Subject: [PATCH 09/13] firmware_loader: simplify sysctl declaration with register_sysctl_subdir()

From: Luis Chamberlain <[email-masked]>
Date: Fri, 29 May 2020 07:41:04 +0000

From: Xiaoming Ni <[email-masked]>

Move the firmware config sysctl table to fallback_table.c and use the
new register_sysctl_subdir() helper. This removes the clutter from
kernel/sysctl.c.

Signed-off-by: Xiaoming Ni <[email-masked]>
Signed-off-by: Luis Chamberlain <[email-masked]>
---
 drivers/base/firmware_loader/fallback.c       |  4 ++++
 drivers/base/firmware_loader/fallback.h       | 11 ++++++++++
 drivers/base/firmware_loader/fallback_table.c | 22 +++++++++++++++++--
 include/linux/sysctl.h                        |  1 -
 kernel/sysctl.c                               |  7 ------
 5 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index d9ac7296205e..8190653ae9a3 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -200,12 +200,16 @@ static struct class firmware_class = {
 
 int register_sysfs_loader(void)
 {
+	int ret = register_firmware_config_sysctl();
+	if (ret != 0)
+		return ret;
 	return class_register(&firmware_class);
 }
 
 void unregister_sysfs_loader(void)
 {
 	class_unregister(&firmware_class);
+	unregister_firmware_config_sysctl();
 }
 
 static ssize_t firmware_loading_show(struct device *dev,
diff --git a/drivers/base/firmware_loader/fallback.h b/drivers/base/firmware_loader/fallback.h
index 06f4577733a8..7d2cb5f6ceb8 100644
--- a/drivers/base/firmware_loader/fallback.h
+++ b/drivers/base/firmware_loader/fallback.h
@@ -42,6 +42,17 @@ void fw_fallback_set_default_timeout(void);
 
 int register_sysfs_loader(void);
 void unregister_sysfs_loader(void);
+#ifdef CONFIG_SYSCTL
+extern int register_firmware_config_sysctl(void);
+extern void unregister_firmware_config_sysctl(void);
+#else
+static inline int register_firmware_config_sysctl(void)
+{
+	return 0;
+}
+static inline void unregister_firmware_config_sysctl(void) { }
+#endif /* CONFIG_SYSCTL */
+
 #else /* CONFIG_FW_LOADER_USER_HELPER */
 static inline int firmware_fallback_sysfs(struct firmware *fw, const char *name,
 					  struct device *device,
diff --git a/drivers/base/firmware_loader/fallback_table.c b/drivers/base/firmware_loader/fallback_table.c
index 46a731dede6f..4234aa5ee5df 100644
--- a/drivers/base/firmware_loader/fallback_table.c
+++ b/drivers/base/firmware_loader/fallback_table.c
@@ -24,7 +24,7 @@ struct firmware_fallback_config fw_fallback_config = {
 EXPORT_SYMBOL_NS_GPL(fw_fallback_config, FIRMWARE_LOADER_PRIVATE);
 
 #ifdef CONFIG_SYSCTL
-struct ctl_table firmware_config_table[] = {
+static struct ctl_table firmware_config_table[] = {
 	{
 		.procname	= "force_sysfs_fallback",
 		.data		= &fw_fallback_config.force_sysfs_fallback,
@@ -45,4 +45,22 @@ struct ctl_table firmware_config_table[] = {
 	},
 	{ }
 };
-#endif
+
+static struct ctl_table_header *hdr;
+int register_firmware_config_sysctl(void)
+{
+	if (hdr)
+		return -EEXIST;
+	hdr = register_sysctl_subdir("kernel", "firmware_config",
+				     firmware_config_table);
+	if (!hdr)
+		return -ENOMEM;
+	return 0;
+}
+
+void unregister_firmware_config_sysctl(void)
+{
+	if (hdr)
+		unregister_sysctl_table(hdr);
+}
+#endif /* CONFIG_SYSCTL */
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 58bc978d4f03..aa01f54d0442 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -217,7 +217,6 @@ extern int no_unaligned_warning;
 
 extern struct ctl_table sysctl_mount_point[];
 extern struct ctl_table random_table[];
-extern struct ctl_table firmware_config_table[];
 extern struct ctl_table epoll_table[];
 
 #else /* CONFIG_SYSCTL */
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 30c2d521502a..e007375c8a11 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2088,13 +2088,6 @@ static struct ctl_table kern_table[] = {
 		.mode		= 0555,
 		.child		= usermodehelper_table,
 	},
-#ifdef CONFIG_FW_LOADER_USER_HELPER
-	{
-		.procname	= "firmware_config",
-		.mode		= 0555,
-		.child		= firmware_config_table,
-	},
-#endif
 	{
 		.procname	= "overflowuid",
 		.data		= &overflowuid,
-- 
2.26.2