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| author | Alexei Starovoitov <ast@kernel.org> | 2021-04-25 21:09:03 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-04-25 21:09:03 -0700 |
| commit | 87bd9e602e39585c5280556a2b6a6363bb334257 (patch) | |
| tree | 472342bc1d5691d102a741505e46de688651fa40 /kernel | |
| parent | 0ea1041bfa3aa2971f858edd9e05477c2d3d54a0 (diff) | |
| parent | 7bb2cc19aee8f7150851bb8668c9ff655a5e7678 (diff) | |
| download | linux-87bd9e602e39585c5280556a2b6a6363bb334257.tar.gz linux-87bd9e602e39585c5280556a2b6a6363bb334257.tar.bz2 linux-87bd9e602e39585c5280556a2b6a6363bb334257.zip | |
Merge branch 'bpf: Tracing and lsm programs re-attach'
Jiri Olsa says:
====================
hi,
while adding test for pinning the module while there's
trampoline attach to it, I noticed that we don't allow
link detach and following re-attach for trampolines.
Adding that for tracing and lsm programs.
You need to have patch [1] from bpf tree for test module
attach test to pass.
v5 changes:
- fixed missing hlist_del_init change
- fixed several ASSERT calls
- added extra patch for missing ';'
- added ASSERT macros to lsm test
- added acks
thanks,
jirka
[1] https://lore.kernel.org/bpf/20210326105900.151466-1-jolsa@kernel.org/
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/syscall.c | 23 | ||||
| -rw-r--r-- | kernel/bpf/trampoline.c | 4 |
2 files changed, 19 insertions, 8 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index fd495190115e..941ca06d9dfa 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2648,14 +2648,25 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog, * target_btf_id using the link_create API. * * - if tgt_prog == NULL when this function was called using the old - * raw_tracepoint_open API, and we need a target from prog->aux - * - * The combination of no saved target in prog->aux, and no target - * specified on load is illegal, and we reject that here. + * raw_tracepoint_open API, and we need a target from prog->aux + * + * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program + * was detached and is going for re-attachment. */ if (!prog->aux->dst_trampoline && !tgt_prog) { - err = -ENOENT; - goto out_unlock; + /* + * Allow re-attach for TRACING and LSM programs. If it's + * currently linked, bpf_trampoline_link_prog will fail. + * EXT programs need to specify tgt_prog_fd, so they + * re-attach in separate code path. + */ + if (prog->type != BPF_PROG_TYPE_TRACING && + prog->type != BPF_PROG_TYPE_LSM) { + err = -EINVAL; + goto out_unlock; + } + btf_id = prog->aux->attach_btf_id; + key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); } if (!prog->aux->dst_trampoline || diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 4aa8b52adf25..2d44b5aa0057 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -444,7 +444,7 @@ int bpf_trampoline_link_prog(struct bpf_prog *prog, struct bpf_trampoline *tr) tr->progs_cnt[kind]++; err = bpf_trampoline_update(tr); if (err) { - hlist_del(&prog->aux->tramp_hlist); + hlist_del_init(&prog->aux->tramp_hlist); tr->progs_cnt[kind]--; } out: @@ -467,7 +467,7 @@ int bpf_trampoline_unlink_prog(struct bpf_prog *prog, struct bpf_trampoline *tr) tr->extension_prog = NULL; goto out; } - hlist_del(&prog->aux->tramp_hlist); + hlist_del_init(&prog->aux->tramp_hlist); tr->progs_cnt[kind]--; err = bpf_trampoline_update(tr); out: |