From: Borislav Petkov <bp@alien8.de>
To: Bob Peterson <rpeterso@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Andy Lutomirski <luto@amacapital.net>,
Andreas Gruenbacher <agruenba@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Andy Lutomirski <luto@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Steven Whitehouse <swhiteho@redhat.com>,
Mel Gorman <mgorman@techsingularity.net>,
linux-mm <linux-mm@kvack.org>
Subject: Re: CONFIG_VMAP_STACK, on-stack struct, and wake_up_bit
Date: Thu, 27 Oct 2016 14:36:23 +0200 [thread overview]
Message-ID: <20161027123623.j2jri5bandimboff@pd.tnic> (raw)
In-Reply-To: <624629879.13118306.1477528645189.JavaMail.zimbra@redhat.com>
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@suse.de>
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@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org # 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.
next prev parent reply other threads:[~2016-10-27 13:56 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-26 12:51 CONFIG_VMAP_STACK, on-stack struct, and wake_up_bit Andreas Gruenbacher
2016-10-26 15:51 ` Andy Lutomirski
2016-10-26 16:32 ` Linus Torvalds
2016-10-26 17:15 ` Linus Torvalds
2016-10-26 17:58 ` Linus Torvalds
2016-10-26 18:04 ` Bob Peterson
2016-10-26 18:10 ` Linus Torvalds
2016-10-26 19:11 ` Bob Peterson
2016-10-26 21:01 ` Bob Peterson
2016-10-26 21:30 ` Linus Torvalds
2016-10-26 22:45 ` Borislav Petkov
2016-10-26 23:13 ` Borislav Petkov
2016-10-27 0:37 ` Bob Peterson
2016-10-27 12:36 ` Borislav Petkov [this message]
2016-10-27 18:51 ` Bob Peterson
2016-10-27 19:19 ` Borislav Petkov
2016-10-27 21:03 ` Bob Peterson
2016-10-27 21:19 ` Borislav Petkov
2016-10-28 8:37 ` [tip:x86/urgent] x86/microcode/AMD: Fix more fallout from CONFIG_RANDOMIZE_MEMORY=y tip-bot for Borislav Petkov
2016-10-26 20:31 ` CONFIG_VMAP_STACK, on-stack struct, and wake_up_bit Mel Gorman
2016-10-26 21:26 ` Linus Torvalds
2016-10-26 22:03 ` Mel Gorman
2016-10-26 22:09 ` Linus Torvalds
2016-10-26 23:07 ` Mel Gorman
2016-10-27 8:08 ` Peter Zijlstra
2016-10-27 9:07 ` Mel Gorman
2016-10-27 9:44 ` Peter Zijlstra
2016-10-27 9:59 ` Mel Gorman
2016-10-27 11:56 ` Nicholas Piggin
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