From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: davem@davemloft.net
Cc: daniel@iogearbox.net, bpf@vger.kernel.org, kernel-team@fb.com
Subject: [PATCH v4 bpf-next 8/9] bpf: Allows per-cpu maps and map-in-map in sleepable programs
Date: Tue, 9 Feb 2021 19:36:33 -0800 [thread overview]
Message-ID: <20210210033634.62081-9-alexei.starovoitov@gmail.com> (raw)
In-Reply-To: <20210210033634.62081-1-alexei.starovoitov@gmail.com>
From: Alexei Starovoitov <ast@kernel.org>
Since sleepable programs are now executing under migrate_disable
the per-cpu maps are safe to use.
The map-in-map were ok to use in sleepable from the time sleepable
progs were introduced.
Note that non-preallocated maps are still not safe, since there is
no rcu_read_lock yet in sleepable programs and dynamically allocated
map elements are relying on rcu protection. The sleepable programs
have rcu_read_lock_trace instead. That limitation will be addresses
in the future.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: KP Singh <kpsingh@kernel.org>
---
kernel/bpf/hashtab.c | 4 ++--
kernel/bpf/verifier.c | 7 ++++++-
2 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index c1ac7f964bc9..d63912e73ad9 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -1148,7 +1148,7 @@ static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key,
/* unknown flags */
return -EINVAL;
- WARN_ON_ONCE(!rcu_read_lock_held());
+ WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held());
key_size = map->key_size;
@@ -1202,7 +1202,7 @@ static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
/* unknown flags */
return -EINVAL;
- WARN_ON_ONCE(!rcu_read_lock_held());
+ WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held());
key_size = map->key_size;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 4189edb41b73..9561f2af7710 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -10020,9 +10020,14 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
case BPF_MAP_TYPE_HASH:
case BPF_MAP_TYPE_LRU_HASH:
case BPF_MAP_TYPE_ARRAY:
+ case BPF_MAP_TYPE_PERCPU_HASH:
+ case BPF_MAP_TYPE_PERCPU_ARRAY:
+ case BPF_MAP_TYPE_LRU_PERCPU_HASH:
+ case BPF_MAP_TYPE_ARRAY_OF_MAPS:
+ case BPF_MAP_TYPE_HASH_OF_MAPS:
if (!is_preallocated_map(map)) {
verbose(env,
- "Sleepable programs can only use preallocated hash maps\n");
+ "Sleepable programs can only use preallocated maps\n");
return -EINVAL;
}
break;
--
2.24.1
next prev parent reply other threads:[~2021-02-10 3:38 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-10 3:36 [PATCH v4 bpf-next 0/9] bpf: Misc improvements Alexei Starovoitov
2021-02-10 3:36 ` [PATCH v4 bpf-next 1/9] bpf: Optimize program stats Alexei Starovoitov
2021-02-12 3:26 ` Ilya Leoshkevich
2021-02-12 3:43 ` Alexei Starovoitov
2021-02-12 3:51 ` Ilya Leoshkevich
2021-02-10 3:36 ` [PATCH v4 bpf-next 2/9] bpf: Run sleepable programs with migration disabled Alexei Starovoitov
2021-02-10 3:36 ` [PATCH v4 bpf-next 3/9] bpf: Compute program stats for sleepable programs Alexei Starovoitov
2021-02-10 3:36 ` [PATCH v4 bpf-next 4/9] bpf: Add per-program recursion prevention mechanism Alexei Starovoitov
2021-02-10 3:36 ` [PATCH v4 bpf-next 5/9] selftest/bpf: Add a recursion test Alexei Starovoitov
2021-02-10 3:36 ` [PATCH v4 bpf-next 6/9] bpf: Count the number of times recursion was prevented Alexei Starovoitov
2021-02-10 3:36 ` [PATCH v4 bpf-next 7/9] selftests/bpf: Improve recursion selftest Alexei Starovoitov
2021-02-10 3:36 ` Alexei Starovoitov [this message]
2021-02-10 3:36 ` [PATCH v4 bpf-next 9/9] selftests/bpf: Add a test for map-in-map and per-cpu maps in sleepable progs Alexei Starovoitov
2021-02-11 15:30 ` [PATCH v4 bpf-next 0/9] bpf: Misc improvements patchwork-bot+netdevbpf
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