| Message ID | 20240905115124.1503998-2-jolsa@kernel.org (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Commit | 900f362e2062e4a23a53bf89fd3b248cd021f5af |
| Headers | show |
| Series | selftests/bpf: Add uprobe multi pid filter test | expand |
On 09/05, Jiri Olsa wrote: > > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -3207,7 +3207,7 @@ static int uprobe_prog_run(struct bpf_uprobe *uprobe, > struct bpf_run_ctx *old_run_ctx; > int err = 0; > > - if (link->task && current->mm != link->task->mm) > + if (link->task && !same_thread_group(current, link->task)) > return 0; plus the current check can return false negative if link->task->mm == NULL Acked-by: Oleg Nesterov <oleg@redhat.com>
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index b69a39316c0c..98e395f1baae 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -3207,7 +3207,7 @@ static int uprobe_prog_run(struct bpf_uprobe *uprobe, struct bpf_run_ctx *old_run_ctx; int err = 0; - if (link->task && current->mm != link->task->mm) + if (link->task && !same_thread_group(current, link->task)) return 0; if (sleepable)
Uprobe multi link does its own process (thread leader) filtering before running the bpf program by comparing task's vm pointers. But as Oleg pointed out there can be processes sharing the vm (CLONE_VM), so we can't just compare task->vm pointers, but instead we need to use same_thread_group call. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- kernel/trace/bpf_trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)