Thread (5 messages) 5 messages, 2 authors, 2016-11-13

[patch net v2 1/2] mlxsw: spectrum: Fix refcount bug on span entries

flat view
STALE3627d REVIEWED: 1 (0M)

From: Jiri Pirko <jiri@resnulli.us>
Date: 2016-11-11 15:34:30
Subsystem: mellanox ethernet switch drivers, networking drivers, the rest · Maintainers: Ido Schimmel, Petr Machata, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds

Revision v2 of 25 in this series; 1 review trailer.

Revisions (25)
  1. v1 [diff vs current]
  2. v1 [diff vs current]
  3. v1 [diff vs current]
  4. v2
  5. v1 [diff vs current]
  6. v1 [diff vs current]
  7. v1 [diff vs current]
  8. v1 [diff vs current]
  9. v1 [diff vs current]
  10. v1 [diff vs current]
  11. v1 [diff vs current]
  12. v1 [diff vs current]
  13. v1 [diff vs current]
  14. v1 [diff vs current]
  15. v1 [diff vs current]
  16. v1 [diff vs current]
  17. v1 [diff vs current]
  18. v2 current
  19. v1 [diff vs current]
  20. v1 [diff vs current]
  21. v1 [diff vs current]
  22. v1 [diff vs current]
  23. v1 [diff vs current]
  24. v1 [diff vs current]
  25. v2
From: Yotam Gigi <redacted>

When binding port to a newly created span entry, its refcount is
initialized to zero even though it has a bound port. That leads
to unexpected behaviour when the user tries to delete that port
from the span entry.

Fix this by initializing the reference count to 1.

Also add a warning to put function.

Fixes: 763b4b70afcd ("mlxsw: spectrum: Add support in matchall mirror TC offloading")
Signed-off-by: Yotam Gigi <redacted>
Reviewed-by: Ido Schimmel <redacted>
Signed-off-by: Jiri Pirko <redacted>
---
v1->v2:
- fix this rather by initializing refcount to 1
- fix typo in description
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index 1ec0a4c..dda5761 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -231,7 +231,7 @@ mlxsw_sp_span_entry_create(struct mlxsw_sp_port *port)
 
 	span_entry->used = true;
 	span_entry->id = index;
-	span_entry->ref_count = 0;
+	span_entry->ref_count = 1;
 	span_entry->local_port = local_port;
 	return span_entry;
 }
@@ -270,6 +270,7 @@ static struct mlxsw_sp_span_entry
 
 	span_entry = mlxsw_sp_span_entry_find(port);
 	if (span_entry) {
+		/* Already exists, just take a reference */
 		span_entry->ref_count++;
 		return span_entry;
 	}
@@ -280,6 +281,7 @@ static struct mlxsw_sp_span_entry
 static int mlxsw_sp_span_entry_put(struct mlxsw_sp *mlxsw_sp,
 				   struct mlxsw_sp_span_entry *span_entry)
 {
+	WARN_ON(!span_entry->ref_count);
 	if (--span_entry->ref_count == 0)
 		mlxsw_sp_span_entry_destroy(mlxsw_sp, span_entry);
 	return 0;
-- 
2.7.4
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help