From: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
Broken vbq->free reported on a v6.6 based system which is caused
by invalid vbq->lock protect over vbq->free in purge_fragmented_block.
This should be introduced by the Fixes below which ignored vbq->lock
matter.
Fixes: fc1e0d980037 ("mm/vmalloc: prevent stale TLBs in fully utilized blocks")
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
---
mm/vmalloc.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 22aa63f4ef63..112b50431725 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2614,9 +2614,10 @@ static void free_vmap_block(struct vmap_block *vb)
}
static bool purge_fragmented_block(struct vmap_block *vb,
- struct vmap_block_queue *vbq, struct list_head *purge_list,
- bool force_purge)
+ struct list_head *purge_list, bool force_purge)
{
+ struct vmap_block_queue *vbq;
+
if (vb->free + vb->dirty != VMAP_BBMAP_BITS ||
vb->dirty == VMAP_BBMAP_BITS)
return false;
@@ -2625,6 +2626,8 @@ static bool purge_fragmented_block(struct vmap_block *vb,
if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD))
return false;
+ vbq = container_of(addr_to_vb_xa(vb->va->va_start),
+ struct vmap_block_queue, vmap_blocks);
/* prevent further allocs after releasing lock */
WRITE_ONCE(vb->free, 0);
/* prevent purging it again */
@@ -2664,7 +2667,7 @@ static void purge_fragmented_blocks(int cpu)
continue;
spin_lock(&vb->lock);
- purge_fragmented_block(vb, vbq, &purge, true);
+ purge_fragmented_block(vb, &purge, true);
spin_unlock(&vb->lock);
}
rcu_read_unlock();
@@ -2801,7 +2804,7 @@ static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush)
* not purgeable, check whether there is dirty
* space to be flushed.
*/
- if (!purge_fragmented_block(vb, vbq, &purge_list, false) &&
+ if (!purge_fragmented_block(vb, &purge_list, false) &&
vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) {
unsigned long va_start = vb->va->va_start;
unsigned long s, e;
--
2.25.1
