From nobody Fri Dec 19 07:24:10 2025 Received: from mailgw.kylinos.cn (mailgw.kylinos.cn [124.126.103.232]) (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 617E22DAFAF; Wed, 17 Dec 2025 06:14:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=124.126.103.232 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765952098; cv=none; b=Zk4E6OfbnNbUr8wWZ8FLYiXI0PWhYs85oh49FY6JbtFb+lCvMT6kof75sRCQiDZf02tiTvHHciXIw+BMSHda0klRVxoQmSyuAuvOmdis3K7ZuWn9IaCbDgaG5eGwn7GpHnkdVE7Lgis71BjbEPMq7Sh4dtbw34wEO8psvsucZn0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765952098; c=relaxed/simple; bh=wZLOMETjgoJ2dGINqkm2V8I5bmIvypzJ/UXmJA+ST2I=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=qqSQEberkUSZPsiqs/Qry/yAoN04gxBqh47WsDI+ibphItSxWDmxs9c7rC9Po/h2hSPqK4hf6mv1GTuGH0yym0p4tsaFOuKwEckCkm/5hhAZ/PJmBnPIfpPav41YkanE9lM23BYUaDpWCzdbqs2EHM68SXtKKKfC6fRcus61oE0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn; spf=pass smtp.mailfrom=kylinos.cn; arc=none smtp.client-ip=124.126.103.232 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kylinos.cn X-UUID: b17e2dc0db0f11f0a38c85956e01ac42-20251217 X-CTIC-Tags: HR_CC_COUNT, HR_CC_DOMAIN_COUNT, HR_CC_NO_NAME, HR_CTE_8B, HR_CTT_MISS HR_DATE_H, HR_DATE_WKD, HR_DATE_ZONE, HR_FROM_NAME, HR_SJ_DIGIT_LEN HR_SJ_LANG, HR_SJ_LEN, HR_SJ_LETTER, HR_SJ_NOR_SYM, HR_SJ_PHRASE HR_SJ_PHRASE_LEN, HR_SJ_WS, HR_TO_COUNT, HR_TO_DOMAIN_COUNT, HR_TO_NO_NAME IP_UNTRUSTED, SRC_UNTRUSTED, IP_UNFAMILIAR, SRC_UNFAMILIAR, DN_TRUSTED SRC_TRUSTED, SA_EXISTED, SN_EXISTED, SPF_NOPASS, DKIM_NOPASS DMARC_NOPASS, CIE_BAD, CIE_GOOD_SPF, CIE_UNKNOWN, GTI_FG_BS GTI_RG_INFO, GTI_C_BU, AMN_GOOD, ABX_MISS_RDNS X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.6,REQID:54636725-8111-4a94-bf27-e8707e41cefc,IP:10,U RL:0,TC:0,Content:0,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTION :release,TS:5 X-CID-INFO: VERSION:1.3.6,REQID:54636725-8111-4a94-bf27-e8707e41cefc,IP:10,URL :0,TC:0,Content:0,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTION:r elease,TS:5 X-CID-META: VersionHash:a9d874c,CLOUDID:ba6e0229970adc7d7e96f99048600b0c,BulkI D:2512171414511WY777SV,BulkQuantity:0,Recheck:0,SF:17|19|38|66|78|81|82|10 2|127|850|898,TC:nil,Content:0|15|50,EDM:-3,IP:-2,URL:0,File:nil,RT:nil,Bu lk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1,SPR:NO,DKR:0,DKP:0,BRR: 0,BRE:0,ARC:0 X-CID-BVR: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_FAS,TF_CID_SPAM_FSD,TF_CID_SPAM_SNR X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: b17e2dc0db0f11f0a38c85956e01ac42-20251217 X-User: duanchenghao@kylinos.cn Received: from localhost.localdomain [(183.242.174.20)] by mailgw.kylinos.cn (envelope-from ) (Generic MTA) with ESMTP id 1517111480; Wed, 17 Dec 2025 14:14:49 +0800 From: Chenghao Duan To: yangtiezhu@loongson.cn, rostedt@goodmis.org, mhiramat@kernel.org, mark.rutland@arm.com, hengqi.chen@gmail.com, chenhuacai@kernel.org Cc: kernel@xen0n.name, zhangtianyang@loongson.cn, masahiroy@kernel.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, bpf@vger.kernel.org, duanchenghao@kylinos.cn, youling.tang@linux.dev, jianghaoran@kylinos.cn, vincent.mc.li@gmail.com, linux-trace-kernel@vger.kernel.org Subject: [PATCH v4 4/7] LoongArch: BPF: Save return address register ra to t0 before trampoline Date: Wed, 17 Dec 2025 14:14:32 +0800 Message-Id: <20251217061435.802204-5-duanchenghao@kylinos.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20251217061435.802204-1-duanchenghao@kylinos.cn> References: <20251217061435.802204-1-duanchenghao@kylinos.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Modify the build_prologue function to ensure the return address register ra is saved to t0 before entering trampoline operations. This change ensures accurate return address handling when a BPF program calls another BPF program, preventing errors in the BPF-to-BPF call chain. Signed-off-by: Chenghao Duan --- arch/loongarch/net/bpf_jit.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c index 76cd24646bec..c560d1e14b9d 100644 --- a/arch/loongarch/net/bpf_jit.c +++ b/arch/loongarch/net/bpf_jit.c @@ -139,6 +139,7 @@ static void build_prologue(struct jit_ctx *ctx) stack_adjust =3D round_up(stack_adjust, 16); stack_adjust +=3D bpf_stack_adjust; =20 + move_reg(ctx, LOONGARCH_GPR_T0, LOONGARCH_GPR_RA); /* Reserve space for the move_imm + jirl instruction */ for (i =3D 0; i < LOONGARCH_LONG_JUMP_NINSNS; i++) emit_insn(ctx, nop); --=20 2.25.1