From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.55 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793001794; b=SjP7Sb1i2g59lxct1ngcU7gmZFkATd0vH0DGpX355UOCkl3gr0YEOYUeIDg/LZlaPGW+ 8xtPz9aqsmIVErMv4N5nLmQWXG+NeZzfzI3yhAt+UmYIRkR8E70hf+q8WppZdrHYJV4hN WOizH1rRBUl5XE20hLu9FHc6kyoEvnB3F22AmPW8/XZhGEtn4kKg5l35cmyKuuY60dlVr LD9fSePxJ2l8FwhWRnJQ/5CdcN9ltPJAg6XoxJf25iUN5Mb+W8FeqZu/DWJcDo06Xksco tmiMpUzMvdi+1EiA9GxkHd3HnT5B2wpn61Iuq1/6KlAdCFherrnxaepEiBtBNsbW+OQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793001794; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-Id: X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=xQRfqxKZWPdgYi3rSnDhlWYdHqbhXbBOf3zmvKiqynk=; b=IgpN+EgYGGl61rp3TjLPc7liUf3a9CYV04t2YcDm5rv+6fJE/K0nCVjdMmdQ04Z3qfcl I5FRfPZMoZ2koiz8SWoL8imUZ/FTgjpvaNYufIrZbDgV1x+O2lAeXzGVOmsfrugsoJ7Fe zAYLhscp0PEWB6hr2g90i9cbyqO+1BRfaox+3rbT5dbicBHsloxDibpThhZKbE4VvlHD3 Rxy6wrL7Fe8ID3TmQ1e5i0Dn0kyr3wTXLZ/OsH1aAbxoK791DGWjfbJ0tntEyDixfUA/1 aXQuhCuhUbA0cWvKf3QxdLpy7usfi1eJZ4NVaJZ8msJaP6o0qdajnyBQoKxg3yAxC3A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=AQj7bhNX; arc=none smtp.remote-ip=95.215.58.55 Received: from mta1.migadu.com (out-55.mta1.migadu.com [95.215.58.55]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3EF6A606A31A for ; Mon, 26 Oct 2026 08:03:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 3EF6A606A31A Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=AQj7bhNX X-Envelope-To: linux-kernel@vger.kernel.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=1793001791; v=1; x=1793606591; b=AQj7bhNXAHMCiF8Q3PW/JjBLKEVJ9ZBNHWhP2/o9/aXfivUREuCa565zQP75zTcCqlyf1Qnn EQj/8dEZcXq9t21QITldHdN5V7PEVb2GPp/kWHTPYxr0zHywlec5JH8RdAfBbss54nyIg1stBQo XGcKHvpH7CfX8d+jVB5Y/Yig= X-Envelope-To: linux-kernel@vger.kernel.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: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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