Fix a bug in mm_cpumask maintenance where a CPU can have switched to an
mm but it's not present in the cpumask, resulting in possible lost TLB
flushes. switch_mm() can be called without switching thread (exec(2),
kthread_use_mm()). Move mm_cpumask setting there, matching sparc64.
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
---
arch/sparc/include/asm/switch_to_32.h | 1 -
arch/sparc/mm/srmmu.c | 3 +++
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/sparc/include/asm/switch_to_32.h b/arch/sparc/include/asm/switch_to_32.h
index 42eeafcb8a41..1d9855abbc00 100644
--- a/arch/sparc/include/asm/switch_to_32.h
+++ b/arch/sparc/include/asm/switch_to_32.h
@@ -58,7 +58,6 @@ extern struct thread_info *current_set[NR_CPUS];
#define switch_to(prev, next, last) do { \
SWITCH_ENTER(prev); \
SWITCH_DO_LAZY_FPU(next); \
- cpumask_set_cpu(smp_processor_id(), mm_cpumask(next->active_mm)); \
__asm__ __volatile__( \
"sethi %%hi(here - 0x8), %%o7\n\t" \
"mov %%g6, %%g3\n\t" \
diff --git a/arch/sparc/mm/srmmu.c b/arch/sparc/mm/srmmu.c
index fefbd08bdc91..dc07b3d68fc1 100644
--- a/arch/sparc/mm/srmmu.c
+++ b/arch/sparc/mm/srmmu.c
@@ -473,6 +473,9 @@ void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm,
{
unsigned long flags;
+ if (!cpumask_test_cpu(smp_processor_id(), mm_cpumask(mm)))
+ cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
+
if (mm->context == NO_CONTEXT) {
spin_lock_irqsave(&srmmu_context_spinlock, flags);
alloc_context(old_mm, mm);
--
2.23.0
