Commit 7d66d3ab authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'printk-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux 

Pull printk updates from Petr Mladek:

 - Print more precise information about the printk log buffer memory
   usage.

 - Make sure that the sysrq title is shown on the console even when
   deferred.

 - Do not enable earlycon by `console=` which is meant to disable the
   default console.

* tag 'printk-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: add dummy printk_force_console_enter/exit helpers
  tty: sysrq: Use printk_force_console context on __handle_sysrq
  printk: Introduce FORCE_CON flag
  printk: Improve memory usage logging during boot
  init: Don't proxy `console=` to earlycon
parents c3cda60e 34767e53

drivers/tty/serial/earlycon.c

+23 −0
Original line number Diff line number Diff line
@@ -248,6 +248,29 @@ static int __init param_setup_earlycon(char *buf) 
}

early_param("earlycon", param_setup_earlycon);



/*

 * The `console` parameter is overloaded. It's handled here as an early param

 * and in `printk.c` as a late param. It's possible to specify an early

 * `bootconsole` using `earlycon=uartXXXX` (handled above), or via

 * the `console=uartXXX` alias. See the comment in `8250_early.c`.

 */

static int __init param_setup_earlycon_console_alias(char *buf)

{

	/*

	 * A plain `console` parameter must not enable the SPCR `bootconsole`

	 * like a plain `earlycon` does.

	 *

	 * A `console=` parameter that specifies an empty value is used to

	 * disable the `console`, not the `earlycon` `bootconsole`. The

	 * disabling of the `console` is handled by `printk.c`.

	 */

	if (!buf || !buf[0])

		return 0;



	return param_setup_earlycon(buf);

}

early_param("console", param_setup_earlycon_console_alias);



#ifdef CONFIG_OF_EARLY_FLATTREE



int __init of_setup_earlycon(const struct earlycon_id *match,

drivers/tty/sysrq.c

+8 −10
Original line number Diff line number Diff line
@@ -583,7 +583,6 @@ static void __sysrq_put_key_op(u8 key, const struct sysrq_key_op *op_p) 
void __handle_sysrq(u8 key, bool check_mask)

{

	const struct sysrq_key_op *op_p;

	int orig_log_level;

	int orig_suppress_printk;

	int i;
@@ -593,13 +592,12 @@ void __handle_sysrq(u8 key, bool check_mask) 
	rcu_sysrq_start();

	rcu_read_lock();

	/*

	 * Raise the apparent loglevel to maximum so that the sysrq header

	 * is shown to provide the user with positive feedback.  We do not

	 * simply emit this at KERN_EMERG as that would change message

	 * routing in the consumers of /proc/kmsg.

	 * Enter in the force_console context so that sysrq header is shown to

	 * provide the user with positive feedback.  We do not simply emit this

	 * at KERN_EMERG as that would change message routing in the consumers

	 * of /proc/kmsg.

	 */

	orig_log_level = console_loglevel;

	console_loglevel = CONSOLE_LOGLEVEL_DEFAULT;

	printk_force_console_enter();



	op_p = __sysrq_get_key_op(key);

	if (op_p) {
@@ -609,11 +607,11 @@ void __handle_sysrq(u8 key, bool check_mask) 
		 */

		if (!check_mask || sysrq_on_mask(op_p->enable_mask)) {

			pr_info("%s\n", op_p->action_msg);

			console_loglevel = orig_log_level;

			printk_force_console_exit();

			op_p->handler(key);

		} else {

			pr_info("This sysrq operation is disabled.\n");

			console_loglevel = orig_log_level;

			printk_force_console_exit();

		}

	} else {

		pr_info("HELP : ");
@@ -631,7 +629,7 @@ void __handle_sysrq(u8 key, bool check_mask) 
			}

		}

		pr_cont("\n");

		console_loglevel = orig_log_level;

		printk_force_console_exit();

	}

	rcu_read_unlock();

	rcu_sysrq_end();

include/linux/printk.h

+11 −0
Original line number Diff line number Diff line
@@ -166,6 +166,9 @@ __printf(1, 2) __cold int _printk_deferred(const char *fmt, ...); 
extern void __printk_deferred_enter(void);

extern void __printk_deferred_exit(void);



extern void printk_force_console_enter(void);

extern void printk_force_console_exit(void);



/*

 * The printk_deferred_enter/exit macros are available only as a hack for

 * some code paths that need to defer all printk console printing. Interrupts
@@ -229,6 +232,14 @@ static inline void printk_deferred_exit(void) 
{

}



static inline void printk_force_console_enter(void)

{

}



static inline void printk_force_console_exit(void)

{

}



static inline int printk_ratelimit(void)

{

	return 0;

init/main.c

+1 −4
Original line number Diff line number Diff line
@@ -754,10 +754,7 @@ static int __init do_early_param(char *param, char *val, 
	const struct obs_kernel_param *p;



	for (p = __setup_start; p < __setup_end; p++) {

		if ((p->early && parameq(param, p->str)) ||

		    (strcmp(param, "console") == 0 &&

		     strcmp(p->str, "earlycon") == 0)

		) {

		if (p->early && parameq(param, p->str)) {

			if (p->setup_func(val) != 0)

				pr_warn("Malformed early option '%s'\n", param);

		}

kernel/printk/internal.h

+3 −0
Original line number Diff line number Diff line
@@ -53,6 +53,8 @@ int devkmsg_sysctl_set_loglvl(const struct ctl_table *table, int write, 


/* Flags for a single printk record. */

enum printk_info_flags {

	/* always show on console, ignore console_loglevel */

	LOG_FORCE_CON	= 1,

	LOG_NEWLINE	= 2,	/* text ended with a newline */

	LOG_CONT	= 8,	/* text is a fragment of a continuation line */

};
@@ -90,6 +92,7 @@ bool printk_percpu_data_ready(void); 


void defer_console_output(void);

bool is_printk_legacy_deferred(void);

bool is_printk_force_console(void);



u16 printk_parse_prefix(const char *text, int *level,

			enum printk_info_flags *flags);