linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Nadav Amit <nadav.amit@gmail.com>
To: David Hildenbrand <david@redhat.com>
Cc: Peter Xu <peterx@redhat.com>, LKML <linux-kernel@vger.kernel.org>,
	Linux MM <linux-mm@kvack.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Andrea Arcangeli <aarcange@redhat.com>
Subject: Re: [PATCH v3 1/3] mm/mprotect: Fix soft-dirty check in can_change_pte_writable()
Date: Fri, 22 Jul 2022 10:21:00 -0700	[thread overview]
Message-ID: <C2910936-FDCF-4ECF-B014-D985284B225A@gmail.com> (raw)
In-Reply-To: <e35e42ce-e942-141d-09e7-a3a7868f4abb@redhat.com>

On Jul 22, 2022, at 12:08 AM, David Hildenbrand <david@redhat.com> wrote:

>> +static inline bool vma_soft_dirty_enabled(struct vm_area_struct *vma)
>> +{
>> +	/*
>> +	 * NOTE: we must check this before VM_SOFTDIRTY on soft-dirty
>> +	 * enablements, because when without soft-dirty being compiled in,
>> +	 * VM_SOFTDIRTY is defined as 0x0, then !(vm_flags & VM_SOFTDIRTY)
>> +	 * will be constantly true.
>> +	 */
>> +	if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
>> +		return false;
>> +
>> +	/*
>> +	 * Soft-dirty is kind of special: its tracking is enabled when the
>> +	 * vma flags not set.
>> +	 */
>> +	return !(vma->vm_flags & VM_SOFTDIRTY);
>> +}
> 
> That will come in handy in other patches I'm cooking.

clear_refs_write() also comes to mind as well (for consistency; I see no
correctness or performance issue).


  parent reply	other threads:[~2022-07-22 17:21 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-21 18:33 [PATCH v3 0/3] mm/mprotect: Fix soft-dirty checks Peter Xu
2022-07-21 18:33 ` [PATCH v3 1/3] mm/mprotect: Fix soft-dirty check in can_change_pte_writable() Peter Xu
2022-07-22  7:08   ` David Hildenbrand
2022-07-22 13:51     ` Peter Xu
2022-07-22 13:59       ` David Hildenbrand
2022-07-22 17:21     ` Nadav Amit [this message]
2022-07-25 13:59       ` Peter Xu
2022-07-25 14:11         ` David Hildenbrand
2022-07-21 18:33 ` [PATCH v3 2/3] selftests: soft-dirty: Add test for mprotect Peter Xu
2022-07-22  7:17   ` David Hildenbrand
2022-07-22 13:44     ` Peter Xu
2022-07-22 14:00       ` David Hildenbrand
2022-07-22 14:07         ` David Hildenbrand
2022-07-22 14:37           ` Peter Xu
2022-07-21 18:33 ` [PATCH v3 3/3] selftests: Add soft-dirty into run_vmtests.sh Peter Xu
2022-07-22  7:18   ` David Hildenbrand

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=C2910936-FDCF-4ECF-B014-D985284B225A@gmail.com \
    --to=nadav.amit@gmail.com \
    --cc=aarcange@redhat.com \
    --cc=akpm@linux-foundation.org \
    --cc=david@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=peterx@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).