Commit bac30ea9 authored Mar 10, 2023 by Nico Boehr Committed by Vasily Gorbik Apr 13, 2023

s390/ipl: fix physical-virtual confusion for diag308



Diag 308 subcodes expect a physical address as their parameter.

This currently is not a bug, but in the future physical and virtual
addresses might differ.

Fix the confusion by doing a virtual-to-physical conversion in the
exported diag308() and leave the assembly wrapper __diag308() alone.

Note that several callers pass NULL as addr, so check for the case when
NULL is passed and pass 0 to hardware since virt_to_phys(0) might be
nonzero.

Suggested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

parent 34644cc2

arch/s390/kernel/ipl.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -176,11 +176,11 @@ static bool reipl_fcp_clear;
		static bool reipl_ccw_clear;
		static bool reipl_eckd_clear;

		static inline int __diag308(unsigned long subcode, void *addr)
		static inline int __diag308(unsigned long subcode, unsigned long addr)
		{
		union register_pair r1;

		r1.even = (unsigned long) addr;
		r1.even = addr;
		r1.odd = 0;
		asm volatile(
		" diag %[r1],%[subcode],0x308\n"
		@@ -195,7 +195,7 @@ static inline int __diag308(unsigned long subcode, void *addr)
		int diag308(unsigned long subcode, void *addr)
		{
		diag_stat_inc(DIAG_STAT_X308);
		return __diag308(subcode, addr);
		return __diag308(subcode, addr ? virt_to_phys(addr) : 0);
		}
		EXPORT_SYMBOL_GPL(diag308);