From: Jann Horn <jannh@xxxxxxxxxx>
Subject: mm/vmstat.c: skip NR_TLB_REMOTE_FLUSH* properly
5dd0b16cdaff ("mm/vmstat: Make NR_TLB_REMOTE_FLUSH_RECEIVED available even
on UP") made the availability of the NR_TLB_REMOTE_FLUSH* counters inside
the kernel unconditional to reduce #ifdef soup, but (either to avoid
showing dummy zero counters to userspace, or because that code was missed)
didn't update the vmstat_array, meaning that all following counters would
be shown with incorrect values.
This only affects kernel builds with
CONFIG_VM_EVENT_COUNTERS=y && CONFIG_DEBUG_TLBFLUSH=y && CONFIG_SMP=n.
Link: http://lkml.kernel.org/r/20181001143138.95119-2-jannh@xxxxxxxxxx
Fixes: 5dd0b16cdaff ("mm/vmstat: Make NR_TLB_REMOTE_FLUSH_RECEIVED available even on UP")
Signed-off-by: Jann Horn <jannh@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Acked-by: Roman Gushchin <guro@xxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Christoph Lameter <clameter@xxxxxxx>
Cc: Kemi Wang <kemi.wang@xxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmstat.c | 3 +++
1 file changed, 3 insertions(+)
--- a/mm/vmstat.c~mm-vmstat-skip-nr_tlb_remote_flush-properly
+++ a/mm/vmstat.c
@@ -1275,6 +1275,9 @@ const char * const vmstat_text[] = {
#ifdef CONFIG_SMP
"nr_tlb_remote_flush",
"nr_tlb_remote_flush_received",
+#else
+ "", /* nr_tlb_remote_flush */
+ "", /* nr_tlb_remote_flush_received */
#endif /* CONFIG_SMP */
"nr_tlb_local_flush_all",
"nr_tlb_local_flush_one",
_
