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From: Christian Brauner <christian.brauner@ubuntu.com>
To: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	bpf@vger.kernel.org
Cc: Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	Christian Brauner <christian.brauner@ubuntu.com>
Subject: [PATCH 0/3] bpf: switch to new usercopy helpers
Date: Wed,  9 Oct 2019 18:09:04 +0200	[thread overview]
Message-ID: <20191009160907.10981-1-christian.brauner@ubuntu.com> (raw)

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

/* Reference */
[1]: f5a1a536fa14 ("lib: introduce copy_struct_from_user() helper")

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 | 38 ++++++++++++--------------------------
 1 file changed, 12 insertions(+), 26 deletions(-)

-- 
2.23.0


             reply	other threads:[~2019-10-09 16:09 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-09 16:09 Christian Brauner [this message]
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   ` [PATCH v2 0/3] bpf: switch to new usercopy helpers Christian Brauner
2019-10-16  2:14   ` 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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