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
Brian Geffon 64e0b5894c x86/fpu: Correct pkru/xstate inconsistency
When eagerly switching PKRU in switch_fpu_finish() it checks that
current is not a kernel thread as kernel threads will never use PKRU.
It's possible that this_cpu_read_stable() on current_task
(ie. get_current()) is returning an old cached value. To resolve this
reference next_p directly rather than relying on current.

As written it's possible when switching from a kernel thread to a
userspace thread to observe a cached PF_KTHREAD flag and never restore
the PKRU. And as a result this issue only occurs when switching
from a kernel thread to a userspace thread, switching from a non kernel
thread works perfectly fine because all that is considered in that
situation are the flags from some other non kernel task and the next fpu
is passed in to switch_fpu_finish().

This behavior only exists between 5.2 and 5.13 when it was fixed by a
rewrite decoupling PKRU from xstate, in:
  commit 954436989cc5 ("x86/fpu: Remove PKRU handling from switch_fpu_finish()")

Unfortunately backporting the fix from 5.13 is probably not realistic as
it's part of a 60+ patch series which rewrites most of the PKRU handling.

Fixes: 0cecca9d03 ("x86/fpu: Eager switch PKRU state")
Signed-off-by: Brian Geffon <bgeffon@google.com>
Signed-off-by: Willis Kung <williskung@google.com>
Tested-by: Willis Kung <williskung@google.com>
Cc: <stable@vger.kernel.org> # v5.4.x
Cc: <stable@vger.kernel.org> # v5.10.x
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02 11:41:03 +01:00
arch x86/fpu: Correct pkru/xstate inconsistency 2022-03-02 11:41:03 +01:00
block block/wbt: fix negative inflight counter when remove scsi device 2022-02-23 11:59:59 +01:00
certs certs: Trigger creation of RSA module signing key if it's not an RSA key 2021-09-15 09:47:29 +02:00
crypto crypto: pcrypt - Delay write to padata->info 2021-11-17 09:48:40 +01:00
Documentation bpf: Add kconfig knob for disabling unpriv bpf by default 2022-02-16 12:52:49 +01:00
drivers USB: zaurus: support another broken Zaurus 2022-03-02 11:41:02 +01:00
fs NFS: Do not report writeback errors in nfs_getattr() 2022-02-23 11:59:59 +01:00
include netfilter: nf_tables_offload: incorrect flow offload action array size 2022-03-02 11:41:03 +01:00
init bpf: Add kconfig knob for disabling unpriv bpf by default 2022-02-16 12:52:49 +01:00
ipc shm: extend forced shm destroy to support objects from several IPC nses 2021-12-01 09:23:35 +01:00
kernel cgroup/cpuset: Fix a race between cpuset_attach() and cpu hotplug 2022-03-02 11:41:00 +01:00
lib lib/iov_iter: initialize "flags" in new pipe_buffer 2022-02-23 11:59:59 +01:00
LICENSES
mm mm/kmemleak: avoid scanning potential huge holes 2022-02-08 18:24:28 +01:00
net netfilter: nf_tables_offload: incorrect flow offload action array size 2022-03-02 11:41:03 +01:00
samples samples/kretprobes: Fix return value if register_kretprobe() failed 2021-11-17 09:48:39 +01:00
scripts kconfig: fix failing to generate auto.conf 2022-02-23 12:00:01 +01:00
security ima: Do not print policy rule with inactive LSM labels 2022-02-16 12:52:47 +01:00
sound ASoC: ops: Fix stereo change notifications in snd_soc_put_volsw_range() 2022-02-23 11:59:58 +01:00
tools libsubcmd: Fix use-after-free for realloc(..., 0) 2022-02-23 11:59:58 +01:00
usr
virt KVM: do not shrink halt_poll_ns below grow_start 2021-10-09 14:39:50 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile Linux 5.4.181 2022-02-23 12:00:01 +01:00
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.