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>		2021-08-04 12:46:44 +02:00
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boot	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
configs	scsi: sr: remove references to BLK_DEV_SR_VENDOR, leave it enabled	2020-02-24 14:59:01 -05:00
crypto	crypto: sparc - rename sha256 to sha256_alg	2020-07-16 21:49:04 +10:00
include	sparc64: Use arch_validate_flags() to validate ADI flag	2021-03-17 17:06:24 +01:00
kernel	sched/core: Initialize the idle task with preemption disabled	2021-07-14 16:55:50 +02:00
lib	sparc32: fix a user-triggerable oops in clear_user()	2021-03-04 11:38:43 +01:00
math-emu	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
mm	sparc32: Limit memblock allocation to low memory	2021-03-17 17:06:24 +01:00
net	bpf: Introduce BPF nospec instruction for mitigating Spectre v4	2021-08-04 12:46:44 +02:00
oprofile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
power	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
prom
vdso	treewide: remove DISABLE_LTO	2020-10-21 00:28:53 +09:00
Kbuild	treewide: Add SPDX license identifier - Kbuild	2019-05-30 11:32:33 -07:00
Kconfig	sparc64: only select COMPAT_BINFMT_ELF if BINFMT_ELF is set	2021-03-04 11:38:10 +01:00
Kconfig.debug
Makefile