernel.org> # 5.0.x- Reported-by: kernelci.org bot <bot@kernelci.org> Reported-by: Quentin Perret <qperret@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Cc: Alan Modra <amodra@gmail.com> Cc: FÄng-ruƬ SĆ²ng <maskray@google.com> Link: https://lore.kernel.org/r/20201218002432.788499-1-ndesaulniers@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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0fea6e9a |
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22-Dec-2020 |
Andrey Konovalov <andreyknvl@google.com> |
kasan, arm64: expand CONFIG_KASAN checks Some #ifdef CONFIG_KASAN checks are only relevant for software KASAN modes (either related to shadow memory or compiler instrumentation). Expand those into CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS. Link: https://lkml.kernel.org/r/e6971e432dbd72bb897ff14134ebb7e169bdcf0c.1606161801.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Alexander Potapenko <glider@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Marco Elver <elver@google.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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f469c032 |
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22-Dec-2020 |
Vincenzo Frascino <vincenzo.frascino@arm.com> |
arm64: enable armv8.5-a asm-arch option Hardware tag-based KASAN relies on Memory Tagging Extension (MTE) which is an armv8.5-a architecture extension. Enable the correct asm option when the compiler supports it in order to allow the usage of ALTERNATIVE()s with MTE instructions. Link: https://lkml.kernel.org/r/d03d1157124ea3532eaeb77507988733f5734986.1606161801.git.andreyknvl@google.com Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Alexander Potapenko <glider@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Marco Elver <elver@google.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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59612b24 |
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19-Nov-2020 |
Nathan Chancellor <nathan@kernel.org> |
kbuild: Hoist '--orphan-handling' into Kconfig Currently, '--orphan-handling=warn' is spread out across four different architectures in their respective Makefiles, which makes it a little unruly to deal with in case it needs to be disabled for a specific linker version (in this case, ld.lld 10.0.1). To make it easier to control this, hoist this warning into Kconfig and the main Makefile so that disabling it is simpler, as the warning will only be enabled in a couple places (main Makefile and a couple of compressed boot folders that blow away LDFLAGS_vmlinx) and making it conditional is easier due to Kconfig syntax. One small additional benefit of this is saving a call to ld-option on incremental builds because we will have already evaluated it for CONFIG_LD_ORPHAN_WARN. To keep the list of supported architectures the same, introduce CONFIG_ARCH_WANT_LD_ORPHAN_WARN, which an architecture can select to gain this automatically after all of the sections are specified and size asserted. A special thanks to Kees Cook for the help text on this config. Link: https://github.com/ClangBuiltLinux/linux/issues/1187 Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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3b92fa74 |
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16-Oct-2020 |
Nick Desaulniers <ndesaulniers@google.com> |
arm64: link with -z norelro regardless of CONFIG_RELOCATABLE With CONFIG_EXPERT=y, CONFIG_KASAN=y, CONFIG_RANDOMIZE_BASE=n, CONFIG_RELOCATABLE=n, we observe the following failure when trying to link the kernel image with LD=ld.lld: error: section: .exit.data is not contiguous with other relro sections ld.lld defaults to -z relro while ld.bfd defaults to -z norelro. This was previously fixed, but only for CONFIG_RELOCATABLE=y. Fixes: 3bbd3db86470 ("arm64: relocatable: fix inconsistencies in linker script and options") Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201016175339.2429280-1-ndesaulniers@google.com Signed-off-by: Will Deacon <will@kernel.org>
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596b0474 |
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07-Sep-2020 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: preprocess module linker script There was a request to preprocess the module linker script like we do for the vmlinux one. (https://lkml.org/lkml/2020/8/21/512) The difference between vmlinux.lds and module.lds is that the latter is needed for external module builds, thus must be cleaned up by 'make mrproper' instead of 'make clean'. Also, it must be created by 'make modules_prepare'. You cannot put it in arch/$(SRCARCH)/kernel/, which is cleaned up by 'make clean'. I moved arch/$(SRCARCH)/kernel/module.lds to arch/$(SRCARCH)/include/asm/module.lds.h, which is included from scripts/module.lds.S. scripts/module.lds is fine because 'make clean' keeps all the build artifacts under scripts/. You can add arch-specific sections in <asm/module.lds.h>. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Jessica Yu <jeyu@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Jessica Yu <jeyu@kernel.org>
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120dc60d |
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25-Aug-2020 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: get rid of TEXT_OFFSET TEXT_OFFSET serves no purpose, and for this reason, it was redefined as 0x0 in the v5.8 timeframe. Since this does not appear to have caused any issues that require us to revisit that decision, let's get rid of the macro entirely, along with any references to it. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20200825135440.11288-1-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
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b3e5d80d |
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01-Sep-2020 |
Kees Cook <keescook@chromium.org> |
arm64/build: Warn on orphan section placement We don't want to depend on the linker's orphan section placement heuristics as these can vary between linkers, and may change between versions. All sections need to be explicitly handled in the linker script. With all sections now handled, enable orphan section warnings. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Will Deacon <will@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20200902025347.2504702-2-keescook@chromium.org
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6e0a66d1 |
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21-Aug-2020 |
Kees Cook <keescook@chromium.org> |
arm64/build: Remove .eh_frame* sections due to unwind tables Avoid .eh_frame* section generation by making sure both CFLAGS and AFLAGS contain -fno-asychronous-unwind-tables and -fno-unwind-tables. With all sources of .eh_frame now removed from the build, drop this DISCARD so we can be alerted in the future if it returns unexpectedly once orphan section warnings have been enabled. Suggested-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200821194310.3089815-11-keescook@chromium.org
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5d28ba5f |
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27-Aug-2020 |
Frank van der Linden <fllinden@amazon.com> |
arm64: vdso32: make vdso32 install conditional vdso32 should only be installed if CONFIG_COMPAT_VDSO is enabled, since it's not even supposed to be compiled otherwise, and arm64 builds without a 32bit crosscompiler will fail. Fixes: 8d75785a8142 ("ARM64: vdso32: Install vdso32 from vdso_install") Signed-off-by: Frank van der Linden <fllinden@amazon.com> Cc: stable@vger.kernel.org [5.4+] Link: https://lore.kernel.org/r/20200827234012.19757-1-fllinden@amazon.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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1764c3ed |
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27-Aug-2020 |
Sami Tolvanen <samitolvanen@google.com> |
arm64: use a common .arch preamble for inline assembly Commit 7c78f67e9bd9 ("arm64: enable tlbi range instructions") breaks LLVM's integrated assembler, because -Wa,-march is only passed to external assemblers and therefore, the new instructions are not enabled when IAS is used. This change adds a common architecture version preamble, which can be used in inline assembly blocks that contain instructions that require a newer architecture version, and uses it to fix __TLBI_0 and __TLBI_1 with ARM64_TLB_RANGE. Fixes: 7c78f67e9bd9 ("arm64: enable tlbi range instructions") Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://github.com/ClangBuiltLinux/linux/issues/1106 Link: https://lore.kernel.org/r/20200827203608.1225689-1-samitolvanen@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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8d75785a |
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17-Aug-2020 |
Stephen Boyd <swboyd@chromium.org> |
ARM64: vdso32: Install vdso32 from vdso_install Add the 32-bit vdso Makefile to the vdso_install rule so that 'make vdso_install' installs the 32-bit compat vdso when it is compiled. Fixes: a7f71a2c8903 ("arm64: compat: Add vDSO") Signed-off-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Acked-by: Will Deacon <will@kernel.org> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lore.kernel.org/r/20200818014950.42492-1-swboyd@chromium.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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7c78f67e |
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15-Jul-2020 |
Zhenyu Ye <yezhenyu2@huawei.com> |
arm64: enable tlbi range instructions TLBI RANGE feature instoduces new assembly instructions and only support by binutils >= 2.30. Add necessary Kconfig logic to allow this to be enabled and pass '-march=armv8.4-a' to KBUILD_CFLAGS. Signed-off-by: Zhenyu Ye <yezhenyu2@huawei.com> Link: https://lore.kernel.org/r/20200715071945.897-3-yezhenyu2@huawei.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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c1aac64d |
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03-Jun-2020 |
Masahiro Yamada <masahiroy@kernel.org> |
efi/libstub/arm64: link stub lib.a conditionally Since commit 799c43415442 ("kbuild: thin archives make default for all archs"), core-y is passed to the linker with --whole-archive. Hence, the whole of stub library is linked to vmlinux. Use libs-y so that lib.a is passed after --no-whole-archive for conditional linking. The unused drivers/firmware/efi/libstub/relocate.o will be dropped for ARCH=arm64. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20200604022031.164207-1-masahiroy@kernel.org Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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751c263b |
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14-Jun-2020 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: remove TEXT_OFFSET randomization TEXT_OFFSET was recently changed to 0x0, in preparation for its removal at a later stage, and a warning is emitted into the kernel log when the bootloader appears to have failed to take the TEXT_OFFSET image header value into account. Ironically, this warning itself fails to take TEXT_OFFSET into account, and compares the kernel image's alignment modulo 2M against a hardcoded value of 0x0, and so the warning will trigger spuriously when TEXT_OFFSET randomization is enabled. Given the intent to get rid of TEXT_OFFSET entirely, let's fix this oversight by just removing support for TEXT_OFFSET randomization. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20200615101939.634391-1-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
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da64e9d1 |
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27-Apr-2020 |
Sami Tolvanen <samitolvanen@google.com> |
arm64: Reserve register x18 from general allocation with SCS Reserve the x18 register from general allocation when SCS is enabled, because the compiler uses the register to store the current task's shadow stack pointer. Note that all external kernel modules must also be compiled with -ffixed-x18 if the kernel has SCS enabled. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
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#
1ca0c2f6 |
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26-Apr-2020 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: remove unused AS assignment $(AS) is not used anywhere in the kernel build, hence commit aa824e0c962b ("kbuild: remove AS variable") killed it. Remove the left-over code in arch/{arm,arm64}/Makefile. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Acked-by: Will Deacon <will@kernel.org>
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92e2294d |
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06-May-2020 |
Mark Brown <broonie@kernel.org> |
arm64: bti: Support building kernel C code using BTI When running with BTI enabled we need to ask the compiler to enable generation of BTI landing pads beyond those generated as a result of pointer authentication instructions being landing pads. Since the two features are practically speaking unlikely to be used separately we will make kernel mode BTI depend on pointer authentication in order to simplify the Makefile. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200506195138.22086-3-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
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717b938e |
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06-May-2020 |
Mark Brown <broonie@kernel.org> |
arm64: Document why we enable PAC support for leaf functions Document the fact that we enable pointer authentication protection for leaf functions since there is some narrow potential for ROP protection benefits and little overhead has been observed. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20200506195138.22086-2-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
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cfa7ede2 |
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15-Apr-2020 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: set TEXT_OFFSET to 0x0 in preparation for removing it entirely TEXT_OFFSET on arm64 is a historical artifact from the early days of the arm64 port where the boot protocol was basically 'copy this image to the base of memory + 512k', giving us 512 KB of guaranteed BSS space to put the swapper page tables. When the arm64 Image header was added in v3.10, it already carried the actual value of TEXT_OFFSET, to allow the bootloader to discover it dynamically rather than hardcode it to 512 KB. Today, this memory window is not used for any particular purpose, and it is simply handed to the page allocator at boot. The only reason it still exists is because of the 512k misalignment it causes with respect to the 2 MB aligned virtual base address of the kernel, which affects the virtual addresses of all statically allocated objects in the kernel image. However, with the introduction of KASLR in v4.6, we added the concept of relocatable kernels, which rewrite all absolute symbol references at boot anyway, and so the placement of such kernels in the physical address space is irrelevant, provided that the minimum segment alignment is honoured (64 KB in most cases, 128 KB for 64k pages kernels with vmap'ed stacks enabled). This makes 0x0 and 512 KB equally suitable values for TEXT_OFFSET on the off chance that we are dealing with boot loaders that ignore the value passed via the header entirely. Considering that the distros as well as Android ship KASLR-capable kernels today, and the fact that TEXT_OFFSET was discoverable from the Image header from the very beginning, let's change this value to 0x0, in preparation for removing it entirely at a later date. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20200415082922.32709-1-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
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4cf23494 |
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15-Apr-2020 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: drop GZFLAGS definition and export Drop the definition and export of GZFLAGS, which was never referenced on arm64, and whose last recorded use in the ARM port (on which arm64 was based original) was removed by patch commit 5e89d379edb5ae08b57f39dd8d91697275245cbf [*] Author: Russell King <rmk@flint.arm.linux.org.uk> Date: Wed Oct 16 14:32:17 2002 +0100 [ARM] Convert ARM makefiles to new kbuild (Sam Ravnborg, Kai, rmk) [*] git commit ID based on Thomas Gleixner's historical GIT repository at git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20200415123049.25504-1-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
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b8fdef31 |
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31-Mar-2020 |
Mark Brown <broonie@kernel.org> |
arm64: Always force a branch protection mode when the compiler has one Compilers with branch protection support can be configured to enable it by default, it is likely that distributions will do this as part of deploying branch protection system wide. As well as the slight overhead from having some extra NOPs for unused branch protection features this can cause more serious problems when the kernel is providing pointer authentication to userspace but not built for pointer authentication itself. In that case our switching of keys for userspace can affect the kernel unexpectedly, causing pointer authentication instructions in the kernel to corrupt addresses. To ensure that we get consistent and reliable behaviour always explicitly initialise the branch protection mode, ensuring that the kernel is built the same way regardless of the compiler defaults. Fixes: 7503197562567 (arm64: add basic pointer authentication support) Reported-by: Szabolcs Nagy <szabolcs.nagy@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org [catalin.marinas@arm.com: remove Kconfig option in favour of Makefile check] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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74afda40 |
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13-Mar-2020 |
Kristina Martsenko <kristina.martsenko@arm.com> |
arm64: compile the kernel with ptrauth return address signing Compile all functions with two ptrauth instructions: PACIASP in the prologue to sign the return address, and AUTIASP in the epilogue to authenticate the return address (from the stack). If authentication fails, the return will cause an instruction abort to be taken, followed by an oops and killing the task. This should help protect the kernel against attacks using return-oriented programming. As ptrauth protects the return address, it can also serve as a replacement for CONFIG_STACKPROTECTOR, although note that it does not protect other parts of the stack. The new instructions are in the HINT encoding space, so on a system without ptrauth they execute as NOPs. CONFIG_ARM64_PTR_AUTH now not only enables ptrauth for userspace and KVM guests, but also automatically builds the kernel with ptrauth instructions if the compiler supports it. If there is no compiler support, we do not warn that the kernel was built without ptrauth instructions. GCC 7 and 8 support the -msign-return-address option, while GCC 9 deprecates that option and replaces it with -mbranch-protection. Support both options. Clang uses an external assembler hence this patch makes sure that the correct parameters (-march=armv8.3-a) are passed down to help it recognize the ptrauth instructions. Ftrace function tracer works properly with Ptrauth only when patchable-function-entry feature is present and is ensured by the Kconfig dependency. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com> # not co-dev parts Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> [Amit: Cover leaf function, comments, Ftrace Kconfig] Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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8bf9284d |
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15-Jan-2020 |
Vladimir Murzin <vladimir.murzin@arm.com> |
arm64: Turn "broken gas inst" into real config option Use the new 'as-instr' Kconfig macro to define CONFIG_BROKEN_GAS_INST directly, making it available everywhere. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> [will: Drop redundant 'y if' logic] Signed-off-by: Will Deacon <will@kernel.org>
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395af861 |
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15-Jan-2020 |
Catalin Marinas <catalin.marinas@arm.com> |
arm64: Move the LSE gas support detection to Kconfig As the Kconfig syntax gained support for $(as-instr) tests, move the LSE gas support detection from Makefile to the main arm64 Kconfig and remove the additional CONFIG_AS_LSE definition and check. Cc: Will Deacon <will@kernel.org> Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
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3b23e499 |
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08-Feb-2019 |
Torsten Duwe <duwe@lst.de> |
arm64: implement ftrace with regs This patch implements FTRACE_WITH_REGS for arm64, which allows a traced function's arguments (and some other registers) to be captured into a struct pt_regs, allowing these to be inspected and/or modified. This is a building block for live-patching, where a function's arguments may be forwarded to another function. This is also necessary to enable ftrace and in-kernel pointer authentication at the same time, as it allows the LR value to be captured and adjusted prior to signing. Using GCC's -fpatchable-function-entry=N option, we can have the compiler insert a configurable number of NOPs between the function entry point and the usual prologue. This also ensures functions are AAPCS compliant (e.g. disabling inter-procedural register allocation). For example, with -fpatchable-function-entry=2, GCC 8.1.0 compiles the following: | unsigned long bar(void); | | unsigned long foo(void) | { | return bar() + 1; | } ... to: | <foo>: | nop | nop | stp x29, x30, [sp, #-16]! | mov x29, sp | bl 0 <bar> | add x0, x0, #0x1 | ldp x29, x30, [sp], #16 | ret This patch builds the kernel with -fpatchable-function-entry=2, prefixing each function with two NOPs. To trace a function, we replace these NOPs with a sequence that saves the LR into a GPR, then calls an ftrace entry assembly function which saves this and other relevant registers: | mov x9, x30 | bl <ftrace-entry> Since patchable functions are AAPCS compliant (and the kernel does not use x18 as a platform register), x9-x18 can be safely clobbered in the patched sequence and the ftrace entry code. There are now two ftrace entry functions, ftrace_regs_entry (which saves all GPRs), and ftrace_entry (which saves the bare minimum). A PLT is allocated for each within modules. Signed-off-by: Torsten Duwe <duwe@suse.de> [Mark: rework asm, comments, PLTs, initialization, commit message] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Torsten Duwe <duwe@suse.de> Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Tested-by: Torsten Duwe <duwe@suse.de> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Julien Thierry <jthierry@redhat.com> Cc: Will Deacon <will@kernel.org>
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7c4791c9 |
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07-Oct-2019 |
Will Deacon <will@kernel.org> |
arm64: Kconfig: Make CONFIG_COMPAT_VDSO a proper Kconfig option CONFIG_COMPAT_VDSO is defined by passing '-DCONFIG_COMPAT_VDSO' to the compiler when the generic compat vDSO code is in use. It's much cleaner and simpler to expose this as a proper Kconfig option (like x86 does), so do that and remove the bodge. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
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bcaf9b57 |
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04-Oct-2019 |
Will Deacon <will@kernel.org> |
arm64: vdso32: Move definition of COMPATCC into vdso32/Makefile There's no need to export COMPATCC, so just define it locally in the vdso32/Makefile, which is the only place where it is used. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
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24ee01a9 |
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04-Oct-2019 |
Will Deacon <will@kernel.org> |
arm64: Default to building compat vDSO with clang when CONFIG_CC_IS_CLANG Rather than force the use of GCC for the compat cross-compiler, instead extract the target from CROSS_COMPILE_COMPAT and pass it to clang if the main compiler is clang. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
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e0de01aa |
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03-Oct-2019 |
Vincenzo Frascino <vincenzo.frascino@arm.com> |
arm64: vdso32: Fix broken compat vDSO build warnings The .config file and the generated include/config/auto.conf can end up out of sync after a set of commands since CONFIG_CROSS_COMPILE_COMPAT_VDSO is not updated correctly. The sequence can be reproduced as follows: $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig [...] $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- menuconfig [set CONFIG_CROSS_COMPILE_COMPAT_VDSO="arm-linux-gnueabihf-"] $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- Which results in: arch/arm64/Makefile:62: CROSS_COMPILE_COMPAT not defined or empty, the compat vDSO will not be built even though the compat vDSO has been built: $ file arch/arm64/kernel/vdso32/vdso.so arch/arm64/kernel/vdso32/vdso.so: ELF 32-bit LSB pie executable, ARM, EABI5 version 1 (SYSV), dynamically linked, BuildID[sha1]=c67f6c786f2d2d6f86c71f708595594aa25247f6, stripped A similar case that involves changing the configuration parameter multiple times can be reconducted to the same family of problems. Remove the use of CONFIG_CROSS_COMPILE_COMPAT_VDSO altogether and instead rely on the cross-compiler prefix coming from the environment via CROSS_COMPILE_COMPAT, much like we do for the rest of the kernel. Cc: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Will Deacon <will@kernel.org> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
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03adcbd9 |
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29-Aug-2019 |
Will Deacon <will@kernel.org> |
arm64: atomics: Use K constraint when toolchain appears to support it The 'K' constraint is a documented AArch64 machine constraint supported by GCC for matching integer constants that can be used with a 32-bit logical instruction. Unfortunately, some released compilers erroneously accept the immediate '4294967295' for this constraint, which is later refused by GAS at assembly time. This had led us to avoid the use of the 'K' constraint altogether. Instead, detect whether the compiler is up to the job when building the kernel and pass the 'K' constraint to our 32-bit atomic macros when it appears to be supported. Signed-off-by: Will Deacon <will@kernel.org>
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6bfa3134 |
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21-Aug-2019 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
arm64: add arch/arm64/Kbuild Use the standard obj-y form to specify the sub-directories under arch/arm64/. No functional change intended. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Will Deacon <will@kernel.org>
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10df0638 |
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14-Aug-2019 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
kbuild: rebuild modules when module linker scripts are updated Currently, the timestamp of module linker scripts are not checked. Add them to the dependency of modules so they are correctly rebuilt. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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6bd1d0be |
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07-Aug-2019 |
Steve Capper <steve.capper@arm.com> |
arm64: kasan: Switch to using KASAN_SHADOW_OFFSET KASAN_SHADOW_OFFSET is a constant that is supplied to gcc as a command line argument and affects the codegen of the inline address sanetiser. Essentially, for an example memory access: *ptr1 = val; The compiler will insert logic similar to the below: shadowValue = *(ptr1 >> KASAN_SHADOW_SCALE_SHIFT + KASAN_SHADOW_OFFSET) if (somethingWrong(shadowValue)) flagAnError(); This code sequence is inserted into many places, thus KASAN_SHADOW_OFFSET is essentially baked into many places in the kernel text. If we want to run a single kernel binary with multiple address spaces, then we need to do this with KASAN_SHADOW_OFFSET fixed. Thankfully, due to the way the KASAN_SHADOW_OFFSET is used to provide shadow addresses we know that the end of the shadow region is constant w.r.t. VA space size: KASAN_SHADOW_END = ~0 >> KASAN_SHADOW_SCALE_SHIFT + KASAN_SHADOW_OFFSET This means that if we increase the size of the VA space, the start of the KASAN region expands into lower addresses whilst the end of the KASAN region is fixed. Currently the arm64 code computes KASAN_SHADOW_OFFSET at build time via build scripts with the VA size used as a parameter. (There are build time checks in the C code too to ensure that expected values are being derived). It is sufficient, and indeed is a simplification, to remove the build scripts (and build time checks) entirely and instead provide KASAN_SHADOW_OFFSET values. This patch removes the logic to compute the KASAN_SHADOW_OFFSET in the arm64 Makefile, and instead we adopt the approach used by x86 to supply offset values in kConfig. To help debug/develop future VA space changes, the Makefile logic has been preserved in a script file in the arm64 Documentation folder. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
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14c127c9 |
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07-Aug-2019 |
Steve Capper <steve.capper@arm.com> |
arm64: mm: Flip kernel VA space In order to allow for a KASAN shadow that changes size at boot time, one must fix the KASAN_SHADOW_END for both 48 & 52-bit VAs and "grow" the start address. Also, it is highly desirable to maintain the same function addresses in the kernel .text between VA sizes. Both of these requirements necessitate us to flip the kernel address space halves s.t. the direct linear map occupies the lower addresses. This patch puts the direct linear map in the lower addresses of the kernel VA range and everything else in the higher ranges. We need to adjust: *) KASAN shadow region placement logic, *) KASAN_SHADOW_OFFSET computation logic, *) virt_to_phys, phys_to_virt checks, *) page table dumper. These are all small changes, that need to take place atomically, so they are bundled into this commit. As part of the re-arrangement, a guard region of 2MB (to preserve alignment for fixed map) is added after the vmemmap. Otherwise the vmemmap could intersect with IS_ERR pointers. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
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a22c5cf5 |
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29-Jul-2019 |
Vincenzo Frascino <vincenzo.frascino@arm.com> |
arm64: vdso: Fix Makefile regression Using an old .config in combination with "make oldconfig" can cause an incorrect detection of the compat compiler: $ grep CROSS_COMPILE_COMPAT .config CONFIG_CROSS_COMPILE_COMPAT_VDSO="" $ make oldconfig && make arch/arm64/Makefile:58: gcc not found, check CROSS_COMPILE_COMPAT. Stop. Accordingly to the section 7.2 of the GNU Make manual "Syntax of Conditionals", "When the value results from complex expansions of variables and functions, expansions you would consider empty may actually contain whitespace characters and thus are not seen as empty. However, you can use the strip function to avoid interpreting whitespace as a non-empty value." Fix the issue adding strip to the CROSS_COMPILE_COMPAT string evaluation. Reported-by: Matteo Croce <mcroce@redhat.com> Tested-by: Matteo Croce <mcroce@redhat.com> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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bfe801eb |
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21-Jun-2019 |
Vincenzo Frascino <vincenzo.frascino@arm.com> |
arm64: vdso: Enable vDSO compat support Add vDSO compat support to the arm64 build system. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Shijith Thotton <sthotton@marvell.com> Tested-by: Andre Przywara <andre.przywara@arm.com> Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Huw Davies <huw@codeweavers.com> Link: https://lkml.kernel.org/r/20190621095252.32307-16-vincenzo.frascino@arm.com
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fa63da2a |
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11-Jun-2019 |
Nathan Chancellor <nathan@kernel.org> |
arm64: Don't unconditionally add -Wno-psabi to KBUILD_CFLAGS This is a GCC only option, which warns about ABI changes within GCC, so unconditionally adding it breaks Clang with tons of: warning: unknown warning option '-Wno-psabi' [-Wunknown-warning-option] and link time failures: ld.lld: error: undefined symbol: __efistub___stack_chk_guard >>> referenced by arm-stub.c:73 (/home/nathan/cbl/linux/drivers/firmware/efi/libstub/arm-stub.c:73) >>> arm-stub.stub.o:(__efistub_install_memreserve_table) in archive ./drivers/firmware/efi/libstub/lib.a These failures come from the lack of -fno-stack-protector, which is added via cc-option in drivers/firmware/efi/libstub/Makefile. When an unknown flag is added to KBUILD_CFLAGS, clang will noisily warn that it is ignoring the option like above, unlike gcc, who will just error. $ echo "int main() { return 0; }" > tmp.c $ clang -Wno-psabi tmp.c; echo $? warning: unknown warning option '-Wno-psabi' [-Wunknown-warning-option] 1 warning generated. 0 $ gcc -Wsometimes-uninitialized tmp.c; echo $? gcc: error: unrecognized command line option ā-Wsometimes-uninitializedā; did you mean ā-Wmaybe-uninitializedā? 1 For cc-option to work properly with clang and behave like gcc, -Werror is needed, which was done in commit c3f0d0bc5b01 ("kbuild, LLVMLinux: Add -Werror to cc-option to support clang"). $ clang -Werror -Wno-psabi tmp.c; echo $? error: unknown warning option '-Wno-psabi' [-Werror,-Wunknown-warning-option] 1 As a consequence of this, when an unknown flag is unconditionally added to KBUILD_CFLAGS, it will cause cc-option to always fail and those flags will never get added: $ clang -Werror -Wno-psabi -fno-stack-protector tmp.c; echo $? error: unknown warning option '-Wno-psabi' [-Werror,-Wunknown-warning-option] 1 This can be seen when compiling the whole kernel as some warnings that are normally disabled (see below) show up. The full list of flags missing from drivers/firmware/efi/libstub are the following (gathered from diffing .arm64-stub.o.cmd): -fno-delete-null-pointer-checks -Wno-address-of-packed-member -Wframe-larger-than=2048 -Wno-unused-const-variable -fno-strict-overflow -fno-merge-all-constants -fno-stack-check -Werror=date-time -Werror=incompatible-pointer-types -ffreestanding -fno-stack-protector Use cc-disable-warning so that it gets disabled for GCC and does nothing for Clang. Fixes: ebcc5928c5d9 ("arm64: Silence gcc warnings about arch ABI drift") Link: https://github.com/ClangBuiltLinux/linux/issues/511 Reported-by: Qian Cai <cai@lca.pw> Acked-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
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bd305f25 |
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27-May-2019 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
kconfig: make arch/*/configs/defconfig the default of KBUILD_DEFCONFIG Until recently, if KBUILD_DEFCONFIG was not set by the arch Makefile, the default path arch/*/defconfig was used. The last users of the default are gone by the following commits: - Commit f3e20ad67b4c ("s390: move arch/s390/defconfig to arch/s390/configs/defconfig") - Commit 986a13769c4b ("alpha: move arch/alpha/defconfig to arch/alpha/configs/defconfig") Let's set arch/*/configs/defconfig as a new default. This saves KBUILD_DEFCONFIG for some architectures. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
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ebcc5928 |
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06-Jun-2019 |
Dave Martin <Dave.Martin@arm.com> |
arm64: Silence gcc warnings about arch ABI drift Since GCC 9, the compiler warns about evolution of the platform-specific ABI, in particular relating for the marshaling of certain structures involving bitfields. The kernel is a standalone binary, and of course nobody would be so stupid as to expose structs containing bitfields as function arguments in ABI. (Passing a pointer to such a struct, however inadvisable, should be unaffected by this change. perf and various drivers rely on that.) So these warnings do more harm than good: turn them off. We may miss warnings about future ABI drift, but that's too bad. Future ABI breaks of this class will have to be debugged and fixed the traditional way unless the compiler evolves finer-grained diagnostics. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
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b2f557ea |
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28-Dec-2018 |
Andrey Konovalov <andreyknvl@google.com> |
kasan, arm64: adjust shadow size for tag-based mode 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>
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#
0a1213fa |
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12-Dec-2018 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: enable per-task stack canaries 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>
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#
3bbd3db8 |
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03-Dec-2018 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: relocatable: fix inconsistencies in linker script and options 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>
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98356eb0 |
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30-Oct-2018 |
Victor Kamensky <kamensky@cisco.com> |
arm64: makefile fix build of .i file in external module case 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>
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37c8a5fa |
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10-Jan-2018 |
Rob Herring <robh@kernel.org> |
kbuild: consolidate Devicetree dtb build rules 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>
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d503ac53 |
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23-Aug-2018 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
kbuild: rename LDFLAGS to KBUILD_LDFLAGS 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>
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c931d34e |
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13-Jul-2018 |
Olof Johansson <olof@lixom.net> |
arm64: build with baremetal linker target instead of Linux when available 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>
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96f95a17 |
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09-Jul-2018 |
Laura Abbott <labbott@redhat.com> |
Revert "arm64: Use aarch64elf and aarch64elfb emulation mode variants" 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>
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1a381d4a |
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27-Jun-2018 |
Greg Hackmann <ghackmann@android.com> |
arm64: remove no-op -p linker flag 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>
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2893af07 |
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02-Jul-2018 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
arm64: add endianness option to LDFLAGS instead of LD 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>
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38fc4248 |
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02-Jul-2018 |
Paul Kocialkowski <contact@paulk.fr> |
arm64: Use aarch64elf and aarch64elfb emulation mode variants 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>
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#
f3a53f7b |
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17-May-2018 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
arm64: move GCC version check for ARCH_SUPPORTS_INT128 to Kconfig 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>
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#
1f2f01b1 |
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30-May-2018 |
Luc Van Oostenryck <luc.vanoostenryck@gmail.com> |
kbuild: add machine size to CHECKFLAGS 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>
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ad40bdaf |
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22-Dec-2017 |
Jason A. Donenfeld <Jason@zx2c4.com> |
arm64: support __int128 with clang 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>
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#
a257e025 |
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06-Mar-2018 |
Ard Biesheuvel <ardb@kernel.org> |
arm64/kernel: don't ban ADRP to work around Cortex-A53 erratum #843419 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>
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9597e743 |
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01-Mar-2018 |
Andrey Konovalov <andreyknvl@google.com> |
kasan, arm64: clean up KASAN_SHADOW_SCALE_SHIFT usage 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>
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be0f272b |
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20-Nov-2017 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: ftrace: emit ftrace-mod.o contents through code 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>
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fb872273 |
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03-Nov-2017 |
Jason A. Donenfeld <Jason@zx2c4.com> |
arm64: support __int128 on gcc 5+ 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>
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fd9dde6a |
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27-Oct-2017 |
Nick Desaulniers <ndesaulniers@google.com> |
arm64: prevent regressions in compressed kernel image size when upgrading to 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>
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#
3d6a7b99 |
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18-Sep-2017 |
Andrew Pinski <apinski@cavium.com> |
arm64: ensure the kernel is compiled for LP64 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>
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#
bcde519e |
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24-Jun-2017 |
Luc Van Oostenryck <luc.vanoostenryck@gmail.com> |
arm64: pass endianness info to sparse 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>
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#
f5d28490 |
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20-Jun-2017 |
Luc Van Oostenryck <luc.vanoostenryck@gmail.com> |
arm64: pass machine size to sparse 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>
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#
e71a4e1b |
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06-Jun-2017 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: ftrace: add support for far branches to dynamic ftrace 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>
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d91750f1 |
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11-Apr-2017 |
Marc Zyngier <maz@kernel.org> |
arm64: Silence spurious kbuild warning on menuconfig 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>
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#
06995804 |
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22-Nov-2016 |
Michal Marek <mmarek@suse.com> |
arm64: Use full path in KBUILD_IMAGE definition 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>
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#
bbb56c27 |
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06-Dec-2016 |
Marc Zyngier <maz@kernel.org> |
arm64: Add detection code for broken .inst support in binutils 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>
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b9dce7f1 |
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20-Oct-2016 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: kernel: force ET_DYN ELF type for CONFIG_RELOCATABLE=y 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>
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cfa88c79 |
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30-Aug-2016 |
Michal Marek <mmarek@suse.com> |
arm64: Set UTS_MACHINE in the Makefile 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>
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#
6ffe9923 |
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22-Aug-2016 |
Will Deacon <will@kernel.org> |
arm64: errata: Pass --fix-cortex-a53-843419 to ld if workaround enabled 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>
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#
08cc55b2 |
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24-Jul-2016 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: relocatable: suppress R_AARCH64_ABS64 relocations in vmlinux 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>
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#
f8fa70f3 |
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12-Jul-2016 |
Mark Rutland <mark.rutland@arm.com> |
arm64: localise Image objcopy flags 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>
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#
a66649da |
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12-May-2016 |
Kevin Brodsky <kevin.brodsky@arm.com> |
arm64: fix vdso-offsets.h dependency 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>
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9ca4e58c |
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20-Jun-2016 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
arm64: fix boot image dependencies to not generate invalid images 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>
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aed7eb83 |
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31-May-2016 |
Mark Rutland <mark.rutland@arm.com> |
arm64: fix alignment when RANDOMIZE_TEXT_OFFSET is enabled 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>
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1e48ef7f |
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26-Jan-2016 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: add support for building vmlinux as a relocatable PIE binary 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>
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fd045f6c |
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23-Nov-2015 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: add support for module PLTs 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>
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8684fa3e |
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18-Feb-2016 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
arm64: kbuild: make "make install" not depend on vmlinux 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>
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67dfa175 |
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25-Jan-2016 |
dann frazier <dann.frazier@canonical.com> |
arm64: errata: Add -mpc-relative-literal-loads to build flags 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>
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728dabd6 |
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21-Jan-2016 |
William Cohen <wcohen@redhat.com> |
Eliminate the .eh_frame sections from the aarch64 vmlinux and kernel modules 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>
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39d114dd |
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12-Oct-2015 |
Andrey Ryabinin <ryabinin.a.a@gmail.com> |
arm64: add KASAN support 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>
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b6dd8e07 |
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08-Oct-2015 |
Will Deacon <will@kernel.org> |
arm64: errata: use KBUILD_CFLAGS_MODULE for erratum #843419 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>
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df057cc7 |
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16-Mar-2015 |
Will Deacon <will@kernel.org> |
arm64: errata: add module build workaround for erratum #843419 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>
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c09d6a04 |
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03-Feb-2015 |
Will Deacon <will@kernel.org> |
arm64: atomics: patch in lse instructions when supported by the CPU 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>
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0723c05f |
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16-Jul-2015 |
Olof Johansson <olof@lixom.net> |
arm64: enable more compressed Image formats Plumb up Makefile arguments for the already supported formats in the kbuild system: lz4, bzip2, lzma, and lzo. Note that just as with Image.gz, these images are not self-decompressing and the booting firmware still needs to handle decompression before launching the kernel image. Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Will Deacon <will.deacon@arm.com>
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ad08fd49 |
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16-Mar-2015 |
Steve Capper <steve.capper@linaro.org> |
arm64: Adjust EFI libstub object include logic Commit f4f75ad5 ("efi: efistub: Convert into static library") introduced a static library for EFI stub, libstub. The EFI libstub directory is referenced by the kernel build system via a obj subdirectory rule in: drivers/firmware/efi/Makefile Unfortunately, arm64 also references the EFI libstub via: libs-$(CONFIG_EFI_STUB) += drivers/firmware/efi/libstub/ If we're unlucky, the kernel build system can enter libstub via two simultaneous threads resulting in build failures such as: fixdep: error opening depfile: drivers/firmware/efi/libstub/.efi-stub-helper.o.d: No such file or directory scripts/Makefile.build:257: recipe for target 'drivers/firmware/efi/libstub/efi-stub-helper.o' failed make[1]: *** [drivers/firmware/efi/libstub/efi-stub-helper.o] Error 2 Makefile:939: recipe for target 'drivers/firmware/efi/libstub' failed make: *** [drivers/firmware/efi/libstub] Error 2 make: *** Waiting for unfinished jobs.... This patch adjusts the arm64 Makefile to reference the compiled library explicitly (as is currently done in x86), rather than the directory. Fixes: f4f75ad5 efi: efistub: Convert into static library Signed-off-by: Steve Capper <steve.capper@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
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c7c52e48 |
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19-Jan-2015 |
Jungseok Lee <jungseoklee85@gmail.com> |
arm64: Add dtb files to archclean rule As dts files have been reorganised under vendor subdirs, dtb files cannot be removed with "make distclean" now. Thus, this patch moves dtb files under archclean rule and removes unnecessary entries. Cc: Robert Richter <rrichter@cavium.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
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d67703a8 |
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14-Jan-2015 |
Kevin Hao <haokexin@gmail.com> |
arm64: kill off the libgcc dependency The arm64 kernel builds fine without the libgcc. Actually it should not be used at all in the kernel. The following are the reasons indicated by Russell King: Although libgcc is part of the compiler, libgcc is built with the expectation that it will be running in userland - it expects to link to a libc. That's why you can't build libgcc without having the glibc headers around. [...] Meanwhile, having the kernel build the compiler support functions that it needs ensures that (a) we know what compiler support functions are being used, (b) we know the implementation of those support functions are sane for use in the kernel, (c) we can build them with appropriate compiler flags for best performance, and (d) we remove an unnecessary dependency on the build toolchain. Signed-off-by: Kevin Hao <haokexin@gmail.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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d38726c4 |
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03-Sep-2014 |
Robert Richter <rrichter@cavium.com> |
dts, arm/arm64: Remove dtbs build rules in sub-makes Add dtb files to build targets and let kbuild handle them. Thus, special dtbs rules can be removed. This eases Makefiles and the implementation of the support of vendor dtb subdirectories. Signed-off-by: Robert Richter <rrichter@cavium.com>
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9fb5e537 |
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03-Sep-2014 |
Robert Richter <rrichter@cavium.com> |
dts, kbuild: Factor out dtbs install rules to Makefile.dtbinst Move dtbs install rules to Makefile.dtbinst. This change is needed to implement support for dts vendor subdirs. The change makes Makefiles easier and smaller as no longer the dtbs_install rule needs to be defined. Another advantage is that install goals are not encoded in targets anymore (%.dtb_dtbinst_). Signed-off-by: Robert Richter <rrichter@cavium.com>
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862f464a |
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29-Aug-2014 |
Robert Richter <rrichter@cavium.com> |
dts, arm64: Add dtbs_install make target This adds the dtbs_install make target to arm64. The target has been introduced already to arch/arm with the following commit: f4d4ffc03efc kbuild: dtbs_install: new make target Implementation for arm64 is the same as for arm. With 'dtbs_install' all config enabled dtb files are installed to either the INSTALL_DTBS_PATH directory or the default location: $INSTALL_PATH/dtbs/$KERNELRELEASE Signed-off-by: Robert Richter <rrichter@cavium.com>
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226422d0 |
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22-Aug-2014 |
Masahiro Yamada <yamada.m@jp.panasonic.com> |
kbuild: arm: Do not define "comma" twice The definition of "comma" exists in scripts/Kbuild.include. We should not double it. Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Michal Marek <mmarek@suse.cz>
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e54bcde3 |
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26-Aug-2014 |
Zi Shen Lim <zlim.lnx@gmail.com> |
arm64: eBPF JIT compiler The JIT compiler emits A64 instructions. It supports eBPF only. Legacy BPF is supported thanks to conversion by BPF core. JIT is enabled in the same way as for other architectures: echo 1 > /proc/sys/net/core/bpf_jit_enable Or for additional compiler output: echo 2 > /proc/sys/net/core/bpf_jit_enable See Documentation/networking/filter.txt for more information. The implementation passes all 57 tests in lib/test_bpf.c on ARMv8 Foundation Model :) Also tested by Will on Juno platform. Signed-off-by: Zi Shen Lim <zlim.lnx@gmail.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
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4190312b |
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13-Aug-2014 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: align randomized TEXT_OFFSET on 4 kB boundary When booting via UEFI, the kernel Image is loaded at a 4 kB boundary and the embedded EFI stub is executed in place. The EFI stub relocates the Image to reside TEXT_OFFSET bytes above a 2 MB boundary, and jumps into the kernel proper. In AArch64, PC relative symbol references are emitted using adrp/add or adrp/ldr pairs, where the offset into a 4 kB page is resolved using a separate :lo12: relocation. This implicitly assumes that the code will always be executed at the same relative offset with respect to a 4 kB boundary, or the references will point to the wrong address. This means we should link the kernel at a 4 kB aligned base address in order to remain compatible with the base address the UEFI loader uses when doing the initial load of Image. So update the code that generates TEXT_OFFSET to choose a multiple of 4 kB. At the same time, update the code so it chooses from the interval [0..2MB) as the author originally intended. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
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f4f75ad5 |
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02-Jul-2014 |
Ard Biesheuvel <ardb@kernel.org> |
efi: efistub: Convert into static library This patch changes both x86 and arm64 efistub implementations from #including shared .c files under drivers/firmware/efi to building shared code as a static library. The x86 code uses a stub built into the boot executable which uncompresses the kernel at boot time. In this case, the library is linked into the decompressor. In the arm64 case, the stub is part of the kernel proper so the library is linked into the kernel proper as well. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
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da57a369 |
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24-Jun-2014 |
Mark Rutland <mark.rutland@arm.com> |
arm64: Enable TEXT_OFFSET fuzzing The arm64 Image header contains a text_offset field which bootloaders are supposed to read to determine the offset (from a 2MB aligned "start of memory" per booting.txt) at which to load the kernel. The offset is not well respected by bootloaders at present, and due to the lack of variation there is little incentive to support it. This is unfortunate for the sake of future kernels where we may wish to vary the text offset (even zeroing it). This patch adds options to arm64 to enable fuzz-testing of text_offset. CONFIG_ARM64_RANDOMIZE_TEXT_OFFSET forces the text offset to a random 16-byte aligned value value in the range [0..2MB) upon a build of the kernel. It is recommended that distribution kernels enable randomization to test bootloaders such that any compliance issues can be fixed early. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Tom Rini <trini@ti.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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2c98833a |
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06-Mar-2014 |
Ard Biesheuvel <ardb@kernel.org> |
arm64/crypto: SHA-1 using ARMv8 Crypto Extensions This patch adds support for the SHA-1 Secure Hash Algorithm for CPUs that have support for the SHA-1 part of the ARM v8 Crypto Extensions. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
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a0974e6e |
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11-Oct-2013 |
Will Deacon <will@kernel.org> |
arm64: big-endian: add big-endian support to top-level arch Makefile This patch adds big-endian support to the AArch64 top-level Makefile. This currently just passes the relevant flags to the toolchain and is predicated on a Kconfig option that will be introduced later on. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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3c01742a |
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16-Jun-2013 |
Kyle McMartin <kyle@redhat.com> |
arm64/Makefile: provide vdso_install target Provide a vdso_install target in the arm64 Makefile, as other architectures with a vdso do. Signed-off-by: Kyle McMartin <kyle@redhat.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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6211753f |
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10-Dec-2012 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Build system integration Only the Makefile is plugged in. The Kconfig stuff is in a separate patch to allow for an easier merge process. Reviewed-by: Christopher Covington <cov@codeaurora.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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aa42aa13 |
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03-Jun-2013 |
Stefano Stabellini <stefano.stabellini@eu.citrix.com> |
arm64/xen: introduce CONFIG_XEN and hypercall.S on ARM64 Introduce CONFIG_XEN and the implementation of hypercall.S (that is the only ARMv8 specific code in Xen support for ARM). Compile enlighten.c and grant_table.c from arch/arm. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
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58fea354 |
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21-Nov-2012 |
Catalin Marinas <catalin.marinas@arm.com> |
arm64: Fix the dtbs target building The arch/arm64/Makefile was not passing the right target to the boot/dts/Makefile. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Rob Herring <rob.herring@calxeda.com>
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70f915a2 |
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03-Dec-2012 |
Rob Herring <rob.herring@calxeda.com> |
arm64: Add dtbs target for building all the enabled dtb files Based on Rob Herring's patches for arch/arm, this patch adds a dtbs target to arch/arm64/boot/Makefile. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Rob Herring <rob.herring@calxeda.com>
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da4cbc6d |
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27-Nov-2012 |
Stephen Warren <swarren@nvidia.com> |
arm64: use new common dtc rule The current rules have the .dtb files build in a different directory from the .dts files. This patch changes arm64 to use the generic dtb rule which builds .dtb files in the same directory as the source .dts. This requires moving parts of arch/arm64/boot/Makefile into newly created arch/arm64/boot/dts/Makefile, and updating arch/arm64/Makefile to call the new Makefile. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Rob Herring <rob.herring@calxeda.com>
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8c2c3df3 |
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20-Apr-2012 |
Catalin Marinas <catalin.marinas@arm.com> |
arm64: Build infrastructure This patch adds Makefile and Kconfig files required for building an AArch64 kernel. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
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