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Borislav Petkov 3ea7da6a97 x86/microcode/AMD: Apply the patch early on every logical thread
commit e7ad18d116 upstream.

Currently, the patch application logic checks whether the revision
needs to be applied on each logical CPU (SMT thread). Therefore, on SMT
designs where the microcode engine is shared between the two threads,
the application happens only on one of them as that is enough to update
the shared microcode engine.

However, there are microcode patches which do per-thread modification,
see Link tag below.

Therefore, drop the revision check and try applying on each thread. This
is what the BIOS does too so this method is very much tested.

Btw, change only the early paths. On the late loading paths, there's no
point in doing per-thread modification because if is it some case like
in the bugzilla below - removing a CPUID flag - the kernel cannot go and
un-use features it has detected are there early. For that, one should
use early loading anyway.

  [ bp: Fixes does not contain the oldest commit which did check for
    equality but that is good enough. ]

Fixes: 8801b3fcb5 ("x86/microcode/AMD: Rework container parsing")
Reported-by:  Ștefan Talpalaru <stefantalpalaru@yahoo.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by:  Ștefan Talpalaru <stefantalpalaru@yahoo.com>
Cc: <stable@vger.kernel.org>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216211
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-29 10:20:34 +02:00
arch x86/microcode/AMD: Apply the patch early on every logical thread 2022-10-29 10:20:34 +02:00
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fs ocfs2: fix BUG when iput after ocfs2_mknod fails 2022-10-29 10:20:34 +02:00
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Makefile Linux 5.4.220 2022-10-26 13:23:01 +02:00
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.