kernel-ark/arch/s390/kernel/early_printk.c
Vasily Gorbik 54fb07d030 s390/sclp: avoid using strncmp with hardcoded length
"earlyprintk" option documentation does not clearly state which
platform supports which additional values (e.g. ",keep"). Preserve old
option behaviour and reuse str_has_prefix instead of strncmp for prefix
testing.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-08-29 15:34:58 +02:00

37 lines
829 B
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright IBM Corp. 2017
*/
#include <linux/console.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <asm/sclp.h>
static void sclp_early_write(struct console *con, const char *s, unsigned int len)
{
__sclp_early_printk(s, len, 0);
}
static struct console sclp_early_console = {
.name = "earlysclp",
.write = sclp_early_write,
.flags = CON_PRINTBUFFER | CON_BOOT,
.index = -1,
};
static int __init setup_early_printk(char *buf)
{
if (early_console)
return 0;
/* Accept only "earlyprintk" and "earlyprintk=sclp" */
if (buf && !str_has_prefix(buf, "sclp"))
return 0;
if (!sclp.has_linemode && !sclp.has_vt220)
return 0;
early_console = &sclp_early_console;
register_console(early_console);
return 0;
}
early_param("earlyprintk", setup_early_printk);