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Luke Nelson bb9562cf5c arm, bpf: Fix bugs with ALU64 {RSH, ARSH} BPF_K shift by 0
The current arm BPF JIT does not correctly compile RSH or ARSH when the
immediate shift amount is 0. This causes the "rsh64 by 0 imm" and "arsh64
by 0 imm" BPF selftests to hang the kernel by reaching an instruction
the verifier determines to be unreachable.

The root cause is in how immediate right shifts are encoded on arm.
For LSR and ASR (logical and arithmetic right shift), a bit-pattern
of 00000 in the immediate encodes a shift amount of 32. When the BPF
immediate is 0, the generated code shifts by 32 instead of the expected
behavior (a no-op).

This patch fixes the bugs by adding an additional check if the BPF
immediate is 0. After the change, the above mentioned BPF selftests pass.

Fixes: 39c13c204b ("arm: eBPF JIT compiler")
Co-developed-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200408181229.10909-1-luke.r.nels@gmail.com
2020-04-09 01:05:53 +02:00
arch arm, bpf: Fix bugs with ALU64 {RSH, ARSH} BPF_K shift by 0 2020-04-09 01:05:53 +02:00
block Merge branch 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-03-30 16:13:08 -07:00
certs certs: Add wrapper function to check blacklisted binary hash 2019-11-12 12:25:50 +11:00
crypto Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 2020-02-20 15:15:16 -08:00
Documentation dt-bindings: net: mvusb: Fix example errors 2020-04-01 11:26:03 -07:00
drivers net: stmmac: xgmac: Fix VLAN register handling 2020-04-02 07:04:45 -07:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-03-31 17:29:33 -07:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-03-31 17:29:33 -07:00
init Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-03-31 17:29:33 -07:00
ipc Revert "ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()" 2020-02-21 11:22:15 -08:00
kernel bpf: Fix a typo "inacitve" -> "inactive" 2020-04-06 21:54:10 +02:00
lib kbuild, btf: Fix dependencies for DEBUG_INFO_BTF 2020-04-03 00:27:36 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm arm64 updates for 5.7: 2020-03-31 10:05:01 -07:00
net bpf: Fix use of sk->sk_reuseport from sk_assign 2020-04-09 01:02:14 +02:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-03-31 17:29:33 -07:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-03-31 17:29:33 -07:00
security Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-03-31 17:29:33 -07:00
sound Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-03-31 17:29:33 -07:00
tools selftests/bpf: Add test for bpf_get_link_xdp_id 2020-04-08 01:35:24 +02:00
usr initramfs: restore default compression behavior 2020-03-17 09:50:37 +09:00
virt irqchip/gic-v4.1: Move doorbell management to the GICv4 abstraction layer 2020-03-24 12:15:51 +00:00
.clang-format clang-format: Update with the latest for_each macro list 2020-03-06 21:50:05 +01:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore selftest/lkdtm: Use local .gitignore 2020-03-02 08:39:39 -07:00
.mailmap media updates for v5.7-rc1 2020-03-30 13:42:05 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Hand MIPS over to Thomas 2020-02-24 22:43:18 -08:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-03-31 17:29:33 -07:00
Makefile Kbuild updates for v5.7 2020-03-31 16:03:39 -07:00
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.