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authorEric Dumazet <edumazet@google.com>2022-02-17 10:19:02 -0800
committerAlexei Starovoitov <ast@kernel.org>2022-02-17 10:48:26 -0800
commit75134f16e7dd0007aa474b281935c5f42e79f2c8 (patch)
treea9c3a90aad2989c2c3067a900fb43b03841092f5 /kernel
parent45ce4b4f9009102cd9f581196d480a59208690c1 (diff)
bpf: Add schedule points in batch ops
syzbot reported various soft lockups caused by bpf batch operations. INFO: task kworker/1:1:27 blocked for more than 140 seconds. INFO: task hung in rcu_barrier Nothing prevents batch ops to process huge amount of data, we need to add schedule points in them. Note that maybe_wait_bpf_programs(map) calls from generic_map_delete_batch() can be factorized by moving the call after the loop. This will be done later in -next tree once we get this fix merged, unless there is strong opinion doing this optimization sooner. Fixes: aa2e93b8e58e ("bpf: Add generic support for update and delete batch ops") Fixes: cb4d03ab499d ("bpf: Add generic support for lookup batch op") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Stanislav Fomichev <sdf@google.com> Acked-by: Brian Vazquez <brianvv@google.com> Link: https://lore.kernel.org/bpf/20220217181902.808742-1-eric.dumazet@gmail.com
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/syscall.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index fa4505f9b611..ca70fe6fba38 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1355,6 +1355,7 @@ int generic_map_delete_batch(struct bpf_map *map,
maybe_wait_bpf_programs(map);
if (err)
break;
+ cond_resched();
}
if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
err = -EFAULT;
@@ -1412,6 +1413,7 @@ int generic_map_update_batch(struct bpf_map *map,
if (err)
break;
+ cond_resched();
}
if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
@@ -1509,6 +1511,7 @@ int generic_map_lookup_batch(struct bpf_map *map,
swap(prev_key, key);
retry = MAP_LOOKUP_RETRIES;
cp++;
+ cond_resched();
}
if (err == -EFAULT)