Commit de35089c authored Nov 17, 2017 by Heiko Carstens Committed by Martin Schwidefsky Nov 20, 2017

s390/disassembler: remove confusing code



When searching the opcode offset table within find_insn() the check
"entry->opcode == 0" was intended to clarify that 1-byte opcodes, the
first one being 0, are special.

However there is no mnemonic for an illegal opcode starting with 0.
Therefore there is also no opcode offset table entry that matches,
which again means that the check never is true. Therefore just remove
the confusing check, and add a comment which hopefully explains how
this works.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

parent 3241d3eb

arch/s390/kernel/dis.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -396,9 +396,14 @@ struct s390_insn find_insn(unsigned char code)
		unsigned char opfrag;
		int i;

		/* Search the opcode offset table to find an entry which
		* matches the beginning of the opcode. If there is no match
		* the last entry will be used, which is the default entry for
		* unknown instructions as well as 1-byte opcode instructions.
		*/
		for (i = 0; i < ARRAY_SIZE(opcode_offset); i++) {
		entry = &opcode_offset[i];
		if (entry->opcode == code[0] \|\| entry->opcode == 0)
		if (entry->opcode == code[0])
		break;
		}

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