From: Dave Hansen <dave.hansen@intel.com>
To: David Laight <David.Laight@ACULAB.COM>,
'Bharata B Rao' <bharata@amd.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>,
"x86@kernel.org" <x86@kernel.org>,
"kirill.shutemov@linux.intel.com"
<kirill.shutemov@linux.intel.com>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"mingo@redhat.com" <mingo@redhat.com>,
"bp@alien8.de" <bp@alien8.de>,
"dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
"will@kernel.org" <will@kernel.org>,
"shuah@kernel.org" <shuah@kernel.org>,
"oleg@redhat.com" <oleg@redhat.com>,
"ananth.narayan@amd.com" <ananth.narayan@amd.com>
Subject: Re: [RFC PATCH v0 0/6] x86/AMD: Userspace address tagging
Date: Thu, 10 Mar 2022 08:45:44 -0800 [thread overview]
Message-ID: <286efdb9-7dbf-82f3-b172-29c575a3791b@intel.com> (raw)
In-Reply-To: <699fb763ac054833bc8c29c9814c63b2@AcuMS.aculab.com>
On 3/10/22 06:32, David Laight wrote:
>> UAI allows software to store a tag in the upper 7 bits of a logical
>> address [63:57]. When enabled, the processor will suppress the
>> traditional canonical address checks on the addresses. More information
>> about UAI can be found in section 5.10 of 'AMD64 Architecture
>> Programmer's Manual, Vol 2: System Programming' which is available from
>>
>> https://bugzilla.kernel.org/attachment.cgi?id=300549
> Is that really allowing bit 63 to be used?
> That is normally the user-kernel bit.
> I can't help feeling that will just badly break things.
Yeah, this does seem worrisome. The LAM approach[1] retains
canonicality checking for bit 63.
1.
https://www.intel.com/content/www/us/en/develop/download/intel-architecture-instruction-set-extensions-programming-reference.html
next prev parent reply other threads:[~2022-03-10 16:47 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-10 11:15 [RFC PATCH v0 0/6] x86/AMD: Userspace address tagging Bharata B Rao
2022-03-10 11:15 ` [RFC PATCH v0 1/6] mm, arm64: Update PR_SET/GET_TAGGED_ADDR_CTRL interface Bharata B Rao
2022-03-10 11:15 ` [RFC PATCH v0 2/6] x86/cpufeatures: Add Upper Address Ignore(UAI) as CPU feature Bharata B Rao
2022-03-10 11:15 ` [RFC PATCH v0 3/6] x86: Enable Upper Address Ignore(UAI) feature Bharata B Rao
2022-03-10 19:46 ` Andrew Cooper
2022-03-10 22:37 ` David Laight
2022-03-10 22:46 ` Dave Hansen
2022-03-11 12:37 ` Boris Petkov
2022-03-10 11:15 ` [RFC PATCH v0 4/6] x86: Provide an implementation of untagged_addr() Bharata B Rao
2022-03-10 11:15 ` [RFC PATCH v0 5/6] x86: Untag user pointers in access_ok() Bharata B Rao
2022-03-10 11:15 ` [RFC PATCH v0 6/6] x86: Add prctl() options to control tagged user addresses ABI Bharata B Rao
2022-03-10 14:32 ` [RFC PATCH v0 0/6] x86/AMD: Userspace address tagging David Laight
2022-03-10 16:45 ` Dave Hansen [this message]
2022-03-10 17:19 ` David Laight
2022-03-11 5:42 ` Bharata B Rao
2022-03-11 8:15 ` David Laight
2022-03-11 9:11 ` Bharata B Rao
2022-03-11 9:36 ` David Laight
2022-03-11 16:51 ` Dave Hansen
2022-03-10 15:16 ` Dave Hansen
2022-03-10 15:22 ` Dave Hansen
2022-03-14 5:00 ` Bharata B Rao
2022-03-14 7:03 ` Dave Hansen
2022-03-21 22:29 ` Andy Lutomirski
2022-03-21 22:59 ` Thomas Gleixner
2022-03-22 5:31 ` David Laight
2022-03-23 7:48 ` Bharata B Rao
2022-04-01 19:25 ` Dave Hansen
2022-04-05 5:58 ` Bharata B Rao
2022-04-01 19:41 ` Andy Lutomirski
2022-04-05 8:14 ` Peter Zijlstra
2022-04-05 8:40 ` Bharata B Rao
2022-04-08 17:41 ` Catalin Marinas
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=286efdb9-7dbf-82f3-b172-29c575a3791b@intel.com \
--to=dave.hansen@intel.com \
--cc=David.Laight@ACULAB.COM \
--cc=ananth.narayan@amd.com \
--cc=bharata@amd.com \
--cc=bp@alien8.de \
--cc=catalin.marinas@arm.com \
--cc=dave.hansen@linux.intel.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mingo@redhat.com \
--cc=oleg@redhat.com \
--cc=shuah@kernel.org \
--cc=tglx@linutronix.de \
--cc=will@kernel.org \
--cc=x86@kernel.org \
/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).