From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 208743C10 for ; Fri, 24 Feb 2023 10:00:49 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 3470733FFB; Fri, 24 Feb 2023 10:00:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1677232841; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bQMJWpenP6OEu3AR0STwSIwzPSjq3AkhCnZCUwU4em4=; b=eOJS6frdV5UgXb66LQirAS9ZQ/sN6R7VVfUyUQO93GuJ7YDYy+gCcVKQpNK3ME6ofsbj+u qNoA75ZP+SCcWx6iNzv+kDslqOfh6KioPYBLkFW6Vm5wsP0uKlXfxMhG+f33PGKL2I+nON vlLQQ7NCxHTEb09vqsuUXAqKdYuwsts= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1677232841; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bQMJWpenP6OEu3AR0STwSIwzPSjq3AkhCnZCUwU4em4=; b=8uSvZSyN2Kf6MO7A0WVXIqBZpcPjWwSrokqUDvePSMNZCMXdTvp4Mz2BcsSD0D1/fRbS9I yWrCVUnAmFfSuECg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 1B8B213A3C; Fri, 24 Feb 2023 10:00:41 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id qEYfBsmK+GPeTgAAMHmgww (envelope-from ); Fri, 24 Feb 2023 10:00:41 +0000 From: Vlastimil Babka To: linux-mm@kvack.org, "Liam R. Howlett" Cc: linux-kernel@vger.kernel.org, patches@lists.linux.dev, maple-tree@lists.infradead.org, Vlastimil Babka Subject: [RFC 01/11] mm/mremap: fix dup_anon_vma() in vma_merge() case 4 Date: Fri, 24 Feb 2023 11:00:12 +0100 Message-Id: <20230224100022.11268-2-vbabka@suse.cz> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230224100022.11268-1-vbabka@suse.cz> References: <20230224100022.11268-1-vbabka@suse.cz> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit In case 4, we are shrinking 'prev' (PPPP in the comment) and expanding 'mid' (NNNN). So we need to make sure 'mid' clones the anon_vma from 'prev', if it doesn't have any. After commit 0503ea8f5ba7 ("mm/mmap: remove __vma_adjust()") we can fail to do that due to wrong parameters for dup_anon_vma(). The call is a no-op because res == next, adjust == mid and mid == next. Fix it. Fixes: 0503ea8f5ba7 ("mm/mmap: remove __vma_adjust()") Signed-off-by: Vlastimil Babka --- mm/mmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/mmap.c b/mm/mmap.c index 20f21f0949dd..740b54be3ed4 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -973,7 +973,7 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm, vma_end = addr; adjust = mid; adj_next = -(vma->vm_end - addr); - err = dup_anon_vma(res, adjust); + err = dup_anon_vma(adjust, prev); } else { vma = next; /* case 3 */ vma_start = addr; -- 2.39.2