panic: add an option to replay all the printk message in buffer
Currently on panic, kernel will lower the loglevel and print out pending printk msg only with console_flush_on_panic(). Add an option for users to configure the "panic_print" to replay all dmesg in buffer, some of which they may have never seen due to the loglevel setting, which will help panic debugging . [feng.tang@intel.com: keep the original console_flush_on_panic() inside panic()] Link: http://lkml.kernel.org/r/1556199137-14163-1-git-send-email-feng.tang@intel.com [feng.tang@intel.com: use logbuf lock to protect the console log index] Link: http://lkml.kernel.org/r/1556269868-22654-1-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1556095872-36838-1-git-send-email-feng.tang@intel.com Signed-off-by: Feng Tang <feng.tang@intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Aaro Koskinen <aaro.koskinen@nokia.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
5d59aa8f9c
commit
de6da1e8bc
|
@ -3212,6 +3212,7 @@
|
|||
bit 2: print timer info
|
||||
bit 3: print locks info if CONFIG_LOCKDEP is on
|
||||
bit 4: print ftrace buffer
|
||||
bit 5: print all printk messages in buffer
|
||||
|
||||
panic_on_warn panic() instead of WARN(). Useful to cause kdump
|
||||
on a WARN().
|
||||
|
|
|
@ -179,7 +179,7 @@ extern void panic_flush_kmsg_end(void)
|
|||
kmsg_dump(KMSG_DUMP_PANIC);
|
||||
bust_spinlocks(0);
|
||||
debug_locks_off();
|
||||
console_flush_on_panic();
|
||||
console_flush_on_panic(CONSOLE_FLUSH_PENDING);
|
||||
}
|
||||
|
||||
static unsigned long oops_begin(struct pt_regs *regs)
|
||||
|
|
|
@ -166,6 +166,11 @@ struct console {
|
|||
extern int console_set_on_cmdline;
|
||||
extern struct console *early_console;
|
||||
|
||||
enum con_flush_mode {
|
||||
CONSOLE_FLUSH_PENDING,
|
||||
CONSOLE_REPLAY_ALL,
|
||||
};
|
||||
|
||||
extern int add_preferred_console(char *name, int idx, char *options);
|
||||
extern void register_console(struct console *);
|
||||
extern int unregister_console(struct console *);
|
||||
|
@ -175,7 +180,7 @@ extern int console_trylock(void);
|
|||
extern void console_unlock(void);
|
||||
extern void console_conditional_schedule(void);
|
||||
extern void console_unblank(void);
|
||||
extern void console_flush_on_panic(void);
|
||||
extern void console_flush_on_panic(enum con_flush_mode mode);
|
||||
extern struct tty_driver *console_device(int *);
|
||||
extern void console_stop(struct console *);
|
||||
extern void console_start(struct console *);
|
||||
|
|
|
@ -51,6 +51,7 @@ EXPORT_SYMBOL_GPL(panic_timeout);
|
|||
#define PANIC_PRINT_TIMER_INFO 0x00000004
|
||||
#define PANIC_PRINT_LOCK_INFO 0x00000008
|
||||
#define PANIC_PRINT_FTRACE_INFO 0x00000010
|
||||
#define PANIC_PRINT_ALL_PRINTK_MSG 0x00000020
|
||||
unsigned long panic_print;
|
||||
|
||||
ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
|
||||
|
@ -134,6 +135,9 @@ EXPORT_SYMBOL(nmi_panic);
|
|||
|
||||
static void panic_print_sys_info(void)
|
||||
{
|
||||
if (panic_print & PANIC_PRINT_ALL_PRINTK_MSG)
|
||||
console_flush_on_panic(CONSOLE_REPLAY_ALL);
|
||||
|
||||
if (panic_print & PANIC_PRINT_TASK_INFO)
|
||||
show_state();
|
||||
|
||||
|
@ -277,7 +281,7 @@ void panic(const char *fmt, ...)
|
|||
* panic() is not being callled from OOPS.
|
||||
*/
|
||||
debug_locks_off();
|
||||
console_flush_on_panic();
|
||||
console_flush_on_panic(CONSOLE_FLUSH_PENDING);
|
||||
|
||||
panic_print_sys_info();
|
||||
|
||||
|
|
|
@ -2535,10 +2535,11 @@ void console_unblank(void)
|
|||
|
||||
/**
|
||||
* console_flush_on_panic - flush console content on panic
|
||||
* @mode: flush all messages in buffer or just the pending ones
|
||||
*
|
||||
* Immediately output all pending messages no matter what.
|
||||
*/
|
||||
void console_flush_on_panic(void)
|
||||
void console_flush_on_panic(enum con_flush_mode mode)
|
||||
{
|
||||
/*
|
||||
* If someone else is holding the console lock, trylock will fail
|
||||
|
@ -2549,6 +2550,15 @@ void console_flush_on_panic(void)
|
|||
*/
|
||||
console_trylock();
|
||||
console_may_schedule = 0;
|
||||
|
||||
if (mode == CONSOLE_REPLAY_ALL) {
|
||||
unsigned long flags;
|
||||
|
||||
logbuf_lock_irqsave(flags);
|
||||
console_seq = log_first_seq;
|
||||
console_idx = log_first_idx;
|
||||
logbuf_unlock_irqrestore(flags);
|
||||
}
|
||||
console_unlock();
|
||||
}
|
||||
|
||||
|
|
Loading…
Reference in a new issue