From: KP Singh <kpsingh@xxxxxxxxxx>
# v1 -> v2
- Updated the refcounting for task_struct and simplified conversion
of fd -> struct pid.
- Some fixes suggested by Martin and Andrii, notably:
* long return type for the bpf_task_storage_delete helper (update
for bpf_inode_storage_delete will be sent separately).
* Remove extra nullness check to task_storage_ptr in map syscall
ops.
* Changed the argument signature of the BPF helpers to use
task_struct pointer in uapi headers.
* Remove unnecessary verifier logic for the bpf_get_current_task_btf
helper.
* Split the changes for bpftool and libbpf.
- Exercised syscall operations for local storage (kept a simpler verison
in test_local_storage.c, the eventual goal will be to update
sk_storage_map.c for all local storage types).
- Formatting fixes + Rebase.
We already have socket and inode local storage since [1]
This patch series:
* Implements bpf_local_storage for task_struct.
* Implements the bpf_get_current_task_btf helper which returns a BTF
pointer to the current task. Not only is this generally cleaner
(reading from the task_struct currently requires BPF_CORE_READ), it
also allows the BTF pointer to be used in task_local_storage helpers.
* In order to implement this helper, a RET_PTR_TO_BTF_ID is introduced
which works similar to RET_PTR_TO_BTF_ID_OR_NULL but does not require
a nullness check.
* Implements a detection in selftests which uses the
task local storage to deny a running executable from unlinking itself.
[1]: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=f836a56e84ffc9f1a1cd73f77e10404ca46a4616
KP Singh (8):
bpf: Implement task local storage
libbpf: Add support for task local storage
bpftool: Add support for task local storage
bpf: Implement get_current_task_btf and RET_PTR_TO_BTF_ID
bpf: Fix tests for local_storage
bpf: Update selftests for local_storage to use vmlinux.h
bpf: Add tests for task_local_storage
bpf: Exercise syscall operations for inode and sk storage
include/linux/bpf.h | 1 +
include/linux/bpf_lsm.h | 23 ++
include/linux/bpf_types.h | 1 +
include/uapi/linux/bpf.h | 48 +++
kernel/bpf/Makefile | 1 +
kernel/bpf/bpf_lsm.c | 4 +
kernel/bpf/bpf_task_storage.c | 313 ++++++++++++++++++
kernel/bpf/syscall.c | 3 +-
kernel/bpf/verifier.c | 17 +-
kernel/trace/bpf_trace.c | 16 +
security/bpf/hooks.c | 2 +
.../bpf/bpftool/Documentation/bpftool-map.rst | 3 +-
tools/bpf/bpftool/bash-completion/bpftool | 2 +-
tools/bpf/bpftool/map.c | 4 +-
tools/include/uapi/linux/bpf.h | 48 +++
tools/lib/bpf/libbpf_probes.c | 2 +
.../bpf/prog_tests/test_local_storage.c | 181 +++++++++-
.../selftests/bpf/progs/local_storage.c | 87 +++--
18 files changed, 705 insertions(+), 51 deletions(-)
create mode 100644 kernel/bpf/bpf_task_storage.c
--
2.29.1.341.ge80a0c044ae-goog
