diff options
Diffstat (limited to 'x86-mm-Fix-vmalloc_fault-oops-during-lazy-MMU-updates.patch')
-rw-r--r-- | x86-mm-Fix-vmalloc_fault-oops-during-lazy-MMU-updates.patch | 48 |
1 files changed, 0 insertions, 48 deletions
diff --git a/x86-mm-Fix-vmalloc_fault-oops-during-lazy-MMU-updates.patch b/x86-mm-Fix-vmalloc_fault-oops-during-lazy-MMU-updates.patch deleted file mode 100644 index 31b0de8fb..000000000 --- a/x86-mm-Fix-vmalloc_fault-oops-during-lazy-MMU-updates.patch +++ /dev/null @@ -1,48 +0,0 @@ -From: Samu Kallio <> -Subject: [PATCH] x86: mm: Fix vmalloc_fault oops during lazy MMU updates. -Date: Sun, 17 Feb 2013 04:35:52 +0200 - -In paravirtualized x86_64 kernels, vmalloc_fault may cause an oops -when lazy MMU updates are enabled, because set_pgd effects are being -deferred. - -One instance of this problem is during process mm cleanup with memory -cgroups enabled. The chain of events is as follows: - -- zap_pte_range enables lazy MMU updates -- zap_pte_range eventually calls mem_cgroup_charge_statistics, - which accesses the vmalloc'd mem_cgroup per-cpu stat area -- vmalloc_fault is triggered which tries to sync the corresponding - PGD entry with set_pgd, but the update is deferred -- vmalloc_fault oopses due to a mismatch in the PUD entries - -Calling arch_flush_lazy_mmu_mode immediately after set_pgd makes the -changes visible to the consistency checks. - -Signed-off-by: Samu Kallio <samu.kallio@aberdeencloud.com> ---- - arch/x86/mm/fault.c | 6 ++++-- - 1 file changed, 4 insertions(+), 2 deletions(-) -diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c -index 8e13ecb..0a45298 100644 ---- a/arch/x86/mm/fault.c -+++ b/arch/x86/mm/fault.c -@@ -378,10 +378,12 @@ static noinline __kprobes int vmalloc_fault(unsigned long address) - if (pgd_none(*pgd_ref)) - return -1; - -- if (pgd_none(*pgd)) -+ if (pgd_none(*pgd)) { - set_pgd(pgd, *pgd_ref); -- else -+ arch_flush_lazy_mmu_mode(); -+ } else { - BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref)); -+ } - - /* - * Below here mismatches are bugs because these lower tables --- -1.8.1.3 - - |