[PATCHv8 bpf-next 02/13] bpf: Force uprobe bpf program to always return 0

[Jiri Olsa]

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: 89ae89f53d20 ("bpf: Add multi uprobe link")
Suggested-by: Andrii Nakryiko <and...@kernel.org>
Acked-by: Andrii Nakryiko <and...@kernel.org>
Signed-off-by: Jiri Olsa <jo...@kernel.org>
---
 kernel/trace/bpf_trace.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index fdab7ecd8dfa..3c1e5a561df4 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -3209,7 +3209,6 @@ 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;
@@ -3222,7 +3221,7 @@ 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();
@@ -3231,7 +3230,7 @@ static int uprobe_prog_run(struct bpf_uprobe *uprobe,
                rcu_read_unlock_trace();
        else
                rcu_read_unlock();
-       return err;
+       return 0;
 }
 
 static bool
-- 
2.46.2