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| author |   Alexei Starovoitov <ast@kernel.org> | 2020-06-29 21:33:39 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-07-01 08:07:13 -0700 |
| commit | bba1dc0b55ac462d24ed1228ad49800c238cd6d7 (patch) | |
| tree | d83554930260fe70393ea2d74734357577035dce /kernel/bpf/stackmap.c | |
| parent | selftests/bpf: Add byte swapping selftest (diff) | |
| download | linux-dev-bba1dc0b55ac462d24ed1228ad49800c238cd6d7.tar.xz linux-dev-bba1dc0b55ac462d24ed1228ad49800c238cd6d7.zip | |
bpf: Remove redundant synchronize_rcu.
bpf_free_used_maps() or close(map_fd) will trigger map_free callback.
bpf_free_used_maps() is called after bpf prog is no longer executing:
bpf_prog_put->call_rcu->bpf_prog_free->bpf_free_used_maps.
Hence there is no need to call synchronize_rcu() to protect map elements.
Note that hash_of_maps and array_of_maps update/delete inner maps via
sys_bpf() that calls maybe_wait_bpf_programs() and synchronize_rcu().
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/bpf/20200630043343.53195-2-alexei.starovoitov@gmail.com
Diffstat (limited to '')
| -rw-r--r-- | kernel/bpf/stackmap.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 27dc9b1b08a5..071f98d0f7c6 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -604,9 +604,6 @@ static void stack_map_free(struct bpf_map *map) { struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map); - /* wait for bpf programs to complete before freeing stack map */ - synchronize_rcu(); - bpf_map_area_free(smap->elems); pcpu_freelist_destroy(&smap->freelist); bpf_map_area_free(smap); |