[PATCH bpf-next 02/13] bpf: Factor out update_fentry_multi helper

[Leon Hwang]

The tracing_multi register, unregister, and modify callbacks differ only
in the trampoline image and ftrace hash they use. Move their common
address setup, hash insertion, and current image update into
update_fentry_multi().

No functional changes intended.

Signed-off-by: Leon Hwang <leon.hw...@linux.dev>
---
 kernel/bpf/trampoline.c | 34 ++++++++++++++--------------------
 1 file changed, 14 insertions(+), 20 deletions(-)

diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index 8c2c1d1b9094..6e1898e1b200 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -1568,47 +1568,41 @@ static void ftrace_hash_add(struct ftrace_hash *hash, 
struct ftrace_func_entry *
        add_ftrace_hash_entry(hash, entry);
 }
 
-static int register_fentry_multi(struct bpf_trampoline *tr, struct 
bpf_tramp_image *im, void *ptr)
+static int update_fentry_multi(struct bpf_trampoline *tr, u32 orig_flags,
+                              struct bpf_tramp_image *im, struct ftrace_hash 
*hash,
+                              struct bpf_tracing_multi_data *data)
 {
-       unsigned long addr = (unsigned long) im->image;
+       unsigned long addr = (unsigned long)(im ? im->image : 
tr->cur_image->image);
        unsigned long ip = ftrace_location(tr->ip);
-       struct bpf_tracing_multi_data *data = ptr;
 
        if (bpf_trampoline_use_jmp(tr->flags))
                addr = ftrace_jmp_set(addr);
 
-       ftrace_hash_add(data->reg, data->entry, ip, addr);
+       ftrace_hash_add(hash, data->entry, ip, addr);
        tr->cur_image = im;
        return 0;
 }
 
-static int unregister_fentry_multi(struct bpf_trampoline *tr, u32 orig_flags, 
void *ptr)
+static int register_fentry_multi(struct bpf_trampoline *tr, struct 
bpf_tramp_image *im, void *ptr)
 {
-       unsigned long addr = (unsigned long) tr->cur_image->image;
-       unsigned long ip = ftrace_location(tr->ip);
        struct bpf_tracing_multi_data *data = ptr;
 
-       if (bpf_trampoline_use_jmp(tr->flags))
-               addr = ftrace_jmp_set(addr);
+       return update_fentry_multi(tr, 0, im, data->reg, data);
+}
 
-       ftrace_hash_add(data->unreg, data->entry, ip, addr);
-       tr->cur_image = NULL;
-       return 0;
+static int unregister_fentry_multi(struct bpf_trampoline *tr, u32 orig_flags, 
void *ptr)
+{
+       struct bpf_tracing_multi_data *data = ptr;
+
+       return update_fentry_multi(tr, orig_flags, NULL, data->unreg, data);
 }
 
 static int modify_fentry_multi(struct bpf_trampoline *tr, u32 orig_flags, 
struct bpf_tramp_image *im,
                               bool lock_direct_mutex, void *ptr)
 {
-       unsigned long addr = (unsigned long) im->image;
-       unsigned long ip = ftrace_location(tr->ip);
        struct bpf_tracing_multi_data *data = ptr;
 
-       if (bpf_trampoline_use_jmp(tr->flags))
-               addr = ftrace_jmp_set(addr);
-
-       ftrace_hash_add(data->modify, data->entry, ip, addr);
-       tr->cur_image = im;
-       return 0;
+       return update_fentry_multi(tr, orig_flags, im, data->modify, data);
 }
 
 static const struct bpf_trampoline_ops trampoline_multi_ops = {
-- 
2.55.0