panic: generalize panic_print's function to show sys info

'panic_print' was introduced to help debugging kernel panic by dumping
different kinds of system information like tasks' call stack, memory,
ftrace buffer, etc.  Actually this function could also be used to help
debugging other cases like task-hung, soft/hard lockup, etc.  where user
may need the snapshot of system info at that time.

Extract system info dump function related code from panic.c to separate
file sys_info.[ch], for wider usage by other kernel parts for debugging.

Also modify the macro names about singulars/plurals.

Link: https://lkml.kernel.org/r/20250703021004.42328-3-feng.tang@linux.alibaba.com
Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com>
Suggested-by: Petr Mladek <pmladek@suse.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 32 insertions, 0 deletions

diff --git a/lib/sys_info.c b/lib/sys_info.c
new file mode 100644
index 000000000000..53031e5cb98e
--- /dev/null
+++ b/lib/sys_info.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/sched/debug.h>
+#include <linux/console.h>
+#include <linux/kernel.h>
+#include <linux/ftrace.h>
+#include <linux/nmi.h>
+
+#include <linux/sys_info.h>
+
+void sys_info(unsigned long si_mask)
+{
+	if (si_mask & SYS_INFO_TASKS)
+		show_state();
+
+	if (si_mask & SYS_INFO_MEM)
+		show_mem();
+
+	if (si_mask & SYS_INFO_TIMERS)
+		sysrq_timer_list_show();
+
+	if (si_mask & SYS_INFO_LOCKS)
+		debug_show_all_locks();
+
+	if (si_mask & SYS_INFO_FTRACE)
+		ftrace_dump(DUMP_ALL);
+
+	if (si_mask & SYS_INFO_ALL_CPU_BT)
+		trigger_all_cpu_backtrace();
+
+	if (si_mask & SYS_INFO_BLOCKED_TASKS)
+		show_state_filter(TASK_UNINTERRUPTIBLE);
+}