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| author | Tomas Glozar <tglozar@redhat.com> | 2023-07-28 08:44:11 +0200 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2023-08-01 09:24:34 +0200 |
| commit | 13d2618b48f15966d1adfe1ff6a1985f5eef40ba (patch) | |
| tree | 8751c5b8b2ee2f10ffaffefb178759ed6de623a7 | |
| parent | c5ccff70501d92db445a135fa49cf9bc6b98c444 (diff) | |
| download | kvm-s390-vfio-13d2618b48f15966d1adfe1ff6a1985f5eef40ba.tar.gz | |
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>
| -rw-r--r-- | net/core/sock_map.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 19538d6287144..08ab108206bf8 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); } |