diff mbox series

[bpf-next,v2] bpf/devmap: convert remaining READ_ONCE() to rcu_dereference_check()

Message ID 20210629093907.573598-1-toke@redhat.com (mailing list archive)
State Accepted
Commit 0fc4dcc13f090c941abfab453a24945a4005b350
Delegated to: BPF
Headers show
Series [bpf-next,v2] bpf/devmap: convert remaining READ_ONCE() to rcu_dereference_check() | expand

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netdev/cc_maintainers fail 1 blamed authors not CCed: daniel@iogearbox.net; 9 maintainers not CCed: yhs@fb.com kpsingh@kernel.org daniel@iogearbox.net andrii@kernel.org hawk@kernel.org ast@kernel.org john.fastabend@gmail.com songliubraving@fb.com davem@davemloft.net
netdev/source_inline success Was 0 now: 0
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netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 3 this patch: 1
netdev/kdoc success Errors and warnings before: 0 this patch: 0
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netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 18 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 3 this patch: 1
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Commit Message

Toke Høiland-Jørgensen June 29, 2021, 9:39 a.m. UTC
There were a couple of READ_ONCE()-invocations left-over by the devmap RCU
conversion. Convert these to rcu_dereference_check() as well to avoid
complaints from sparse.

v2:
 - Use rcu_dereference_check()

Fixes: 782347b6bcad ("xdp: Add proper __rcu annotations to redirect map entries")
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
---
 kernel/bpf/devmap.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Martin KaFai Lau June 30, 2021, 12:08 a.m. UTC | #1
On Tue, Jun 29, 2021 at 11:39:07AM +0200, Toke Høiland-Jørgensen wrote:
> There were a couple of READ_ONCE()-invocations left-over by the devmap RCU
> conversion. Convert these to rcu_dereference_check() as well to avoid
> complaints from sparse.
> 
> v2:
>  - Use rcu_dereference_check()
Acked-by: Martin KaFai Lau <kafai@fb.com>
patchwork-bot+netdevbpf@kernel.org July 1, 2021, 7:30 a.m. UTC | #2
Hello:

This patch was applied to bpf/bpf.git (refs/heads/master):

On Tue, 29 Jun 2021 11:39:07 +0200 you wrote:
> There were a couple of READ_ONCE()-invocations left-over by the devmap RCU
> conversion. Convert these to rcu_dereference_check() as well to avoid
> complaints from sparse.
> 
> v2:
>  - Use rcu_dereference_check()
> 
> [...]

Here is the summary with links:
  - [bpf-next,v2] bpf/devmap: convert remaining READ_ONCE() to rcu_dereference_check()
    https://git.kernel.org/bpf/bpf/c/0fc4dcc13f09

You are awesome, thank you!
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diff mbox series

Patch

diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 2f6bd75cd682..e4ebe70cf201 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -558,7 +558,8 @@  int dev_map_enqueue_multi(struct xdp_buff *xdp, struct net_device *dev_rx,
 
 	if (map->map_type == BPF_MAP_TYPE_DEVMAP) {
 		for (i = 0; i < map->max_entries; i++) {
-			dst = READ_ONCE(dtab->netdev_map[i]);
+			dst = rcu_dereference_check(dtab->netdev_map[i],
+						    rcu_read_lock_bh_held());
 			if (!is_valid_dst(dst, xdp, exclude_ifindex))
 				continue;
 
@@ -654,7 +655,8 @@  int dev_map_redirect_multi(struct net_device *dev, struct sk_buff *skb,
 
 	if (map->map_type == BPF_MAP_TYPE_DEVMAP) {
 		for (i = 0; i < map->max_entries; i++) {
-			dst = READ_ONCE(dtab->netdev_map[i]);
+			dst = rcu_dereference_check(dtab->netdev_map[i],
+						    rcu_read_lock_bh_held());
 			if (!dst || dst->dev->ifindex == exclude_ifindex)
 				continue;