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authorFeng Tang <feng.tang@intel.com>2019-01-03 15:28:17 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-01-04 13:13:47 -0800
commitd999bd9392dea7c1a9ac43b8680b22c4425ae4c7 (patch)
tree55636facade107a4c2205b4c59cf769a1e9ef9bc
parentd1877155891020cb26ad4fba45bfee52d8da9951 (diff)
downloadlinux-d999bd9392dea7c1a9ac43b8680b22c4425ae4c7.tar.bz2
panic: add options to print system info when panic happens
Kernel panic issues are always painful to debug, partially because it's not easy to get enough information of the context when panic happens. And we have ramoops and kdump for that, while this commit tries to provide a easier way to show the system info by adding a cmdline parameter, referring some idea from sysrq handler. Link: http://lkml.kernel.org/r/1543398842-19295-2-git-send-email-feng.tang@intel.com Signed-off-by: Feng Tang <feng.tang@intel.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt8
-rw-r--r--kernel/panic.c28
2 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 408781ee142c..e7b5c49702bb 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3092,6 +3092,14 @@
timeout < 0: reboot immediately
Format: <timeout>
+ panic_print= Bitmask for printing system info when panic happens.
+ User can chose combination of the following bits:
+ bit 0: print all tasks info
+ bit 1: print system memory info
+ bit 2: print timer info
+ bit 3: print locks info if CONFIG_LOCKDEP is on
+ bit 4: print ftrace buffer
+
panic_on_warn panic() instead of WARN(). Useful to cause kdump
on a WARN().
diff --git a/kernel/panic.c b/kernel/panic.c
index d10c340c43b0..855f66738bc7 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -46,6 +46,13 @@ int panic_on_warn __read_mostly;
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
+static unsigned long panic_print;
+
ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
EXPORT_SYMBOL(panic_notifier_list);
@@ -125,6 +132,24 @@ void nmi_panic(struct pt_regs *regs, const char *msg)
}
EXPORT_SYMBOL(nmi_panic);
+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(0, NULL);
+
+ 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);
+}
+
/**
* panic - halt the system
* @fmt: The text string to print
@@ -254,6 +279,8 @@ void panic(const char *fmt, ...)
debug_locks_off();
console_flush_on_panic();
+ panic_print_sys_info();
+
if (!panic_blink)
panic_blink = no_blink;
@@ -658,6 +685,7 @@ void refcount_error_report(struct pt_regs *regs, const char *err)
#endif
core_param(panic, panic_timeout, int, 0644);
+core_param(panic_print, panic_print, ulong, 0644);
core_param(pause_on_oops, pause_on_oops, int, 0644);
core_param(panic_on_warn, panic_on_warn, int, 0644);
core_param(crash_kexec_post_notifiers, crash_kexec_post_notifiers, bool, 0644);