From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jbMdI-0003mp-Hw for linux-um@lists.infradead.org; Wed, 20 May 2020 11:11:34 +0000 Date: Wed, 20 May 2020 20:11:26 +0900 From: Masami Hiramatsu Subject: Re: [PATCH 13/20] maccess: always use strict semantics for probe_kernel_read Message-Id: <20200520201126.f37d3b1e46355199216404e2@kernel.org> In-Reply-To: <20200519134449.1466624-14-hch@lst.de> References: <20200519134449.1466624-1-hch@lst.de> <20200519134449.1466624-14-hch@lst.de> Mime-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-um" Errors-To: linux-um-bounces+geert=linux-m68k.org@lists.infradead.org To: Christoph Hellwig Cc: linux-parisc@vger.kernel.org, Daniel Borkmann , netdev@vger.kernel.org, x86@kernel.org, linux-um@lists.infradead.org, Alexei Starovoitov , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Linus Torvalds , bpf@vger.kernel.org T24gVHVlLCAxOSBNYXkgMjAyMCAxNTo0NDo0MiArMDIwMApDaHJpc3RvcGggSGVsbHdpZyA8aGNo QGxzdC5kZT4gd3JvdGU6Cgo+IGRpZmYgLS1naXQgYS9rZXJuZWwvdHJhY2UvdHJhY2Vfa3Byb2Jl LmMgYi9rZXJuZWwvdHJhY2UvdHJhY2Vfa3Byb2JlLmMKPiBpbmRleCAyZjY3MzdjYzUzZTZjLi44 MmRhMjBlNzEyNTA3IDEwMDY0NAo+IC0tLSBhL2tlcm5lbC90cmFjZS90cmFjZV9rcHJvYmUuYwo+ ICsrKyBiL2tlcm5lbC90cmFjZS90cmFjZV9rcHJvYmUuYwo+IEBAIC0xMjA4LDcgKzEyMDgsMTMg QEAgZmV0Y2hfc3RvcmVfc3RybGVuKHVuc2lnbmVkIGxvbmcgYWRkcikKPiAgCXU4IGM7Cj4gIAo+ ICAJZG8gewo+IC0JCXJldCA9IHByb2JlX2tlcm5lbF9yZWFkKCZjLCAodTggKilhZGRyICsgbGVu LCAxKTsKPiArCQlpZiAoSVNfRU5BQkxFRChDT05GSUdfQVJDSF9IQVNfTk9OX09WRVJMQVBQSU5H X0FERFJFU1NfU1BBQ0UpICYmCj4gKwkJICAgICh1bnNpZ25lZCBsb25nKWFkZHIgPCBUQVNLX1NJ WkUpIHsKPiArCQkJcmV0ID0gcHJvYmVfdXNlcl9yZWFkKCZjLAo+ICsJCQkJKF9fZm9yY2UgdTgg X191c2VyICopYWRkciArIGxlbiwgMSk7Cj4gKwkJfSBlbHNlIHsKPiArCQkJcmV0ID0gcHJvYmVf a2VybmVsX3JlYWQoJmMsICh1OCAqKWFkZHIgKyBsZW4sIDEpOwo+ICsJCX0KPiAgCQlsZW4rKzsK PiAgCX0gd2hpbGUgKGMgJiYgcmV0ID09IDAgJiYgbGVuIDwgTUFYX1NUUklOR19TSVpFKTsKClRv IGF2b2lkIHJlZHVuZGFudCBjaGVjayBpbiB0aGUgbG9vcCwgd2UgY2FuIHVzZSBzdHJubGVuX3Vz ZXJfbm9mYXVsdCgpIG91dCBvZgp0aGUgbG9vcC4gU29tZXRoaW5nIGxpa2UgYmVsb3cuCgouLi4K CXU4IGM7CgoJaWYgKElTX0VOQUJMRUQoQ09ORklHX0FSQ0hfSEFTX05PTl9PVkVSTEFQUElOR19B RERSRVNTX1NQQUNFKSAmJgoJICAgICh1bnNpZ25lZCBsb25nKWFkZHIgPCBUQVNLX1NJWkUpIHsK CQlyZXR1cm4gc3Rybmxlbl91c2VyX25vZmF1bHQoKF9fZm9yY2UgdTggX191c2VyICopYWRkciwg TUFYX1NUUklOR19TSVpFKTsKCglkbyB7CgkJcmV0ID0gcHJvYmVfa2VybmVsX3JlYWQoJmMsICh1 OCAqKWFkZHIgKyBsZW4sIDEpOwoJCWxlbisrOwoJfSB3aGlsZSAoYyAmJiByZXQgPT0gMCAmJiBs ZW4gPCBNQVhfU1RSSU5HX1NJWkUpOwouLi4KClRoaXMgbXVzdCB3b3JrIGJlY2F1c2Ugd2UgbXVz dCBub3QgaGF2ZSBhIHN0cmluZyB0aGF0IGNvbnRpbnVlcyBhY3Jvc3MKa2VybmVs44CAc3BhY2Ug YW5kIHVzZXIgc3BhY2UuCgpUaGFuayB5b3UsCgoKLS0gCk1hc2FtaSBIaXJhbWF0c3UgPG1oaXJh bWF0QGtlcm5lbC5vcmc+CgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fXwpsaW51eC11bSBtYWlsaW5nIGxpc3QKbGludXgtdW1AbGlzdHMuaW5mcmFkZWFkLm9y ZwpodHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2xpbnV4LXVtCg==