[PATCH 3/4] btf: Switch vmlinux BTF attribute to sysfs_bin_attr_simple_read()

["Thomas Weißschuh" <linux@weissschuh.net>]

The generic function from the sysfs core can replace the custom one.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

---
This is a replacement for [0], as Alexei was not happy about BIN_ATTR_SIMPLE_RO()

[0] https://lore.kernel.org/lkml/20241122-sysfs-const-bin_attr-bpf-v1-1-823aea399b53@weissschuh.net/
---
 kernel/bpf/sysfs_btf.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/kernel/bpf/sysfs_btf.c b/kernel/bpf/sysfs_btf.c
index fedb54c94cdb830a4890d33677dcc5a6e236c13f..81d6cf90584a7157929c50f62a5c6862e7a3d081 100644
--- a/kernel/bpf/sysfs_btf.c
+++ b/kernel/bpf/sysfs_btf.c
@@ -12,24 +12,16 @@
 extern char __start_BTF[];
 extern char __stop_BTF[];
 
-static ssize_t
-btf_vmlinux_read(struct file *file, struct kobject *kobj,
-		 struct bin_attribute *bin_attr,
-		 char *buf, loff_t off, size_t len)
-{
-	memcpy(buf, __start_BTF + off, len);
-	return len;
-}
-
 static struct bin_attribute bin_attr_btf_vmlinux __ro_after_init = {
 	.attr = { .name = "vmlinux", .mode = 0444, },
-	.read = btf_vmlinux_read,
+	.read_new = sysfs_bin_attr_simple_read,
 };
 
 struct kobject *btf_kobj;
 
 static int __init btf_vmlinux_init(void)
 {
+	bin_attr_btf_vmlinux.private = __start_BTF;
 	bin_attr_btf_vmlinux.size = __stop_BTF - __start_BTF;
 
 	if (bin_attr_btf_vmlinux.size == 0)

-- 
2.47.1