[kvm-unit-tests PATCH v3 2/2] s390x: Fix gcc 12 warning about array bounds

[Janis Schoetterl-Glausch <scgl@xxxxxxxxxxxxx>]

gcc 12 warns about pointer constant <4k dereference.
Silence the warning by using the extern lowcore symbol to derive the
pointers. This way gcc cannot conclude that the pointer is <4k.

Signed-off-by: Janis Schoetterl-Glausch <scgl@xxxxxxxxxxxxx>
---
 lib/s390x/asm/mem.h | 4 ++++
 s390x/emulator.c    | 5 +++--
 s390x/skey.c        | 2 +-
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/lib/s390x/asm/mem.h b/lib/s390x/asm/mem.h
index 845c00cc..64ef59b5 100644
--- a/lib/s390x/asm/mem.h
+++ b/lib/s390x/asm/mem.h
@@ -7,6 +7,10 @@
  */
 #ifndef _ASMS390X_MEM_H_
 #define _ASMS390X_MEM_H_
+#include <asm/arch_def.h>
+
+/* create pointer while avoiding compiler warnings */
+#define OPAQUE_PTR(x) ((void *)(((uint64_t)&lowcore) + (x)))
 
 #define SKEY_ACC	0xf0
 #define SKEY_FP		0x08
diff --git a/s390x/emulator.c b/s390x/emulator.c
index c9182ea4..2c42f96f 100644
--- a/s390x/emulator.c
+++ b/s390x/emulator.c
@@ -12,6 +12,7 @@
 #include <asm/cpacf.h>
 #include <asm/interrupt.h>
 #include <asm/float.h>
+#include <asm/mem.h>
 #include <linux/compiler.h>
 
 static inline void __test_spm_ipm(uint8_t cc, uint8_t key)
@@ -138,7 +139,7 @@ static __always_inline void __test_cpacf_invalid_parm(unsigned int opcode)
 {
 	report_prefix_push("invalid parm address");
 	expect_pgm_int();
-	__cpacf_query(opcode, (void *) -1);
+	__cpacf_query(opcode, OPAQUE_PTR(-1));
 	check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
 	report_prefix_pop();
 }
@@ -148,7 +149,7 @@ static __always_inline void __test_cpacf_protected_parm(unsigned int opcode)
 	report_prefix_push("protected parm address");
 	expect_pgm_int();
 	low_prot_enable();
-	__cpacf_query(opcode, (void *) 8);
+	__cpacf_query(opcode, OPAQUE_PTR(8));
 	low_prot_disable();
 	check_pgm_int_code(PGM_INT_CODE_PROTECTION);
 	report_prefix_pop();
diff --git a/s390x/skey.c b/s390x/skey.c
index 32bf1070..445476a0 100644
--- a/s390x/skey.c
+++ b/s390x/skey.c
@@ -349,7 +349,7 @@ static void test_set_prefix(void)
 	set_storage_key(pagebuf, 0x28, 0);
 	expect_pgm_int();
 	install_page(root, virt_to_pte_phys(root, pagebuf), 0);
-	set_prefix_key_1((uint32_t *)2048);
+	set_prefix_key_1(OPAQUE_PTR(2048));
 	install_page(root, 0, 0);
 	check_pgm_int_code(PGM_INT_CODE_PROTECTION);
 	report(get_prefix() == old_prefix, "did not set prefix");
-- 
2.33.1