linux-kernel - Re: [PATCH v9 16/17] mm: make vma cache SLAB_TYPESAFE_BY

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250115022703.hqbqdqawvqgrfgxb@master>
Date: Wed, 15 Jan 2025 02:27:03 +0000
From: Wei Yang <richard.weiyang@...il.com>
To: Suren Baghdasaryan <surenb@...gle.com>
Cc: akpm@...ux-foundation.org, peterz@...radead.org, willy@...radead.org,
	liam.howlett@...cle.com, lorenzo.stoakes@...cle.com,
	david.laight.linux@...il.com, mhocko@...e.com, vbabka@...e.cz,
	hannes@...xchg.org, mjguzik@...il.com, oliver.sang@...el.com,
	mgorman@...hsingularity.net, david@...hat.com, peterx@...hat.com,
	oleg@...hat.com, dave@...olabs.net, paulmck@...nel.org,
	brauner@...nel.org, dhowells@...hat.com, hdanton@...a.com,
	hughd@...gle.com, lokeshgidra@...gle.com, minchan@...gle.com,
	jannh@...gle.com, shakeel.butt@...ux.dev, souravpanda@...gle.com,
	pasha.tatashin@...een.com, klarasmodin@...il.com,
	richard.weiyang@...il.com, corbet@....net,
	linux-doc@...r.kernel.org, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org, kernel-team@...roid.com
Subject: Re: [PATCH v9 16/17] mm: make vma cache SLAB_TYPESAFE_BY_RCU

On Fri, Jan 10, 2025 at 08:26:03PM -0800, Suren Baghdasaryan wrote:

>diff --git a/kernel/fork.c b/kernel/fork.c
>index 9d9275783cf8..151b40627c14 100644
>--- a/kernel/fork.c
>+++ b/kernel/fork.c
>@@ -449,6 +449,42 @@ struct vm_area_struct *vm_area_alloc(struct mm_struct *mm)
> 	return vma;
> }
> 
>+static void vm_area_init_from(const struct vm_area_struct *src,
>+			      struct vm_area_struct *dest)
>+{
>+	dest->vm_mm = src->vm_mm;
>+	dest->vm_ops = src->vm_ops;
>+	dest->vm_start = src->vm_start;
>+	dest->vm_end = src->vm_end;
>+	dest->anon_vma = src->anon_vma;
>+	dest->vm_pgoff = src->vm_pgoff;
>+	dest->vm_file = src->vm_file;
>+	dest->vm_private_data = src->vm_private_data;
>+	vm_flags_init(dest, src->vm_flags);
>+	memcpy(&dest->vm_page_prot, &src->vm_page_prot,
>+	       sizeof(dest->vm_page_prot));
>+	/*
>+	 * src->shared.rb may be modified concurrently when called from
>+	 * dup_mmap(), but the clone will reinitialize it.
>+	 */
>+	data_race(memcpy(&dest->shared, &src->shared, sizeof(dest->shared)));
>+	memcpy(&dest->vm_userfaultfd_ctx, &src->vm_userfaultfd_ctx,
>+	       sizeof(dest->vm_userfaultfd_ctx));
>+#ifdef CONFIG_ANON_VMA_NAME
>+	dest->anon_name = src->anon_name;
>+#endif
>+#ifdef CONFIG_SWAP
>+	memcpy(&dest->swap_readahead_info, &src->swap_readahead_info,
>+	       sizeof(dest->swap_readahead_info));
>+#endif
>+#ifndef CONFIG_MMU
>+	dest->vm_region = src->vm_region;
>+#endif
>+#ifdef CONFIG_NUMA
>+	dest->vm_policy = src->vm_policy;
>+#endif
>+}

Would this be difficult to maintain? We should make sure not miss or overwrite
anything.

-- 
Wei Yang
Help you, Help me