From bac30ea9ef80624dfe4bf20c0fc2073dcc771a87 Mon Sep 17 00:00:00 2001
From: Nico Boehr <nrb@linux.ibm.com>
Date: Fri, 10 Mar 2023 12:52:37 +0100
Subject: [PATCH] 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>
---
arch/s390/kernel/ipl.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index 0f91cd401eefb..43de939b7af19 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -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);
--
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