panic: sys_info:replace struct sys_info_name with plain array of strings

There is no need to keep a custom structure just for the need of a plain
array of strings.  Replace struct sys_info_name with plain array of
strings.

With that done, simplify the code, in particular, naturally use
for_each_set_bit() when iterating over si_bits_global bitmap.

Link: https://lkml.kernel.org/r/20251030132007.3742368-4-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 6b0188b30227f7b8a267ac48fea1b1ebbe9d009a..29a63238b31d2b0781c7cec5dfc6d4d18abe8bdd 100644 (file)
--- a/lib/sys_info.c
+++ b/lib/sys_info.c
@@ -1,30 +1,29 @@
 // SPDX-License-Identifier: GPL-2.0-only
-#include <linux/sched/debug.h>
+#include <linux/bitops.h>
 #include <linux/console.h>
+#include <linux/log2.h>
 #include <linux/kernel.h>
 #include <linux/ftrace.h>
-#include <linux/sysctl.h>
 #include <linux/nmi.h>
+#include <linux/sched/debug.h>
+#include <linux/string.h>
+#include <linux/sysctl.h>
 
 #include <linux/sys_info.h>
 
-struct sys_info_name {
-       unsigned long bit;
-       const char *name;
-};
-
 /*
  * When 'si_names' gets updated,  please make sure the 'sys_info_avail'
  * below is updated accordingly.
  */
-static const struct sys_info_name  si_names[] = {
-       { SYS_INFO_TASKS,               "tasks" },
-       { SYS_INFO_MEM,                 "mem" },
-       { SYS_INFO_TIMERS,              "timers" },
-       { SYS_INFO_LOCKS,               "locks" },
-       { SYS_INFO_FTRACE,              "ftrace" },
-       { SYS_INFO_ALL_BT,              "all_bt" },
-       { SYS_INFO_BLOCKED_TASKS,       "blocked_tasks" },
+static const char * const si_names[] = {
+       [ilog2(SYS_INFO_TASKS)]                 = "tasks",
+       [ilog2(SYS_INFO_MEM)]                   = "mem",
+       [ilog2(SYS_INFO_TIMERS)]                = "timers",
+       [ilog2(SYS_INFO_LOCKS)]                 = "locks",
+       [ilog2(SYS_INFO_FTRACE)]                = "ftrace",
+       [ilog2(SYS_INFO_PANIC_CONSOLE_REPLAY)]  = "",
+       [ilog2(SYS_INFO_ALL_BT)]                = "all_bt",
+       [ilog2(SYS_INFO_BLOCKED_TASKS)]         = "blocked_tasks",
 };
 
 /* Expecting string like "xxx_sys_info=tasks,mem,timers,locks,ftrace,..." */
@@ -36,12 +35,9 @@ unsigned long sys_info_parse_param(char *str)
 
        s = str;
        while ((name = strsep(&s, ",")) && *name) {
-               for (i = 0; i < ARRAY_SIZE(si_names); i++) {
-                       if (!strcmp(name, si_names[i].name)) {
-                               si_bits |= si_names[i].bit;
-                               break;
-                       }
-               }
+               i = match_string(si_names, ARRAY_SIZE(si_names), name);
+               if (i >= 0)
+                       __set_bit(i, &si_bits);
        }
 
        return si_bits;
@@ -85,10 +81,10 @@ int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write,
                si_bits = READ_ONCE(*si_bits_global);
 
                names[0] = '\0';
-               for (i = 0; i < ARRAY_SIZE(si_names); i++) {
-                       if (si_bits & si_names[i].bit) {
+               for_each_set_bit(i, &si_bits, ARRAY_SIZE(si_names)) {
+                       if (*si_names[i]) {
                                len += scnprintf(names + len, sizeof(names) - len,
-                                       "%s%s", delim, si_names[i].name);
+                                                "%s%s", delim, si_names[i]);
                                delim = ",";
                        }
                }