Certain bpf syscall subcommands are available for usage from both
userspace and the kernel. LSM modules or eBPF gatekeeper programs may
need to take a different course of action depending on whether or not
a BPF syscall originated from the kernel or userspace.
Additionally, some of the bpf_attr struct fields contain pointers to
arbitrary memory. Currently the functionality to determine whether or
not a pointer refers to kernel memory or userspace memory is exposed
to the bpf verifier, but that information is missing from various LSM
hooks.
Here we augment the LSM hooks to provide this data, by simply passing
a boolean flag indicating whether or not the call originated in the
kernel, in any hook that contains a bpf_attr struct that corresponds
to a subcommand that may be called from the kernel.
Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20250310221737.821889-2-bboscaccy@linux.microsoft.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add selftests for cgroup1 hierarchy.
The result as follows,
$ tools/testing/selftests/bpf/test_progs --name=cgroup1_hierarchy
#36/1 cgroup1_hierarchy/test_cgroup1_hierarchy:OK
#36/2 cgroup1_hierarchy/test_root_cgid:OK
#36/3 cgroup1_hierarchy/test_invalid_level:OK
#36/4 cgroup1_hierarchy/test_invalid_cgid:OK
#36/5 cgroup1_hierarchy/test_invalid_hid:OK
#36/6 cgroup1_hierarchy/test_invalid_cgrp_name:OK
#36/7 cgroup1_hierarchy/test_invalid_cgrp_name2:OK
#36/8 cgroup1_hierarchy/test_sleepable_prog:OK
#36 cgroup1_hierarchy:OK
Summary: 1/8 PASSED, 0 SKIPPED, 0 FAILED
Besides, I also did some stress test similar to the patch #2 in this
series, as follows (with CONFIG_PROVE_RCU_LIST enabled):
- Continuously mounting and unmounting named cgroups in some tasks,
for example:
cgrp_name=$1
while true
do
mount -t cgroup -o none,name=$cgrp_name none /$cgrp_name
umount /$cgrp_name
done
- Continuously run this selftest concurrently,
while true; do ./test_progs --name=cgroup1_hierarchy; done
They can ran successfully without any RCU warnings in dmesg.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20231111090034.4248-7-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
