| Message ID | 617d61727a8c73fd28a1eb4136f8159f7f6779d9.1632216695.git.aclaudi@redhat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Stephen Hemminger |
| Headers | show |
| Series | [iproute2] lib: bpf_legacy: fix bpffs mount when /sys/fs/bpf exists | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
Andrea Claudi <aclaudi@redhat.com> writes: > bpf selftests using iproute2 fails with: > > $ ip link set dev veth0 xdp object ../bpf/xdp_dummy.o section xdp_dummy > Continuing without mounted eBPF fs. Too old kernel? > mkdir (null)/globals failed: No such file or directory > Unable to load program > > This happens when the /sys/fs/bpf directory exists. In this case, mkdir > in bpf_mnt_check_target() fails with errno == EEXIST, and the function > returns -1. Thus bpf_get_work_dir() does not call bpf_mnt_fs() and the > bpffs is not mounted. > > Fix this in bpf_mnt_check_target(), returning 0 when the mountpoint > exists. > > Fixes: d4fcdbbec9df ("lib/bpf: Fix and simplify bpf_mnt_check_target()") > Reported-by: Mingyu Shi <mshi@redhat.com> > Reported-by: Jiri Benc <jbenc@redhat.com> > Suggested-by: Jiri Benc <jbenc@redhat.com> > Signed-off-by: Andrea Claudi <aclaudi@redhat.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
diff --git a/lib/bpf_legacy.c b/lib/bpf_legacy.c index 91086aa2..275941dd 100644 --- a/lib/bpf_legacy.c +++ b/lib/bpf_legacy.c @@ -513,9 +513,12 @@ static int bpf_mnt_check_target(const char *target) int ret; ret = mkdir(target, S_IRWXU); - if (ret && errno != EEXIST) + if (ret) { + if (errno == EEXIST) + return 0; fprintf(stderr, "mkdir %s failed: %s\n", target, strerror(errno)); + } return ret; }
bpf selftests using iproute2 fails with: $ ip link set dev veth0 xdp object ../bpf/xdp_dummy.o section xdp_dummy Continuing without mounted eBPF fs. Too old kernel? mkdir (null)/globals failed: No such file or directory Unable to load program This happens when the /sys/fs/bpf directory exists. In this case, mkdir in bpf_mnt_check_target() fails with errno == EEXIST, and the function returns -1. Thus bpf_get_work_dir() does not call bpf_mnt_fs() and the bpffs is not mounted. Fix this in bpf_mnt_check_target(), returning 0 when the mountpoint exists. Fixes: d4fcdbbec9df ("lib/bpf: Fix and simplify bpf_mnt_check_target()") Reported-by: Mingyu Shi <mshi@redhat.com> Reported-by: Jiri Benc <jbenc@redhat.com> Suggested-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: Andrea Claudi <aclaudi@redhat.com> --- lib/bpf_legacy.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)