Commit ad8cd1db authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Petr Mladek
Browse files

printk: Move console matching logic into a separate function 

This moves the loop that tries to match a newly registered console
with the command line or add_preferred_console list into a separate
helper, in order to be able to call it multiple times in subsequent
patches.

Link: https://lore.kernel.org/r/20200213095133.23176-2-pmladek@suse.com


Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
parent a4fe2b4d

kernel/printk/printk.c

+65 −40
Original line number Diff line number Diff line
@@ -280,6 +280,7 @@ static struct console *exclusive_console; 
static struct console_cmdline console_cmdline[MAX_CMDLINECONSOLES];



static int preferred_console = -1;

static bool has_preferred_console;

int console_set_on_cmdline;

EXPORT_SYMBOL(console_set_on_cmdline);
@@ -2626,6 +2627,60 @@ static int __init keep_bootcon_setup(char *str) 


early_param("keep_bootcon", keep_bootcon_setup);



/*

 * This is called by register_console() to try to match

 * the newly registered console with any of the ones selected

 * by either the command line or add_preferred_console() and

 * setup/enable it.

 *

 * Care need to be taken with consoles that are statically

 * enabled such as netconsole

 */

static int try_enable_new_console(struct console *newcon)

{

	struct console_cmdline *c;

	int i;



	for (i = 0, c = console_cmdline;

	     i < MAX_CMDLINECONSOLES && c->name[0];

	     i++, c++) {

		if (!newcon->match ||

		    newcon->match(newcon, c->name, c->index, c->options) != 0) {

			/* default matching */

			BUILD_BUG_ON(sizeof(c->name) != sizeof(newcon->name));

			if (strcmp(c->name, newcon->name) != 0)

				continue;

			if (newcon->index >= 0 &&

			    newcon->index != c->index)

				continue;

			if (newcon->index < 0)

				newcon->index = c->index;



			if (_braille_register_console(newcon, c))

				return 0;



			if (newcon->setup &&

			    newcon->setup(newcon, c->options) != 0)

				return -EIO;

		}

		newcon->flags |= CON_ENABLED;

		if (i == preferred_console) {

			newcon->flags |= CON_CONSDEV;

			has_preferred_console = true;

		}

		return 0;

	}



	/*

	 * Some consoles, such as pstore and netconsole, can be enabled even

	 * without matching.

	 */

	if (newcon->flags & CON_ENABLED)

		return 0;



	return -ENOENT;

}



/*

 * The console driver calls this routine during kernel initialization

 * to register the console printing procedure with printk() and to
@@ -2647,11 +2702,9 @@ early_param("keep_bootcon", keep_bootcon_setup); 
 */

void register_console(struct console *newcon)

{

	int i;

	unsigned long flags;

	struct console *bcon = NULL;

	struct console_cmdline *c;

	static bool has_preferred;

	int err;



	if (console_drivers)

		for_each_console(bcon)
@@ -2678,15 +2731,15 @@ void register_console(struct console *newcon) 
	if (console_drivers && console_drivers->flags & CON_BOOT)

		bcon = console_drivers;



	if (!has_preferred || bcon || !console_drivers)

		has_preferred = preferred_console >= 0;

	if (!has_preferred_console || bcon || !console_drivers)

		has_preferred_console = preferred_console >= 0;



	/*

	 *	See if we want to use this console driver. If we

	 *	didn't select a console we take the first one

	 *	that registers here.

	 */

	if (!has_preferred) {

	if (!has_preferred_console) {

		if (newcon->index < 0)

			newcon->index = 0;

		if (newcon->setup == NULL ||
@@ -2694,47 +2747,19 @@ void register_console(struct console *newcon) 
			newcon->flags |= CON_ENABLED;

			if (newcon->device) {

				newcon->flags |= CON_CONSDEV;

				has_preferred = true;

				has_preferred_console = true;

			}

		}

	}



	/*

	 * See if this console matches one we selected on

	 *	the command line.

	 * the command line or if it was statically enabled

	 */

	for (i = 0, c = console_cmdline;

	     i < MAX_CMDLINECONSOLES && c->name[0];

	     i++, c++) {

		if (!newcon->match ||

		    newcon->match(newcon, c->name, c->index, c->options) != 0) {

			/* default matching */

			BUILD_BUG_ON(sizeof(c->name) != sizeof(newcon->name));

			if (strcmp(c->name, newcon->name) != 0)

				continue;

			if (newcon->index >= 0 &&

			    newcon->index != c->index)

				continue;

			if (newcon->index < 0)

				newcon->index = c->index;



			if (_braille_register_console(newcon, c))

				return;



			if (newcon->setup &&

			    newcon->setup(newcon, c->options) != 0)

				break;

		}



		newcon->flags |= CON_ENABLED;

		if (i == preferred_console) {

			newcon->flags |= CON_CONSDEV;

			has_preferred = true;

		}

		break;

	}

	err = try_enable_new_console(newcon);



	if (!(newcon->flags & CON_ENABLED))

	/* printk() messages are not printed to the Braille console. */

	if (err || newcon->flags & CON_BRL)

		return;



	/*