Reference in a new issue

Blame

Copy permalink

Reference in a new issue

Copy permalink

Daniel Borkmann bea9e2fd18 bpf: Introduce BPF nospec instruction for mitigating Spectre v4 ... [ Upstream commit f5e81d1117 ] In case of JITs, each of the JIT backends compiles the BPF nospec instruction /either/ to a machine instruction which emits a speculation barrier /or/ to /no/ machine instruction in case the underlying architecture is not affected by Speculative Store Bypass or has different mitigations in place already. This covers both x86 and (implicitly) arm64: In case of x86, we use 'lfence' instruction for mitigation. In case of arm64, we rely on the firmware mitigation as controlled via the ssbd kernel parameter. Whenever the mitigation is enabled, it works for all of the kernel code with no need to provide any additional instructions here (hence only comment in arm64 JIT). Other archs can follow as needed. The BPF nospec instruction is specifically targeting Spectre v4 since i) we don't use a serialization barrier for the Spectre v1 case, and ii) mitigation instructions for v1 and v4 might be different on some archs. The BPF nospec is required for a future commit, where the BPF verifier does annotate intermediate BPF programs with speculation barriers. Co-developed-by: Piotr Krysiuk <piotras@gmail.com> Co-developed-by: Benedict Schlueter <benedict.schlueter@rub.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Piotr Krysiuk <piotras@gmail.com> Signed-off-by: Benedict Schlueter <benedict.schlueter@rub.de> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		History 2021-08-04 12:46:44 +02:00
..
boot	arm64: dts: marvell: armada-37xx: move firmware node to generic dtsi file	2021-07-25 14:36:17 +02:00
configs	arm64: defconfig: Build in CONFIG_GPIO_MXC by default	2020-10-26 15:48:58 +08:00
crypto	crypto: poly1305 - fix poly1305_core_setkey() declaration	2021-05-14 09:50:13 +02:00
include	arm64: tlb: fix the TTL value of tlb_get_level	2021-07-19 09:44:59 +02:00
kernel	arm64/mm: Fix ttbr0 values stored in struct thread_info for software-pan	2021-07-14 16:56:07 +02:00
kvm	KVM: arm64: Don't zero the cycle count register when PMCR_EL0.P is set	2021-07-14 16:56:08 +02:00
lib	arm64: Change .weak to SYM_FUNC_START_WEAK_PI for arch/arm64/lib/mem*.S	2020-10-30 08:32:31 +00:00
mm	arm64: consistently use reserved_pg_dir	2021-07-14 16:56:06 +02:00
net	bpf: Introduce BPF nospec instruction for mitigating Spectre v4	2021-08-04 12:46:44 +02:00
xen	arm64: xen: Use modern annotations for assembly functions	2020-01-09 16:09:42 +00:00
Kbuild	arm64: add arch/arm64/Kbuild	2019-08-21 18:47:15 +01:00
Kconfig	arm64: mte: Ensure TIF_MTE_ASYNC_FAULT is set atomically	2021-04-21 13:01:00 +02:00
Kconfig.debug	arm64: remove TEXT_OFFSET randomization	2020-06-15 13:10:59 +01:00
Kconfig.platforms	arm64: berlin: Select DW_APB_TIMER_OF	2020-10-26 10:45:03 +01:00
Makefile	arm64: link with -z norelro for LLD or aarch64-elf	2021-01-12 20:18:24 +01:00