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.

[akpm@linux-foundation.org: coding-style cleanups]
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>

diff --git a/lib/sys_info.c b/lib/sys_info.c
index 94526de8482b761df901f71922aa650d96e05f20..323624093e547a88f9c850f3d3fd62830b780d10 100644 (file)
--- a/lib/sys_info.c
+++ b/lib/sys_info.c
@@ -43,18 +43,56 @@ unsigned long sys_info_parse_param(char *str)
 
 #ifdef CONFIG_SYSCTL
 
+static int sys_info_write_handler(const 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(const 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 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)) {
-                       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