The previous patch "mm: wrap calls to set_pte_at_notify with
invalidate_range_start and invalidate_range_end" only called the
invalidate_range_end mmu notifier function in do_wp_page when the new_page
variable wasn't NULL. This was done in order to only call
invalidate_range_end after invalidate_range_start was called.
Unfortunately, there are situations where new_page is NULL and
invalidate_range_start is called. This caused invalidate_range_start to
be called without a matching invalidate_range_end, causing kvm to loop
indefinitely on the first page fault.
This patch adds a flag variable to do_wp_page that marks whether the
invalidate_range_start notifier was called. invalidate_range_end is then
called if the flag is true.
Reported-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Cc: Andrea Arcangeli <andrea@qumranet.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Haggai Eran <haggaie@mellanox.com>
Cc: Shachar Raindel <raindel@mellanox.com>
Cc: Liran Liss <liranl@mellanox.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
struct page *dirty_page = NULL;
unsigned long mmun_start; /* For mmu_notifiers */
unsigned long mmun_end; /* For mmu_notifiers */
struct page *dirty_page = NULL;
unsigned long mmun_start; /* For mmu_notifiers */
unsigned long mmun_end; /* For mmu_notifiers */
+ bool mmun_called = false; /* For mmu_notifiers */
old_page = vm_normal_page(vma, address, orig_pte);
if (!old_page) {
old_page = vm_normal_page(vma, address, orig_pte);
if (!old_page) {
if (mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))
goto oom_free_new;
if (mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))
goto oom_free_new;
- mmun_start = address & PAGE_MASK;
- mmun_end = (address & PAGE_MASK) + PAGE_SIZE;
+ mmun_start = address & PAGE_MASK;
+ mmun_end = (address & PAGE_MASK) + PAGE_SIZE;
+ mmun_called = true;
mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
/*
mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
/*
page_cache_release(new_page);
unlock:
pte_unmap_unlock(page_table, ptl);
page_cache_release(new_page);
unlock:
pte_unmap_unlock(page_table, ptl);
- if (new_page)
- /* Only call the end notifier if the begin was called. */
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
if (old_page) {
/*
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
if (old_page) {
/*