[PATCH 1/1] lib/alloc_tag: do not register sysctl interface when CONFIG_SYSCTL=n

[Suren Baghdasaryan]

Memory allocation profiling is trying to register sysctl interface even
when CONFIG_SYSCTL=n, resulting in proc_do_static_key() being undefined.
Prevent that by skipping sysctl registration for such configurations.

Fixes: 22d407b164ff ("lib: add allocation tagging support for memory allocation profiling")
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202405280616.wcOGWJEj-lkp@xxxxxxxxx/
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
---
 lib/alloc_tag.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
index 11ed973ac359..c347b8b72d78 100644
--- a/lib/alloc_tag.c
+++ b/lib/alloc_tag.c
@@ -227,6 +227,7 @@ struct page_ext_operations page_alloc_tagging_ops = {
 };
 EXPORT_SYMBOL(page_alloc_tagging_ops);
 
+#ifdef CONFIG_SYSCTL
 static struct ctl_table memory_allocation_profiling_sysctls[] = {
 	{
 		.procname	= "mem_profiling",
@@ -241,6 +242,17 @@ static struct ctl_table memory_allocation_profiling_sysctls[] = {
 	{ }
 };
 
+static void __init sysctl_init(void)
+{
+	if (!mem_profiling_support)
+		memory_allocation_profiling_sysctls[0].mode = 0444;
+
+	register_sysctl_init("vm", memory_allocation_profiling_sysctls);
+}
+#else /* CONFIG_SYSCTL */
+static inline void sysctl_init(void) {}
+#endif /* CONFIG_SYSCTL */
+
 static int __init alloc_tag_init(void)
 {
 	const struct codetag_type_desc desc = {
@@ -253,9 +265,7 @@ static int __init alloc_tag_init(void)
 	if (IS_ERR(alloc_tag_cttype))
 		return PTR_ERR(alloc_tag_cttype);
 
-	if (!mem_profiling_support)
-		memory_allocation_profiling_sysctls[0].mode = 0444;
-	register_sysctl_init("vm", memory_allocation_profiling_sysctls);
+	sysctl_init();
 	procfs_init();
 
 	return 0;

base-commit: 065d3634d60843b8e338d405b844cc7f2e5e1c66
-- 
2.45.1.288.g0e0cd299f1-goog