From: Mykyta Yatsenko <yatsenko@xxxxxxxx> Freplace programs can't be loaded from user namespace, as bpf_program__set_attach_target() requires searching for target prog BTF, which is locked under CAP_SYS_ADMIN. This patch set enables this use case by: 1. Relaxing capable check in bpf's BPF_BTF_GET_FD_BY_ID, check for CAP_BPF instead of CAP_SYS_ADMIN, support BPF token in attr argument. 2. Pass BPF token around libbpf from bpf_program__set_attach_target() to bpf syscall where capable check is. 3. Validate positive/negative scenarios in selftests This patch set is enabled by the recent libbpf change[1], that introduced bpf_object__prepare() API. Calling bpf_object__prepare() for freplace program before bpf_program__set_attach_target() initializes BPF token, which is then passed to bpf syscall by libbpf. [1] https://lore.kernel.org/all/20250303135752.158343-1-mykyta.yatsenko5@xxxxxxxxx/ Mykyta Yatsenko (3): bpf: BPF token support for BPF_BTF_GET_FD_BY_ID libbpf: pass BPF token from find_prog_btf_id to BPF_BTF_GET_FD_BY_ID selftests/bpf: test freplace from user namespace include/uapi/linux/bpf.h | 1 + kernel/bpf/syscall.c | 12 ++- tools/include/uapi/linux/bpf.h | 1 + tools/lib/bpf/bpf.c | 3 +- tools/lib/bpf/bpf.h | 4 +- tools/lib/bpf/btf.c | 10 +- tools/lib/bpf/libbpf.c | 10 +- tools/lib/bpf/libbpf_internal.h | 1 + .../testing/selftests/bpf/prog_tests/token.c | 94 +++++++++++++++++++ .../selftests/bpf/progs/priv_freplace_prog.c | 13 +++ tools/testing/selftests/bpf/progs/priv_prog.c | 4 +- 11 files changed, 138 insertions(+), 15 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/priv_freplace_prog.c -- 2.48.1
