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From: Andy Lutomirski <luto@amacapital.net>
To: linuxram@us.ibm.com
Cc: Florian Weimer <fweimer@redhat.com>,
	Dave Hansen <dave.hansen@intel.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>
Subject: Re: [PATCH] pkeys: Introduce PKEY_ALLOC_SIGNALINHERIT and change signal semantics
Date: Wed, 02 May 2018 21:18:11 +0000	[thread overview]
Message-ID: <CALCETrUfO=vXg5rT-n=y8pLktcq5+ORvgpsOXCHG4GaugB3k2A@mail.gmail.com> (raw)
In-Reply-To: <20180502211254.GA5863@ram.oc3035372033.ibm.com>

On Wed, May 2, 2018 at 2:13 PM Ram Pai <linuxram@us.ibm.com> wrote:


> > Ram, would you please comment?

> on POWER the pkey behavior will remain the same at entry or at exit from
> the signal handler.  For eg:  if a key is read-disabled on entry into
> the signal handler, and gets read-enabled in the signal handler, than it
> will continue to be read-enabled on return from the signal handler.

> In other words, changes to key permissions persist across signal
> boundaries.

I don't know about POWER's ISA, but this is crappy behavior.  If a thread
temporarily grants itself access to a restrictive memory key and then gets
a signal, the signal handler should *not* have access to that key.

  reply	other threads:[~2018-05-02 21:18 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
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 [this message]
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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