From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yu Zhang Subject: Re: [PATCH v2 2/2] x86/mm: fix a potential race condition in modify_xen_mappings(). Date: Fri, 10 Nov 2017 22:02:47 +0800 Message-ID: <713e7e37-00ae-7bc5-c8de-6ed31abdfb99@linux.intel.com> References: <1510298286-30952-1-git-send-email-yu.c.zhang@linux.intel.com> <1510298286-30952-2-git-send-email-yu.c.zhang@linux.intel.com> <5A058608020000780018DD9C@prv-mh.provo.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; Format="flowed" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <5A058608020000780018DD9C@prv-mh.provo.novell.com> Content-Language: en-US List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: Jan Beulich Cc: Andrew Cooper , min.he@intel.com, xen-devel@lists.xen.org, yi.z.zhang@intel.com List-Id: xen-devel@lists.xenproject.org CgpPbiAxMS8xMC8yMDE3IDU6NTcgUE0sIEphbiBCZXVsaWNoIHdyb3RlOgo+Pj4+IE9uIDEwLjEx LjE3IGF0IDA4OjE4LCA8eXUuYy56aGFuZ0BsaW51eC5pbnRlbC5jb20+IHdyb3RlOgo+PiAtLS0g YS94ZW4vYXJjaC94ODYvbW0uYwo+PiArKysgYi94ZW4vYXJjaC94ODYvbW0uYwo+PiBAQCAtNTA5 Nyw2ICs1MDk3LDE3IEBAIGludCBtb2RpZnlfeGVuX21hcHBpbmdzKHVuc2lnbmVkIGxvbmcgcywg dW5zaWduZWQgbG9uZyBlLCB1bnNpZ25lZCBpbnQgbmYpCj4+ICAgICAgICAgICAgICAgICovCj4+ ICAgICAgICAgICAgICAgaWYgKCAobmYgJiBfUEFHRV9QUkVTRU5UKSB8fCAoKHYgIT0gZSkgJiYg KGwxX3RhYmxlX29mZnNldCh2KSAhPSAwKSkgKQo+PiAgICAgICAgICAgICAgICAgICBjb250aW51 ZTsKPj4gKyAgICAgICAgICAgIGlmICggbG9ja2luZyApCj4+ICsgICAgICAgICAgICAgICAgc3Bp bl9sb2NrKCZtYXBfcGdkaXJfbG9jayk7Cj4+ICsKPj4gKyAgICAgICAgICAgIC8qIEwyRSBtYXkg YmUgY2xlYXJlZCBvbiBhbm90aGVyIENQVS4gKi8KPj4gKyAgICAgICAgICAgIGlmICggIShsMmVf Z2V0X2ZsYWdzKCpwbDJlKSAmIF9QQUdFX1BSRVNFTlQpICkKPiBJIHRoaW5rIHlvdSBhbHNvIG5l ZWQgYSBQU0UgY2hlY2sgaGVyZSwgb3IgZWxzZSB0aGUgbDJlX3RvX2wxZSgpIGJlbG93Cj4gbWF5 IGJlIGlsbGVnYWwuCgpIbW0sIGludGVyZXN0aW5nIHBvaW50LCBhbmQgdGhhbmtzISA6LSkKSSBk aWQgbm90IGNoZWNrIHRoZSBQU0UsIGJlY2F1c2UgbW9kaWZ5X3hlbl9tYXBwaW5ncygpIHdpbGwg bm90IGRvIHRoZSAKcmUtY29uc29saWRhdGlvbiwgYW5kCmNvbmN1cnJlbnQgaW52b2tlcyBvZiB0 aGlzIHJvdXRpbmUgd2lsbCBub3QgY2hhbmdlIHRoaXMgZmxhZy4gQnV0IG5vdyBJIApiZWxpZXZl IHRoaXMgcHJlc3VtcHRpb24Kc2hhbGwgbm90IGJlIG1hZGUsIGJlY2F1c2UgdGhlIHBhZ2luZyBz dHJ1Y3R1cmVzIG1heSBiZSBtb2RpZmllZCBieSAKb3RoZXIgcm91dGluZXMsIGxpa2UKbWFwX3Bh Z2VzX3RvX3hlbigpIG9uIG90aGVyIENQVXMuCgpTbyB5ZXMsIEkgdGhpbmsgYSBfUEFHRV9QU0Ug Y2hlY2sgaXMgbmVjZXNzYXJ5IGhlcmUuIEFuZCBJIHN1Z2dlc3Qgd2UgCmFsc28gY2hlY2sgdGhl IF9QQUdFX1BSRVNFTlQKZmxhZyBhcyB3ZWxsLCBmb3IgdGhlIHJlLWNvbnNvbGlkYXRpb24gcGFy dCBpbiBteSBmaXJzdCBwYXRjaCBmb3IgCm1hcF9wYWdlc190b194ZW4oKS4gRG8geW91IGFncmVl PwoKPj4gQEAgLTUxMDUsMTEgKzUxMTYsMTYgQEAgaW50IG1vZGlmeV94ZW5fbWFwcGluZ3ModW5z aWduZWQgbG9uZyBzLCB1bnNpZ25lZCBsb25nIGUsIHVuc2lnbmVkIGludCBuZikKPj4gICAgICAg ICAgICAgICB7Cj4+ICAgICAgICAgICAgICAgICAgIC8qIEVtcHR5OiB6YXAgdGhlIEwyRSBhbmQg ZnJlZSB0aGUgTDEgcGFnZS4gKi8KPj4gICAgICAgICAgICAgICAgICAgbDJlX3dyaXRlX2F0b21p YyhwbDJlLCBsMmVfZW1wdHkoKSk7Cj4+ICsgICAgICAgICAgICAgICAgaWYgKCBsb2NraW5nICkK Pj4gKyAgICAgICAgICAgICAgICAgICAgc3Bpbl91bmxvY2soJm1hcF9wZ2Rpcl9sb2NrKTsKPj4g ICAgICAgICAgICAgICAgICAgZmx1c2hfYXJlYShOVUxMLCBGTFVTSF9UTEJfR0xPQkFMKTsgLyog Zmx1c2ggYmVmb3JlIGZyZWUgKi8KPj4gICAgICAgICAgICAgICAgICAgZnJlZV94ZW5fcGFnZXRh YmxlKHBsMWUpOwo+PiAgICAgICAgICAgICAgIH0KPj4gKyAgICAgICAgICAgIGVsc2UgaWYgKCBs b2NraW5nICkKPj4gKyAgICAgICAgICAgICAgICBzcGluX3VubG9jaygmbWFwX3BnZGlyX2xvY2sp Owo+PiAgICAgICAgICAgfQo+PiAgIAo+PiArY2hlY2tfbDM6Cj4gTGFiZWxzIGluZGVudGVkIGJ5 IGF0IGxlYXN0IG9uZSBzcGFjZSBwbGVhc2UuCgpHb3QgaXQgLiBUaGFua3MuCgpZdQo+Cj4gSmFu Cj4KPgoKCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fClhl bi1kZXZlbCBtYWlsaW5nIGxpc3QKWGVuLWRldmVsQGxpc3RzLnhlbi5vcmcKaHR0cHM6Ly9saXN0 cy54ZW4ub3JnL3hlbi1kZXZlbAo=