commit dac6ca243c upstream.
With CONFIG_DEBUG_PREEMPT enabled, I get:
BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
caller is debug_smp_processor_id
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc2+ #2
Call Trace:
dump_stack
check_preemption_disabled
debug_smp_processor_id
save_microcode_in_initrd_amd
? microcode_init
save_microcode_in_initrd
...
because, well, it says it above, we're using smp_processor_id() in
preemptible code.
But passing the CPU number is not really needed. It is only used to
determine whether we're on the BSP, and, if so, to save the microcode
patch for early loading.
[ We don't absolutely need to do it on the BSP but we do that
customarily there. ]
Instead, convert that function parameter to a boolean which denotes
whether the patch should be saved or not, thereby avoiding the use of
smp_processor_id() in preemptible code.
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/20170528200414.31305-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[arnd: rebased to 4.9, after running into warning:
arch/x86/kernel/cpu/microcode/amd.c:881:30: self-comparison always evaluates to true]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a15a753539 upstream with minor
adjustments.
Doing so is completely void of sense for multiple reasons so prevent
it. Set dis_ucode_ldr to true and thus disable the microcode loader by
default to address xen pv guests which execute the AP path but not the
BSP path.
By having it turned off by default, the APs won't run into the loader
either.
Also, check CPUID(1).ECX[31] which hypervisors set. Well almost, not the
xen pv one. That one gets the aforementioned "fix".
Also, improve the detection method by caching the final decision whether
to continue loading in dis_ucode_ldr and do it once on the BSP. The APs
then simply test that value.
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Juergen Gross <jgross@suse.com>
Link: http://lkml.kernel.org/r/20161218164414.9649-4-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7e702d17ed upstream.
Commit b94b737331 ("x86/microcode/intel: Extend BDW late-loading with a
revision check") reduced the impact of erratum BDF90 for Broadwell model
79.
The impact can be reduced further by checking the size of the last level
cache portion per core.
Tony: "The erratum says the problem only occurs on the large-cache SKUs.
So we only need to avoid the update if we are on a big cache SKU that is
also running old microcode."
For more details, see erratum BDF90 in document #334165 (Intel Xeon
Processor E7-8800/4800 v4 Product Family Specification Update) from
September 2017.
Fixes: b94b737331 ("x86/microcode/intel: Extend BDW late-loading with a revision check")
Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/1516321542-31161-1-git-send-email-zhang.jia@linux.alibaba.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The backport of commit b94b737331 ("x86/microcode/intel: Extend BDW
late-loading with a revision check") to 4.4-stable deleted a "return true"
statement. This bug is not present upstream or other stable branches.
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b94b737331 upstream.
Instead of blacklisting all model 79 CPUs when attempting a late
microcode loading, limit that only to CPUs with microcode revisions <
0x0b000021 because only on those late loading may cause a system hang.
For such processors either:
a) a BIOS update which might contain a newer microcode revision
or
b) the early microcode loading method
should be considered.
Processors with revisions 0x0b000021 or higher will not experience such
hangs.
For more details, see erratum BDF90 in document #334165 (Intel Xeon
Processor E7-8800/4800 v4 Product Family Specification Update) from
September 2017.
[ bp: Heavily massage commit message and pr_* statements. ]
Fixes: 723f2828a9 ("x86/microcode/intel: Disable late loading on model 79")
Signed-off-by: Jia Zhang <qianyue.zj@alibaba-inc.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/1514772287-92959-1-git-send-email-qianyue.zj@alibaba-inc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pave the way for checking the current patch level of the
microcode in a core. We want to be able to do stuff depending on
the patch level - in this case decide whether to update or not.
But that will be added in a later patch.
Drop unused local var uci assignment, while at it.
Integrate a fix for 32-bit and CONFIG_PARAVIRT from Takashi Iwai:
Use native_rdmsr() in check_current_patch_level() because with
CONFIG_PARAVIRT enabled and on 32-bit, where we run before
paging has been enabled, we cannot deref pv_info yet. Or we
could, but we'd need to access its physical address. This way of
fixing it is simpler. See:
https://bugzilla.suse.com/show_bug.cgi?id=943179 for the background.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Takashi Iwai <tiwai@suse.com>:
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1444641762-9437-6-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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>
Andy Shevchenko reported machine freezes when booting latest tip
on 32-bit setups. Problem is, the builtin microcode handling cannot
really work that early, when we haven't even enabled paging.
A proper fix would involve handling that case specially as every
other early 32-bit boot case in the microcode loader and would
require much more involved changes for which it is too late now,
more than a week before the upcoming merge window.
So, disable the builtin microcode loading on 32-bit for now.
Reported-and-tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
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/1433436928-31903-20-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Apparently, people do build microcode into the kernel image, i.e.
CONFIG_FIRMWARE_IN_KERNEL=y.
Make that work in the early loader which is where microcode should be
preferably loaded anyway.
Note that you need to specify the microcode filename with the path
relative to the toplevel firmware directory (the same like the late
loading method) in CONFIG_EXTRA_FIRMWARE=y so that early loader can
find it.
I.e., something like this (Intel variant):
CONFIG_FIRMWARE_IN_KERNEL=y
CONFIG_EXTRA_FIRMWARE="intel-ucode/06-3a-09"
CONFIG_EXTRA_FIRMWARE_DIR="/lib/firmware/"
While at it, add me to the loader copyright boilerplate.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
It is a one-liner for checking microcode header revisions. On top of
that, it can be used wrong as it was the case in _save_mc(). Get rid of
it.
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When doing
echo 1 > /sys/devices/system/cpu/microcode/reload
in order to reload microcode, I get:
microcode: Total microcode saved: 1
BUG: using smp_processor_id() in preemptible [00000000] code: bash/2606
caller is debug_smp_processor_id+0x17/0x20
CPU: 1 PID: 2606 Comm: bash Not tainted 3.19.0-rc7+ #9
Hardware name: LENOVO 2320CTO/2320CTO, BIOS G2ET86WW (2.06 ) 11/13/2012
ffffffff81a4266d ffff8802131db808 ffffffff81666588 0000000000000007
0000000000000001 ffff8802131db838 ffffffff812e6eef ffff8802131db868
00000000000306a9 0000000000000010 0000000000000015 ffff8802131db848
Call Trace:
dump_stack
check_preemption_disabled
debug_smp_processor_id
show_saved_mc
? save_microcode.constprop.8
save_mc_for_early
? print_context_stack
? dump_trace
? __bfs
? mark_held_locks
? get_page_from_freelist
? trace_hardirqs_on_caller
? trace_hardirqs_on
? __alloc_pages_nodemask
? __get_vm_area_node
? map_vm_area
? __vmalloc_node_range
? generic_load_microcode
generic_load_microcode
? microcode_fini_cpu
request_microcode_fw
reload_store
dev_attr_store
sysfs_kf_write
kernfs_fop_write
vfs_write
? sysret_check
SyS_write
system_call_fastpath
microcode: CPU1: sig=0x306a9, pf=0x10, rev=0x15
microcode: mc_saved[0]: sig=0x306a9, pf=0x12, rev=0x1b, toal size=0x3000, date = 2014-05-29
because we're using smp_processor_id() in preemtible context. And we
don't really need to use it there because the microcode container we're
dumping is global and CPU-specific info is irrelevant.
While at it, make pr_* stuff use "microcode: " prefix for easier
grepping and document how to enable the DEBUG build.
Signed-off-by: Borislav Petkov <bp@suse.de>
... arguments list so that it comes more natural for those functions to
have the signature, processor flags and revision together, before the
rest of the args.
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
* remove state variable and out label
* get rid of completely unused mc_size
* shorten variable names
* get rid of local variables
* don't do assignments in local var declarations for less cluttered code
* finally rename it to the shorter and perfectly fine load_microcode_early()
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
... to the header. Split the family acquiring function into a
main one, doing CPUID and a helper which computes the extended
family and is used in multiple places. Get rid of the locally-grown
get_x86_{family,model}().
While at it, rename local variables to something more descriptive and
vertically align assignments for better readability.
There should be no functionality change resulting from this patch.
Signed-off-by: Borislav Petkov <bp@suse.de>
Shorten local variable names for better readability and flatten loop
indentation levels.
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
... of microcode patches instead of handing in a pointer which is used
for I/O in an otherwise void function.
Signed-off-by: Borislav Petkov <bp@suse.de>
Don't compute start and end from start and size in order to compute size
again down the path in scan_microcode(). So pass size directly instead
and simplify a bunch. Shorten variable names and remove useless ones.
Signed-off-by: Borislav Petkov <bp@suse.de>
... and only then deref it. Also, shorten some variable names and rename
others so as to diminish the ubiquitous presence of the "mc_" prefix
everywhere and make it a bit more readable.
Use kcalloc so that we don't kfree() uninitialized memory on the unwind
path, as suggested by Quentin.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
We should check the return value of the routines fishing out the proper
microcode and not try to apply if we haven't found a suitable blob.
Signed-off-by: Borislav Petkov <bp@suse.de>
Pull microcode fixes from Borislav Petkov:
- Two fixes hardening microcode data handling. (Quentin Casasnovas)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
