5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Harald Freudenberger <freude@xxxxxxxxxxxxx>
[ Upstream commit 32e8bd6423fc127d2b37bdcf804fd76af3bbec79 ]
Instead of calling BUG() at runtime introduce and use a prototype for a
non-existing function to produce a link error during compile when a not
supported opcode is used with the __cpacf_query() or __cpacf_check_opcode()
inline functions.
Suggested-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Harald Freudenberger <freude@xxxxxxxxxxxxx>
Reviewed-by: Holger Dengler <dengler@xxxxxxxxxxxxx>
Reviewed-by: Juergen Christ <jchrist@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/s390/include/asm/cpacf.h | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/arch/s390/include/asm/cpacf.h b/arch/s390/include/asm/cpacf.h
index fa31f71cf5746..0f6ff2008a159 100644
--- a/arch/s390/include/asm/cpacf.h
+++ b/arch/s390/include/asm/cpacf.h
@@ -161,6 +161,13 @@
typedef struct { unsigned char bytes[16]; } cpacf_mask_t;
+/*
+ * Prototype for a not existing function to produce a link
+ * error if __cpacf_query() or __cpacf_check_opcode() is used
+ * with an invalid compile time const opcode.
+ */
+void __cpacf_bad_opcode(void);
+
static __always_inline void __cpacf_query_rre(u32 opc, u8 r1, u8 r2,
cpacf_mask_t *mask)
{
@@ -232,7 +239,7 @@ static __always_inline void __cpacf_query(unsigned int opcode,
__cpacf_query_rre(CPACF_PRNO, 2, 4, mask);
break;
default:
- BUG();
+ __cpacf_bad_opcode();
}
}
@@ -257,7 +264,8 @@ static __always_inline int __cpacf_check_opcode(unsigned int opcode)
case CPACF_KMA:
return test_facility(146); /* check for MSA8 */
default:
- BUG();
+ __cpacf_bad_opcode();
+ return 0;
}
}
--
2.43.0
