Commit 32e8bd64 authored by Harald Freudenberger's avatar Harald Freudenberger Committed by Heiko Carstens
Browse files

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: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarHarald Freudenberger <freude@linux.ibm.com>
Reviewed-by: default avatarHolger Dengler <dengler@linux.ibm.com>
Reviewed-by: default avatarJuergen Christ <jchrist@linux.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 830999bd

arch/s390/include/asm/cpacf.h

+10 −2
Original line number Diff line number Diff line
@@ -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;

	}

}