There was some confusion amongst Meta sched_ext folks regarding whether
stashing bpf_rb_root - the tree itself, rather than a single node - was
supported. This patch adds a small test which demonstrates this
functionality: a local kptr with rb_root is created, a node is created
and added to the tree, then the tree is kptr_xchg'd into a mapval.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20231204211722.571346-1-davemarchevsky@fb.com
This patch demonstrates that verifier changes earlier in this series
result in bpf_refcount_acquire(mapval->stashed_kptr) passing
verification. The added test additionally validates that stashing a kptr
in mapval and - in a separate BPF program - refcount_acquiring the kptr
without unstashing works as expected at runtime.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20231107085639.3016113-7-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Move all kfunc exports into separate bpf_testmod_kfunc.h header file
and include it in tests that need it.
We will move all test kfuncs into bpf_testmod in following change,
so it's convenient to have declarations in single place.
The bpf_testmod_kfunc.h is included by both bpf_testmod and bpf
programs that use test kfuncs.
As suggested by David, the bpf_testmod_kfunc.h includes vmlinux.h
and bpf/bpf_helpers.h for bpf programs build, so the declarations
have proper __ksym attribute and we can resolve all the structs.
Note in kfunc_call_test_subprog.c we can no longer use the sk_state
define from bpf_tcp_helpers.h (because it clashed with vmlinux.h)
and we need to address __sk_common.skc_state field directly.
Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-3-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a new selftest, local_kptr_stash, which uses bpf_kptr_xchg to stash
a bpf_obj_new-allocated object in a map. Test the following scenarios:
* Stash two rb_nodes in an arraymap, don't unstash them, rely on map
free to destruct them
* Stash two rb_nodes in an arraymap, unstash the second one in a
separate program, rely on map free to destruct first
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230310230743.2320707-4-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
