| Message ID | 20200916204453.2003915-1-kafai@fb.com |
|---|---|
| State | Accepted |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | [bpf-next] bpf: Use hlist_add_head_rcu when linking to local_storage | expand |
On Thu, Sep 17, 2020 at 9:57 AM Martin KaFai Lau <kafai@fb.com> wrote: > > The local_storage->list will be traversed by rcu reader in parallel. > Thus, hlist_add_head_rcu() is needed in bpf_selem_link_storage_nolock(). > This patch fixes it. > > This part of the code has recently been refactored in bpf-next > and this patch makes changes to the new file "bpf_local_storage.c". > Instead of using the original offending commit in the Fixes tag, > the commit that created the file "bpf_local_storage.c" is used. > > A separate fix has been provided to the bpf tree. > > Fixes: 450af8d0f6be ("bpf: Split bpf_local_storage to bpf_sk_storage") > Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Song Liu <songliubraving@fb.com>
On 9/16/20 10:44 PM, Martin KaFai Lau wrote: > The local_storage->list will be traversed by rcu reader in parallel. > Thus, hlist_add_head_rcu() is needed in bpf_selem_link_storage_nolock(). > This patch fixes it. > > This part of the code has recently been refactored in bpf-next > and this patch makes changes to the new file "bpf_local_storage.c". > Instead of using the original offending commit in the Fixes tag, > the commit that created the file "bpf_local_storage.c" is used. > > A separate fix has been provided to the bpf tree. > > Fixes: 450af8d0f6be ("bpf: Split bpf_local_storage to bpf_sk_storage") > Signed-off-by: Martin KaFai Lau <kafai@fb.com> Applied, thanks!
diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c index ffa7d11fc2bd..5d3a7af9ba9b 100644 --- a/kernel/bpf/bpf_local_storage.c +++ b/kernel/bpf/bpf_local_storage.c @@ -159,7 +159,7 @@ void bpf_selem_link_storage_nolock(struct bpf_local_storage *local_storage, struct bpf_local_storage_elem *selem) { RCU_INIT_POINTER(selem->local_storage, local_storage); - hlist_add_head(&selem->snode, &local_storage->list); + hlist_add_head_rcu(&selem->snode, &local_storage->list); } void bpf_selem_unlink_map(struct bpf_local_storage_elem *selem)
The local_storage->list will be traversed by rcu reader in parallel. Thus, hlist_add_head_rcu() is needed in bpf_selem_link_storage_nolock(). This patch fixes it. This part of the code has recently been refactored in bpf-next and this patch makes changes to the new file "bpf_local_storage.c". Instead of using the original offending commit in the Fixes tag, the commit that created the file "bpf_local_storage.c" is used. A separate fix has been provided to the bpf tree. Fixes: 450af8d0f6be ("bpf: Split bpf_local_storage to bpf_sk_storage") Signed-off-by: Martin KaFai Lau <kafai@fb.com> --- kernel/bpf/bpf_local_storage.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)