"XArray: Remove radix tree compatibility", changes the definition
of "radix_tree_root" back to be a struct. However, the content of
the new structure differs from the original structure, so without
the patch, current linux-next kernels fail during initialization
with the error message "radix trees do not exist or have changed
their format". Because the new "radix_tree_root" and "xarray"
structures have nearly the same layout, the existing functionality
for XArrays can be reused.
(prudo@linux.ibm.com)
Without the patch, the command may fail on Linux 4.20 and later
kernels with the error message "irq: radix trees do not exist or have
changed their format".
(anderson@redhat.com)
the radix_tree_pair and xarray_pair structures into a unified
list_pair structure that is used by both facilities, and fixes the
"bpf" command. Without the patch, the command fails with the error
message "bpf: radix trees do not exist or have changed their format".
(anderson@redhat.com)
3.10-based RHEL7 kernels, which contain a backport of the upstream
eBPF code, but still use the older, pre-4.11, IDR facility that does
not use radix trees for linking the active bpf_prog and bpf_map
structures. Without the patch, the command indicates "bpf: command
not supported or applicable on this architecture or kernel".
(anderson@redhat.com)
error where IPCS entries are not displayed because of a faulty
read of the "deleted" member of the embedded "kern_ipc_perm" data
structure. The "deleted" member was being read as a 4-byte integer,
but since it is declared as a "bool" type, only the lowest byte gets
set to 1 or 0. Since the structure is not zeroed-out when allocated,
stale data may be left in the upper 3 bytes, and the IPCS entry
gets rejected. The update is required for Linux 4.11 and greater
kernels, which reimplemented the IDR facility to use radix trees
in kernel commit 0a835c4f090af2c76fc2932c539c3b32fd21fbbb, titled
"Reimplement IDR and IDA using the radix tree". Without the patch,
if any IPCS entry exists, the command would fail with the message
"ipcs: invalid structure member offset: idr_top"
(anderson@redhat.com)
