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>

diff --git a/include/linux/sys_info.h b/include/linux/sys_info.h
new file mode 100644 (file)
index 0000000..53b7e27
--- /dev/null
+++ b/include/linux/sys_info.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_SYS_INFO_H
+#define _LINUX_SYS_INFO_H
+
+/*
+ * SYS_INFO_PANIC_CONSOLE_REPLAY is for panic case only, as it needs special
+ * handling which only fits panic case.
+ */
+#define SYS_INFO_TASKS                 0x00000001
+#define SYS_INFO_MEM                   0x00000002
+#define SYS_INFO_TIMERS                        0x00000004
+#define SYS_INFO_LOCKS                 0x00000008
+#define SYS_INFO_FTRACE                        0x00000010
+#define SYS_INFO_PANIC_CONSOLE_REPLAY  0x00000020
+#define SYS_INFO_ALL_CPU_BT            0x00000040
+#define SYS_INFO_BLOCKED_TASKS         0x00000080
+
+void sys_info(unsigned long si_mask);
+
+#endif /* _LINUX_SYS_INFO_H */

diff --git a/kernel/panic.c b/kernel/panic.c
index 9b6c5dc28a653d3750fe314d78a7c3db153a1b47..cbb0681177b345b727b0c1c46ce675e77dfac634 100644 (file)
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -36,6 +36,7 @@
 #include <linux/sysfs.h>
 #include <linux/context_tracking.h>
 #include <linux/seq_buf.h>
+#include <linux/sys_info.h>
 #include <trace/events/error_report.h>
 #include <asm/sections.h>
 
@@ -69,14 +70,6 @@ bool panic_triggering_all_cpu_backtrace;
 int panic_timeout = CONFIG_PANIC_TIMEOUT;
 EXPORT_SYMBOL_GPL(panic_timeout);
 
-#define PANIC_PRINT_TASK_INFO          0x00000001
-#define PANIC_PRINT_MEM_INFO           0x00000002
-#define PANIC_PRINT_TIMER_INFO         0x00000004
-#define PANIC_PRINT_LOCK_INFO          0x00000008
-#define PANIC_PRINT_FTRACE_INFO                0x00000010
-#define PANIC_CONSOLE_REPLAY           0x00000020
-#define PANIC_PRINT_ALL_CPU_BT         0x00000040
-#define PANIC_PRINT_BLOCKED_TASKS      0x00000080
 unsigned long panic_print;
 
 ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
@@ -240,31 +233,10 @@ EXPORT_SYMBOL(nmi_panic);
 
 static void panic_console_replay(void)
 {
-       if (panic_print & PANIC_CONSOLE_REPLAY)
+       if (panic_print & SYS_INFO_PANIC_CONSOLE_REPLAY)
                console_flush_on_panic(CONSOLE_REPLAY_ALL);
 }
 
-static void panic_print_sys_info(void)
-{
-       if (panic_print & PANIC_PRINT_TASK_INFO)
-               show_state();
-
-       if (panic_print & PANIC_PRINT_MEM_INFO)
-               show_mem();
-
-       if (panic_print & PANIC_PRINT_TIMER_INFO)
-               sysrq_timer_list_show();
-
-       if (panic_print & PANIC_PRINT_LOCK_INFO)
-               debug_show_all_locks();
-
-       if (panic_print & PANIC_PRINT_FTRACE_INFO)
-               ftrace_dump(DUMP_ALL);
-
-       if (panic_print & PANIC_PRINT_BLOCKED_TASKS)
-               show_state_filter(TASK_UNINTERRUPTIBLE);
-}
-
 void check_panic_on_warn(const char *origin)
 {
        unsigned int limit;
@@ -285,7 +257,7 @@ void check_panic_on_warn(const char *origin)
  */
 static void panic_other_cpus_shutdown(bool crash_kexec)
 {
-       if (panic_print & PANIC_PRINT_ALL_CPU_BT) {
+       if (panic_print & SYS_INFO_ALL_CPU_BT) {
                /* Temporary allow non-panic CPUs to write their backtraces. */
                panic_triggering_all_cpu_backtrace = true;
                trigger_all_cpu_backtrace();
@@ -410,7 +382,7 @@ void panic(const char *fmt, ...)
         */
        atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
 
-       panic_print_sys_info();
+       sys_info(panic_print);
 
        kmsg_dump_desc(KMSG_DUMP_PANIC, buf);
 

diff --git a/lib/Makefile b/lib/Makefile
index c38582f187dd81916113319072e5cfef26f26c84..88d6228089a8b0049b3541d7167a26f8cc70d36c 100644 (file)
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -40,7 +40,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
         is_single_threaded.o plist.o decompress.o kobject_uevent.o \
         earlycpio.o seq_buf.o siphash.o dec_and_lock.o \
         nmi_backtrace.o win_minmax.o memcat_p.o \
-        buildid.o objpool.o iomem_copy.o
+        buildid.o objpool.o iomem_copy.o sys_info.o
 
 lib-$(CONFIG_UNION_FIND) += union_find.o
 lib-$(CONFIG_PRINTK) += dump_stack.o

diff --git a/lib/sys_info.c b/lib/sys_info.c
new file mode 100644 (file)
index 0000000..53031e5
--- /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);
+}