+ panic-sys_info-factor-out-read-and-write-handlers.patch added to mm-nonmm-unstable branch

+ panic-sys_info-factor-out-read-and-write-handlers.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: panic: sys_info: factor out read and write handlers
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     panic-sys_info-factor-out-read-and-write-handlers.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/panic-sys_info-factor-out-read-and-write-handlers.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: panic: sys_info: factor out read and write handlers
Date: Thu, 30 Oct 2025 12:44:22 +0100

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

Link: https://lkml.kernel.org/r/20251030132007.3742368-7-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Feng Tang <feng.tang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/sys_info.c |   79 +++++++++++++++++++++++++++--------------------
 1 file changed, 46 insertions(+), 33 deletions(-)

--- a/lib/sys_info.c~panic-sys_info-factor-out-read-and-write-handlers
+++ a/lib/sys_info.c
@@ -43,18 +43,56 @@ unsigned long sys_info_parse_param(char
 
 #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)) {
+		if (*si_names[i]) {
+			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;
 
-	si_bits_global = ro_table->data;
-
 	maxlen = 0;
 	for (i = 0; i < ARRAY_SIZE(si_names); i++)
 		maxlen += strlen(si_names[i]) + 1;
@@ -67,35 +105,10 @@ int sysctl_sys_info_handler(const struct
 	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)) {
-			if (*si_names[i]) {
-				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, ro_table->data);
+	else
+		return sys_info_read_handler(&table, buffer, lenp, ppos, ro_table->data);
 }
 #endif
 
_

Patches currently in -mm which might be from andriy.shevchenko@linux.intel.com are

panic-sys_info-capture-si_bits_global-before-iterating-over-it.patch
panic-sys_info-align-constant-definition-names-with-parameters.patch
panic-sys_info-replace-struct-sys_info_name-with-plain-array-of-strings.patch
panic-sys_info-rewrite-a-fix-for-a-compilation-error-make-w=1.patch
panic-sys_info-deduplicate-local-variable-table-assignments.patch
panic-sys_info-factor-out-read-and-write-handlers.patch