This is a note to let you know that I've just added the patch titled
sparc64: Do not insert non-valid PTEs into the TSB hash table.
to the 3.16-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:
sparc64-do-not-insert-non-valid-ptes-into-the-tsb-hash-table.patch
and it can be found in the queue-3.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Fri Aug 8 09:26:33 PDT 2014
From: "David S. Miller" <davem@xxxxxxxxxxxxx>
Date: Mon, 4 Aug 2014 16:34:01 -0700
Subject: sparc64: Do not insert non-valid PTEs into the TSB hash table.
From: "David S. Miller" <davem@xxxxxxxxxxxxx>
[ Upstream commit 18f38132528c3e603c66ea464727b29e9bbcb91b ]
The assumption was that update_mmu_cache() (and the equivalent for PMDs) would
only be called when the PTE being installed will be accessible by the user.
This is not true for code paths originating from remove_migration_pte().
There are dire consequences for placing a non-valid PTE into the TSB. The TLB
miss frramework assumes thatwhen a TSB entry matches we can just load it into
the TLB and return from the TLB miss trap.
So if a non-valid PTE is in there, we will deadlock taking the TLB miss over
and over, never satisfying the miss.
Just exit early from update_mmu_cache() and friends in this situation.
Based upon a report and patch from Christopher Alexander Tobias Schulze.
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/sparc/mm/init_64.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -351,6 +351,10 @@ void update_mmu_cache(struct vm_area_str
mm = vma->vm_mm;
+ /* Don't insert a non-valid PTE into the TSB, we'll deadlock. */
+ if (!pte_accessible(mm, pte))
+ return;
+
spin_lock_irqsave(&mm->context.lock, flags);
#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
@@ -2619,6 +2623,10 @@ void update_mmu_cache_pmd(struct vm_area
pte = pmd_val(entry);
+ /* Don't insert a non-valid PMD into the TSB, we'll deadlock. */
+ if (!(pte & _PAGE_VALID))
+ return;
+
/* We are fabricating 8MB pages using 4MB real hw pages. */
pte |= (addr & (1UL << REAL_HPAGE_SHIFT));
Patches currently in stable-queue which might be from davem@xxxxxxxxxxxxx are
queue-3.16/sctp-fix-possible-seqlock-seadlock-in-sctp_packet_transmit.patch
queue-3.16/revert-net-phy-set-the-driver-when-registering-an-mdio-bus-device.patch
queue-3.16/sparc64-ldc_connect-should-not-return-einval-when-handshake-is-in-progress.patch
queue-3.16/sparc64-do-not-insert-non-valid-ptes-into-the-tsb-hash-table.patch
queue-3.16/iovec-make-sure-the-caller-actually-wants-anything-in-memcpy_fromiovecend.patch
queue-3.16/arch-sparc-math-emu-math_32.c-drop-stray-break-operator.patch
queue-3.16/net-correctly-set-segment-mac_len-in-skb_segment.patch
queue-3.16/tg3-modify-tg3_tso_bug-to-handle-multiple-tx-rings.patch
queue-3.16/bbc-i2c-fix-bbc-i2c-envctrl-on-sunblade-2000.patch
queue-3.16/sunsab-fix-detection-of-break-on-sunsab-serial-console.patch
queue-3.16/ip_tunnel-ipv4-fix-tunnels-with-local-any-remote-remote_ip.patch
queue-3.16/macvlan-initialize-vlan_features-to-turn-on-offload-support.patch
queue-3.16/tcp-fix-integer-overflow-in-tcp-vegas.patch
queue-3.16/bna-fix-performance-regression.patch
queue-3.16/sparc64-guard-against-flushing-openfirmware-mappings.patch
queue-3.16/tcp-fix-integer-overflows-in-tcp-veno.patch
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