diff options
| author | Kui-Feng Lee <thinker.li@gmail.com> | 2024-01-19 14:50:00 -0800 |
|---|---|---|
| committer | Martin KaFai Lau <martin.lau@kernel.org> | 2024-01-23 16:37:44 -0800 |
| commit | e3f87fdfed7b770dd7066b02262b12747881e76d (patch) | |
| tree | aba3b44c97564fd8d0e61f4b1eec1b90d7b13ee2 /include/linux/bpf_verifier.h | |
| parent | fcc2c1fb0651477c8ed78a3a293c175ccd70697a (diff) | |
bpf: hold module refcnt in bpf_struct_ops map creation and prog verification.
To ensure that a module remains accessible whenever a struct_ops object of
a struct_ops type provided by the module is still in use.
struct bpf_struct_ops_map doesn't hold a refcnt to btf anymore since a
module will hold a refcnt to it's btf already. But, struct_ops programs are
different. They hold their associated btf, not the module since they need
only btf to assure their types (signatures).
However, verifier holds the refcnt of the associated module of a struct_ops
type temporarily when verify a struct_ops prog. Verifier needs the help
from the verifier operators (struct bpf_verifier_ops) provided by the owner
module to verify data access of a prog, provide information, and generate
code.
This patch also add a count of links (links_cnt) to bpf_struct_ops_map. It
avoids bpf_struct_ops_map_put_progs() from accessing btf after calling
module_put() in bpf_struct_ops_map_free().
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240119225005.668602-10-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Diffstat (limited to 'include/linux/bpf_verifier.h')
| -rw-r--r-- | include/linux/bpf_verifier.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index e11baecbde68..7f5816482a10 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -662,6 +662,7 @@ struct bpf_verifier_env { u32 prev_insn_idx; struct bpf_prog *prog; /* eBPF program being verified */ const struct bpf_verifier_ops *ops; + struct module *attach_btf_mod; /* The owner module of prog->aux->attach_btf */ struct bpf_verifier_stack_elem *head; /* stack of verifier states to be processed */ int stack_size; /* number of states to be processed */ bool strict_alignment; /* perform strict pointer alignment checks */ |