From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 599C7CA600A for ; Thu, 8 Oct 2026 07:30:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=7XwukL8/yd82nFdVG9qm4VBZNIyM/fBMMvZK+hA2jjo=; b=Ca7v2KweQhhjmVQ1TyFedIxFSX QcjqP2iIMnuWRYI0QxayI2TzGQtsZNr26Rdw7O2hZreMKT8uX5y8oNGm7GsnDQnqL7dO9QlmpHcXy O/gHkgqg5LzMFuQZXjglol2w2p6kKsU4q684TQFp8+WlyVTyFiT1ynHjoqf+goDT9a3ums+FD5fPf +GMQDg3bxEYrbQsbp9rdfNc1FaPBr7vyn8PSBFHJ9bQnn0e3XKuqUW4A0WrBJeJGktsEg+wG7mBxs rYLTyqg3L/2hAZLkkADOUrCL8utzr7w4qqGNBgRgKVG294E6NJV/ltfFY8EGwY98JznTuY51rPR/1 wGe/0uCg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xEiaZ-00000003ke9-2rgD; Thu, 08 Oct 2026 07:30:51 +0000 Received: from mail-pl1-x636.google.com ([2607:f8b0:4864:20::636]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xEiaW-00000003kaN-18pW for linux-arm-kernel@lists.infradead.org; Thu, 08 Oct 2026 07:30:50 +0000 Received: by mail-pl1-x636.google.com with SMTP id d9443c01a7336-2d6d28aa26cso24219135ad.2 for ; Thu, 08 Oct 2026 00:30:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1791444647; x=1792049447; darn=lists.infradead.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=7XwukL8/yd82nFdVG9qm4VBZNIyM/fBMMvZK+hA2jjo=; b=BABKwXyqi8VMVWvSrxxrCTOzGbYXGyx04JDTZOoMm5jyY+WgviQc+U3Al3izW8lYIx u7abdrSxiwJk848SiNlNoyDrRj88yliado4cimebresp5jzmuXh9YVGlv11eNb/ST+Q1 /sccXyXUfOU/dAN9IwfBVR24eIk4PziHVfBG2+sBzXxvmVNe/5M1aZdn6uYDKRYsI8lw XUwx8DoySUF5A1OAgXt+JsuwDw/yoUgB6I8dDZjZIdDCt493nc4GiJ4dfH9YAgv7sFR0 +246exzALsV0eeI6dLWtKy4ig9WZ6K94Y9lwPFwt6t01xeTQEvL8435AQVYjvIhko0q8 5N7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791444647; x=1792049447; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=7XwukL8/yd82nFdVG9qm4VBZNIyM/fBMMvZK+hA2jjo=; b=zbFEmNWLAH3ZsRp8Vzo8fVVw5psfw5/3mdUsvkhen0HQMrGTDAaiqqBvEBWR11rtv2 sydU4fs15v+kKuBW+YD9QgYJT7ghTokxuBZV2h6BJn0ISJB7rgONFzSwPHOzkRGTh24r KGtkKCa1x1YEi4bNyJVWm5s5mOF8+uuKsKQReutCDGX30LkiBzKBu0hNRWwP5kPtPAEe b1M+XaIk7gM9IKVy+qg28GCbeYX73SqBGA5sU6f6vcECWuzt8Td7HiYHoHklN900ZqJu HyPAPLQhy3agmFBZ+P6imB38sekQcpBj/rHQwesg5F+VSQ2xMfuM3DxK3aO06VqqEWtn a8dQ== X-Forwarded-Encrypted: i=1; AKwUvBxpDfV2l0sKcfcqpCooryZVHE2T+G4otYP4eZN77HBewQsekuROZN6U1mAW3wypDPPLypO2yV2ZVA/1Od+EZgF+@lists.infradead.org X-Gm-Message-State: AFq9FYLOdRwbQSWhffmZva1Y+x996BxpjSuZ2hBnWBKOBIME7VTvDPRa dnmPKL/BYd01YKCUS8pSHxLa3NDzHurj+Zws6Ahhr4GPeAHqscLgGQtcf9100vdBDpY= X-Gm-Gg: AYBFou36lSJATt7jRvMACqwDxjlvcm9kJpCYEc5uTf0afrwbkXmCqtFhqt0hCKY2Qnc RiQzrP3dHYlY0sQarDHd4epYSsDpygHdFx6q9ApussLsLU1icWxT9GYAApO/3D4iU8LtIEi5cDk eBwL8CBYQCUg/xytyEgC8gC3M7PJhpjH09HNburNbtYAOGPygdjuaPwOliFT0erwmhgWPD1dLsA EsUeQVjYLw6oQO9S9i0JtzfBnp/K90+CKcJc16BId2BK2gV7SJ+j7IqLQz51/ohnBnikUur+UNW 6DcBXrCx0nLiiZexqmTrQtF2XQ0CKH/9Uu/t9annhhYr9V3uLoYr2Hj8bGE2yTQ6NBIm8ofiOF0 Hi9EYyzeTnmXBSgElQPmNVTSItMWboaqdjmGqP3xXy9dmFi0pzKQWXLJ9Sd4X1qwv1WJ5VeJOc7 jTxYaCxw7yqn8jX7XDv4x8n0wcw0+E19u0S8/+FAZwhIfKRSrVfBOxYLbsg/JbA/8YkiVoa/qZs vpHgVZJzESc7Fteox0= X-Received: by 2002:a17:90b:2652:b0:3a7:b260:9cc6 with SMTP id 98e67ed59e1d1-3a8a1b91be4mr3069089a91.42.1791444647313; Thu, 08 Oct 2026 00:30:47 -0700 (PDT) Received: from n232-176-004.byted.org ([36.110.163.99]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3a8a438f25dsm3114715a91.2.2026.10.08.00.30.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 08 Oct 2026 00:30:46 -0700 (PDT) From: Muchun Song To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, stable@vger.kernel.org, david@kernel.org, osalvador@suse.de, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr, linux-riscv@lists.infradead.org, agordeev@linux.ibm.com, kevin.brodsky@arm.com, bjorn@rivosinc.com, apopple@nvidia.com, linux-kernel@vger.kernel.org, muchun.song@linux.dev Subject: [PATCH 2/4] riscv/mm: fix hotplug page-table destructor handling Date: Thu, 8 Oct 2026 15:30:19 +0800 Message-ID: <20261008073021.2512665-3-songmuchun@bytedance.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20261008073021.2512665-1-songmuchun@bytedance.com> References: <20261008073021.2512665-1-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261008_003048_316804_68A7090E X-CRM114-Status: GOOD ( 13.63 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org RISC-V uses the same memory-hotplug teardown code for the linear map and vmemmap, although their page-table pages are not always allocated in the same way. Late linear-map allocations run page-table constructors, while vmemmap and early allocations may provide constructor-free pages. The PTE path unconditionally runs the destructor, which is wrong for constructor-free vmemmap tables. The PMD path avoids that problem by using is_vmemmap as a proxy for constructor state, but that assumption will no longer hold once runtime vmemmap allocations use the normal pgalloc helpers. Page-table constructors record their state in PG_table. Centralize page-table freeing and use PageTable() to decide whether the destructor is required. Keep reserved and constructor-free pages on their existing freeing paths. Fixes: c75a74f4ba19 ("riscv: mm: Add memory hotplugging support") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Muchun Song --- arch/riscv/mm/init.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 857f9a55039c..429a0b015ec1 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1486,10 +1486,19 @@ struct execmem_info __init *execmem_arch_setup(void) #endif /* CONFIG_EXECMEM */ #ifdef CONFIG_MEMORY_HOTPLUG +static void __meminit free_pagetable(struct page *page) +{ + if (PageReserved(page)) + free_reserved_page(page); + else if (PageTable(page)) + pagetable_dtor_free(page_ptdesc(page)); + else + pagetable_free(page_ptdesc(page)); +} + static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd) { struct page *page = pmd_page(*pmd); - struct ptdesc *ptdesc = page_ptdesc(page); pte_t *pte; int i; @@ -1499,18 +1508,13 @@ static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd) return; } - pagetable_dtor(ptdesc); - if (PageReserved(page)) - free_reserved_page(page); - else - pagetable_free(ptdesc); + free_pagetable(page); pmd_clear(pmd); } -static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud, bool is_vmemmap) +static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud) { struct page *page = pud_page(*pud); - struct ptdesc *ptdesc = page_ptdesc(page); pmd_t *pmd; int i; @@ -1520,12 +1524,7 @@ static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud, bool is_vmemm return; } - if (!is_vmemmap) - pagetable_dtor(ptdesc); - if (PageReserved(page)) - free_reserved_page(page); - else - pagetable_free(ptdesc); + free_pagetable(page); pud_clear(pud); } @@ -1645,7 +1644,7 @@ static void __meminit remove_pud_mapping(pud_t *pud_base, unsigned long addr, un remove_pmd_mapping(pmd_base, addr, next, is_vmemmap, altmap); if (pgtable_l4_enabled) - free_pmd_table(pmd_base, pudp, is_vmemmap); + free_pmd_table(pmd_base, pudp); } } -- 2.54.0