From: Christian Brauner <christian.brauner@ubuntu.com>
To: ast@kernel.org
Cc: bpf@vger.kernel.org, daniel@iogearbox.net, kafai@fb.com,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
songliubraving@fb.com, yhs@fb.com
Subject: Re: [PATCH v2 0/3] bpf: switch to new usercopy helpers
Date: Wed, 16 Oct 2019 02:48:10 +0200 [thread overview]
Message-ID: <20191016004809.tgw6zznr6ukppplp@wittgenstein> (raw)
In-Reply-To: <20191016004138.24845-1-christian.brauner@ubuntu.com>
On Wed, Oct 16, 2019 at 02:41:35AM +0200, Christian Brauner wrote:
> Hey everyone,
>
> In v5.4-rc2 we added two new helpers check_zeroed_user() and
> copy_struct_from_user() including selftests (cf. [1]). It is a generic
> interface designed to copy a struct from userspace. The helpers will be
> especially useful for structs versioned by size of which we have quite a
> few.
>
> The most obvious benefit is that this helper lets us get rid of
> duplicate code. We've already switched over sched_setattr(), perf_event_open(),
> and clone3(). More importantly it will also help to ensure that users
> implementing versioning-by-size end up with the same core semantics.
>
> This point is especially crucial since we have at least one case where
> versioning-by-size is used but with slighly different semantics:
> sched_setattr(), perf_event_open(), and clone3() all do do similar
> checks to copy_struct_from_user() while rt_sigprocmask(2) always rejects
> differently-sized struct arguments.
>
> This little series switches over bpf codepaths that have hand-rolled
> implementations of these helpers.
>
> Thanks!
> Christian
>
> /* v1 */
> Link: https://lore.kernel.org/r/20191009160907.10981-1-christian.brauner@ubuntu.com
>
> /* v2 */
> - rebase onto bpf-next
>
> /* Reference */
> [1]: f5a1a536fa14 ("lib: introduce copy_struct_from_user() helper")
Alexei, instead of applying the series you can also just pull from me:
The following changes since commit 5bc60de50dfea235634fdf38cbc992fb968d113b:
selftests: bpf: Don't try to read files without read permission (2019-10-15 16:27:25 -0700)
are available in the Git repository at:
git@gitolite.kernel.org:pub/scm/linux/kernel/git/brauner/linux tags/bpf-copy-struct-from-user
for you to fetch changes up to da1699b959d182bb161be3ffc17eab063b2aedd2:
bpf: use copy_struct_from_user() in bpf() syscall (2019-10-16 02:35:11 +0200)
----------------------------------------------------------------
bpf-copy-struct-from-user
----------------------------------------------------------------
Christian Brauner (3):
bpf: use check_zeroed_user() in bpf_check_uarg_tail_zero()
bpf: use copy_struct_from_user() in bpf_prog_get_info_by_fd()
bpf: use copy_struct_from_user() in bpf() syscall
kernel/bpf/syscall.c | 46 ++++++++++++++++++----------------------------
1 file changed, 18 insertions(+), 28 deletions(-)
next prev parent reply other threads:[~2019-10-16 0:48 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-09 16:09 [PATCH 0/3] bpf: switch to new usercopy helpers Christian Brauner
2019-10-09 16:09 ` [PATCH 1/3] bpf: use check_zeroed_user() in bpf_check_uarg_tail_zero() Christian Brauner
2019-10-10 10:50 ` Aleksa Sarai
2019-10-09 16:09 ` [PATCH 2/3] bpf: use copy_struct_from_user() in bpf_prog_get_info_by_fd() Christian Brauner
2019-10-10 10:51 ` Aleksa Sarai
2019-10-09 16:09 ` [PATCH 3/3] bpf: use copy_struct_from_user() in bpf() syscall Christian Brauner
2019-10-10 10:51 ` Aleksa Sarai
2019-10-09 23:06 ` [PATCH 0/3] bpf: switch to new usercopy helpers Alexei Starovoitov
2019-10-10 9:26 ` Christian Brauner
2019-10-15 22:45 ` Alexei Starovoitov
2019-10-15 22:55 ` Christian Brauner
2019-10-15 23:02 ` Alexei Starovoitov
2019-10-15 23:08 ` Christian Brauner
2019-10-16 0:41 ` [PATCH v2 " Christian Brauner
2019-10-16 0:41 ` [PATCH v2 1/3] bpf: use check_zeroed_user() in bpf_check_uarg_tail_zero() Christian Brauner
2019-10-16 0:41 ` [PATCH v2 2/3] bpf: use copy_struct_from_user() in bpf_prog_get_info_by_fd() Christian Brauner
2019-10-16 0:41 ` [PATCH v2 3/3] bpf: use copy_struct_from_user() in bpf() syscall Christian Brauner
2019-10-16 0:48 ` Christian Brauner [this message]
2019-10-16 2:14 ` [PATCH v2 0/3] bpf: switch to new usercopy helpers Alexei Starovoitov
2019-10-16 3:31 ` Christian Brauner
2019-10-16 3:44 ` [PATCH v3 " Christian Brauner
2019-10-16 3:44 ` [PATCH v3 1/3] bpf: use check_zeroed_user() in bpf_check_uarg_tail_zero() Christian Brauner
2019-10-16 5:23 ` Alexei Starovoitov
2019-10-16 3:44 ` [PATCH v3 2/3] bpf: use copy_struct_from_user() in bpf_prog_get_info_by_fd() Christian Brauner
2019-10-16 5:25 ` Alexei Starovoitov
2019-10-16 7:30 ` [PATCH v3 2/3] bpf: use copy_struct_from_user() in bpf_prog_get_info_by_fd()y Christian Brauner
2019-10-16 7:43 ` [PATCH v3 2/3] bpf: use copy_struct_from_user() in bpf_prog_get_info_by_fd() Christian Brauner
2019-10-16 3:44 ` [PATCH v3 3/3] bpf: use copy_struct_from_user() in bpf() syscall Christian Brauner
2019-10-16 11:18 ` [PATCH bpf-next v4 0/3] bpf: switch to new usercopy helpers Christian Brauner
2019-10-16 11:18 ` [PATCH bpf-next v4 1/3] bpf: use check_zeroed_user() in bpf_check_uarg_tail_zero() Christian Brauner
2019-10-16 11:18 ` [PATCH bpf-next v4 2/3] bpf: use copy_struct_from_user() in bpf_prog_get_info_by_fd() Christian Brauner
2019-10-16 11:18 ` [PATCH bpf-next v4 3/3] bpf: use copy_struct_from_user() in bpf() syscall Christian Brauner
2019-10-16 18:31 ` [PATCH bpf-next v4 0/3] bpf: switch to new usercopy helpers Alexei Starovoitov
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