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authorTomas Glozar2023-07-28 08:44:11 +0200
committerPaolo Abeni2023-08-01 09:24:34 +0200
commit13d2618b48f15966d1adfe1ff6a1985f5eef40ba (patch)
tree8751c5b8b2ee2f10ffaffefb178759ed6de623a7 /net
parentc5ccff70501d92db445a135fa49cf9bc6b98c444 (diff)
bpf: sockmap: Remove preempt_disable in sock_map_sk_acquire
Disabling preemption in sock_map_sk_acquire conflicts with GFP_ATOMIC allocation later in sk_psock_init_link on PREEMPT_RT kernels, since GFP_ATOMIC might sleep on RT (see bpf: Make BPF and PREEMPT_RT co-exist patchset notes for details). This causes calling bpf_map_update_elem on BPF_MAP_TYPE_SOCKMAP maps to BUG (sleeping function called from invalid context) on RT kernels. preempt_disable was introduced together with lock_sk and rcu_read_lock in commit 99ba2b5aba24e ("bpf: sockhash, disallow bpf_tcp_close and update in parallel"), probably to match disabled migration of BPF programs, and is no longer necessary. Remove preempt_disable to fix BUG in sock_map_update_common on RT. Signed-off-by: Tomas Glozar <tglozar@redhat.com> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/all/20200224140131.461979697@linutronix.de/ Fixes: 99ba2b5aba24 ("bpf: sockhash, disallow bpf_tcp_close and update in parallel") Reviewed-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/r/20230728064411.305576-1-tglozar@redhat.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net')
-rw-r--r--net/core/sock_map.c2
1 files changed, 0 insertions, 2 deletions
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index 19538d628714..08ab108206bf 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -115,7 +115,6 @@ static void sock_map_sk_acquire(struct sock *sk)
__acquires(&sk->sk_lock.slock)
{
lock_sock(sk);
- preempt_disable();
rcu_read_lock();
}
@@ -123,7 +122,6 @@ static void sock_map_sk_release(struct sock *sk)
__releases(&sk->sk_lock.slock)
{
rcu_read_unlock();
- preempt_enable();
release_sock(sk);
}