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James Morse e1e8527469 KVM: arm64: Avoid consuming a stale esr value when SError occur
commit 1c71dbc8a1 upstream.

When any exception other than an IRQ occurs, the CPU updates the ESR_EL2
register with the exception syndrome. An SError may also become pending,
and will be synchronised by KVM. KVM notes the exception type, and whether
an SError was synchronised in exit_code.

When an exception other than an IRQ occurs, fixup_guest_exit() updates
vcpu->arch.fault.esr_el2 from the hardware register. When an SError was
synchronised, the vcpu esr value is used to determine if the exception
was due to an HVC. If so, ELR_EL2 is moved back one instruction. This
is so that KVM can process the SError first, and re-execute the HVC if
the guest survives the SError.

But if an IRQ synchronises an SError, the vcpu's esr value is stale.
If the previous non-IRQ exception was an HVC, KVM will corrupt ELR_EL2,
causing an unrelated guest instruction to be executed twice.

Check ARM_EXCEPTION_CODE() before messing with ELR_EL2, IRQs don't
update this register so don't need to check.

Fixes: defe21f49b ("KVM: arm64: Move PC rollback on SError to HYP")
Cc: stable@vger.kernel.org
Reported-by: Steven Price <steven.price@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220127122052.1584324-3-james.morse@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-08 18:34:06 +01:00
arch KVM: arm64: Avoid consuming a stale esr value when SError occur 2022-02-08 18:34:06 +01:00
block block: bio-integrity: Advance seed correctly for larger interval sizes 2022-02-08 18:34:05 +01:00
certs certs: Add support for using elliptic curve keys for signing modules 2021-08-23 19:55:42 +03:00
crypto crypto: jitter - consider 32 LSB for APT 2022-01-27 11:04:31 +01:00
Documentation Revert "fbcon: Disable accelerated scrolling" 2022-02-08 18:34:06 +01:00
drivers Revert "ASoC: mediatek: Check for error clk pointer" 2022-02-08 18:34:06 +01:00
fs Revert "fs/9p: search open fids first" 2022-02-08 18:34:04 +01:00
include mm/pgtable: define pte_index so that preprocessor could recognize it 2022-02-08 18:34:05 +01:00
init init: make unknown command line param message clearer 2021-11-18 19:17:11 +01:00
ipc ipc/sem: do not sleep with a spin lock held 2022-02-08 18:34:03 +01:00
kernel audit: improve audit queue handling when "audit=1" on cmdline 2022-02-08 18:34:03 +01:00
lib lib/test_meminit: destroy cache in kmem_cache_alloc_bulk() test 2022-01-27 11:05:44 +01:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm mm/kmemleak: avoid scanning potential huge holes 2022-02-08 18:34:05 +01:00
net mptcp: fix msk traversal in mptcp_nl_cmd_set_flags() 2022-02-08 18:34:06 +01:00
samples samples: bpf: Fix 'unknown warning group' build warning on Clang 2022-01-27 11:03:29 +01:00
scripts scripts: sphinx-pre-install: Fix ctex support on Debian 2022-01-27 11:05:44 +01:00
security selinux: fix double free of cond_list on error paths 2022-02-08 18:34:02 +01:00
sound ALSA: hda/realtek: Fix silent output on Gigabyte X570 Aorus Xtreme after reboot from Windows 2022-02-08 18:34:04 +01:00
tools selftests: mptcp: fix ipv6 routing setup 2022-02-05 12:38:56 +01:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:27:15 +01:00
virt Revert "KVM: SVM: avoid infinite loop on NPF from bad address" 2022-02-01 17:27:01 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.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 .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS drm fixes for 5.15 final 2021-10-28 12:17:01 -07:00
Makefile Linux 5.15.21 2022-02-05 19:21:09 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.