From nobody Mon Feb 9 04:23:22 2026 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 410C523B61E; Tue, 6 Jan 2026 02:55:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767668135; cv=none; b=m4Q4hakSXJDEp0OLnEkVGBDsBYgs4aJO5WUaaq7JmWSmCUysoFIwhSL2EnYGSMSVHdb93sThZKlbPplAkFN7SrREuX/XfsS8w1nrXcs9XqDtKmAVvQNthiBoOL1eGTNveu7MeeST5ThhLI4NNT1kNj0GeoEcEPthoZvDM23Zn0g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767668135; c=relaxed/simple; bh=fmT91oIOnqReX/Vuc295d8fDIpY7NrtNMKwQyfTV0vk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=JhER7QrtHWqacbYPtyzFLuwOLCaY+gqnnd+BGi5ue3+zlt5IhmTbJj0FxLYXJP14znTBuHw2c72X3aX+myLt6BFW5ZlVHR2meBgG6BQmFSkMRg8Mg2MLF9SmO8zR/GGWATz7mCIxGqF8hUG/u4vapyOxrac8APwYK9ZSD9WEkOU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [223.64.69.1]) by gateway (Coremail) with SMTP id _____8BxWcKVeVxpT9MFAA--.18158S3; Tue, 06 Jan 2026 10:55:17 +0800 (CST) Received: from localhost.localdomain (unknown [223.64.69.1]) by front1 (Coremail) with SMTP id qMiowJBxiuCQeVxp450PAA--.7830S2; Tue, 06 Jan 2026 10:55:15 +0800 (CST) From: Huacai Chen To: Greg Kroah-Hartman , Sasha Levin , Huacai Chen Cc: Xuerui Wang , stable@vger.kernel.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, Chenghao Duan , Huacai Chen Subject: [PATCH 6.18] LoongArch: BPF: Enhance the bpf_arch_text_poke() function Date: Tue, 6 Jan 2026 10:55:02 +0800 Message-ID: <20260106025502.951868-1-chenhuacai@loongson.cn> X-Mailer: git-send-email 2.47.3 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 X-CM-TRANSID: qMiowJBxiuCQeVxp450PAA--.7830S2 X-CM-SenderInfo: hfkh0x5xdftxo6or00hjvr0hdfq/ X-Coremail-Antispam: 1Uk129KBj93XoW7KFWUZrWkKw4fCr43ZF1fAFc_yoW8ur15pr 1DArs5XrWUWr47Ja9rJw45Xry5Ja93Wr47WF43KryrCw13Xwn7Zw1Sk3ZxXasYkw48ur1r ZFZ8trnIg3WDZacCm3ZEXasCq-sJn29KB7ZKAUJUUUUr529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUU90b4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_JFI_Gr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVWxJVW8Jr1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6r4UJVWxJr1ln4kS14v26r1Y6r17M2AIxVAIcxkEcVAq07x20xvEncxIr21l57IF6xkI12 xvs2x26I8E6xACxx1l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1Y 6r17McIj6I8E87Iv67AKxVW8JVWxJwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64 vIr41l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1l4IxYO2xFxVAFwI0_ Jrv_JF1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1V AY17CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAI cVC0I7IYx2IY6xkF7I0E14v26r1j6r4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42 IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r1j6r4UYxBIdaVFxhVj vjDU0xZFpf9x07jFa0PUUUUU= Content-Type: text/plain; charset="utf-8" From: Chenghao Duan commit 73721d8676771c6c7b06d4e636cc053fc76afefd upstream. Enhance the bpf_arch_text_poke() function to enable accurate location of BPF program entry points. When modifying the entry point of a BPF program, skip the "move t0, ra" instruction to ensure the correct logic and copy of the jump address. Cc: stable@vger.kernel.org Fixes: 677e6123e3d2 ("LoongArch: BPF: Disable trampoline for kernel module = function trace") Signed-off-by: Chenghao Duan Signed-off-by: Huacai Chen --- arch/loongarch/net/bpf_jit.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c index 95c214e2cf09..87ff02513787 100644 --- a/arch/loongarch/net/bpf_jit.c +++ b/arch/loongarch/net/bpf_jit.c @@ -1307,6 +1307,10 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_= type poke_type, void *old_addr, void *new_addr) { int ret; + unsigned long size =3D 0; + unsigned long offset =3D 0; + void *image =3D NULL; + char namebuf[KSYM_NAME_LEN]; bool is_call =3D (poke_type =3D=3D BPF_MOD_CALL); u32 old_insns[LOONGARCH_LONG_JUMP_NINSNS] =3D {[0 ... 4] =3D INSN_NOP}; u32 new_insns[LOONGARCH_LONG_JUMP_NINSNS] =3D {[0 ... 4] =3D INSN_NOP}; @@ -1314,9 +1318,20 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_= type poke_type, /* Only poking bpf text is supported. Since kernel function entry * is set up by ftrace, we rely on ftrace to poke kernel functions. */ - if (!is_bpf_text_address((unsigned long)ip)) + if (!__bpf_address_lookup((unsigned long)ip, &size, &offset, namebuf)) return -ENOTSUPP; =20 + image =3D ip - offset; + + /* zero offset means we're poking bpf prog entry */ + if (offset =3D=3D 0) { + /* skip to the nop instruction in bpf prog entry: + * move t0, ra + * nop + */ + ip =3D image + LOONGARCH_INSN_SIZE; + } + ret =3D emit_jump_or_nops(old_addr, ip, old_insns, is_call); if (ret) return ret; --=20 2.47.3