| Message ID | 1408353808-8483-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c index ed82edad1a39..774ba41dba4d 100644 --- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -350,6 +350,10 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t * 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)
This is a note to let you know that I have just added a patch titled sparc64: Do not insert non-valid PTEs into the TSB hash table. to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From da242588a11cd4f971f0241ba8ffaff8bd6f8d17 Mon Sep 17 00:00:00 2001 From: "David S. Miller" <davem@davemloft.net> Date: Mon, 4 Aug 2014 16:34:01 -0700 Subject: sparc64: Do not insert non-valid PTEs into the TSB hash table. commit 18f38132528c3e603c66ea464727b29e9bbcb91b upstream. 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@davemloft.net> [ luis: backported to 3.11: used davem's backport to 3.10 and 3.12 ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- arch/sparc/mm/init_64.c | 4 ++++ 1 file changed, 4 insertions(+) -- 1.9.1