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authorYonghong Song <yhs@fb.com>2019-02-27 13:22:56 -0800
committerAlexei Starovoitov <ast@kernel.org>2019-02-27 17:03:13 -0800
commita115d0ed7201a5904c084ae6f07913fe2b9396a6 (patch)
tree95fefb6e10dc05e5c1114ff4c7e5b4f9ee2e903a
parentd2e614cb0795d935aee879e47aab231247274f13 (diff)
bpf: set inner_map_meta->spin_lock_off correctly
Commit d83525ca62cf ("bpf: introduce bpf_spin_lock") introduced bpf_spin_lock and the field spin_lock_off in kernel internal structure bpf_map has the following meaning: >=0 valid offset, <0 error For every map created, the kernel will ensure spin_lock_off has correct value. Currently, bpf_map->spin_lock_off is not copied from the inner map to the map_in_map inner_map_meta during a map_in_map type map creation, so inner_map_meta->spin_lock_off = 0. This will give verifier wrong information that inner_map has bpf_spin_lock and the bpf_spin_lock is defined at offset 0. An access to offset 0 of a value pointer will trigger the following error: bpf_spin_lock cannot be accessed directly by load/store This patch fixed the issue by copy inner map's spin_lock_off value to inner_map_meta->spin_lock_off. Fixes: d83525ca62cf ("bpf: introduce bpf_spin_lock") Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
-rw-r--r--kernel/bpf/map_in_map.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c
index 583346a0ab29..3dff41403583 100644
--- a/kernel/bpf/map_in_map.c
+++ b/kernel/bpf/map_in_map.c
@@ -58,6 +58,7 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd)
inner_map_meta->value_size = inner_map->value_size;
inner_map_meta->map_flags = inner_map->map_flags;
inner_map_meta->max_entries = inner_map->max_entries;
+ inner_map_meta->spin_lock_off = inner_map->spin_lock_off;
/* Misc members not needed in bpf_map_meta_equal() check. */
inner_map_meta->ops = inner_map->ops;