[PATCH v3 bpf-next 5/8] printk: initialize vmlinux BTF outside of printk in late_initcall()

[Alan Maguire <alan.maguire@xxxxxxxxxx>]

vmlinux BTF initialization can take time so it's best to do that
outside of printk context; otherwise the first printk() using %pT
will trigger BTF initialization.

Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
---
 lib/vsprintf.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index c0d209d..8ac136a 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -3628,3 +3628,15 @@ int sscanf(const char *buf, const char *fmt, ...)
 	return i;
 }
 EXPORT_SYMBOL(sscanf);
+
+/*
+ * Initialize vmlinux BTF as it may be used by printk()s and it's better
+ * to incur the cost of initialization outside of printk context.
+ */
+static int __init init_btf_vmlinux(void)
+{
+	(void) bpf_get_btf_vmlinux();
+
+	return 0;
+}
+late_initcall(init_btf_vmlinux);
-- 
1.8.3.1