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authorJesper Dangaard Brouer <brouer@redhat.com>2019-11-16 12:22:38 +0100
committerDavid S. Miller <davem@davemloft.net>2019-11-18 17:03:17 -0800
commitc491eae8f9c0720520ebdeb4d335671f84b84b71 (patch)
tree1e73aa503c482accbead40e2d8fd28c78cfd0cf7 /net/core
parentb95e86d846b63b02ecdc94802ddbeaf9005fb6d9 (diff)
downloadlinux-c491eae8f9c0720520ebdeb4d335671f84b84b71.tar.bz2
xdp: remove memory poison on free for struct xdp_mem_allocator
When looking at the details I realised that the memory poison in __xdp_mem_allocator_rcu_free doesn't make sense. This is because the SLUB allocator uses the first 16 bytes (on 64 bit), for its freelist, which overlap with members in struct xdp_mem_allocator, that were updated. Thus, SLUB already does the "poisoning" for us. I still believe that poisoning memory make sense in other cases. Kernel have gained different use-after-free detection mechanism, but enabling those is associated with a huge overhead. Experience is that debugging facilities can change the timing so much, that that a race condition will not be provoked when enabled. Thus, I'm still in favour of poisoning memory where it makes sense. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/xdp.c5
1 files changed, 0 insertions, 5 deletions
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 8e405abaf05a..e334fad0a6b8 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -73,11 +73,6 @@ static void __xdp_mem_allocator_rcu_free(struct rcu_head *rcu)
/* Allow this ID to be reused */
ida_simple_remove(&mem_id_pool, xa->mem.id);
- /* Poison memory */
- xa->mem.id = 0xFFFF;
- xa->mem.type = 0xF0F0;
- xa->allocator = (void *)0xDEAD9001;
-
kfree(xa);
}