kernel.git/arch/arm64/kernel/bpi.S, branch linux-4.14.y

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

KVM: arm64: Add templates for BHB mitigation sequences

2022-04-02T10:41:10Z

KVM writes the Spectre-v2 mitigation template at the beginning of each vector when a CPU requires a specific sequence to run. Because the template is copied, it can not be modified by the alternatives at runtime. As the KVM template code is intertwined with the bp-hardening callbacks, all templates must have a bp-hardening callback. Add templates for calling ARCH_WORKAROUND_3 and one for each value of K in the brancy-loop. Identify these sequences by a new parameter template_start, and add a copy of install_bp_hardening_cb() that is able to install them. Signed-off-by: James Morse Signed-off-by: Greg Kroah-Hartman

arm64: Get rid of __smccc_workaround_1_hvc_*

2019-10-29T08:17:23Z

[ Upstream commit 22765f30dbaf1118c6ff0fcb8b99c9f2b4d396d5 ] The very existence of __smccc_workaround_1_hvc_* is a thinko, as KVM will never use a HVC call to perform the branch prediction invalidation. Even as a nested hypervisor, it would use an SMC instruction. Let's get rid of it. Signed-off-by: Marc Zyngier Signed-off-by: Will Deacon Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP hardening

2019-10-29T08:17:23Z

[ Upstream commit 4bc352ffb39e4eec253e70f8c076f2f48a6c1926 ] The function SMCCC_ARCH_WORKAROUND_1 was introduced as part of SMC V1.1 Calling Convention to mitigate CVE-2017-5715. This patch uses the standard call SMCCC_ARCH_WORKAROUND_1 for Falkor chips instead of Silicon provider service ID 0xC2001700. Cc: # 4.14+ Signed-off-by: Shanker Donthineni [maz: reworked errata framework integration] Signed-off-by: Marc Zyngier Signed-off-by: Will Deacon Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

arm64: Kill PSCI_GET_VERSION as a variant-2 workaround

2018-02-16T19:22:56Z

Commit 3a0a397ff5ff upstream. Now that we've standardised on SMCCC v1.1 to perform the branch prediction invalidation, let's drop the previous band-aid. If vendors haven't updated their firmware to do SMCCC 1.1, they haven't updated PSCI either, so we don't loose anything. Tested-by: Ard Biesheuvel Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas Signed-off-by: Will Deacon Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support

2018-02-16T19:22:56Z

Commit b092201e0020 upstream. Add the detection and runtime code for ARM_SMCCC_ARCH_WORKAROUND_1. It is lovely. Really. Tested-by: Ard Biesheuvel Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas Signed-off-by: Will Deacon Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

arm64: Implement branch predictor hardening for Falkor

2018-02-16T19:22:54Z

Commit ec82b567a74f upstream. Falkor is susceptible to branch predictor aliasing and can theoretically be attacked by malicious code. This patch implements a mitigation for these attacks, preventing any malicious entries from affecting other victim contexts. Signed-off-by: Shanker Donthineni [will: fix label name when !CONFIG_KVM and remove references to MIDR_FALKOR] Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

arm64: Implement branch predictor hardening for affected Cortex-A CPUs

2018-02-16T19:22:54Z

Commit aa6acde65e03 upstream. Cortex-A57, A72, A73 and A75 are susceptible to branch predictor aliasing and can theoretically be attacked by malicious code. This patch implements a PSCI-based mitigation for these CPUs when available. The call into firmware will invalidate the branch predictor state, preventing any malicious entries from affecting other victim contexts. Co-developed-by: Marc Zyngier Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

arm64: Add skeleton to harden the branch predictor against aliasing attacks

2018-02-16T19:22:53Z

Commit 0f15adbb2861 upstream. Aliasing attacks against CPU branch predictors can allow an attacker to redirect speculative control flow on some CPUs and potentially divulge information from one context to another. This patch adds initial skeleton code behind a new Kconfig option to enable implementation-specific mitigations against these attacks for CPUs that are affected. Co-developed-by: Marc Zyngier Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman