From: Hui Zhu <[email protected]>

bpf_trampoline_multi_detach() always returns 0 and the sole caller
ignores the return value.  Change it to return void and drop the
WARN_ON_ONCE at the call site.

Signed-off-by: Hui Zhu <[email protected]>
---
 include/linux/bpf.h      | 9 ++++-----
 kernel/bpf/trampoline.c  | 4 ++--
 kernel/trace/bpf_trace.c | 2 +-
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 73bacfc6444d..3255c6f5ea6b 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1518,8 +1518,8 @@ int arch_prepare_bpf_dispatcher(void *image, void *buf, 
s64 *funcs, int num_func
 
 int bpf_trampoline_multi_attach(struct bpf_prog *prog, u32 *ids,
                                struct bpf_tracing_multi_link *link);
-int bpf_trampoline_multi_detach(struct bpf_prog *prog,
-                               struct bpf_tracing_multi_link *link);
+void bpf_trampoline_multi_detach(struct bpf_prog *prog,
+                                struct bpf_tracing_multi_link *link);
 void bpf_trampoline_set_flags(struct bpf_trampoline *tr, u32 flags);
 
 /*
@@ -1639,10 +1639,9 @@ static inline int bpf_trampoline_multi_attach(struct 
bpf_prog *prog, u32 *ids,
 {
        return -ENOTSUPP;
 }
-static inline int bpf_trampoline_multi_detach(struct bpf_prog *prog,
-                                             struct bpf_tracing_multi_link 
*link)
+static inline void bpf_trampoline_multi_detach(struct bpf_prog *prog,
+                                              struct bpf_tracing_multi_link 
*link)
 {
-       return -ENOTSUPP;
 }
 static inline void bpf_trampoline_set_flags(struct bpf_trampoline *tr, u32 
flags) {}
 #endif
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index ea4d3c62f289..e30425789487 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -1729,7 +1729,8 @@ int bpf_trampoline_multi_attach(struct bpf_prog *prog, 
u32 *ids,
        return err;
 }
 
-int bpf_trampoline_multi_detach(struct bpf_prog *prog, struct 
bpf_tracing_multi_link *link)
+void bpf_trampoline_multi_detach(struct bpf_prog *prog,
+                                struct bpf_tracing_multi_link *link)
 {
        struct bpf_tracing_multi_data *data = &link->data;
        struct bpf_tracing_multi_node *mnode;
@@ -1759,7 +1760,6 @@ int bpf_trampoline_multi_detach(struct bpf_prog *prog, 
struct bpf_tracing_multi_
                bpf_trampoline_put(mnode->trampoline);
 
        clear_tracing_multi_data(data);
-       return 0;
 }
 
 #undef for_each_mnode_cnt
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 891897f8a1b3..29260951aa87 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -3687,7 +3687,7 @@ static void bpf_tracing_multi_link_release(struct 
bpf_link *link)
        struct bpf_tracing_multi_link *tr_link =
                container_of(link, struct bpf_tracing_multi_link, link);
 
-       WARN_ON_ONCE(bpf_trampoline_multi_detach(link->prog, tr_link));
+       bpf_trampoline_multi_detach(link->prog, tr_link);
 }
 
 static void bpf_tracing_multi_link_dealloc(struct bpf_link *link)
-- 
2.53.0


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