diff options
| author | Delyan Kratunov | 2022-06-14 23:10:43 +0000 |
|---|---|---|
| committer | Alexei Starovoitov | 2022-06-16 19:27:29 -0700 |
| commit | 64ad7556c75ea102eec2f5bcd60fe2d66ce70308 (patch) | |
| tree | 2919d1f75b3bff6aa6d91cf99c3866fe5deb25f9 | |
| parent | 8c7dcb84e3b744b2b70baa7a44a9b1881c33a9c9 (diff) | |
bpf: allow sleepable uprobe programs to attach
uprobe and kprobe programs have the same program type, KPROBE, which is
currently not allowed to load sleepable programs.
To avoid adding a new UPROBE type, instead allow sleepable KPROBE
programs to load and defer the is-it-actually-a-uprobe-program check
to attachment time, where there's already validation of the
corresponding perf_event.
A corollary of this patch is that you can now load a sleepable kprobe
program but cannot attach it.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Delyan Kratunov <delyank@fb.com>
Link: https://lore.kernel.org/r/fcd44a7cd204f372f6bb03ef794e829adeaef299.1655248076.git.delyank@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | kernel/bpf/verifier.c | 4 | ||||
| -rw-r--r-- | kernel/events/core.c | 16 |
2 files changed, 12 insertions, 8 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 2d2872682278..eadc23a8452c 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -14829,8 +14829,8 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) } if (prog->aux->sleepable && prog->type != BPF_PROG_TYPE_TRACING && - prog->type != BPF_PROG_TYPE_LSM) { - verbose(env, "Only fentry/fexit/fmod_ret and lsm programs can be sleepable\n"); + prog->type != BPF_PROG_TYPE_LSM && prog->type != BPF_PROG_TYPE_KPROBE) { + verbose(env, "Only fentry/fexit/fmod_ret, lsm, and kprobe/uprobe programs can be sleepable\n"); return -EINVAL; } diff --git a/kernel/events/core.c b/kernel/events/core.c index 950b25c3f210..deee6815bdd3 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -10069,26 +10069,30 @@ static inline bool perf_event_is_tracing(struct perf_event *event) int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie) { - bool is_kprobe, is_tracepoint, is_syscall_tp; + bool is_kprobe, is_uprobe, is_tracepoint, is_syscall_tp; if (!perf_event_is_tracing(event)) return perf_event_set_bpf_handler(event, prog, bpf_cookie); - is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_UKPROBE; + is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_KPROBE; + is_uprobe = event->tp_event->flags & TRACE_EVENT_FL_UPROBE; is_tracepoint = event->tp_event->flags & TRACE_EVENT_FL_TRACEPOINT; is_syscall_tp = is_syscall_trace_event(event->tp_event); - if (!is_kprobe && !is_tracepoint && !is_syscall_tp) + if (!is_kprobe && !is_uprobe && !is_tracepoint && !is_syscall_tp) /* bpf programs can only be attached to u/kprobe or tracepoint */ return -EINVAL; - if ((is_kprobe && prog->type != BPF_PROG_TYPE_KPROBE) || + if (((is_kprobe || is_uprobe) && prog->type != BPF_PROG_TYPE_KPROBE) || (is_tracepoint && prog->type != BPF_PROG_TYPE_TRACEPOINT) || (is_syscall_tp && prog->type != BPF_PROG_TYPE_TRACEPOINT)) return -EINVAL; + if (prog->type == BPF_PROG_TYPE_KPROBE && prog->aux->sleepable && !is_uprobe) + /* only uprobe programs are allowed to be sleepable */ + return -EINVAL; + /* Kprobe override only works for kprobes, not uprobes. */ - if (prog->kprobe_override && - !(event->tp_event->flags & TRACE_EVENT_FL_KPROBE)) + if (prog->kprobe_override && !is_kprobe) return -EINVAL; if (is_tracepoint || is_syscall_tp) { |