From nobody Wed Dec 17 14:20:25 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2609EEE4992 for ; Fri, 18 Aug 2023 20:58:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238688AbjHRU62 (ORCPT ); Fri, 18 Aug 2023 16:58:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229727AbjHRU6Q (ORCPT ); Fri, 18 Aug 2023 16:58:16 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3FB0D10E for ; Fri, 18 Aug 2023 13:58:15 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C4A0563146 for ; Fri, 18 Aug 2023 20:58:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1BE8C433C7; Fri, 18 Aug 2023 20:58:12 +0000 (UTC) Date: Fri, 18 Aug 2023 22:58:09 +0200 From: Helge Deller To: linux-arm-kernel@lists.infradead.org, "Russell King (Oracle)" , Arnd Bergmann , Andrew Morton , linux-kernel@vger.kernel.org Subject: [PATCH][RESEND] arm: Fix flush_dcache_page() for usage from irq context Message-ID: MIME-Version: 1.0 Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Since at least kernel 6.1, flush_dcache_page() is called with IRQs disabled, e.g. from aio_complete(). But the current implementation for flush_dcache_page() on ARM (32-bit) unintentionally re-enables IRQs, which may lead to deadlocks. Fix it by using xa_lock_irqsave() and xa_unlock_irqrestore() for the flush_dcache_mmap_*lock() macros instead. Cc: "Russell King (Oracle)" Cc: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org Reviewed-by: Arnd Bergmann Signed-off-by: Helge Deller --- diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cache= flush.h index a094f964c869..5b8a1ef0dc50 100644 --- a/arch/arm/include/asm/cacheflush.h +++ b/arch/arm/include/asm/cacheflush.h @@ -315,6 +315,10 @@ static inline void flush_anon_page(struct vm_area_stru= ct *vma, =20 #define flush_dcache_mmap_lock(mapping) xa_lock_irq(&mapping->i_pages) #define flush_dcache_mmap_unlock(mapping) xa_unlock_irq(&mapping->i_pages) +#define flush_dcache_mmap_lock_irqsave(mapping, flags) \ + xa_lock_irqsave(&mapping->i_pages, flags) +#define flush_dcache_mmap_unlock_irqrestore(mapping, flags) \ + xa_unlock_irqrestore(&mapping->i_pages, flags) =20 /* * We don't appear to need to do anything here. In fact, if we did, we'd diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c index 2508be91b7a0..e70dd5e354ae 100644 --- a/arch/arm/mm/flush.c +++ b/arch/arm/mm/flush.c @@ -238,6 +238,7 @@ static void __flush_dcache_aliases(struct address_space= *mapping, struct page *p { struct mm_struct *mm =3D current->active_mm; struct vm_area_struct *mpnt; + unsigned long flags; pgoff_t pgoff; =20 /* @@ -248,7 +249,7 @@ static void __flush_dcache_aliases(struct address_space= *mapping, struct page *p */ pgoff =3D page->index; =20 - flush_dcache_mmap_lock(mapping); + flush_dcache_mmap_lock_irqsave(mapping, flags); vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) { unsigned long offset; =20 @@ -262,7 +263,7 @@ static void __flush_dcache_aliases(struct address_space= *mapping, struct page *p offset =3D (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT; flush_cache_page(mpnt, mpnt->vm_start + offset, page_to_pfn(page)); } - flush_dcache_mmap_unlock(mapping); + flush_dcache_mmap_unlock_irqrestore(mapping, flags); } =20 #if __LINUX_ARM_ARCH__ >=3D 6