kernel.git/arch/arm64/include/asm/sysreg.h, branch linux-4.14.y

arm64: Add missing Set/Way CMO encodings

2023-06-28T08:14:20Z

[ Upstream commit 8d0f019e4c4f2ee2de81efd9bf1c27e9fb3c0460 ] Add the missing Set/Way CMOs that apply to tagged memory. Signed-off-by: Marc Zyngier Reviewed-by: Cornelia Huck Reviewed-by: Steven Price Reviewed-by: Oliver Upton Link: https://lore.kernel.org/r/20230515204601.1270428-2-maz@kernel.org Signed-off-by: Sasha Levin

arm64: Use the clearbhb instruction in mitigations

2022-04-02T10:41:10Z

commit 228a26b912287934789023b4132ba76065d9491c upstream. Future CPUs may implement a clearbhb instruction that is sufficient to mitigate SpectreBHB. CPUs that implement this instruction, but not CSV2.3 must be affected by Spectre-BHB. Add support to use this instruction as the BHB mitigation on CPUs that support it. The instruction is in the hint space, so it will be treated by a NOP as older CPUs. Reviewed-by: Russell King (Oracle) Reviewed-by: Catalin Marinas [ modified for stable: Use a KVM vector template instead of alternatives ] Signed-off-by: James Morse Signed-off-by: Greg Kroah-Hartman

arm64: add ID_AA64ISAR2_EL1 sys register

2022-04-02T10:41:10Z

commit 9e45365f1469ef2b934f9d035975dbc9ad352116 upstream. This is a new ID register, introduced in 8.7. Signed-off-by: Joey Gouly Cc: Will Deacon Cc: Marc Zyngier Cc: James Morse Cc: Alexandru Elisei Cc: Suzuki K Poulose Cc: Reiji Watanabe Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20211210165432.8106-3-joey.gouly@arm.com Signed-off-by: Catalin Marinas Signed-off-by: James Morse Signed-off-by: Greg Kroah-Hartman

arm64: Mitigate spectre style branch history side channels

2022-04-02T10:41:10Z

commit 558c303c9734af5a813739cd284879227f7297d2 upstream. Speculation attacks against some high-performance processors can make use of branch history to influence future speculation. When taking an exception from user-space, a sequence of branches or a firmware call overwrites or invalidates the branch history. The sequence of branches is added to the vectors, and should appear before the first indirect branch. For systems using KPTI the sequence is added to the kpti trampoline where it has a free register as the exit from the trampoline is via a 'ret'. For systems not using KPTI, the same register tricks are used to free up a register in the vectors. For the firmware call, arch-workaround-3 clobbers 4 registers, so there is no choice but to save them to the EL1 stack. This only happens for entry from EL0, so if we take an exception due to the stack access, it will not become re-entrant. For KVM, the existing branch-predictor-hardening vectors are used. When a spectre version of these vectors is in use, the firmware call is sufficient to mitigate against Spectre-BHB. For the non-spectre versions, the sequence of branches is added to the indirect vector. Reviewed-by: Catalin Marinas Cc: # # # Signed-off-by: Greg Kroah-Hartman

arm64: Delete the space separator in __emit_inst

2020-05-02T15:24:44Z

[ Upstream commit c9a4ef66450145a356a626c833d3d7b1668b3ded ] In assembly, many instances of __emit_inst(x) expand to a directive. In a few places __emit_inst(x) is used as an assembler macro argument. For example, in arch/arm64/kvm/hyp/entry.S ALTERNATIVE(nop, SET_PSTATE_PAN(1), ARM64_HAS_PAN, CONFIG_ARM64_PAN) expands to the following by the C preprocessor: alternative_insn nop, .inst (0xd500401f | ((0) << 16 | (4) << 5) | ((!!1) << 8)), 4, 1 Both comma and space are separators, with an exception that content inside a pair of parentheses/quotes is not split, so the clang integrated assembler splits the arguments to: nop, .inst, (0xd500401f | ((0) << 16 | (4) << 5) | ((!!1) << 8)), 4, 1 GNU as preprocesses the input with do_scrub_chars(). Its arm64 backend (along with many other non-x86 backends) sees: alternative_insn nop,.inst(0xd500401f|((0)<<16|(4)<<5)|((!!1)<<8)),4,1 # .inst(...) is parsed as one argument while its x86 backend sees: alternative_insn nop,.inst (0xd500401f|((0)<<16|(4)<<5)|((!!1)<<8)),4,1 # The extra space before '(' makes the whole .inst (...) parsed as two arguments The non-x86 backend's behavior is considered unintentional (https://sourceware.org/bugzilla/show_bug.cgi?id=25750). So drop the space separator inside `.inst (...)` to make the clang integrated assembler work. Suggested-by: Ilie Halip Signed-off-by: Fangrui Song Reviewed-by: Mark Rutland Link: https://github.com/ClangBuiltLinux/linux/issues/939 Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin

arm64: ssbd: Add support for PSTATE.SSBS rather than trapping to EL3

2019-10-29T08:17:24Z

[ Upstream commit 8f04e8e6e29c93421a95b61cad62e3918425eac7 ] On CPUs with support for PSTATE.SSBS, the kernel can toggle the SSBD state without needing to call into firmware. This patch hooks into the existing SSBD infrastructure so that SSBS is used on CPUs that support it, but it's all made horribly complicated by the very real possibility of big/little systems that don't uniformly provide the new capability. Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas [ardb: add #include of asm/compat.h] Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

arm64: cpufeature: Detect SSBS and advertise to userspace

2019-10-29T08:17:24Z

[ Upstream commit d71be2b6c0e19180b5f80a6d42039cc074a693a2 ] Armv8.5 introduces a new PSTATE bit known as Speculative Store Bypass Safe (SSBS) which can be used as a mitigation against Spectre variant 4. Additionally, a CPU may provide instructions to manipulate PSTATE.SSBS directly, so that userspace can toggle the SSBS control without trapping to the kernel. This patch probes for the existence of SSBS and advertise the new instructions to userspace if they exist. Reviewed-by: Suzuki K Poulose Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

arm64: Introduce sysreg_clear_set()

2019-10-29T08:17:12Z

[ Upstream commit 6ebdf4db8fa564a150f46d32178af0873eb5abbb ] Currently we have a couple of helpers to manipulate bits in particular sysregs: * config_sctlr_el1(u32 clear, u32 set) * change_cpacr(u64 val, u64 mask) The parameters of these differ in naming convention, order, and size, which is unfortunate. They also differ slightly in behaviour, as change_cpacr() skips the sysreg write if the bits are unchanged, which is a useful optimization when sysreg writes are expensive. Before we gain yet another sysreg manipulation function, let's unify these with a common helper, providing a consistent order for clear/set operands, and the write skipping behaviour from change_cpacr(). Code will be migrated to the new helper in subsequent patches. Signed-off-by: Mark Rutland Reviewed-by: Dave Martin Acked-by: Catalin Marinas Signed-off-by: Marc Zyngier Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

arm64: move SCTLR_EL{1,2} assertions to

2019-10-29T08:17:11Z

[ Upstream commit 1c312e84c2d71da4101754fa6118f703f7473e01 ] Currently we assert that the SCTLR_EL{1,2}_{SET,CLEAR} bits are self-consistent with an assertion in config_sctlr_el1(). This is a bit unusual, since config_sctlr_el1() doesn't make use of these definitions, and is far away from the definitions themselves. We can use the CPP #error directive to have equivalent assertions in , next to the definitions of the set/clear bits, which is a bit clearer and simpler. At the same time, lets fill in the upper 32 bits for both registers in their respective RES0 definitions. This could be a little nicer with GENMASK_ULL(63, 32), but this currently lives in , which cannot safely be included from assembly, as can. Note the when the preprocessor evaluates an expression for an #if directive, all signed or unsigned values are treated as intmax_t or uintmax_t respectively. To avoid ambiguity, we define explicitly define the mask of all 64 bits. Signed-off-by: Mark Rutland Acked-by: Catalin Marinas Cc: Dave Martin Cc: James Morse Cc: Will Deacon Signed-off-by: Will Deacon Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

arm64: Expose Arm v8.4 features

2019-10-29T08:17:10Z

[ Upstream commit 7206dc93a58fb76421c4411eefa3c003337bcb2d ] Expose the new features introduced by Arm v8.4 extensions to Arm v8-A profile. These include : 1) Data indpendent timing of instructions. (DIT, exposed as HWCAP_DIT) 2) Unaligned atomic instructions and Single-copy atomicity of loads and stores. (AT, expose as HWCAP_USCAT) 3) LDAPR and STLR instructions with immediate offsets (extension to LRCPC, exposed as HWCAP_ILRCPC) 4) Flag manipulation instructions (TS, exposed as HWCAP_FLAGM). Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Reviewed-by: Dave Martin Signed-off-by: Suzuki K Poulose Signed-off-by: Will Deacon [ardb: fix up context for missing SVE] Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman