From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 108990 invoked by alias); 30 Sep 2019 19:16:32 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 108981 invoked by uid 89); 30 Sep 2019 19:16:32 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-11.7 required=5.0 tests=BAYES_00,GIT_PATCH_2,GIT_PATCH_3,KAM_MANYTO,SPF_PASS autolearn=ham version=3.3.1 spammy= X-HELO: mx1.suse.de From: Aleksa Sarai To: Ingo Molnar , Peter Zijlstra , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Christian Brauner , Kees Cook Cc: Aleksa Sarai , Rasmus Villemoes , Al Viro , Linus Torvalds , libc-alpha@sourceware.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH RESEND v3 0/4] lib: introduce copy_struct_from_user() helper Date: Mon, 30 Sep 2019 19:16:00 -0000 Message-Id: <20190930191526.19544-1-asarai@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SW-Source: 2019-09/txt/msg00543.txt.bz2 From: Aleksa Sarai Patch changelog: v3: [] * Rename is_zeroed_user() to check_zeroed_user(). [Christian Brauner] * Various minor cleanups. [Christian Brauner] * Add copy_struct_from_user() tests. v2: v1: This series was split off from the openat2(2) syscall discussion[1]. However, the copy_struct_to_user() helper has been dropped, because after some discussion it appears that there is no really obvious semantics for how copy_struct_to_user() should work on mixed-vintages (for instance, whether [2] is the correct semantics for all syscalls). A common pattern for syscall extensions is increasing the size of a struct passed from userspace, such that the zero-value of the new fields result in the old kernel behaviour (allowing for a mix of userspace and kernel vintages to operate on one another in most cases). Previously there was no common lib/ function that implemented the necessary extension-checking semantics (and different syscalls implemented them slightly differently or incompletely[3]). This series implements the helper and ports several syscalls to use it. Some in-kernel selftests are included in this patch. More complete self-tests for copy_struct_from_user() are included in the openat2() patchset. [1]: https://lore.kernel.org/lkml/20190904201933.10736-1-cyphar@cyphar.com/ [2]: commit 1251201c0d34 ("sched/core: Fix uclamp ABI bug, clean up and robustify sched_read_attr() ABI logic and code") [3]: For instance {sched_setattr,perf_event_open,clone3}(2) all do do similar checks to copy_struct_from_user() while rt_sigprocmask(2) always rejects differently-sized struct arguments. Aleksa Sarai (4): lib: introduce copy_struct_from_user() helper clone3: switch to copy_struct_from_user() sched_setattr: switch to copy_struct_from_user() perf_event_open: switch to copy_struct_from_user() include/linux/bitops.h | 7 ++ include/linux/uaccess.h | 4 ++ include/uapi/linux/sched.h | 2 + kernel/events/core.c | 47 +++---------- kernel/fork.c | 34 ++-------- kernel/sched/core.c | 43 ++---------- lib/strnlen_user.c | 8 +-- lib/test_user_copy.c | 133 +++++++++++++++++++++++++++++++++++-- lib/usercopy.c | 123 ++++++++++++++++++++++++++++++++++ 9 files changed, 287 insertions(+), 114 deletions(-) -- 2.23.0