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| author | Nuoqi Gui <gnq25@mails.tsinghua.edu.cn> | 2026-09-04 12:41:55 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-09-04 12:24:25 -0700 |
| commit | 2b97956af60810cd382b86b9ce9aea421b889861 (patch) | |
| tree | 7d9b0d8a91f77e63deff23976f68555a4895346a /Documentation/userspace-api/ebpf | |
| download | linux-stable-2b97956af60810cd382b86b9ce9aea421b889861.tar.gz linux-stable-2b97956af60810cd382b86b9ce9aea421b889861.zip | |
selftests/bpf: Test rhtab kptr cancellation semanticsgrafted
Resizable hash-map updates and deletions must not perform full special-field
destruction in their caller context. In particular, a referenced kptr must
remain attached to the allocation until the memory allocator destructor can
release it safely.
Add separate coverage for both affected paths. The update test stores a task
kptr, replaces the ordinary value bytes with BPF_EXIST, and verifies that the
kptr survived. The delete test removes an element and exchanges its kptr
through the still-valid map-value pointer before the allocation is reclaimed.
Both cases observe a NULL kptr when rhtab uses bpf_obj_free_fields(). They
recover and release the reference after rhtab switches to cancellation
semantics.
Signed-off-by: Nuoqi Gui <gnq25@mails.tsinghua.edu.cn>
[ kkd: Split update and delete coverage and rewrote the commit log ]
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904104203.345917-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'Documentation/userspace-api/ebpf')
| -rw-r--r-- | Documentation/userspace-api/ebpf/index.rst | 17 | ||||
| -rw-r--r-- | Documentation/userspace-api/ebpf/syscall.rst | 24 |
2 files changed, 41 insertions, 0 deletions
diff --git a/Documentation/userspace-api/ebpf/index.rst b/Documentation/userspace-api/ebpf/index.rst new file mode 100644 index 000000000..473dfba78 --- /dev/null +++ b/Documentation/userspace-api/ebpf/index.rst @@ -0,0 +1,17 @@ +.. SPDX-License-Identifier: GPL-2.0 + +eBPF Userspace API +================== + +eBPF is a kernel mechanism to provide a sandboxed runtime environment in the +Linux kernel for runtime extension and instrumentation without changing kernel +source code or loading kernel modules. eBPF programs can be attached to various +kernel subsystems, including networking, tracing and Linux security modules +(LSM). + +For internal kernel documentation on eBPF, see Documentation/bpf/index.rst. + +.. toctree:: + :maxdepth: 1 + + syscall diff --git a/Documentation/userspace-api/ebpf/syscall.rst b/Documentation/userspace-api/ebpf/syscall.rst new file mode 100644 index 000000000..ea9918084 --- /dev/null +++ b/Documentation/userspace-api/ebpf/syscall.rst @@ -0,0 +1,24 @@ +.. SPDX-License-Identifier: GPL-2.0 + +eBPF Syscall +------------ + +:Authors: - Alexei Starovoitov <ast@kernel.org> + - Joe Stringer <joe@wand.net.nz> + - Michael Kerrisk <mtk.manpages@gmail.com> + +The primary info for the bpf syscall is available in the `man-pages`_ +for `bpf(2)`_. + +bpf() subcommand reference +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: include/uapi/linux/bpf.h + :doc: eBPF Syscall Preamble + +.. kernel-doc:: include/uapi/linux/bpf.h + :doc: eBPF Syscall Commands + +.. Links: +.. _man-pages: https://www.kernel.org/doc/man-pages/ +.. _bpf(2): https://man7.org/linux/man-pages/man2/bpf.2.html |