diff options
| author | Toke Høiland-Jørgensen <toke@redhat.com> | 2020-09-29 15:45:50 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-09-29 23:09:23 +0300 |
| commit | 3aac1ead5eb6b76f3d2b8d111e6de1c2de23fb34 (patch) | |
| tree | fb66fb0f2de431275e8c5a09d896a97f9641dacb /kernel/bpf/btf.c | |
| parent | 85e3f318506ece12714535821d0b3186f7121b5b (diff) | |
| download | linux-3aac1ead5eb6b76f3d2b8d111e6de1c2de23fb34.tar.xz | |
bpf: Move prog->aux->linked_prog and trampoline into bpf_link on attach
In preparation for allowing multiple attachments of freplace programs, move
the references to the target program and trampoline into the
bpf_tracing_link structure when that is created. To do this atomically,
introduce a new mutex in prog->aux to protect writing to the two pointers
to target prog and trampoline, and rename the members to make it clear that
they are related.
With this change, it is no longer possible to attach the same tracing
program multiple times (detaching in-between), since the reference from the
tracing program to the target disappears on the first attach. However,
since the next patch will let the caller supply an attach target, that will
also make it possible to attach to the same place multiple times.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/160138355059.48470.2503076992210324984.stgit@toke.dk
Diffstat (limited to 'kernel/bpf/btf.c')
| -rw-r--r-- | kernel/bpf/btf.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 498e5e553825..05816471bac6 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -4428,7 +4428,7 @@ errout: struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog) { - struct bpf_prog *tgt_prog = prog->aux->linked_prog; + struct bpf_prog *tgt_prog = prog->aux->dst_prog; if (tgt_prog) { return tgt_prog->aux->btf; @@ -4455,7 +4455,7 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type, struct bpf_insn_access_aux *info) { const struct btf_type *t = prog->aux->attach_func_proto; - struct bpf_prog *tgt_prog = prog->aux->linked_prog; + struct bpf_prog *tgt_prog = prog->aux->dst_prog; struct btf *btf = bpf_prog_get_target_btf(prog); const char *tname = prog->aux->attach_func_name; struct bpf_verifier_log *log = info->log; @@ -5281,7 +5281,7 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog, return -EFAULT; } if (prog_type == BPF_PROG_TYPE_EXT) - prog_type = prog->aux->linked_prog->type; + prog_type = prog->aux->dst_prog->type; t = btf_type_by_id(btf, t->type); if (!t || !btf_type_is_func_proto(t)) { |