BPF Archive on lore.kernel.org
 help / color / Atom feed
From: Wenbo Zhang <ethercflow@gmail.com>
To: bpf@vger.kernel.org
Cc: ast@kernel.org, daniel@iogearbox.net, yhs@fb.com,
	andrii.nakryiko@gmail.com, netdev@vger.kernel.org
Subject: [PATCH bpf-next v12 0/2] bpf: adding get_file_path helper
Date: Sat, 14 Dec 2019 23:01:08 -0500
Message-ID: <cover.1576381511.git.ethercflow@gmail.com> (raw)
In-Reply-To: <afe4deb020b781c76e9df8403a744f88a8725cd2.1575517685.git.ethercflow@gmail.com>

This patch series introduce a bpf helper that can be used to map a file
descriptor to a pathname.

This requirement is mainly discussed here:

  https://github.com/iovisor/bcc/issues/237

This implementation supports both local and mountable pseudo file systems,
and ensure we're in user context which is safe for this helper to run.

Changes since v11:

* only allow tracepoints to make sure it won't dead lock


Changes since v10:

* fix missing fput


Changes since v9:

* Associate help patch with its selftests patch to this series

* Refactor selftests code for further simplification  


Changes since v8:

* format helper description 
 

Changes since v7:

* Use fget_raw instead of fdget_raw, as fdget_raw is only used inside fs/

* Ensure we're in user context which is safe fot the help to run

* Filter unmountable pseudo filesystem, because they don't have real path

* Supplement the description of this helper function


Changes since v6:

* Fix missing signed-off-by line


Changes since v5:

* Refactor helper avoid unnecessary goto end by having two explicit returns


Changes since v4:

* Rename bpf_fd2path to bpf_get_file_path to be consistent with other
helper's names

* When fdget_raw fails, set ret to -EBADF instead of -EINVAL

* Remove fdput from fdget_raw's error path

* Use IS_ERR instead of IS_ERR_OR_NULL as d_path ether returns a pointer
into the buffer or an error code if the path was too long

* Modify the normal path's return value to return copied string length
including NUL

* Update helper description's Return bits.

* Refactor selftests code for further simplification  


Changes since v3:

* Remove unnecessary LOCKDOWN_BPF_READ

* Refactor error handling section for enhanced readability

* Provide a test case in tools/testing/selftests/bpf

* Refactor sefltests code to use real global variables instead of maps


Changes since v2:

* Fix backward compatibility

* Add helper description

* Refactor selftests use global data instead of perf_buffer to simplified
code

* Fix signed-off name


Wenbo Zhang (2):
  bpf: add new helper get_file_path for mapping a file descriptor to a
    pathname
  selftests/bpf: test for bpf_get_file_path() from tracepoint

 include/uapi/linux/bpf.h                      |  29 ++-
 kernel/trace/bpf_trace.c                      |  70 +++++++
 tools/include/uapi/linux/bpf.h                |  29 ++-
 .../selftests/bpf/prog_tests/get_file_path.c  | 171 ++++++++++++++++++
 .../selftests/bpf/progs/test_get_file_path.c  |  43 +++++
 5 files changed, 340 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/get_file_path.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_get_file_path.c

-- 
2.17.1


  parent reply index

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-19 13:27 [PATCH bpf-next v10 " Wenbo Zhang
2019-11-19 13:27 ` [PATCH bpf-next v10 1/2] bpf: add new helper get_file_path for mapping a file descriptor to a pathname Wenbo Zhang
2019-11-23  3:18   ` Alexei Starovoitov
2019-11-23  4:43     ` Al Viro
2019-11-23  4:51     ` Al Viro
2019-11-23  5:19       ` Alexei Starovoitov
2019-11-23  5:35         ` Al Viro
2019-11-23  6:04           ` Alexei Starovoitov
2019-12-13 19:51             ` Brendan Gregg
2019-12-05  4:20   ` [PATCH bpf-next v11 0/2] bpf: adding get_file_path helper Wenbo Zhang
2019-12-05  4:20     ` [PATCH bpf-next v11 1/2] bpf: add new helper get_file_path for mapping a file descriptor to a pathname Wenbo Zhang
2019-12-05  7:19       ` Alexei Starovoitov
2019-12-05  9:47         ` Wenbo Zhang
2019-12-15  4:01       ` Wenbo Zhang [this message]
2019-12-15  4:01         ` [PATCH bpf-next v12 " Wenbo Zhang
2019-12-15 16:05           ` Yonghong Song
2019-12-17  6:26             ` Wenbo Zhang
2019-12-17  6:33               ` Yonghong Song
2019-12-15 16:10           ` Yonghong Song
2019-12-17  6:27             ` Wenbo Zhang
2019-12-16 22:09           ` Brendan Gregg
2019-12-17  4:05             ` Wenbo Zhang
2019-12-17  9:47           ` [PATCH bpf-next v13 0/2] bpf: adding get_fd_path helper Wenbo Zhang
2019-12-17  9:47             ` [PATCH bpf-next v13 1/2] bpf: add new helper get_fd_path for mapping a file descriptor to a pathname Wenbo Zhang
2019-12-17 16:29               ` Yonghong Song
2019-12-17 19:39                 ` Daniel Borkmann
2019-12-18  0:11                   ` Wenbo Zhang
2019-12-18  0:06                 ` Wenbo Zhang
2019-12-18  0:56               ` [PATCH bpf-next v14 0/2] bpf: adding get_fd_path helper Wenbo Zhang
2019-12-18  0:56                 ` [PATCH bpf-next v14 1/2] bpf: add new helper get_fd_path for mapping a file descriptor to a pathname Wenbo Zhang
2019-12-18  3:27                   ` Yonghong Song
2019-12-19 16:14                   ` Daniel Borkmann
2019-12-20  3:35                     ` Wenbo Zhang
2020-01-16  8:59                       ` Jiri Olsa
2020-02-10  4:43                         ` Brendan Gregg
2020-02-11  0:01                           ` Daniel Borkmann
2020-02-12 15:21                             ` Jiri Olsa
2019-12-18  0:56                 ` [PATCH bpf-next v14 2/2] selftests/bpf: test for bpf_get_fd_path() from tracepoint Wenbo Zhang
2019-12-18  3:27                   ` Yonghong Song
2019-12-17  9:47             ` [PATCH bpf-next v13 " Wenbo Zhang
2019-12-17 16:32               ` Yonghong Song
2019-12-15  4:01         ` [PATCH bpf-next v12 2/2] selftests/bpf: test for bpf_get_file_path() " Wenbo Zhang
2019-12-15 16:24           ` Yonghong Song
2019-12-17  4:01             ` Wenbo Zhang
2019-12-17  4:13               ` Yonghong Song
2019-12-17  9:44                 ` Wenbo Zhang
2019-12-05  4:20     ` [PATCH bpf-next v11 " Wenbo Zhang
2019-11-19 13:27 ` [PATCH bpf-next v10 " Wenbo Zhang

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=cover.1576381511.git.ethercflow@gmail.com \
    --to=ethercflow@gmail.com \
    --cc=andrii.nakryiko@gmail.com \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=netdev@vger.kernel.org \
    --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

BPF Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/bpf/0 bpf/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 bpf bpf/ https://lore.kernel.org/bpf \
		bpf@vger.kernel.org
	public-inbox-index bpf

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.bpf


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git