It was pretty clumsy before and the whole work of parsing the microcode
containers was spread around the functions wrongly.
Clean it up so that there's a main scan_containers() function which
iterates over the microcode blob and picks apart the containers glued
together. For each container, it calls a parse_container() helper which
concentrates on one container only: sanity-checking, parsing, counting
microcode patches in there, etc.
It makes much more sense now and it is actually very readable. Oh, and
we luvz a diffstat removing more crap than adding.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-8-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Make it into a container descriptor which is being passed around and
stores important info like the matching container and the patch for the
current CPU. Make it static too.
Later patches will use this and thus get rid of a double container
parsing.
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-7-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
No need to have it marked "inline" - let gcc decide. Also, shorten the
argument name and simplify while-test.
While at it, make it into a proper for-loop and simplify it even more,
as tglx suggests.
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-5-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This was meant to save us the scanning of the microcode containter in
the initrd since the first AP had already done that but it can also hurt
us:
Imagine a single hyperthreaded CPU (Intel(R) Atom(TM) CPU N270, for
example) which updates the microcode on the BSP but since the microcode
engine is shared between the two threads, the update on CPU1 doesn't
happen because it has already happened on CPU0 and we don't find a newer
microcode revision on CPU1.
Which doesn't set the intel_ucode_patch pointer and at initrd
jettisoning time we don't save the microcode patch for later
application.
Now, when we suspend to RAM, the loaded microcode gets cleared so we
need to reload but there's no patch saved in the cache.
Removing the optimization fixes this issue and all is fine and dandy.
Fixes: 06b8534cb7 ("x86/microcode: Rework microcode loading")
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-2-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
In generic_load_microcode(), curr_mc_size is the size of the last
allocated buffer and since we have this performance "optimization"
there to vmalloc a new buffer only when the current one is bigger,
curr_mc_size ends up becoming the size of the biggest buffer we've seen
so far.
However, we end up saving the microcode patch which matches our CPU
and its size is not curr_mc_size but the respective mc_size during the
iteration while we're staring at it.
So save that mc_size into a separate variable and use it to store the
previously found microcode buffer.
Without this fix, we could get oops like this:
BUG: unable to handle kernel paging request at ffffc9000e30f000
IP: __memcpy+0x12/0x20
...
Call Trace:
? kmemdup+0x43/0x60
__alloc_microcode_buf+0x44/0x70
save_microcode_patch+0xd4/0x150
generic_load_microcode+0x1b8/0x260
request_microcode_user+0x15/0x20
microcode_write+0x91/0x100
__vfs_write+0x34/0x120
vfs_write+0xc1/0x130
SyS_write+0x56/0xc0
do_syscall_64+0x6c/0x160
entry_SYSCALL64_slow_path+0x25/0x25
Fixes: 06b8534cb7 ("x86/microcode: Rework microcode loading")
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/4f33cbfd-44f2-9bed-3b66-7446cd14256f@ce.jp.nec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Since on Intel we're required to do CPUID(1) first, before reading
the microcode revision MSR, let's add a special helper which does the
required steps so that we don't forget to do them next time, when we
want to read the microcode revision.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170109114147.5082-4-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Intel supplies the microcode revision value in MSR 0x8b
(IA32_BIOS_SIGN_ID) after CPUID(1) has been executed. Execute it each
time before reading that MSR.
It used to do sync_core() which did do CPUID but
c198b121b1 ("x86/asm: Rewrite sync_core() to use IRET-to-self")
changed the sync_core() implementation so we better make the microcode
loading case explicit, as the SDM documents it.
Reported-and-tested-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170109114147.5082-3-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When we switch to virtual addresses and, especially after
reserve_initrd()->relocate_initrd() have run, we have the updated initrd
address in initrd_start. Use initrd_start then instead of the address
which has been passed to us through boot params. (That still gets used
when we're running the very early routines on the BSP).
Reported-and-tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20161220144012.lc4cwrg6dphqbyqu@pd.tnic
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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>
Yeah, I know, I know, this is a huuge patch and reviewing it is hard.
Sorry but this is the only way I could think of in which I can rewrite
the microcode patches loading procedure without breaking (knowingly) the
driver.
So maybe this patch is easier to review if one looks at the files after
the patch has been applied instead at the diff. Because then it becomes
pretty obvious:
* The BSP-loading path - load_ucode_bsp() is working independently from
the AP path now and it doesn't save any pointers or patches anymore -
it solely parses the builtin or initrd microcode and applies the patch.
That's it.
This fixes the CONFIG_RANDOMIZE_MEMORY offset fun more solidly.
* The AP-loading path - load_ucode_ap() then goes and scans
builtin/initrd *again* for the microcode patches but it caches them this
time so that we don't have to do that scan on each AP but only once.
This simplifies the code considerably.
Then, when we save the microcode from the initrd/builtin, we go and
add the relevant patches to our own cache. The AMD side did do that
and now the Intel side does it too. So no more pointer copying and
blabla, we save the microcode patches ourselves and are independent from
initrd/builtin.
This whole conversion gives us other benefits like unifying the
initrd parsing into a single function: find_microcode_in_initrd() is
used by both.
The diffstat speaks for itself: 456 insertions(+), 695 deletions(-)
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Josh Poimboeuf <jpoimboe@redhat.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/20161025095522.11964-12-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Borislav Petkov
Junichi Nomura
Andy Lutomirski
Boris Ostrovsky