Commit ab7373bf authored by Hendrik Brueckner's avatar Hendrik Brueckner Committed by Martin Schwidefsky
Browse files

s390/ctrlchar: improve handling of magic sysrequests 



Extract the sysrq handling from the ctrlchar_handle() into a separate
function that can be directly used by other users.

Introduce a new sysrq_work structure to embed the work_struct and to
specify the magic sysrq function to be invoked.

Signed-off-by: default avatarHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent de9c35f3

drivers/s390/char/ctrlchar.c

+11 −5
Original line number Diff line number Diff line
@@ -14,15 +14,21 @@ 
#include "ctrlchar.h"



#ifdef CONFIG_MAGIC_SYSRQ

static int ctrlchar_sysrq_key;

static struct sysrq_work ctrlchar_sysrq;



static void

ctrlchar_handle_sysrq(struct work_struct *work)

{

	handle_sysrq(ctrlchar_sysrq_key);

	struct sysrq_work *sysrq = container_of(work, struct sysrq_work, work);



	handle_sysrq(sysrq->key);

}



static DECLARE_WORK(ctrlchar_work, ctrlchar_handle_sysrq);

void schedule_sysrq_work(struct sysrq_work *sw)

{

	INIT_WORK(&sw->work, ctrlchar_handle_sysrq);

	schedule_work(&sw->work);

}

#endif
@@ -51,8 +57,8 @@ ctrlchar_handle(const unsigned char *buf, int len, struct tty_struct *tty) 
#ifdef CONFIG_MAGIC_SYSRQ

	/* racy */

	if (len == 3 && buf[1] == '-') {

		ctrlchar_sysrq_key = buf[2];

		schedule_work(&ctrlchar_work);

		ctrlchar_sysrq.key = buf[2];

		schedule_sysrq_work(&ctrlchar_sysrq);

		return CTRLCHAR_SYSRQ;

	}

#endif

drivers/s390/char/ctrlchar.h

+12 −0
Original line number Diff line number Diff line
@@ -7,6 +7,8 @@ 
 */



#include <linux/tty.h>

#include <linux/sysrq.h>

#include <linux/workqueue.h>



extern unsigned int

ctrlchar_handle(const unsigned char *buf, int len, struct tty_struct *tty);
@@ -17,3 +19,13 @@ ctrlchar_handle(const unsigned char *buf, int len, struct tty_struct *tty); 
#define CTRLCHAR_SYSRQ (3 << 8)



#define CTRLCHAR_MASK (~0xffu)





#ifdef CONFIG_MAGIC_SYSRQ

struct sysrq_work {

	int key;

	struct work_struct work;

};



void schedule_sysrq_work(struct sysrq_work *sw);

#endif

CRA Git | Maintained and supported by SUSTech CRA and CCSE