Commit 3b967847 authored by Vasily Gorbik's avatar Vasily Gorbik Committed by Martin Schwidefsky
Browse files

s390/ipl: correct kdump reipl block checksum calculation 



s390 kdump reipl implementation relies on os_info kernel structure
residing in old memory being dumped. os_info contains reipl block,
which is used (if valid) by the kdump kernel for reipl parameters.

The problem is that the reipl block and its checksum inside
os_info is updated only when /sys/firmware/reipl/reipl_type is
written. This sets an offset of a reipl block for "reipl_type" and
re-calculates reipl block checksum. Any further alteration of values
under /sys/firmware/reipl/{reipl_type}/ without subsequent write to
/sys/firmware/reipl/reipl_type lead to incorrect os_info reipl block
checksum. In such a case kdump kernel ignores it and reboots using
default logic.

To fix this, os_info reipl block update is moved right before kdump
execution.

Reviewed-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 06496850

arch/s390/include/asm/ipl.h

+1 −0
Original line number Diff line number Diff line
@@ -120,6 +120,7 @@ struct ipl_info 


extern struct ipl_info ipl_info;

extern void setup_ipl(void);

extern void set_os_info_reipl_block(void);



/*

 * DIAG 308 support

arch/s390/kernel/ipl.c

+5 −6
Original line number Diff line number Diff line
@@ -913,11 +913,10 @@ static struct attribute_group reipl_nss_attr_group = { 
	.attrs = reipl_nss_attrs,

};



static void set_reipl_block_actual(struct ipl_parameter_block *reipl_block)

void set_os_info_reipl_block(void)

{

	reipl_block_actual = reipl_block;

	os_info_entry_add(OS_INFO_REIPL_BLOCK, reipl_block_actual,

			  reipl_block->hdr.len);

			  reipl_block_actual->hdr.len);

}



/* reipl type */
@@ -930,18 +929,18 @@ static int reipl_set_type(enum ipl_type type) 
	switch(type) {

	case IPL_TYPE_CCW:

		reipl_method = REIPL_METHOD_CCW_DIAG;

		set_reipl_block_actual(reipl_block_ccw);

		reipl_block_actual = reipl_block_ccw;

		break;

	case IPL_TYPE_FCP:

		reipl_method = REIPL_METHOD_FCP_DIAG;

		set_reipl_block_actual(reipl_block_fcp);

		reipl_block_actual = reipl_block_fcp;

		break;

	case IPL_TYPE_FCP_DUMP:

		reipl_method = REIPL_METHOD_FCP_DUMP;

		break;

	case IPL_TYPE_NSS:

		reipl_method = REIPL_METHOD_NSS_DIAG;

		set_reipl_block_actual(reipl_block_nss);

		reipl_block_actual = reipl_block_nss;

		break;

	case IPL_TYPE_UNKNOWN:

		reipl_method = REIPL_METHOD_DEFAULT;

arch/s390/kernel/machine_kexec.c

+1 −0
Original line number Diff line number Diff line
@@ -252,6 +252,7 @@ void machine_shutdown(void) 


void machine_crash_shutdown(struct pt_regs *regs)

{

	set_os_info_reipl_block();

}



/*

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