From: Dave Hansen <dave.hansen@intel.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>,
Florian Weimer <fweimer@redhat.com>,
Linux-MM <linux-mm@kvack.org>,
Linux API <linux-api@vger.kernel.org>,
linux-x86_64@vger.kernel.org,
linux-arch <linux-arch@vger.kernel.org>, X86 ML <x86@kernel.org>,
linuxram@us.ibm.com
Subject: Re: [PATCH] pkeys: Introduce PKEY_ALLOC_SIGNALINHERIT and change signal semantics
Date: Wed, 2 May 2018 16:58:25 -0700 [thread overview]
Message-ID: <cf71c470-9712-ce7c-a84a-f78468ebb4a8@intel.com> (raw)
In-Reply-To: <2BE03B9A-B1E0-4707-8705-203F88B62A1C@amacapital.net>
On 05/02/2018 04:32 PM, Andy Lutomirski wrote:
>> But, where do those come from in this scenario? I'm not getting
>> the secondary mechanism is that *makes* them unsafe.
> pkey_alloc() itself. If someone tries to allocate a key with a given
> default mode, unless there’s already a key that already had that
> value in all threads or pkey_alloc() needs to asynchronously create
> such a key.
I think you are saying: If a thread calls pkey_alloc(), all threads
should, by default, implicitly get access. That
broadcast-to-other-threads is the thing that the current architecture
doesn't do. In this situation, CPU threads have to go opt-out of
getting access to data protected with a given, allocated key.
Right?
WARNING: multiple messages have this Message-ID (diff)
From: Dave Hansen <dave.hansen@intel.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>,
Florian Weimer <fweimer@redhat.com>,
Linux-MM <linux-mm@kvack.org>,
Linux API <linux-api@vger.kernel.org>,
linux-x86_64@vger.kernel.org,
linux-arch <linux-arch@vger.kernel.org>, X86 ML <x86@kernel.org>,
linuxram@us.ibm.com
Subject: Re: [PATCH] pkeys: Introduce PKEY_ALLOC_SIGNALINHERIT and change signal semantics
Date: Wed, 2 May 2018 16:58:25 -0700 [thread overview]
Message-ID: <cf71c470-9712-ce7c-a84a-f78468ebb4a8@intel.com> (raw)
In-Reply-To: <2BE03B9A-B1E0-4707-8705-203F88B62A1C@amacapital.net>
On 05/02/2018 04:32 PM, Andy Lutomirski wrote:
>> But, where do those come from in this scenario? I'm not getting
>> the secondary mechanism is that *makes* them unsafe.
> pkey_alloc() itself. If someone tries to allocate a key with a given
> default mode, unless therea??s already a key that already had that
> value in all threads or pkey_alloc() needs to asynchronously create
> such a key.
I think you are saying: If a thread calls pkey_alloc(), all threads
should, by default, implicitly get access. That
broadcast-to-other-threads is the thing that the current architecture
doesn't do. In this situation, CPU threads have to go opt-out of
getting access to data protected with a given, allocated key.
Right?
next prev parent reply other threads:[~2018-05-02 23:58 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-02 13:26 [PATCH] pkeys: Introduce PKEY_ALLOC_SIGNALINHERIT and change signal semantics Florian Weimer
2018-05-02 14:30 ` Dave Hansen
2018-05-02 15:12 ` Florian Weimer
2018-05-02 15:12 ` Florian Weimer
2018-05-02 15:28 ` Dave Hansen
2018-05-02 15:28 ` Dave Hansen
2018-05-02 21:08 ` Florian Weimer
2018-05-02 22:03 ` Dave Hansen
2018-05-02 22:03 ` Dave Hansen
2018-05-07 9:47 ` Florian Weimer
2018-05-07 9:47 ` Florian Weimer
2018-05-02 17:09 ` Andy Lutomirski
2018-05-02 17:17 ` Florian Weimer
2018-05-02 17:17 ` Florian Weimer
2018-05-02 20:41 ` Andy Lutomirski
2018-05-02 21:06 ` Florian Weimer
2018-05-02 21:06 ` Florian Weimer
2018-05-02 21:23 ` Andy Lutomirski
2018-05-02 22:08 ` Dave Hansen
2018-05-02 22:22 ` Andy Lutomirski
2018-05-02 22:32 ` Dave Hansen
2018-05-02 23:32 ` Andy Lutomirski
2018-05-02 23:58 ` Dave Hansen [this message]
2018-05-02 23:58 ` Dave Hansen
2018-05-03 1:14 ` Andy Lutomirski
2018-05-03 14:42 ` Dave Hansen
2018-05-03 14:42 ` Dave Hansen
2018-05-03 14:42 ` Florian Weimer
2018-05-03 14:42 ` Florian Weimer
2018-05-03 2:10 ` Ram Pai
2018-05-03 4:05 ` Andy Lutomirski
2018-05-07 9:48 ` Florian Weimer
2018-05-08 2:49 ` Andy Lutomirski
2018-05-08 2:49 ` Andy Lutomirski
2018-05-08 12:40 ` Florian Weimer
2018-05-08 12:40 ` Florian Weimer
2018-05-09 14:41 ` Andy Lutomirski
2018-05-09 14:41 ` Andy Lutomirski
2018-05-14 12:01 ` Florian Weimer
2018-05-14 12:01 ` Florian Weimer
2018-05-14 15:32 ` Andy Lutomirski
2018-05-14 15:32 ` Andy Lutomirski
2018-05-14 15:32 ` Andy Lutomirski
2018-05-14 15:34 ` Florian Weimer
2018-05-14 15:34 ` Florian Weimer
2018-05-14 15:34 ` Florian Weimer
2018-05-16 17:01 ` Dave Hansen
2018-05-16 17:01 ` Dave Hansen
2018-05-16 17:01 ` Dave Hansen
2018-05-16 20:52 ` Ram Pai
2018-05-16 20:52 ` Ram Pai
2018-05-16 20:54 ` Andy Lutomirski
2018-05-16 20:54 ` Andy Lutomirski
2018-05-16 20:35 ` Ram Pai
2018-05-16 20:35 ` Ram Pai
2018-05-16 20:37 ` Andy Lutomirski
2018-05-16 20:37 ` Andy Lutomirski
2018-05-16 21:07 ` Ram Pai
2018-05-16 21:07 ` Ram Pai
2018-05-17 10:09 ` Florian Weimer
2018-05-17 10:09 ` Florian Weimer
2018-05-17 10:11 ` Florian Weimer
2018-05-17 10:11 ` Florian Weimer
2018-05-03 14:37 ` Florian Weimer
2018-05-02 21:12 ` Ram Pai
2018-05-02 21:12 ` Ram Pai
2018-05-02 21:18 ` Andy Lutomirski
2018-05-02 23:38 ` Ram Pai
2018-05-02 23:38 ` Ram Pai
2018-05-07 9:47 ` Florian Weimer
2018-05-07 9:47 ` Florian Weimer
2018-05-07 9:43 ` Florian Weimer
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