No description
  • C 98.2%
  • Assembly 1%
  • Makefile 0.3%
  • Shell 0.2%
  • Python 0.1%
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Daniel Borkmann e80c3533c3 bpf: Introduce BPF nospec instruction for mitigating Spectre v4
commit f5e81d1117501546b7be050c5fbafa6efd2c722c upstream.

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>
[OP: - adjusted context for 5.4
     - apply riscv changes to /arch/riscv/net/bpf_jit_comp.c]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-15 09:47:38 +02:00
arch bpf: Introduce BPF nospec instruction for mitigating Spectre v4 2021-09-15 09:47:38 +02:00
block
certs
crypto
Documentation
drivers octeontx2-af: Fix loop in free and unmap counter 2021-09-15 09:47:38 +02:00
fs CIFS: Fix a potencially linear read overflow 2021-09-15 09:47:36 +02:00
include bpf: Introduce BPF nospec instruction for mitigating Spectre v4 2021-09-15 09:47:38 +02:00
init
ipc
kernel bpf: Introduce BPF nospec instruction for mitigating Spectre v4 2021-09-15 09:47:38 +02:00
lib
LICENSES
mm
net ipv4: fix endianness issue in inet_rtm_getroute_build_skb() 2021-09-15 09:47:38 +02:00
samples
scripts
security
sound ASoC: wcd9335: Disable irq on slave ports in the remove function 2021-09-15 09:47:37 +02:00
tools bpf: Fix a typo of reuseport map in bpf.h. 2021-09-15 09:47:30 +02:00
usr
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.