linux-kernel - [PATCH v2 6/6] panic: sys_info: Factor out read and write handlers

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Message-ID: <20251029111202.3217870-8-andriy.shevchenko@linux.intel.com>
Date: Wed, 29 Oct 2025 12:07:41 +0100
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Feng Tang <feng.tang@...ux.alibaba.com>,
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	linux-kernel@...r.kernel.org
Cc: Andrew Morton <akpm@...ux-foundation.org>,
	Petr Mladek <pmladek@...e.com>
Subject: [PATCH v2 6/6] panic: sys_info: Factor out read and write handlers

For the sake of the code readability and easier maintenance
factor out read and write sys_info handlers.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
 lib/sys_info.c | 72 ++++++++++++++++++++++++++++++--------------------
 1 file changed, 44 insertions(+), 28 deletions(-)

diff --git a/lib/sys_info.c b/lib/sys_info.c
index c86f52644857..8ed3b4b55854 100644
--- a/lib/sys_info.c
+++ b/lib/sys_info.c
@@ -43,13 +43,52 @@ unsigned long sys_info_parse_param(char *str)
 
 #ifdef CONFIG_SYSCTL
 
+static int sys_info_write_handler(struct ctl_table *table,
+				  void *buffer, size_t *lenp, loff_t *ppos,
+				  unsigned long *si_bits_global)
+{
+	unsigned long si_bits;
+	int ret;
+
+	ret = proc_dostring(table, 1, buffer, lenp, ppos);
+	if (ret)
+		return ret;
+
+	si_bits = sys_info_parse_param(table->data);
+
+	/* The access to the global value is not synchronized. */
+	WRITE_ONCE(*si_bits_global, si_bits);
+
+	return 0;
+}
+
+static int sys_info_read_handler(struct ctl_table *table,
+				 void *buffer, size_t *lenp, loff_t *ppos,
+				 unsigned long *si_bits_global)
+{
+	unsigned long si_bits;
+	unsigned int len = 0;
+	char *delim = "";
+	unsigned int i;
+
+	/* The access to the global value is not synchronized. */
+	si_bits = READ_ONCE(*si_bits_global);
+
+	for_each_set_bit(i, &si_bits, ARRAY_SIZE(si_names)) {
+		len += scnprintf(table->data + len, table->maxlen - len,
+				 "%s%s", delim, si_names[i]);
+		delim = ",";
+	}
+
+	return proc_dostring(table, 0, buffer, lenp, ppos);
+}
+
 int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write,
 					  void *buffer, size_t *lenp,
 					  loff_t *ppos)
 {
 	struct ctl_table table;
 	unsigned long *si_bits_global;
-	unsigned long si_bits;
 	unsigned int i;
 	size_t maxlen;
 
@@ -67,33 +106,10 @@ int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write,
 	table.data = names;
 	table.maxlen = maxlen;
 
-	if (write) {
-		int ret;
-
-		ret = proc_dostring(&table, write, buffer, lenp, ppos);
-		if (ret)
-			return ret;
-
-		si_bits = sys_info_parse_param(names);
-		/* The access to the global value is not synchronized. */
-		WRITE_ONCE(*si_bits_global, si_bits);
-		return 0;
-	} else {
-		/* for 'read' operation */
-		unsigned int len = 0;
-		char *delim = "";
-
-		/* The access to the global value is not synchronized. */
-		si_bits = READ_ONCE(*si_bits_global);
-
-		for_each_set_bit(i, &si_bits, ARRAY_SIZE(si_names)) {
-			len += scnprintf(names + len, maxlen - len,
-					 "%s%s", delim, si_names[i]);
-			delim = ",";
-		}
-
-		return proc_dostring(&table, write, buffer, lenp, ppos);
-	}
+	if (write)
+		return sys_info_write_handler(&table, buffer, lenp, ppos, si_bits_global);
+	else
+		return sys_info_read_handler(&table, buffer, lenp, ppos, si_bits_global);
 }
 #endif
 
-- 
2.50.1