Usually, after we have found the proper microcode blob for the current
machine, we stash it away for later use with save_microcode_in_initrd().
However, with builtin microcode which doesn't come from the initrd, we
don't call that function because CONFIG_BLK_DEV_INITRD=n and even if
set, we don't have a valid initrd.
In order to fix this, let's make save_microcode_in_initrd() an
fs_initcall which runs before rootfs_initcall() as this was the time it
was called previously through:
rootfs_initcall(populate_rootfs)
|-> free_initrd()
|-> free_initrd_mem()
|-> save_microcode_in_initrd()
Also, we make it run independently from initrd functionality being
present or not.
And since it is called in the microcode loader only now, we can also
make it static.
Reported-and-tested-by: Jim Bos <jim876@xs4all.nl>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # v4.6
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1465225850-7352-3-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We do parse for the disable microcode loader chicken bit very early.
After the driver merge, the __setup() param parsing method is not needed
anymore so get rid of it.
In addition, fix a compiler warning from an old SLES11 gcc (4.3.4)
reported by Jan Beulich <jbeulich@suse.com>:
arch/x86/kernel/cpu/microcode/core.c: In function ‘load_ucode_bsp’:
arch/x86/kernel/cpu/microcode/core.c:96: warning: array subscript is above array bounds
Tested-by: Thomas Voegtle <tv@lio96.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1454499225-21544-4-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 cpu updates from Ingo Molnar:
"The main changes in this cycle were:
- Improved CPU ID handling code and related enhancements (Borislav
Petkov)
- RDRAND fix (Len Brown)"
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Replace RDRAND forced-reseed with simple sanity check
x86/MSR: Chop off lower 32-bit value
x86/cpu: Fix MSR value truncation issue
x86/cpu/amd, kvm: Satisfy guest kernel reads of IC_CFG MSR
kvm: Add accessors for guest CPU's family, model, stepping
x86/cpu: Unify CPU family, model, stepping calculation
Pull x86 init code fixlet from Ingo Molnar:
"A single change: fix obsolete init code annotations"
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Drop bogus __ref / __refdata annotations
Its return value is not used by the subsys core and nothing meaningful
can be done with it, even if we want to use it. The subsys device is
anyway getting removed.
Update prototype of ->remove_dev() to make its return type as void. Fix
all usage sites as well.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commits 65cef1311d ("x86, microcode: Add a disable chicken bit") and
a18a0f6850 ("x86, microcode: Don't initialize microcode code on
paravirt") allow microcode driver skip initialization when microcode
loading is not permitted.
However, they don't prevent the driver from being loaded since the
init code returns 0. If at some point later the driver gets unloaded
this will result in an oops while trying to deregister the (never
registered) device.
To avoid this, make init code return an error on paravirt or when
microcode loading is disabled. The driver will then never be loaded.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1422411669-25147-1-git-send-email-boris.ostrovsky@oracle.com
Reported-by: James Digwall <james@dingwall.me.uk>
Cc: stable@vger.kernel.org # 3.18
Signed-off-by: Borislav Petkov <bp@suse.de>
Normally, we do reapply microcode on resume. However, in the cases where
that microcode comes from the early loader and the late loader hasn't
been utilized yet, there's no easy way for us to go and apply the patch
applied during boot by the early loader.
Thus, reuse the patch stashed by the early loader for the BSP.
Signed-off-by: Borislav Petkov <bp@suse.de>
Paravirtual guests are not expected to load microcode into processors
and therefore it is not necessary to initialize microcode loading
logic.
In fact, under certain circumstances initializing this logic may cause
the guest to crash. Specifically, 32-bit kernels use __pa_nodebug()
macro which does not work in Xen (the code path that leads to this macro
happens during resume when we call mc_bp_resume()->load_ucode_ap()
->check_loader_disabled_ap())
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1417469264-31470-1-git-send-email-boris.ostrovsky@oracle.com
Signed-off-by: Borislav Petkov <bp@suse.de>
Add a cmdline param which disables the microcode loader. This is useful
mostly in debugging situations where we want to turn off microcode
loading, both early from the initrd and late, as a means to be able to
rule out its influence on the machine.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1400525957-11525-3-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
We've grown a bunch of microcode loader files all prefixed with
"microcode_". They should be under cpu/ because this is strictly
CPU-related functionality so do that and drop the prefix since they're
in their own directory now which gives that prefix. :)
While at it, drop MICROCODE_INTEL_LIB config item and stash the
functionality under CONFIG_MICROCODE_INTEL as it was its only user.
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
