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 4A9C5FF886F for ; Thu, 30 Apr 2026 05:39:30 +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: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:In-Reply-To:References:List-Owner; bh=jThLlSSXsylQBGgxGqp7bsPLq7wPVT1zS0ww5DZkl7c=; b=ldvttQQs/qM4x/WcS/4BtqElyP HG+PZsSy88IPz5QfgcdhREbxxT6Lfv78w4+2dxsq/XdZPfbVcbtFGFEyKo7GMUCIsSS5iKB0qD3U0 eJ42YRbr05OqgdJW7hyUcmIXkpKKvHKml8mcL9Otwjbywf+iGyN8AgkHcAfDvHk0NsVQIcdMcuf0p 8FZSZr4/SB9SkoajpD6E1hM3K2LXcV7CJ4nYiV+6MUW5YL7BCIiair0etgIuBAxWou2CPOR85gl9F M8A1JtWaJ62Zk5Rt7KDMdl6Ev9nTJKtZiAsbyPK1QB7v4DvppaDPwl6w7WT91N2qSip23SknpQv0z 76Na1Wvg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wIK7P-00000004imh-12vz; Thu, 30 Apr 2026 05:39:23 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wIK7N-00000004imC-3RkV for linux-arm-kernel@bombadil.infradead.org; Thu, 30 Apr 2026 05:39:22 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Transfer-Encoding:MIME-Version :Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:In-Reply-To:References; bh=jThLlSSXsylQBGgxGqp7bsPLq7wPVT1zS0ww5DZkl7c=; b=klQiIfmLoTfTI5x2okDzzqMV6V v/9+QfE0r74L5xQ5NbUZ3eVXbBw+epkus2JmjOlTgYHrqq/S7Nx2t8sW2Vd0N0aWPXXKfvJlhbEqP 3DhHJPCwz2tRZ5OD/xaIkd2eBx+MlPUJTZAC5V3aIaHgdPLFYfZqg4yj6AofARMD0PWXsZ9ikyV3P WiACmy1iiXQUP6b16rBZnXvSAP0KYFlMuh8MvXYMncmsG1nL4OrEWtd6LQvviZO35MsgU73AYIw/4 o3IQLuLMUarHhGh3SS3KMFSxbikOdo194ICAoTTltDiRVWdJp59cvkZYrAZUY4bpKZr/6SDXj/m+F XH0wdXXQ==; Received: from foss.arm.com ([217.140.110.172]) by desiato.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wIK7J-00000006g7J-0rZz for linux-arm-kernel@lists.infradead.org; Thu, 30 Apr 2026 05:39:20 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3594B1A9A; Wed, 29 Apr 2026 22:39:07 -0700 (PDT) Received: from ergosum.cambridge.arm.com (ergosum.cambridge.arm.com [10.1.196.45]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 786513F7B4; Wed, 29 Apr 2026 22:39:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1777527552; bh=0bDVVElDdvtEASTlGqfKLB6MoSbVkPd+QhrYWN30FUs=; h=From:To:Cc:Subject:Date:From; b=SRdqVSHc4t46OQaHLg5HaRP57PpGqi6+1RpTZ/+OQGtVLltLy/8g1cxER/T81IGsM K94t2UCG8JsjKcOf/jqDwQRItStYgtXE8rTh9iwdmd7aiR5IEhv2USNX9d9tSJkFXB kIPmTZCnjMNs5cSQv7kqqB/SHrdisD51OZQQdsPI= From: Anshuman Khandual To: linux-arm-kernel@lists.infradead.org Cc: Anshuman Khandual , Catalin Marinas , Will Deacon , Ryan Roberts , David Hildenbrand , linux-kernel@vger.kernel.org Subject: [PATCH] arm64/mm: Replace BUG_ON() with VM_WARN_ON_ONCE() Date: Thu, 30 Apr 2026 06:38:59 +0100 Message-Id: <20260430053859.890613-1-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260430_063918_131318_8EF9C0CB X-CRM114-Status: GOOD ( 10.69 ) 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 Avoid BUG_ON() while checking for inconsistent page table state conditions and instead replace them with VM_WARN_ON_ONCE(). Cc: Catalin Marinas Cc: Will Deacon Cc: Ryan Roberts Cc: David Hildenbrand Cc: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Acked-by: David Hildenbrand (Arm) Suggested-by: David Hildenbrand (Arm) Signed-off-by: Anshuman Khandual --- This patch applies on v7.1-rc1 Took the liberty in including David's tag from an internal discussion. Earlier context during D128 RFC review. https://lore.kernel.org/all/d61a8e11-5b8c-4cea-a7f4-a890f65d62f4@kernel.org/ arch/arm64/include/asm/pgtable.h | 4 ++-- arch/arm64/mm/mmu.c | 12 ++++++------ 2 files changed, 8 insertions(+), 8 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 4dfa42b7d053..c9e4e00a9af2 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -1007,7 +1007,7 @@ static inline pud_t *p4d_pgtable(p4d_t p4d) static inline phys_addr_t pud_offset_phys(p4d_t *p4dp, unsigned long addr) { - BUG_ON(!pgtable_l4_enabled()); + VM_WARN_ON_ONCE(!pgtable_l4_enabled()); return p4d_page_paddr(READ_ONCE(*p4dp)) + pud_index(addr) * sizeof(pud_t); } @@ -1130,7 +1130,7 @@ static inline p4d_t *pgd_to_folded_p4d(pgd_t *pgdp, unsigned long addr) static inline phys_addr_t p4d_offset_phys(pgd_t *pgdp, unsigned long addr) { - BUG_ON(!pgtable_l5_enabled()); + VM_WARN_ON_ONCE(!pgtable_l5_enabled()); return pgd_page_paddr(READ_ONCE(*pgdp)) + p4d_index(addr) * sizeof(p4d_t); } diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index dd85e093ffdb..4c8959153ac4 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -273,8 +273,8 @@ static int init_pmd(pmd_t *pmdp, unsigned long addr, unsigned long end, if (ret) return ret; - BUG_ON(pmd_val(old_pmd) != 0 && - pmd_val(old_pmd) != READ_ONCE(pmd_val(*pmdp))); + VM_WARN_ON_ONCE(pmd_val(old_pmd) != 0 && + pmd_val(old_pmd) != READ_ONCE(pmd_val(*pmdp))); } phys += next - addr; } while (pmdp++, addr = next, addr != end); @@ -394,8 +394,8 @@ static int alloc_init_pud(p4d_t *p4dp, unsigned long addr, unsigned long end, if (ret) goto out; - BUG_ON(pud_val(old_pud) != 0 && - pud_val(old_pud) != READ_ONCE(pud_val(*pudp))); + VM_WARN_ON_ONCE(pud_val(old_pud) != 0 && + pud_val(old_pud) != READ_ONCE(pud_val(*pudp))); } phys += next - addr; } while (pudp++, addr = next, addr != end); @@ -445,8 +445,8 @@ static int alloc_init_p4d(pgd_t *pgdp, unsigned long addr, unsigned long end, if (ret) goto out; - BUG_ON(p4d_val(old_p4d) != 0 && - p4d_val(old_p4d) != READ_ONCE(p4d_val(*p4dp))); + VM_WARN_ON_ONCE(p4d_val(old_p4d) != 0 && + p4d_val(old_p4d) != READ_ONCE(p4d_val(*p4dp))); phys += next - addr; } while (p4dp++, addr = next, addr != end); -- 2.30.2