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@xxxxxxxxxx>
Signed-off-by: Delyan Kratunov <delyank@xxxxxx>
---
kernel/bpf/verifier.c | 4 ++--
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) {
--
2.36.1
