From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0DAA2606A322 for ; Mon, 26 Oct 2026 08:04:51 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4jCmPY5KgGz2ygg; Mon, 26 Oct 2026 19:04:49 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=95.215.58.158 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1793001889; cv=none; b=Niai5t79P+SfeeYp3yU4k6A7YvQtV4YcEJa4TBLAXE5Afq8H+zkvw4i5c5ANbDQ8/ZP0ezDYpuBNw4Qj9SO+RskipUhGvFYOKGANQC2cFscNM4YrwZHM897KhmfrEgRkZ0sAH4FEQHtC041Evw37Kej0rudM6Pb+YfgPmruzShiBKMqTYOOJVSuTgzNxIMbys1fmOQSJQ8THyYtmkvg28d41kFQWKI68IqzKm1pNdscD+QTHRSHk1pssxbRPOk0vMt+xBJwV8ONvGTCCoAhbMc9UvwjRsvWFYp4mPEjWgQHmLr3zjOxsSnYTCIqKFhd1IldzM8vnqC27Binp8wEvjw== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1793001889; c=relaxed/relaxed; bh=xQRfqxKZWPdgYi3rSnDhlWYdHqbhXbBOf3zmvKiqynk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ZeN1Wy2l6zD0SHJ0nbcunf5vLJrhyMfXaJNofjWzRisQEP0l1PtP469ZJoa8UOESjHISxn5gFAfyZyiYp2/ZGMhiNyASjnEe5k2LUVrtNjwLGKvo3dYxD8pnK3b6d3vO6gg5gluuKKABsI2IcxITTR/LGdeCeRysnPO6zTjqdoaholP2QXsdogcu99+EjdDgJIH0ez08xnNeuTuEwXbgIjj0D4QRnV/OXHAperwaAlKTFlp7epnlP1bbCLfTf/DR4p9d1NiR3Jj/ga1oR1/lXhwt2iFwyxup7Z6IH+eZxxpAdlYTMzcFTMHCWnkBUjRwCVsKWEHOM9KITmdWbM15Hw== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=linux.dev; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=M+ToEqvo; dkim-atps=neutral; spf=pass (client-ip=95.215.58.158; helo=mta1.migadu.com; envelope-from=hao.ge@linux.dev; receiver=lists.ozlabs.org) smtp.mailfrom=linux.dev Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=M+ToEqvo; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.dev (client-ip=95.215.58.158; helo=mta1.migadu.com; envelope-from=hao.ge@linux.dev; receiver=lists.ozlabs.org) Received: from mta1.migadu.com (out-158.mta1.migadu.com [95.215.58.158]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4jCmPX5FJsz2ygd for ; Mon, 26 Oct 2026 19:04:48 +1100 (AEDT) X-Envelope-To: linuxppc-dev@lists.ozlabs.org DKIM-Signature: a=rsa-sha256; bh=a517G3/D9CvqFMgtLJh4XZJvZjho3byqSfkgyTokHGQ=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793001870; v=1; x=1793606670; b=M+ToEqvoNfXw+i1jqNb7wKiPTGlGgJlzlPjazrBl0jmZvgaWwgUcqJpIjpq7axs+WB+Ye2zp eh0rcouT8DuCqp3BHu+dQuHXPUWsCp/hFF5/mERACHsBHJ2c91STsUpGpyhEHMbPcKZAEodnAor nEhWxrOrohMy3vbDGie0pkgo= X-Envelope-To: linuxppc-dev@lists.ozlabs.org Received: by smtp.migadu.com with ESMTPS id 8477b878ce637510; Mon, 26 Oct 2026 08:03:10 +0000 X-Mizu-Trace-ID: 8477b878ce637510 X-Migadu-Flow: FLOW_OUT From: Hao Ge To: Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , "Ritesh Harjani (IBM)" , Shrikanth Hegde , Alexander Potapenko , Marco Elver , Dmitry Vyukov , Andrew Morton , Dennis Zhou , Tejun Heo , Christoph Lameter , Uladzislau Rezki , Hao Ge , Suren Baghdasaryan , Dev Jain Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, Sashiko Subject: [PATCH v3 07/10] mm/vmalloc: only flush the cache after the vmap succeeded Date: Mon, 26 Oct 2026 16:03:26 +0800 Message-Id: <20261026080329.140244-8-hao.ge@linux.dev> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20261026080329.140244-1-hao.ge@linux.dev> References: <20261026080329.140244-1-hao.ge@linux.dev> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , Precedence: list X-Archived-By: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 vmap_page_range() and __vmap_pages_range() call flush_cache_vmap() before they even look at the error code. A failed mapping is never used, so the flush is pointless at best. According to the Sashiko review it is worse than pointless on UML: flush_cache_vmap() there is flush_tlb_kernel_range(), which syncs the PTEs into the host OS. Flushing a half-installed mapping therefore leaves host mappings behind for a range that was just freed again. Only flush when the mapping, and for vmap_page_range() also the KMSAN metadata, is fully set up. Reported-by: Sashiko Signed-off-by: Hao Ge --- mm/vmalloc.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 4d74144dfaff..96e15d6cfc6d 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -359,11 +359,14 @@ int vmap_page_range(unsigned long addr, unsigned long end, err = vmap_range_noflush(addr, end, phys_addr, pgprot_nx(prot), ioremap_max_page_shift); - flush_cache_vmap(addr, end); if (!err) err = kmsan_ioremap_page_range(addr, end, phys_addr, prot, ioremap_max_page_shift); - return err; + if (err) + return err; + + flush_cache_vmap(addr, end); + return 0; } int ioremap_page_range(unsigned long addr, unsigned long end, @@ -745,8 +748,11 @@ static int __vmap_pages_range(unsigned long addr, unsigned long end, int err; err = vmap_pages_range_noflush(addr, end, prot, pages, page_shift, gfp_mask); + if (err) + return err; + flush_cache_vmap(addr, end); - return err; + return 0; } /** -- 2.25.1