From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELuy0gF9I8A2f5Aedo5DDxgEM2MMzoTZSY5E30xO3MUwCg7CcPtpM4PcgBBOGOVeC6uU56mN ARC-Seal: i=1; a=rsa-sha256; t=1520285207; cv=none; d=google.com; s=arc-20160816; b=QH56Ribhi9bmsQQH26Zag4WxFQUE6qaMe/4I3/N7XD9VqR8ssD6nl+d0zVzmAhtO2d HyG8N2q5LTTaGXUFTp0P2c9TIzoU+IwX4C9dTTHzh1DZ5LvrW5n18J5bQ8VWkRegcOBd SRGL/6otQgjU9dM2tBpGLQBqH031x+ObZD+HoRO1MaUzGZ8nDPLPrXW8ppz5sp4W2wps c7S+orVuveh8+hSxAMO6WQQMecneiqbHk1u1qWB5PX8ranjamkv3gkP/+8M6unTH2LO7 8Ui8axEs5UN2brcOqLDFeM5AQvlMFiAyrCpRTT6wqE8dz0LfTFHkkbQyoxsAhc57KFHR 6qeg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:cc:references:to:subject :arc-authentication-results; bh=/6QJf62VCk4EC8JVdNGHs2blKGNhLaUIiKD4TDTs9E4=; b=eU4VI1H9252dAWIVGuBDKBFYVtKHXyfvjH4PnyD2BcrVZFrIrZYVoHI++8yFokO3/X JinRmVp8FaduWjxINxITg9Pv8cXF++aV80uJSUgUMzBwXrenNQcZfiUtof7Ouzt2AqYm vncfEVEk5gvYw/bcpFf6xc0fqGLc0fxT+pv32BjBtOB1mofflkw3RYiILsg3LHl37Xq0 R3ue174rXTZ5apiHQ1YXBYbNgFlK7HC9FVphSnYF/fJuf2GnMCJjGGiJHgkEw8wwSr1I Tl66tIkLPcjm/fOlbLumx188LBLPoBXzqlrjuWss7vggpU/KTBDmX2FrdPlN/KijdeI4 ai/Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of dave.hansen@linux.intel.com designates 134.134.136.65 as permitted sender) smtp.mailfrom=dave.hansen@linux.intel.com Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of dave.hansen@linux.intel.com designates 134.134.136.65 as permitted sender) smtp.mailfrom=dave.hansen@linux.intel.com X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.47,428,1515484800"; d="scan'208";a="180108912" Subject: Re: [PATCH v12 10/11] sparc64: Add support for ADI (Application Data Integrity) To: Khalid Aziz , davem@davemloft.net, akpm@linux-foundation.org References: <84931753-9a84-8624-adb8-95bd05d87d56@oracle.com> Cc: corbet@lwn.net, bob.picco@oracle.com, steven.sistare@oracle.com, pasha.tatashin@oracle.com, mike.kravetz@oracle.com, rob.gardner@oracle.com, mingo@kernel.org, nitin.m.gupta@oracle.com, anthony.yznaga@oracle.com, kirill.shutemov@linux.intel.com, tom.hromatka@oracle.com, allen.pais@oracle.com, tklauser@distanz.ch, shannon.nelson@oracle.com, vijay.ac.kumar@oracle.com, mhocko@suse.com, jack@suse.cz, punit.agrawal@arm.com, hughd@google.com, thomas.tai@oracle.com, ross.zwisler@linux.intel.com, dave.jiang@intel.com, willy@infradead.org, minchan@kernel.org, imbrenda@linux.vnet.ibm.com, aarcange@redhat.com, kstewart@linuxfoundation.org, pombredanne@nexb.com, tglx@linutronix.de, gregkh@linuxfoundation.org, nagarathnam.muthusamy@oracle.com, linux@roeck-us.net, jane.chu@oracle.com, dan.j.williams@intel.com, jglisse@redhat.com, ktkhai@virtuozzo.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, sparclinux@vger.kernel.org, Khalid Aziz From: Dave Hansen Message-ID: <098cda37-0e3c-de44-5995-9e5f74b301c6@linux.intel.com> Date: Mon, 5 Mar 2018 13:26:45 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <84931753-9a84-8624-adb8-95bd05d87d56@oracle.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1593031948178483523?= X-GMAIL-MSGID: =?utf-8?q?1594134581747470361?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 03/05/2018 01:14 PM, Khalid Aziz wrote: > On 03/05/2018 12:22 PM, Dave Hansen wrote: >> On 02/21/2018 09:15 AM, Khalid Aziz wrote: >>> +#define arch_validate_prot(prot, addr) sparc_validate_prot(prot, addr) >>> +static inline int sparc_validate_prot(unsigned long prot, unsigned >>> long addr) >>> +{ >>> +    if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | >>> PROT_ADI)) >>> +        return 0; >>> +    if (prot & PROT_ADI) { >>> +        if (!adi_capable()) >>> +            return 0; >>> + >>> +        if (addr) { >>> +            struct vm_area_struct *vma; >>> + >>> +            vma = find_vma(current->mm, addr); >>> +            if (vma) { >>> +                /* ADI can not be enabled on PFN >>> +                 * mapped pages >>> +                 */ >>> +                if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP)) >>> +                    return 0; >> >> You don't hold mmap_sem here.  How can this work? >> > Are you suggesting that vma returned by find_vma() could be split or > merged underneath me if I do not hold mmap_sem and thus make the flag > check invalid? If so, that is a good point. Um, yes. You can't walk the vma tree without holding mmap_sem.