On Wed, Oct 26, 2016 at 08:37:25PM -0400, Bob Peterson wrote:
> Attached, but as Linus suggested, I turned off the AMD microcode driver,
> so it should be the same if you turn it back on. If you want, I can
> do it and re-send so you have a more pristine .config. Let me know.
Thanks, but I was able to reproduce in a VM.
Here's a fix which works here - I'd appreciate it if you ran it and
checked the microcode was applied correctly, i.e.:
$ dmesg | grep -i microcode
before and after the patch. Please paste that output in a mail too.
Thanks!
---
From: Borislav Petkov <bp@xxxxxxx>
Date: Thu, 27 Oct 2016 14:03:59 +0200
Subject: [PATCH] x86/microcode/AMD: Fix more fallout from CONFIG_RANDOMIZE_MEMORY
We needed the physical address of the container in order to compute the
offset within the relocated ramdisk. And we did this by doing __pa() on
the virtual address.
However, __pa() does checks whether the physical address is within
PAGE_OFFSET and __START_KERNEL_map - see __phys_addr() - which fail
if we have CONFIG_RANDOMIZE_MEMORY enabled: we feed a virtual address
which *doesn't* have the randomization offset into a function which uses
PAGE_OFFSET which *does* have that offset.
This makes this check fire:
VIRTUAL_BUG_ON((x > y) || !phys_addr_valid(x));
^^^^^^
due to the randomization offset.
The fix is as simple as using __pa_nodebug() because we do that
randomization offset accounting later in that function ourselves.
Reported-by: Bob Peterson <rpeterso@xxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # 4.9
---
arch/x86/kernel/cpu/microcode/amd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 620ab06bcf45..017bda12caae 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -429,7 +429,7 @@ int __init save_microcode_in_initrd_amd(void)
* We need the physical address of the container for both bitness since
* boot_params.hdr.ramdisk_image is a physical address.
*/
- cont = __pa(container);
+ cont = __pa_nodebug(container);
cont_va = container;
#endif
--
2.10.0
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
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