From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 21D8D1311AC for ; Wed, 6 Nov 2024 01:01:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730854886; cv=none; b=GA1yfEdR6+rDEs8wBrGyB10wt6safOfdkL5x8EwxhiUZTIFWQQLM2rwFtAlAIFeafy4lVZ0ILbC4zi8FSiT17dAFZwqChc9Jklc+63LSDGM395dAy/IN7gOeaAo6uSOlEBS8nngR3nThJwhMERUzNpcftV0sWxY6cm9FrPVOYQ0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730854886; c=relaxed/simple; bh=g0PthcTGOPs/yjnHwD9xJWwd/0X04BetGjDDhQAJYyM=; h=Date:To:From:Subject:Message-Id; b=XJ15AzFm4TcyvNEFjy3/5Jd3c4ESnLHQIxDKtXv+YD4PM3KQnJiDnQFdo2c8RV+bxNF4jAxVJBjm/2oKiv9TL1UjO4JZfVmq3SBuSBWlgtNdSV2bQIXZFGazyHLVOs0zguAJumIIVdA9DpXCTFiQq6MOJQducazTa2vPyknBdYQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=KHg+ca7F; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="KHg+ca7F" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ECBA3C4CECF; Wed, 6 Nov 2024 01:01:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1730854886; bh=g0PthcTGOPs/yjnHwD9xJWwd/0X04BetGjDDhQAJYyM=; h=Date:To:From:Subject:From; b=KHg+ca7FkgUIBNvSBy7H9moFN4gf5ejadtOGRwaXhAqQX5SyRcSadKdMLD68G11dC +JDOgsUI7aiiSmJgsyiiiP4CrpJmv3difsNfNs6J2VzZMuj0aqpe7RrSSygxMBLgFg V/QlEi3s1W3Yv1fjZmSPGi/Oi/YTWwla/RG5jnpc= Date: Tue, 05 Nov 2024 17:01:25 -0800 To: mm-commits@vger.kernel.org,vbabka@suse.cz,torvalds@linux-foundation.org,peterx@redhat.com,Liam.Howlett@Oracle.com,jannh@google.com,lorenzo.stoakes@oracle.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-remove-unnecessary-reset-state-logic-on-merge-new-vma.patch removed from -mm tree Message-Id: <20241106010125.ECBA3C4CECF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm: remove unnecessary reset state logic on merge new VMA has been removed from the -mm tree. Its filename was mm-remove-unnecessary-reset-state-logic-on-merge-new-vma.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Lorenzo Stoakes Subject: mm: remove unnecessary reset state logic on merge new VMA Date: Fri, 25 Oct 2024 13:26:26 +0100 The only place where this was used was in mmap_region(), which we have now adjusted to not require this to be performed (we reset ourselves in effect). It also created a dangerous assumption that VMG state could be safely reused after a merge, at which point it may have been mutated in unexpected ways, leading to subtle bugs. Note that it was discovered by Wei Yang that there was also an error in this code - we are comparing vmg->vma with prev after setting it to NULL. This however had no impact, as we previously reset VMA iterator state before attempting merge again, but it was useless effort. In any case, this patch removes all of the logic so also eliminates this wasted effort. Link: https://lkml.kernel.org/r/5d9a59eee6498ae017cc87d89aa723de7179f75d.1729858176.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Reviewed-by: Vlastimil Babka Cc: Jann Horn Cc: Liam R. Howlett Cc: Linus Torvalds Cc: Peter Xu Signed-off-by: Andrew Morton --- mm/vma.c | 11 ----------- 1 file changed, 11 deletions(-) --- a/mm/vma.c~mm-remove-unnecessary-reset-state-logic-on-merge-new-vma +++ a/mm/vma.c @@ -963,7 +963,6 @@ struct vm_area_struct *vma_merge_new_ran struct vm_area_struct *next = vmg->next; unsigned long start = vmg->start; unsigned long end = vmg->end; - pgoff_t pgoff = vmg->pgoff; pgoff_t pglen = PHYS_PFN(end - start); bool can_merge_left, can_merge_right; bool just_expand = vmg->merge_flags & VMG_FLAG_JUST_EXPAND; @@ -1020,16 +1019,6 @@ struct vm_area_struct *vma_merge_new_ran return vmg->vma; } - /* If expansion failed, reset state. Allows us to retry merge later. */ - if (!just_expand) { - vmg->vma = NULL; - vmg->start = start; - vmg->end = end; - vmg->pgoff = pgoff; - if (vmg->vma == prev) - vma_iter_set(vmg->vmi, start); - } - return NULL; } _ Patches currently in -mm which might be from lorenzo.stoakes@oracle.com are mm-pagewalk-add-the-ability-to-install-ptes.patch mm-add-pte_marker_guard-pte-marker.patch mm-madvise-implement-lightweight-guard-page-mechanism.patch tools-testing-update-tools-uapi-header-for-mman-commonh.patch selftests-mm-add-self-tests-for-guard-page-feature.patch mm-remove-unnecessary-page_table_lock-on-stack-expansion.patch