From 9b7fb990e080f3a7c5dff9a829d11247e629b98f Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Mon, 23 Jul 2012 17:20:28 +0200 Subject: [PATCH] s390/dis: Instruction decoding interface Provide a new function, insn_to_mnemonic, by which e.g. kvm can obtain a human-readable decoding of an instruction's opcode. Reviewed-by: Christian Borntraeger Reviewed-by: Heiko Carstens Signed-off-by: Cornelia Huck Signed-off-by: Avi Kivity --- arch/s390/include/asm/processor.h | 1 + arch/s390/kernel/dis.c | 27 +++++++++++++++++++++++++++ 2 files changed, 28 insertions(+) diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index c40fa91e38a8..31feac630544 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -138,6 +138,7 @@ extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags); extern unsigned long thread_saved_pc(struct task_struct *t); extern void show_code(struct pt_regs *regs); +extern int insn_to_mnemonic(unsigned char *instruction, char buf[8]); unsigned long get_wchan(struct task_struct *p); #define task_pt_regs(tsk) ((struct pt_regs *) \ diff --git a/arch/s390/kernel/dis.c b/arch/s390/kernel/dis.c index 1f6b428e2762..c02310b8db09 100644 --- a/arch/s390/kernel/dis.c +++ b/arch/s390/kernel/dis.c @@ -1468,6 +1468,33 @@ static struct insn *find_insn(unsigned char *code) return NULL; } +/** + * insn_to_mnemonic - decode an s390 instruction + * @instruction: instruction to decode + * @buf: buffer to fill with mnemonic + * + * Decode the instruction at @instruction and store the corresponding + * mnemonic into @buf. + * @buf is left unchanged if the instruction could not be decoded. + * Returns: + * %0 on success, %-ENOENT if the instruction was not found. + */ +int insn_to_mnemonic(unsigned char *instruction, char buf[8]) +{ + struct insn *insn; + + insn = find_insn(instruction); + if (!insn) + return -ENOENT; + if (insn->name[0] == '\0') + snprintf(buf, sizeof(buf), "%s", + long_insn_name[(int) insn->name[1]]); + else + snprintf(buf, sizeof(buf), "%.5s", insn->name); + return 0; +} +EXPORT_SYMBOL_GPL(insn_to_mnemonic); + static int print_insn(char *buffer, unsigned char *code, unsigned long addr) { struct insn *insn; -- 2.34.1