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 1jXCnl-0002nG-E5 for kexec@lists.infradead.org; Fri, 08 May 2020 23:53:10 +0000 Date: Fri, 8 May 2020 16:53:06 -0700 From: Andrew Morton Subject: Re: [PATCH v4 1/4] device-dax: Don't leak kernel memory to user space after unloading kmem Message-Id: <20200508165306.7cd806f7e451c5c9bc2a40ac@linux-foundation.org> In-Reply-To: <20200508084217.9160-2-david@redhat.com> References: <20200508084217.9160-1-david@redhat.com> <20200508084217.9160-2-david@redhat.com> 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: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: David Hildenbrand Cc: Dave Jiang , Pavel Tatashin , linux-nvdimm@lists.01.org, Vishal Verma , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux-mm@kvack.org, Dan Williams T24gRnJpLCAgOCBNYXkgMjAyMCAxMDo0MjoxNCArMDIwMCBEYXZpZCBIaWxkZW5icmFuZCA8ZGF2 aWRAcmVkaGF0LmNvbT4gd3JvdGU6Cgo+IEFzc3VtZSB3ZSBoYXZlIGttZW0gY29uZmlndXJlZCBh bmQgbG9hZGVkOgo+ICAgW3Jvb3RAbG9jYWxob3N0IH5dIyBjYXQgL3Byb2MvaW9tZW0KPiAgIC4u Lgo+ICAgMTQwMDAwMDAwLTMzZmZmZmZmZiA6IFBlcnNpc3RlbnQgTWVtb3J5JAo+ICAgICAxNDAw MDAwMDAtMTQ4MWZmZmZmIDogbmFtZXNwYWNlMC4wCj4gICAgIDE1MDAwMDAwMC0zM2ZmZmZmZmYg OiBkYXgwLjAKPiAgICAgICAxNTAwMDAwMDAtMzNmZmZmZmZmIDogU3lzdGVtIFJBTQo+IAo+IEFz c3VtZSB3ZSB0cnkgdG8gdW5sb2FkIGttZW0uIFRoaXMgZm9yY2UtdW5sb2FkaW5nIHdpbGwgd29y aywgZXZlbiBpZgo+IG1lbW9yeSBjYW5ub3QgZ2V0IHJlbW92ZWQgZnJvbSB0aGUgc3lzdGVtLgo+ ICAgW3Jvb3RAbG9jYWxob3N0IH5dIyBybW1vZCBrbWVtCj4gICBbICAgODYuMzgwMjI4XSByZW1v dmluZyBtZW1vcnkgZmFpbHMsIGJlY2F1c2UgbWVtb3J5IFsweDAwMDAwMDAxNTAwMDAwMDAtMHgw MDAwMDAwMTU3ZmZmZmZmXSBpcyBvbmxpbmVkCj4gICAuLi4KPiAgIFsgICA4Ni40MzEyMjVdIGtt ZW0gZGF4MC4wOiBEQVggcmVnaW9uIFttZW0gMHgxNTAwMDAwMDAtMHgzM2ZmZmZmZmZdIGNhbm5v dCBiZSBob3RyZW1vdmVkIHVudGlsIHRoZSBuZXh0IHJlYm9vdAo+IAo+IE5vdywgd2UgY2FuIHJl Y29uZmlndXJlIHRoZSBuYW1lc3BhY2U6Cj4gICBbcm9vdEBsb2NhbGhvc3Qgfl0jIG5kY3RsIGNy ZWF0ZS1uYW1lc3BhY2UgLS1mb3JjZSAtLXJlY29uZmlnPW5hbWVzcGFjZTAuMCAtLW1vZGU9ZGV2 ZGF4Cj4gICBbICAxMzEuNDA5MzUxXSBuZF9wbWVtIG5hbWVzcGFjZTAuMDogY291bGQgbm90IHJl c2VydmUgcmVnaW9uIFttZW0gMHgxNDAwMDAwMDAtMHgzM2ZmZmZmZmZdZGF4Cj4gICBbICAxMzEu NDEwMTQ3XSBuZF9wbWVtOiBwcm9iZSBvZiBuYW1lc3BhY2UwLjAgZmFpbGVkIHdpdGggZXJyb3Ig LTE2bmFtZXNwYWNlMC4wIC0tbW9kZT1kZXZkYXgKPiAgIC4uLgo+IAo+IFRoaXMgZmFpbHMgYXMg ZXhwZWN0ZWQgZHVlIHRvIHRoZSBidXN5IG1lbW9yeSByZXNvdXJjZSwgYW5kIHRoZSBtZW1vcnkK PiBjYW5ub3QgYmUgdXNlZC4gSG93ZXZlciwgdGhlIGRheDAuMCBkZXZpY2UgaXMgcmVtb3ZlZCwg YW5kIGFsb25nIGl0cyBuYW1lLgo+IAo+IFRoZSBuYW1lIG9mIHRoZSBtZW1vcnkgcmVzb3VyY2Ug bm93IHBvaW50cyBhdCBmcmVlZCBtZW1vcnkgKG5hbWUgb2YgdGhlCj4gZGV2aWNlKS4KPiAgIFty b290QGxvY2FsaG9zdCB+XSMgY2F0IC9wcm9jL2lvbWVtCj4gICAuLi4KPiAgIDE0MDAwMDAwMC0z M2ZmZmZmZmYgOiBQZXJzaXN0ZW50IE1lbW9yeQo+ICAgICAxNDAwMDAwMDAtMTQ4MWZmZmZmIDog bmFtZXNwYWNlMC4wCj4gICAgIDE1MDAwMDAwMC0zM2ZmZmZmZmYgOiDvv71f77+9Xjdf77+977+9 L1/vv73vv713Uu+/ve+/vVdR77+977+977+9Xu+/ve+/ve+/vSAuLi4KPiAgICAgMTUwMDAwMDAw LTMzZmZmZmZmZiA6IFN5c3RlbSBSQU0KPiAKPiBXZSBoYXZlIHRvIG1ha2Ugc3VyZSB0byBkdXBs aWNhdGUgdGhlIHN0cmluZy4gV2hpbGUgYXQgaXQsIHJlbW92ZSB0aGUKPiBzdXBlcmZsdW91cyBz ZXR0aW5nIG9mIHRoZSBuYW1lIGFuZCBmaXh1cCBhIHN0YWxlIGNvbW1lbnQuCj4gCj4gRml4ZXM6 IDlmOTYwZGE3MmIyNSAoImRldmljZS1kYXg6ICJIb3RyZW1vdmUiIHBlcnNpc3RlbnQgbWVtb3J5 IHRoYXQgaXMgdXNlZCBsaWtlIG5vcm1hbCBSQU0iKQo+IENjOiBzdGFibGVAdmdlci5rZXJuZWwu b3JnICMgdjUuMwoKaG0uCgpJcyB0aGlzIHJlYWxseSAtc3RhYmxlIG1hdGVyaWFsPyAgVGhlc2Ug YXJlIGFsbCBwcml2aWxlZ2VkIG9wZXJhdGlvbnMsCkkgZXhwZWN0PwoKQXNzdW1pbmcgInllcyIs IEkndmUgcXVldWVkIHRoaXMgc2VwYXJhdGVseSwgc3RhZ2VkIGZvciA1LjctcmNYLiAgSSdsbApy ZWRvIHBhdGNoZXMgMi00IGFzIGEgdGhyZWUtcGF0Y2ggc2VyaWVzIGZvciA1LjgtcmMxLgoKPiBD YzogRGFuIFdpbGxpYW1zIDxkYW4uai53aWxsaWFtc0BpbnRlbC5jb20+Cj4gQ2M6IFZpc2hhbCBW ZXJtYSA8dmlzaGFsLmwudmVybWFAaW50ZWwuY29tPgo+IENjOiBEYXZlIEppYW5nIDxkYXZlLmpp YW5nQGludGVsLmNvbT4KPiBDYzogUGF2ZWwgVGF0YXNoaW4gPHBhc2hhLnRhdGFzaGluQHNvbGVl bi5jb20+CgpSZXZpZXdlcnMsIHBsZWFzZSA7KQoKCgpfX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fXwprZXhlYyBtYWlsaW5nIGxpc3QKa2V4ZWNAbGlzdHMuaW5m cmFkZWFkLm9yZwpodHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2tl eGVjCg==