bpf: Force uprobe bpf program to always return 0

As suggested by Andrii make uprobe multi bpf programs to always return 0, so they can't force uprobe removal. Keeping the int return type for uprobe_prog_run, because it will be used in following session changes. Fixes: 89ae89f ("bpf: Add multi uprobe link") Suggested-by: Andrii Nakryiko <[email protected]> Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
herbertx · Nov 11, 2024 · f505005 · f505005
1 parent 17c4b65
commit f505005
Showing 1 changed file with 2 additions and 3 deletions.
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
@@ -3229,7 +3229,6 @@ static int uprobe_prog_run(struct bpf_uprobe *uprobe,
 	struct bpf_prog *prog = link->link.prog;
 	bool sleepable = prog->sleepable;
 	struct bpf_run_ctx *old_run_ctx;
-	int err = 0;
 
 	if (link->task && !same_thread_group(current, link->task))
 		return 0;
@@ -3242,7 +3241,7 @@ static int uprobe_prog_run(struct bpf_uprobe *uprobe,
 	migrate_disable();
 
 	old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
-	err = bpf_prog_run(link->link.prog, regs);
+	bpf_prog_run(link->link.prog, regs);
 	bpf_reset_run_ctx(old_run_ctx);
 
 	migrate_enable();
@@ -3251,7 +3250,7 @@ static int uprobe_prog_run(struct bpf_uprobe *uprobe,
 		rcu_read_unlock_trace();
 	else
 		rcu_read_unlock();
-	return err;
+	return 0;
 }
 
 static bool