From nobody Mon Feb 9 19:45:40 2026 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id EFC171C5F35 for ; Mon, 26 May 2025 06:55:19 +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=1748242523; cv=none; b=cSwReBJm4mljDTXD5r00cUKmDjZgOs7hFVRXyALSLTN8wqfxiYkpYMOFs3AMntlfxzs5JSu38LEh3ge8deixZrsxO/SsPrNUOXSrnTza+XY3nfH2pFGbOjeYuampNt668k5aMpRlH9Hk5Ea5ut05avz9wOcoUSSHSsS1iONHznI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748242523; c=relaxed/simple; bh=11uRemiH4yPMy8oCJMxXpaySk1ix9Nd4b3Ls/kbEcvs=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=GWioRoHnm4BCNAIfGF/eTo3s03B6zLWn2GKbhOcuuHKA9uCGy1Z3zTY897YdG/7FrZYUPur1uUKnhuMHutrIITpmsJrDXnV8q7c7R6BU8Pw2ZII+T3oyQFdm4BwlnQCh3JxsmG1zD5p29yTaisk2z3Rj+CNAJTJmj/3M+CTVnzk= 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 [10.2.10.34]) by gateway (Coremail) with SMTP id _____8Axx2lVEDRo+JX8AA--.45027S3; Mon, 26 May 2025 14:55:17 +0800 (CST) Received: from localhost.localdomain (unknown [10.2.10.34]) by front1 (Coremail) with SMTP id qMiowMCx7MRREDRolR3yAA--.32845S2; Mon, 26 May 2025 14:55:16 +0800 (CST) From: Tianyang Zhang To: chenhuacai@kernel.org, kernel@xen0n.name, zhanghongchen@loongson.cn, wangming01@loongson.cn, peterx@redhat.com Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, zhangtianyang Subject: [PATCH] Loongarch:Fixed up panic cause by a NULL-pmd Date: Mon, 26 May 2025 14:55:12 +0800 Message-Id: <20250526065512.13215-1-zhangtianyang@loongson.cn> X-Mailer: git-send-email 2.20.1 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: qMiowMCx7MRREDRolR3yAA--.32845S2 X-CM-SenderInfo: x2kd0wxwld05hdqjqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBj93XoW7Ww1fur4ktryUCFyftry8tFc_yoW8Wr1kpr y7C3Z5Gr40yryDJa17AFWkZFn7XasFkF4kW3Z2ya4DZwnxtw1jqFy8JwnI9F48ArWrJ3y0 9F45Ka9YqF1UJagCm3ZEXasCq-sJn29KB7ZKAUJUUUU5529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUkYb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r106r15M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Cr0_Gr1UM28EF7xvwVC2z280aVAFwI0_Cr1j6rxdM28EF7xvwVC2z280aVCY1x0267AK xVWxJr0_GcWle2I262IYc4CY6c8Ij28IcVAaY2xG8wAqjxCEc2xF0cIa020Ex4CE44I27w Aqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jrv_JF1lYx0Ex4A2jsIE 14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCF04k20xvY0x 0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E 7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcV C0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF 04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7 CjxVAFwI0_Jr0_GrUvcSsGvfC2KfnxnUUI43ZEXa7IU8r9N3UUUUU== Content-Type: text/plain; charset="utf-8" From: zhangtianyang Fixes: bd51834d1cf6 ("LoongArch: Return NULL from huge_pte_offset() for inv= alid PMD") ERROR INFO: CPU 25 Unable to handle kernel paging request at virtual address 0x0 ... Call Trace: [<900000000023c30c>] huge_pte_offset+0x3c/0x58 [<900000000057fd4c>] hugetlb_follow_page_mask+0x74/0x438 [<900000000051fee8>] __get_user_pages+0xe0/0x4c8 [<9000000000522414>] faultin_page_range+0x84/0x380 [<9000000000564e8c>] madvise_vma_behavior+0x534/0xa48 [<900000000056689c>] do_madvise+0x1bc/0x3e8 [<9000000000566df4>] sys_madvise+0x24/0x38 [<90000000015b9e88>] do_syscall+0x78/0x98 [<9000000000221f18>] handle_syscall+0xb8/0x158 In some cases, pmd may be NULL and rely on NULL as the return value for processing, so it is necessary to determine this situation here Signed-off-by: zhangtianyang --- arch/loongarch/mm/hugetlbpage.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/loongarch/mm/hugetlbpage.c b/arch/loongarch/mm/hugetlbpag= e.c index cea84d7f2b91..02dad4624fe3 100644 --- a/arch/loongarch/mm/hugetlbpage.c +++ b/arch/loongarch/mm/hugetlbpage.c @@ -47,7 +47,8 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned lon= g addr, pmd =3D pmd_offset(pud, addr); } } - return pmd_none(pmdp_get(pmd)) ? NULL : (pte_t *) pmd; + + return (!pmd || pmd_none(pmdp_get(pmd))) ? NULL : (pte_t *) pmd; } =20 uint64_t pmd_to_entrylo(unsigned long pmd_val) --=20 2.20.1