diff options
Diffstat (limited to 'kernel/printk/printk.c')
| -rw-r--r-- | kernel/printk/printk.c | 100 |
1 files changed, 72 insertions, 28 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index adf99c05adcafc..6206804d275bac 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -383,9 +383,6 @@ static int console_locked; /* * Array of consoles built from command line options (console=) */ - -#define MAX_CMDLINECONSOLES 8 - static struct console_cmdline console_cmdline[MAX_CMDLINECONSOLES]; static int preferred_console = -1; @@ -2503,6 +2500,17 @@ static int __init console_setup(char *str) if (_braille_console_setup(&str, &brl_options)) return 1; + /* Save the console for driver subsystem use */ + if (console_opt_save(str, brl_options)) + return 1; + + /* Flag register_console() to not call try_enable_default_console() */ + console_set_on_cmdline = 1; + + /* Don't attempt to parse a DEVNAME:0.0 style console */ + if (strchr(str, ':')) + return 1; + /* * Decode str into name, index, options. */ @@ -2533,6 +2541,13 @@ static int __init console_setup(char *str) } __setup("console=", console_setup); +/* Only called from add_preferred_console_match() */ +int console_opt_add_preferred_console(const char *name, const short idx, + char *options, char *brl_options) +{ + return __add_preferred_console(name, idx, options, brl_options, true); +} + /** * add_preferred_console - add a device to the list of preferred consoles. * @name: device name @@ -3146,6 +3161,40 @@ void console_unblank(void) pr_flush(1000, true); } +/* + * Rewind all consoles to the oldest available record. + * + * IMPORTANT: The function is safe only when called under + * console_lock(). It is not enforced because + * it is used as a best effort in panic(). + */ +static void __console_rewind_all(void) +{ + struct console *c; + short flags; + int cookie; + u64 seq; + + seq = prb_first_valid_seq(prb); + + cookie = console_srcu_read_lock(); + for_each_console_srcu(c) { + flags = console_srcu_read_flags(c); + + if (flags & CON_NBCON) { + nbcon_seq_force(c, seq); + } else { + /* + * This assignment is safe only when called under + * console_lock(). On panic, legacy consoles are + * only best effort. + */ + c->seq = seq; + } + } + console_srcu_read_unlock(cookie); +} + /** * console_flush_on_panic - flush console content on panic * @mode: flush all messages in buffer or just the pending ones @@ -3174,30 +3223,8 @@ void console_flush_on_panic(enum con_flush_mode mode) */ console_may_schedule = 0; - if (mode == CONSOLE_REPLAY_ALL) { - struct console *c; - short flags; - int cookie; - u64 seq; - - seq = prb_first_valid_seq(prb); - - cookie = console_srcu_read_lock(); - for_each_console_srcu(c) { - flags = console_srcu_read_flags(c); - - if (flags & CON_NBCON) { - nbcon_seq_force(c, seq); - } else { - /* - * This is an unsynchronized assignment. On - * panic legacy consoles are only best effort. - */ - c->seq = seq; - } - } - console_srcu_read_unlock(cookie); - } + if (mode == CONSOLE_REPLAY_ALL) + __console_rewind_all(); console_flush_all(false, &next_seq, &handover); } @@ -3495,7 +3522,7 @@ void register_console(struct console *newcon) * Note that a console with tty binding will have CON_CONSDEV * flag set and will be first in the list. */ - if (preferred_console < 0) { + if (preferred_console < 0 && !console_set_on_cmdline) { if (hlist_empty(&console_list) || !console_first()->device || console_first()->flags & CON_BOOT) { try_enable_default_console(newcon); @@ -4286,6 +4313,23 @@ void kmsg_dump_rewind(struct kmsg_dump_iter *iter) } EXPORT_SYMBOL_GPL(kmsg_dump_rewind); +/** + * console_replay_all - replay kernel log on consoles + * + * Try to obtain lock on console subsystem and replay all + * available records in printk buffer on the consoles. + * Does nothing if lock is not obtained. + * + * Context: Any context. + */ +void console_replay_all(void) +{ + if (console_trylock()) { + __console_rewind_all(); + /* Consoles are flushed as part of console_unlock(). */ + console_unlock(); + } +} #endif #ifdef CONFIG_SMP |