diff options
Diffstat (limited to 'kernel/printk/printk.c')
| -rw-r--r-- | kernel/printk/printk.c | 55 |
1 files changed, 44 insertions, 11 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 057db78876cd..1eea80d0648e 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2375,6 +2375,22 @@ void printk_legacy_allow_panic_sync(void) } } +bool __read_mostly debug_non_panic_cpus; + +#ifdef CONFIG_PRINTK_CALLER +static int __init debug_non_panic_cpus_setup(char *str) +{ + debug_non_panic_cpus = true; + pr_info("allow messages from non-panic CPUs in panic()\n"); + + return 0; +} +early_param("debug_non_panic_cpus", debug_non_panic_cpus_setup); +module_param(debug_non_panic_cpus, bool, 0644); +MODULE_PARM_DESC(debug_non_panic_cpus, + "allow messages from non-panic CPUs in panic()"); +#endif + asmlinkage int vprintk_emit(int facility, int level, const struct dev_printk_info *dev_info, const char *fmt, va_list args) @@ -2391,7 +2407,9 @@ asmlinkage int vprintk_emit(int facility, int level, * non-panic CPUs are generating any messages, they will be * silently dropped. */ - if (other_cpu_in_panic() && !panic_triggering_all_cpu_backtrace) + if (other_cpu_in_panic() && + !debug_non_panic_cpus && + !panic_triggering_all_cpu_backtrace) return 0; printk_get_console_flush_type(&ft); @@ -2731,11 +2749,11 @@ module_param_named(console_no_auto_verbose, printk_console_no_auto_verbose, bool MODULE_PARM_DESC(console_no_auto_verbose, "Disable console loglevel raise to highest on oops/panic/etc"); /** - * suspend_console - suspend the console subsystem + * console_suspend_all - suspend the console subsystem * * This disables printk() while we go into suspend states */ -void suspend_console(void) +void console_suspend_all(void) { struct console *con; @@ -2758,7 +2776,7 @@ void suspend_console(void) synchronize_srcu(&console_srcu); } -void resume_console(void) +void console_resume_all(void) { struct console_flush_type ft; struct console *con; @@ -3340,7 +3358,12 @@ void console_unblank(void) */ cookie = console_srcu_read_lock(); for_each_console_srcu(c) { - if ((console_srcu_read_flags(c) & CON_ENABLED) && c->unblank) { + short flags = console_srcu_read_flags(c); + + if (flags & CON_SUSPENDED) + continue; + + if ((flags & CON_ENABLED) && c->unblank) { found_unblank = true; break; } @@ -3377,7 +3400,12 @@ void console_unblank(void) cookie = console_srcu_read_lock(); for_each_console_srcu(c) { - if ((console_srcu_read_flags(c) & CON_ENABLED) && c->unblank) + short flags = console_srcu_read_flags(c); + + if (flags & CON_SUSPENDED) + continue; + + if ((flags & CON_ENABLED) && c->unblank) c->unblank(); } console_srcu_read_unlock(cookie); @@ -3495,10 +3523,10 @@ struct tty_driver *console_device(int *index) /* * Prevent further output on the passed console device so that (for example) - * serial drivers can disable console output before suspending a port, and can + * serial drivers can suspend console output before suspending a port, and can * re-enable output afterwards. */ -void console_stop(struct console *console) +void console_suspend(struct console *console) { __pr_flush(console, 1000, true); console_list_lock(); @@ -3513,9 +3541,9 @@ void console_stop(struct console *console) */ synchronize_srcu(&console_srcu); } -EXPORT_SYMBOL(console_stop); +EXPORT_SYMBOL(console_suspend); -void console_start(struct console *console) +void console_resume(struct console *console) { struct console_flush_type ft; bool is_nbcon; @@ -3540,7 +3568,7 @@ void console_start(struct console *console) __pr_flush(console, 1000, true); } -EXPORT_SYMBOL(console_start); +EXPORT_SYMBOL(console_resume); #ifdef CONFIG_PRINTK static int unregister_console_locked(struct console *console); @@ -4275,6 +4303,11 @@ void __init console_init(void) initcall_t call; initcall_entry_t *ce; +#ifdef CONFIG_NULL_TTY_DEFAULT_CONSOLE + if (!console_set_on_cmdline) + add_preferred_console("ttynull", 0, NULL); +#endif + /* Setup the default TTY line discipline. */ n_tty_init(); |