Commit 5ecb2da6 authored by Sven Schnelle's avatar Sven Schnelle Committed by Vasily Gorbik
Browse files

s390: support command lines longer than 896 bytes 



Currently s390 supports a fixed maximum command line length of 896
bytes. This isn't enough as some installers are trying to pass all
configuration data via kernel command line, and even with zfcp alone
it is easy to generate really long command lines. Therefore extend
the command line to 4 kbytes.

In the parm area where the command line is stored there is no indication
of the maximum allowed length, so a new field which contains the maximum
length is added.

The parm area has always been initialized to zero, so with old kernels
this field would read zero. This is important because tools like zipl
could read this field. If it contains a number larger than zero zipl
knows the maximum length that can be stored in the parm area, otherwise
it must assume that it is booting a legacy kernel and only 896 bytes are
available.

The removing of trailing whitespace in head.S is also removed because
code to do this is already present in setup_boot_command_line().

Signed-off-by: default avatarSven Schnelle <svens@linux.ibm.com>
Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 277c8389

arch/s390/boot/head.S

+12 −23
Original line number Diff line number Diff line
@@ -184,35 +184,23 @@ iplstart: 
	bas	%r14,.Lloader		# load parameter file

	ltr	%r2,%r2 		# got anything ?

	bz	.Lnopf

	chi	%r2,895

	bnh	.Lnotrunc

	la	%r2,895

	l	%r3,MAX_COMMAND_LINE_SIZE+ARCH_OFFSET-PARMAREA(%r12)

	ahi	%r3,-1

	clr	%r2,%r3

	bl	.Lnotrunc

	lr	%r2,%r3

.Lnotrunc:

	l	%r4,.Linitrd

	clc	0(3,%r4),.L_hdr		# if it is HDRx

	bz	.Lagain1		# skip dataset header

	clc	0(3,%r4),.L_eof		# if it is EOFx

	bz	.Lagain1		# skip dateset trailer

	la	%r5,0(%r4,%r2)

	lr	%r3,%r2

	la	%r3,COMMAND_LINE-PARMAREA(%r12) # load adr. of command line

	mvc	0(256,%r3),0(%r4)

	mvc	256(256,%r3),256(%r4)

	mvc	512(256,%r3),512(%r4)

	mvc	768(122,%r3),768(%r4)

	slr	%r0,%r0

	b	.Lcntlp

.Ldelspc:

	ic	%r0,0(%r2,%r3)

	chi	%r0,0x20		# is it a space ?

	be	.Lcntlp

	ahi	%r2,1

	b	.Leolp

.Lcntlp:

	brct	%r2,.Ldelspc

.Leolp:

	slr	%r0,%r0

	stc	%r0,0(%r2,%r3)		# terminate buffer



	lr	%r5,%r2

	la	%r6,COMMAND_LINE-PARMAREA(%r12)

	lr	%r7,%r2

	ahi	%r7,1

	mvcl	%r6,%r4

.Lnopf:



#
@@ -394,6 +382,7 @@ SYM_DATA_START(parmarea) 
	.quad	0			# OLDMEM_BASE

	.quad	0			# OLDMEM_SIZE

	.quad	kernel_version		# points to kernel version string

	.quad	COMMAND_LINE_SIZE



	.org	COMMAND_LINE

	.byte	"root=/dev/ram0 ro"

arch/s390/boot/ipl_parm.c

+2 −2
Original line number Diff line number Diff line
@@ -170,10 +170,10 @@ static inline int has_ebcdic_char(const char *str) 


void setup_boot_command_line(void)

{

	parmarea.command_line[ARCH_COMMAND_LINE_SIZE - 1] = 0;

	parmarea.command_line[COMMAND_LINE_SIZE - 1] = 0;

	/* convert arch command line to ascii if necessary */

	if (has_ebcdic_char(parmarea.command_line))

		EBCASC(parmarea.command_line, ARCH_COMMAND_LINE_SIZE);

		EBCASC(parmarea.command_line, COMMAND_LINE_SIZE);

	/* copy arch command line */

	strcpy(early_command_line, strim(parmarea.command_line));

arch/s390/include/asm/setup.h

+5 −2
Original line number Diff line number Diff line
@@ -42,6 +42,8 @@ 
#define STARTUP_NORMAL_OFFSET	0x10000

#define STARTUP_KDUMP_OFFSET	0x10010



#define LEGACY_COMMAND_LINE_SIZE	896



#ifndef __ASSEMBLY__



#include <asm/lowcore.h>
@@ -54,8 +56,9 @@ struct parmarea { 
	unsigned long oldmem_base;			/* 0x10418 */

	unsigned long oldmem_size;			/* 0x10420 */

	unsigned long kernel_version;			/* 0x10428 */

	char pad1[0x10480 - 0x10430];			/* 0x10430 - 0x10480 */

	char command_line[ARCH_COMMAND_LINE_SIZE];	/* 0x10480 */

	unsigned long max_command_line_size;		/* 0x10430 */

	char pad1[0x10480-0x10438];			/* 0x10438 - 0x10480 */

	char command_line[COMMAND_LINE_SIZE];		/* 0x10480 */

};



extern struct parmarea parmarea;

arch/s390/include/uapi/asm/setup.h

+0 −2
Original line number Diff line number Diff line
@@ -9,6 +9,4 @@ 


#define COMMAND_LINE_SIZE	4096



#define ARCH_COMMAND_LINE_SIZE	896



#endif /* _UAPI_ASM_S390_SETUP_H */

arch/s390/kernel/asm-offsets.c

+1 −0
Original line number Diff line number Diff line
@@ -164,5 +164,6 @@ int main(void) 
	DEFINE(OLDMEM_BASE, PARMAREA + offsetof(struct parmarea, oldmem_base));

	DEFINE(OLDMEM_SIZE, PARMAREA + offsetof(struct parmarea, oldmem_size));

	DEFINE(COMMAND_LINE, PARMAREA + offsetof(struct parmarea, command_line));

	DEFINE(MAX_COMMAND_LINE_SIZE, PARMAREA + offsetof(struct parmarea, max_command_line_size));

	return 0;

}