From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-181.mta1.migadu.com (out-181.mta1.migadu.com [95.215.58.181]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E21233B7B8C for ; Mon, 8 Jun 2026 10:10:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.181 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780913436; cv=none; b=VcBCGgSlZPkBOCIiMU8qwylvOirMXs2pTgSsSLSGcYI7vjSJDoLjvgVveg0K9FL090ZtocZ0K74BEpGXta38Qf8JvHxEQkFrdMYjZ3BCqHeXxIaGHQMmcPzml5B7hNDLrD+QIlMkbwl42rP08VsjMYp7zwgmclK0flF31nHd/yU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780913436; c=relaxed/simple; bh=cDfZSz3ivvl1QfWZ9jvAA+VablcjicxvJ0V6T4B9iOk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=JRcJJt+nxL1CzT5jLLMFX3gWIdgZJHxcoKxoliB8yceCgS28xSlCM6Ux2WEzQPJ44k2QEMYRD6qdfC6USgeE0Pn312x51vB/J4K5pFKB3Bk4j4s7oJZRJHgGlsUW7BVVEh5KFsuXBngIPG7sE+28cQTAui1q6I5z8XQckqwtAtA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=VsrgSP1Q; arc=none smtp.client-ip=95.215.58.181 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="VsrgSP1Q" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1780913432; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=WjOt6p1vyAYaMNIqwKJQkplVc88EqcFx+7171iEr4bE=; b=VsrgSP1QY7NJc4YZd03gYluYSCX4Te3CUGZJuyQW6q5ZhIOjEQWuxEra5dWqWYbsco/nrG an/GdU830RXkn1ahmobtXjbe+ayT2Eo2LbTNLWzt8dCffoUUmGnDivgM/IqmcLWf2w3Ctu K1pkSt3VZbd7JJ7K3i6n24+egyBK5l0= From: George Guo To: chenhuacai@kernel.org, jpoimboe@kernel.org, peterz@infradead.org, jikos@kernel.org, mbenes@suse.cz, pmladek@suse.com Cc: kernel@xen0n.name, joe.lawrence@redhat.com, rostedt@goodmis.org, ardb@kernel.org, nathan@kernel.org, nick.desaulniers+lkml@gmail.com, yangtiezhu@loongson.cn, jiaxun.yang@flygoat.com, liukexin@kylinos.cn, guodongtai@kylinos.cn, xry111@xry111.site, wangyuli@aosc.io, loongarch@lists.linux.dev, live-patching@vger.kernel.org, llvm@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v2 6/8] objtool/klp: Add LoongArch jump opcode bytes support Date: Mon, 8 Jun 2026 18:08:50 +0800 Message-Id: <20260608100852.325413-7-dongtai.guo@linux.dev> In-Reply-To: <20260608100852.325413-1-dongtai.guo@linux.dev> References: <20260608100852.325413-1-dongtai.guo@linux.dev> Precedence: bulk X-Mailing-List: live-patching@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: George Guo Implement arch_jump_opcode_bytes() for LoongArch so that klp checksums for jump/call instructions with non-relocated destination offsets are position-independent, mirroring the x86 and arm64 implementations. Mask out the embedded branch offset while preserving the opcode and the register operands, which differ per instruction format: - B/BL (reg0i26): no regs -> 0xfc000000 - BEQZ/BNEZ/BCEQZ/BCNEZ (reg1i21): keep rj/cj -> 0xfc0003e0 - JIRL/BEQ/BNE/.../BGEU (reg2i16): keep rj/rd -> 0xfc0003ff Co-developed-by: Kexin Liu Signed-off-by: Kexin Liu Signed-off-by: George Guo --- tools/objtool/arch/loongarch/decode.c | 41 +++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/tools/objtool/arch/loongarch/decode.c b/tools/objtool/arch/loongarch/decode.c index 674e4efd138f..12facd0cc8d1 100644 --- a/tools/objtool/arch/loongarch/decode.c +++ b/tools/objtool/arch/loongarch/decode.c @@ -432,6 +432,47 @@ unsigned long arch_jump_table_sym_offset(struct reloc *reloc, struct reloc *tabl } } +size_t arch_jump_opcode_bytes(struct objtool_file *file, struct instruction *insn, + unsigned char *buf) +{ + union loongarch_instruction *code; + u32 insn_word; + + insn_word = le32toh(*(u32 *)(insn->sec->data->d_buf + insn->offset)); + code = (union loongarch_instruction *)&insn_word; + + switch (code->reg0i26_format.opcode) { + case b_op: + case bl_op: + /* reg0i26: 26-bit offset, no register operands */ + insn_word &= 0xfc000000; + break; + case beqz_op: + case bnez_op: + case bceqz_op: /* == bcnez_op */ + /* reg1i21: keep opcode + rj/cj at bits[9:5] */ + insn_word &= 0xfc0003e0; + break; + case jirl_op: + case beq_op: + case bne_op: + case blt_op: + case bge_op: + case bltu_op: + case bgeu_op: + /* reg2i16: keep opcode + rj/rd at bits[9:0] */ + insn_word &= 0xfc0003ff; + break; + default: + break; + } + + insn_word = htole32(insn_word); + memcpy(buf, &insn_word, sizeof(insn_word)); + + return LOONGARCH_INSN_SIZE; +} + #ifdef DISAS int arch_disas_info_init(struct disassemble_info *dinfo) -- 2.25.1