Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 10 Jun 2022 21:04:45 +0300
From:   "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To:     "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc:     "peterz@infradead.org" <peterz@infradead.org>,
        "Lutomirski, Andy" <luto@kernel.org>,
        "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "hjl.tools@gmail.com" <hjl.tools@gmail.com>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "kcc@google.com" <kcc@google.com>,
        "andreyknvl@gmail.com" <andreyknvl@gmail.com>,
        "ak@linux.intel.com" <ak@linux.intel.com>,
        "dvyukov@google.com" <dvyukov@google.com>,
        "x86@kernel.org" <x86@kernel.org>,
        "ryabinin.a.a@gmail.com" <ryabinin.a.a@gmail.com>,
        "glider@google.com" <glider@google.com>
Subject: Re: [PATCHv3 6/8] x86/mm: Provide ARCH_GET_UNTAG_MASK and
 ARCH_ENABLE_TAGGED_ADDR
Message-ID: <20220610180445.fmzgrobscwrblxud@black.fi.intel.com>
References: <20220610143527.22974-1-kirill.shutemov@linux.intel.com>
 <20220610143527.22974-7-kirill.shutemov@linux.intel.com>
 <eb22968d0691760f579b90cd4bf75bfc4be0edeb.camel@intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <eb22968d0691760f579b90cd4bf75bfc4be0edeb.camel@intel.com>
Precedence: bulk

On Fri, Jun 10, 2022 at 03:25:02PM +0000, Edgecombe, Rick P wrote:
> On Fri, 2022-06-10 at 17:35 +0300, Kirill A. Shutemov wrote:
> > +static int prctl_enable_tagged_addr(unsigned long nr_bits)
> > +{
> > +       struct mm_struct *mm = current->mm;
> 
> do_arch_prctl_64() can be called via ptrace. I think you need to
> operate on the mm of 'task', or just block the operation if task !=
> current.

Hm. True. Let's see if the interface in general good enough.

Ouch. I just noticied that I missed check for LAM feature :/

-- 
 Kirill A. Shutemov