From 5901781a11175a5e5ee91746ec8627f18d47eebd Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Mon, 7 Sep 2020 15:15:12 +0200 Subject: x86/insn: Add insn_has_rep_prefix() helper Add a function to check whether an instruction has a REP prefix. Signed-off-by: Joerg Roedel Signed-off-by: Borislav Petkov Reviewed-by: Masami Hiramatsu Link: https://lkml.kernel.org/r/20200907131613.12703-12-joro@8bytes.org --- arch/x86/lib/insn-eval.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'arch/x86/lib/insn-eval.c') diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c index f20942ce76c6..58f7fb95c7f4 100644 --- a/arch/x86/lib/insn-eval.c +++ b/arch/x86/lib/insn-eval.c @@ -53,6 +53,30 @@ static bool is_string_insn(struct insn *insn) } } +/** + * insn_has_rep_prefix() - Determine if instruction has a REP prefix + * @insn: Instruction containing the prefix to inspect + * + * Returns: + * + * true if the instruction has a REP prefix, false if not. + */ +bool insn_has_rep_prefix(struct insn *insn) +{ + int i; + + insn_get_prefixes(insn); + + for (i = 0; i < insn->prefixes.nbytes; i++) { + insn_byte_t p = insn->prefixes.bytes[i]; + + if (p == 0xf2 || p == 0xf3) + return true; + } + + return false; +} + /** * get_seg_reg_override_idx() - obtain segment register override index * @insn: Valid instruction with segment override prefixes -- cgit