s390/cpacf: Make use of invalid opcode produce a link error

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@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Harald Freudenberger 2024-05-14 10:09:32 +02:00 committed by Heiko Carstens
parent 830999bd7e
commit 32e8bd6423

View File

@ -166,6 +166,13 @@
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)
{
@ -237,7 +244,7 @@ static __always_inline void __cpacf_query(unsigned int opcode,
__cpacf_query_rre(CPACF_PRNO, 2, 4, mask);
break;
default:
BUG();
__cpacf_bad_opcode();
}
}
@ -262,7 +269,8 @@ 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;
}
}