From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrey Konovalov Subject: [PATCH v4 0/7] arm64: untag user pointers passed to the kernel Date: Wed, 20 Jun 2018 17:24:19 +0200 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Catalin Marinas , Will Deacon , Mark Rutland , Robin Murphy , Al Viro , Andrey Konovalov , Kees Cook , Kate Stewart , Greg Kroah-Hartman , Andrew Morton , Ingo Molnar , "Kirill A . Shutemov" , Shuah Khan , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Chintan Pandya , Jacob Bramley , Ruben Ayrapetyan , Lee Smith , Kostya Serebryany , Dmitry Vyukov , Ramana Radhakrishnan , Evgeniy Stepanov List-Id: linux-arch.vger.kernel.org YXJtNjQgaGFzIGEgZmVhdHVyZSBjYWxsZWQgVG9wIEJ5dGUgSWdub3JlLCB3aGljaCBhbGxvd3Mg dG8gZW1iZWQgcG9pbnRlcgp0YWdzIGludG8gdGhlIHRvcCBieXRlIG9mIGVhY2ggcG9pbnRlci4g VXNlcnNwYWNlIHByb2dyYW1zIChzdWNoIGFzCkhXQVNhbiwgYSBtZW1vcnkgZGVidWdnaW5nIHRv b2wgWzFdKSBtaWdodCB1c2UgdGhpcyBmZWF0dXJlIGFuZCBwYXNzCnRhZ2dlZCB1c2VyIHBvaW50 ZXJzIHRvIHRoZSBrZXJuZWwgdGhyb3VnaCBzeXNjYWxscyBvciBvdGhlciBpbnRlcmZhY2VzLgoK VGhpcyBwYXRjaCBtYWtlcyBhIGZldyBvZiB0aGUga2VybmVsIGludGVyZmFjZXMgYWNjZXB0IHRh Z2dlZCB1c2VyCnBvaW50ZXJzLiBUaGUga2VybmVsIGlzIGFscmVhZHkgYWJsZSB0byBoYW5kbGUg dXNlciBmYXVsdHMgd2l0aCB0YWdnZWQKcG9pbnRlcnMgYW5kIGhhcyB0aGUgdW50YWdnZWRfYWRk ciBtYWNybywgd2hpY2ggdGhpcyBwYXRjaHNldCByZXVzZXMuCgpXZSdyZSBub3QgdHJ5aW5nIHRv IGNvdmVyIGFsbCBwb3NzaWJsZSB3YXlzIHRoZSBrZXJuZWwgYWNjZXB0cyB1c2VyCnBvaW50ZXJz IGluIG9uZSBwYXRjaHNldCwgc28gdGhpcyBvbmUgc2hvdWxkIGJlIGNvbnNpZGVyZWQgYXMgYSBz dGFydC4KClRoYW5rcyEKClsxXSBodHRwOi8vY2xhbmcubGx2bS5vcmcvZG9jcy9IYXJkd2FyZUFz c2lzdGVkQWRkcmVzc1Nhbml0aXplckRlc2lnbi5odG1sCgpDaGFuZ2VzIGluIHY0OgotIEFkZGVk IGEgc2VsZnRlc3QgZm9yIGNoZWNraW5nIHRoYXQgcGFzc2luZyB0YWdnZWQgcG9pbnRlcnMgdG8g dGhlIAogIGtlcm5lbCBzdWNjZWVkcy4KLSBSZWJhc2VkIG9udG8gODFlOTdmMDEzICg0LjE4LXJj MSspLgoKQ2hhbmdlcyBpbiB2MzoKLSBSZWJhc2VkIG9udG8gZTVjNTFmMzAgKDQuMTctcmM2Kyku Ci0gQWRkZWQgbGludXgtYXJjaEAgdG8gdGhlIGxpc3Qgb2YgcmVjaXBpZW50cy4KCkNoYW5nZXMg aW4gdjI6Ci0gUmViYXNlZCBvbnRvIDJkNjE4YmRmICg0LjE3LXJjMyspLgotIFJlbW92ZWQgZXhj ZXNzaXZlIHVudGFnZ2luZyBpbiBndXAuYy4KLSBSZW1vdmVkIHVudGFnZ2luZyBwb2ludGVycyBy ZXR1cm5lZCBmcm9tIF9fdWFjY2Vzc19tYXNrX3B0ci4KCkNoYW5nZXMgaW4gdjE6Ci0gUmViYXNl ZCBvbnRvIDQuMTctcmMxLgoKQ2hhbmdlcyBpbiBSRkMgdjI6Ci0gQWRkZWQgIiNpZm5kZWYgdW50 YWdnZWRfYWRkci4uLiIgZmFsbGJhY2sgaW4gbGludXgvdWFjY2Vzcy5oIGluc3RlYWQgb2YKICBk ZWZpbmluZyBpdCBmb3IgZWFjaCBhcmNoIGluZGl2aWR1YWxseS4KLSBVcGRhdGVkIERvY3VtZW50 YXRpb24vYXJtNjQvdGFnZ2VkLXBvaW50ZXJzLnR4dC4KLSBEcm9wcGVkIOKAnG1tLCBhcm02NDog dW50YWcgdXNlciBhZGRyZXNzZXMgaW4gbWVtb3J5IHN5c2NhbGxz4oCdLgotIFJlYmFzZWQgb250 byAzZWIyY2U4MiAoNC4xNi1yYzcpLgoKQW5kcmV5IEtvbm92YWxvdiAoNyk6CiAgYXJtNjQ6IGFk ZCB0eXBlIGNhc3RzIHRvIHVudGFnZ2VkX2FkZHIgbWFjcm8KICB1YWNjZXNzOiBhZGQgdW50YWdn ZWRfYWRkciBkZWZpbml0aW9uIGZvciBvdGhlciBhcmNoZXMKICBhcm02NDogdW50YWcgdXNlciBh ZGRyZXNzZXMgaW4gYWNjZXNzX29rIGFuZCBfX3VhY2Nlc3NfbWFza19wdHIKICBtbSwgYXJtNjQ6 IHVudGFnIHVzZXIgYWRkcmVzc2VzIGluIG1tL2d1cC5jCiAgbGliLCBhcm02NDogdW50YWcgYWRk cnMgcGFzc2VkIHRvIHN0cm5jcHlfZnJvbV91c2VyIGFuZCBzdHJubGVuX3VzZXIKICBhcm02NDog dXBkYXRlIERvY3VtZW50YXRpb24vYXJtNjQvdGFnZ2VkLXBvaW50ZXJzLnR4dAogIHNlbGZ0ZXN0 cywgYXJtNjQ6IGFkZCBhIHNlbGZ0ZXN0IGZvciBwYXNzaW5nIHRhZ2dlZCBwb2ludGVycyB0byBr ZXJuZWwKCiBEb2N1bWVudGF0aW9uL2FybTY0L3RhZ2dlZC1wb2ludGVycy50eHQgICAgICAgfCAg NSArKystLQogYXJjaC9hcm02NC9pbmNsdWRlL2FzbS91YWNjZXNzLmggICAgICAgICAgICAgIHwg MTQgKysrKysrKysrLS0tLS0KIGluY2x1ZGUvbGludXgvdWFjY2Vzcy5oICAgICAgICAgICAgICAg ICAgICAgICB8ICA0ICsrKysKIGxpYi9zdHJuY3B5X2Zyb21fdXNlci5jICAgICAgICAgICAgICAg ICAgICAgICB8ICAyICsrCiBsaWIvc3Rybmxlbl91c2VyLmMgICAgICAgICAgICAgICAgICAgICAg ICAgICAgfCAgMiArKwogbW0vZ3VwLmMgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAg ICAgIHwgIDQgKysrKwogdG9vbHMvdGVzdGluZy9zZWxmdGVzdHMvYXJtNjQvLmdpdGlnbm9yZSAg ICAgIHwgIDEgKwogdG9vbHMvdGVzdGluZy9zZWxmdGVzdHMvYXJtNjQvTWFrZWZpbGUgICAgICAg IHwgMTEgKysrKysrKysrKysKIC4uLi90ZXN0aW5nL3NlbGZ0ZXN0cy9hcm02NC9ydW5fdGFnc190 ZXN0LnNoICB8IDEyICsrKysrKysrKysrKwogdG9vbHMvdGVzdGluZy9zZWxmdGVzdHMvYXJtNjQv dGFnc190ZXN0LmMgICAgIHwgMTkgKysrKysrKysrKysrKysrKysrKwogMTAgZmlsZXMgY2hhbmdl ZCwgNjcgaW5zZXJ0aW9ucygrKSwgNyBkZWxldGlvbnMoLSkKIGNyZWF0ZSBtb2RlIDEwMDY0NCB0 b29scy90ZXN0aW5nL3NlbGZ0ZXN0cy9hcm02NC8uZ2l0aWdub3JlCiBjcmVhdGUgbW9kZSAxMDA2 NDQgdG9vbHMvdGVzdGluZy9zZWxmdGVzdHMvYXJtNjQvTWFrZWZpbGUKIGNyZWF0ZSBtb2RlIDEw MDc1NSB0b29scy90ZXN0aW5nL3NlbGZ0ZXN0cy9hcm02NC9ydW5fdGFnc190ZXN0LnNoCiBjcmVh dGUgbW9kZSAxMDA2NDQgdG9vbHMvdGVzdGluZy9zZWxmdGVzdHMvYXJtNjQvdGFnc190ZXN0LmMK Ci0tIAoyLjE4LjAucmMxLjI0NC5nY2YxMzRlNjI3NS1nb29nCgoKX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX18KbGludXgtYXJtLWtlcm5lbCBtYWlsaW5nIGxp c3QKbGludXgtYXJtLWtlcm5lbEBsaXN0cy5pbmZyYWRlYWQub3JnCmh0dHA6Ly9saXN0cy5pbmZy YWRlYWQub3JnL21haWxtYW4vbGlzdGluZm8vbGludXgtYXJtLWtlcm5lbAo= From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f194.google.com ([209.85.128.194]:33710 "EHLO mail-wr0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753987AbeFTPYb (ORCPT ); Wed, 20 Jun 2018 11:24:31 -0400 Received: by mail-wr0-f194.google.com with SMTP id k16-v6so3755102wro.0 for ; Wed, 20 Jun 2018 08:24:31 -0700 (PDT) From: Andrey Konovalov Subject: [PATCH v4 0/7] arm64: untag user pointers passed to the kernel Date: Wed, 20 Jun 2018 17:24:19 +0200 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Catalin Marinas , Will Deacon , Mark Rutland , Robin Murphy , Al Viro , Andrey Konovalov , Kees Cook , Kate Stewart , Greg Kroah-Hartman , Andrew Morton , Ingo Molnar , "Kirill A . Shutemov" , Shuah Khan , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Chintan Pandya Message-ID: <20180620152419.nrLkGQrXXOpFo7x9AQfBUpOVDXxV0ssPuGUb7NhmaHY@z> arm64 has a feature called Top Byte Ignore, which allows to embed pointer tags into the top byte of each pointer. Userspace programs (such as HWASan, a memory debugging tool [1]) might use this feature and pass tagged user pointers to the kernel through syscalls or other interfaces. This patch makes a few of the kernel interfaces accept tagged user pointers. The kernel is already able to handle user faults with tagged pointers and has the untagged_addr macro, which this patchset reuses. We're not trying to cover all possible ways the kernel accepts user pointers in one patchset, so this one should be considered as a start. Thanks! [1] http://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html Changes in v4: - Added a selftest for checking that passing tagged pointers to the kernel succeeds. - Rebased onto 81e97f013 (4.18-rc1+). Changes in v3: - Rebased onto e5c51f30 (4.17-rc6+). - Added linux-arch@ to the list of recipients. Changes in v2: - Rebased onto 2d618bdf (4.17-rc3+). - Removed excessive untagging in gup.c. - Removed untagging pointers returned from __uaccess_mask_ptr. Changes in v1: - Rebased onto 4.17-rc1. Changes in RFC v2: - Added "#ifndef untagged_addr..." fallback in linux/uaccess.h instead of defining it for each arch individually. - Updated Documentation/arm64/tagged-pointers.txt. - Dropped “mm, arm64: untag user addresses in memory syscalls”. - Rebased onto 3eb2ce82 (4.16-rc7). Andrey Konovalov (7): arm64: add type casts to untagged_addr macro uaccess: add untagged_addr definition for other arches arm64: untag user addresses in access_ok and __uaccess_mask_ptr mm, arm64: untag user addresses in mm/gup.c lib, arm64: untag addrs passed to strncpy_from_user and strnlen_user arm64: update Documentation/arm64/tagged-pointers.txt selftests, arm64: add a selftest for passing tagged pointers to kernel Documentation/arm64/tagged-pointers.txt | 5 +++-- arch/arm64/include/asm/uaccess.h | 14 +++++++++----- include/linux/uaccess.h | 4 ++++ lib/strncpy_from_user.c | 2 ++ lib/strnlen_user.c | 2 ++ mm/gup.c | 4 ++++ tools/testing/selftests/arm64/.gitignore | 1 + tools/testing/selftests/arm64/Makefile | 11 +++++++++++ .../testing/selftests/arm64/run_tags_test.sh | 12 ++++++++++++ tools/testing/selftests/arm64/tags_test.c | 19 +++++++++++++++++++ 10 files changed, 67 insertions(+), 7 deletions(-) create mode 100644 tools/testing/selftests/arm64/.gitignore create mode 100644 tools/testing/selftests/arm64/Makefile create mode 100755 tools/testing/selftests/arm64/run_tags_test.sh create mode 100644 tools/testing/selftests/arm64/tags_test.c -- 2.18.0.rc1.244.gcf134e6275-goog