From: Linus Torvalds <torvalds@linux-foundation.org>
To: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
"Andrea Arcangeli" <aarcange@redhat.com>,
"Andrew Lutomirski" <luto@kernel.org>,
"Kees Cook" <keescook@google.com>,
"Hugh Dickins" <hughd@google.com>,
"Jürgen Groß" <jgross@suse.com>,
"the arch/x86 maintainers" <x86@kernel.org>,
namit@vmware.com
Subject: Re: [PATCH 01/11] x86/mm: factor out pageattr _PAGE_GLOBAL setting
Date: Mon, 2 Apr 2018 10:52:34 -0700 [thread overview]
Message-ID: <CA+55aFw7mLJrr+VqvEY-T3KqR2-xaYSoyU2Jg7VY1Sb1cu1L-w@mail.gmail.com> (raw)
In-Reply-To: <20180402172701.5D4CA7DD@viggo.jf.intel.com>
On Mon, Apr 2, 2018 at 10:27 AM, Dave Hansen
<dave.hansen@linux.intel.com> wrote:
>
> Aside: _PAGE_GLOBAL is ignored when CR4.PGE=1, so why do we
> even go to the trouble of filtering it anywhere?
I'm assuming this is a typo, and you mean "when CR4.PGE=0".
The question you raise may be valid, but within the particular context
of *this* patch it is not.
In the context of this particular patch, the issue is that we use
_PAGE_GLOBAL as _PAGE_BIT_PROTNONE when the present bit isn't set.
Linus
next prev parent reply other threads:[~2018-04-02 17:52 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-02 17:27 [PATCH 00/11] [v3] Use global pages with PTI Dave Hansen
2018-04-02 17:27 ` [PATCH 01/11] x86/mm: factor out pageattr _PAGE_GLOBAL setting Dave Hansen
2018-04-02 17:52 ` Linus Torvalds [this message]
2018-04-02 20:23 ` Dave Hansen
2018-04-02 17:27 ` [PATCH 02/11] x86/mm: undo double _PAGE_PSE clearing Dave Hansen
2018-04-02 17:27 ` [PATCH 03/11] x86/mm: introduce "default" kernel PTE mask Dave Hansen
2018-04-02 17:27 ` [PATCH 04/11] x86/espfix: document use of _PAGE_GLOBAL Dave Hansen
2018-04-02 17:27 ` [PATCH 05/11] x86/mm: do not auto-massage page protections Dave Hansen
2018-04-02 17:27 ` [PATCH 06/11] x86/mm: remove extra filtering in pageattr code Dave Hansen
2018-04-02 17:27 ` [PATCH 07/11] x86/mm: comment _PAGE_GLOBAL mystery Dave Hansen
2018-04-02 17:27 ` [PATCH 08/11] x86/mm: do not forbid _PAGE_RW before init for __ro_after_init Dave Hansen
2018-04-02 17:27 ` [PATCH 09/11] x86/pti: enable global pages for shared areas Dave Hansen
2018-04-02 17:56 ` Linus Torvalds
2018-04-02 20:41 ` Dave Hansen
2018-04-02 17:27 ` [PATCH 10/11] x86/pti: never implicitly clear _PAGE_GLOBAL for kernel image Dave Hansen
2018-04-02 17:27 ` [PATCH 11/11] x86/pti: leave kernel text global for !PCID Dave Hansen
-- strict thread matches above, loose matches on Subject: below --
2018-04-06 20:55 [PATCH 00/11] [v5] Use global pages with PTI Dave Hansen
2018-04-06 20:55 ` [PATCH 01/11] x86/mm: factor out pageattr _PAGE_GLOBAL setting Dave Hansen
2018-04-04 1:09 [PATCH 00/11] [v4] Use global pages with PTI Dave Hansen
2018-04-04 1:09 ` [PATCH 01/11] x86/mm: factor out pageattr _PAGE_GLOBAL setting Dave Hansen
2018-03-23 17:44 [PATCH 00/11] Use global pages with PTI Dave Hansen
2018-03-23 17:44 ` [PATCH 01/11] x86/mm: factor out pageattr _PAGE_GLOBAL setting Dave Hansen
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