From: <gregkh@linuxfoundation.org>
To: 20180411152437.GC15462@8bytes.org, David.Laight@aculab.com,
aarcange@redhat.com, alexander.levin@microsoft.com,
aliguori@amazon.com, boris.ostrovsky@oracle.com, bp@alien8.de,
brgerst@gmail.com, daniel.gruss@iaik.tugraz.at,
dave.hansen@intel.com, dhgutteridge@sympatico.ca,
dvlasenk@redhat.com, eduval@amazon.com,
gregkh@linuxfoundation.org, hughd@google.com, jgross@suse.com,
jkosina@suse.cz, joro@8bytes.org, jpoimboe@redhat.com,
jroedel@suse.de, keescook@google.com, linux-mm@kvack.org,
llong@redhat.com, luto@kernel.org, mingo@kernel.org,
pavel@ucw.cz, peterz@infradead.org, tglx@linutronix.de,
torvalds@linux-foundation.org, will.deacon@arm.com
Cc: stable-commits@vger.kernel.org
Subject: Patch "x86/pgtable: Don't set huge PUD/PMD on non-leaf entries" has been added to the 4.16-stable tree
Date: Tue, 01 May 2018 15:33:11 -0700 [thread overview]
Message-ID: <152521399136247@kroah.com> (raw)
This is a note to let you know that I've just added the patch titled
x86/pgtable: Don't set huge PUD/PMD on non-leaf entries
to the 4.16-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-pgtable-don-t-set-huge-pud-pmd-on-non-leaf-entries.patch
and it can be found in the queue-4.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
>From foo@baz Tue May 1 14:59:17 PDT 2018
From: Joerg Roedel <joro@8bytes.org>
Date: Wed, 11 Apr 2018 17:24:38 +0200
Subject: x86/pgtable: Don't set huge PUD/PMD on non-leaf entries
From: Joerg Roedel <joro@8bytes.org>
[ Upstream commit e3e288121408c3abeed5af60b87b95c847143845 ]
The pmd_set_huge() and pud_set_huge() functions are used from
the generic ioremap() code to establish large mappings where this
is possible.
But the generic ioremap() code does not check whether the
PMD/PUD entries are already populated with a non-leaf entry,
so that any page-table pages these entries point to will be
lost.
Further, on x86-32 with SHARED_KERNEL_PMD=0, this causes a
BUG_ON() in vmalloc_sync_one() when PMD entries are synced
from swapper_pg_dir to the current page-table. This happens
because the PMD entry from swapper_pg_dir was promoted to a
huge-page entry while the current PGD still contains the
non-leaf entry. Because both entries are present and point
to a different page, the BUG_ON() triggers.
This was actually triggered with pti-x32 enabled in a KVM
virtual machine by the graphics driver.
A real and better fix for that would be to improve the
page-table handling in the generic ioremap() code. But that is
out-of-scope for this patch-set and left for later work.
Reported-by: David H. Gutteridge <dhgutteridge@sympatico.ca>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Waiman Long <llong@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180411152437.GC15462@8bytes.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/mm/pgtable.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/mm.h>
#include <linux/gfp.h>
+#include <linux/hugetlb.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/tlb.h>
@@ -636,6 +637,10 @@ int pud_set_huge(pud_t *pud, phys_addr_t
(mtrr != MTRR_TYPE_WRBACK))
return 0;
+ /* Bail out if we are we on a populated non-leaf entry: */
+ if (pud_present(*pud) && !pud_huge(*pud))
+ return 0;
+
prot = pgprot_4k_2_large(prot);
set_pte((pte_t *)pud, pfn_pte(
@@ -664,6 +669,10 @@ int pmd_set_huge(pmd_t *pmd, phys_addr_t
return 0;
}
+ /* Bail out if we are we on a populated non-leaf entry: */
+ if (pmd_present(*pmd) && !pmd_huge(*pmd))
+ return 0;
+
prot = pgprot_4k_2_large(prot);
set_pte((pte_t *)pmd, pfn_pte(
Patches currently in stable-queue which might be from joro@8bytes.org are
queue-4.16/x86-apic-set-up-through-local-apic-mode-on-the-boot-cpu-if-noapic-specified.patch
queue-4.16/x86-pgtable-don-t-set-huge-pud-pmd-on-non-leaf-entries.patch
next reply other threads:[~2018-05-01 22:36 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-01 22:33 gregkh [this message]
2018-05-27 14:33 Patch "x86/pgtable: Don't set huge PUD/PMD on non-leaf entries" has been added to the 4.16-stable tree gregkh
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=152521399136247@kroah.com \
--to=gregkh@linuxfoundation.org \
--cc=20180411152437.GC15462@8bytes.org \
--cc=David.Laight@aculab.com \
--cc=aarcange@redhat.com \
--cc=alexander.levin@microsoft.com \
--cc=aliguori@amazon.com \
--cc=boris.ostrovsky@oracle.com \
--cc=bp@alien8.de \
--cc=brgerst@gmail.com \
--cc=daniel.gruss@iaik.tugraz.at \
--cc=dave.hansen@intel.com \
--cc=dhgutteridge@sympatico.ca \
--cc=dvlasenk@redhat.com \
--cc=eduval@amazon.com \
--cc=hughd@google.com \
--cc=jgross@suse.com \
--cc=jkosina@suse.cz \
--cc=joro@8bytes.org \
--cc=jpoimboe@redhat.com \
--cc=jroedel@suse.de \
--cc=keescook@google.com \
--cc=linux-mm@kvack.org \
--cc=llong@redhat.com \
--cc=luto@kernel.org \
--cc=mingo@kernel.org \
--cc=pavel@ucw.cz \
--cc=peterz@infradead.org \
--cc=stable-commits@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=will.deacon@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.