bpf.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Christian Brauner <christian.brauner@ubuntu.com>
To: christian.brauner@ubuntu.com
Cc: ast@kernel.org, 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: [PATCH v2 0/3] bpf: switch to new usercopy helpers
Date: Wed, 16 Oct 2019 02:41:35 +0200	[thread overview]
Message-ID: <20191016004138.24845-1-christian.brauner@ubuntu.com> (raw)
In-Reply-To: <20191009160907.10981-1-christian.brauner@ubuntu.com>

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")

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(-)

-- 
2.23.0


  parent reply	other threads:[~2019-10-16  0:42 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 ` Christian Brauner [this message]
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191016004138.24845-1-christian.brauner@ubuntu.com \
    --to=christian.brauner@ubuntu.com \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=kafai@fb.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=songliubraving@fb.com \
    --cc=yhs@fb.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).