Commit dd12805ed1db7 ("XArray: Remove radix tree compatibility") on
linux-next changes the definition of 'radix_tree_root' back to be a struct.
The content however differs from the original 'struct radix_tree_root'.
Thus attempts to debug current linux-next kernels fail with 'radix trees do
not exist or have changed their format'. Because the new 'struct
radix_tree_root' and 'struct xarray' have nearly the same layout the
functionality for XArrays can be reused.
Signed-off-by: Philipp Rudo <prudo(a)linux.ibm.com>
---
bpf.c | 7 ++++++-
ipcs.c | 5 ++++-
task.c | 15 +++++++++++----
3 files changed, 21 insertions(+), 6 deletions(-)
diff --git a/bpf.c b/bpf.c
index 6eacb9a..056e286 100644
--- a/bpf.c
+++ b/bpf.c
@@ -221,7 +221,12 @@ bpf_init(struct bpf_info *bpf)
bpf->idr_type = IDR_ORIG;
do_old_idr(IDR_ORIG_INIT, 0, NULL);
} else if (STREQ(MEMBER_TYPE_NAME("idr", "idr_rt"),
"radix_tree_root"))
- bpf->idr_type = IDR_RADIX;
+ if (MEMBER_EXISTS("radix_tree_root", "rnode"))
+ bpf->idr_type = IDR_RADIX;
+ else if (MEMBER_EXISTS("radix_tree_root", "xa_head"))
+ bpf->idr_type = IDR_XARRAY;
+ else
+ error(FATAL, "cannot determine IDR list type\n");
else if (STREQ(MEMBER_TYPE_NAME("idr", "idr_rt"),
"xarray"))
bpf->idr_type = IDR_XARRAY;
else
diff --git a/ipcs.c b/ipcs.c
index 2553bac..3c26620 100644
--- a/ipcs.c
+++ b/ipcs.c
@@ -206,7 +206,10 @@ ipcs_init(void)
if (STREQ(MEMBER_TYPE_NAME("idr", "idr_rt"), "xarray"))
ipcs_table.init_flags |= IDR_XARRAY;
else
- ipcs_table.init_flags |= IDR_RADIX;
+ if (MEMBER_EXISTS("radix_tree_root", "rnode"))
+ ipcs_table.init_flags |= IDR_RADIX;
+ else if (MEMBER_EXISTS("radix_tree_root", "xa_head"))
+ ipcs_table.init_flags |= IDR_XARRAY;
} else
ipcs_table.init_flags |= IDR_ORIG;
diff --git a/task.c b/task.c
index cd118e5..36a90d6 100644
--- a/task.c
+++ b/task.c
@@ -507,10 +507,17 @@ task_init(void)
OFFSET(pid_namespace_idr) + OFFSET(idr_idr_rt);
tt->flags |= PID_XARRAY;
} else if STREQ(MEMBER_TYPE_NAME("idr", "idr_rt"),
"radix_tree_root") {
- tt->refresh_task_table = refresh_radix_tree_task_table;
- tt->pid_radix_tree = symbol_value("init_pid_ns") +
- OFFSET(pid_namespace_idr) + OFFSET(idr_idr_rt);
- tt->flags |= PID_RADIX_TREE;
+ if (MEMBER_EXISTS("radix_tree_root", "rnode")) {
+ tt->refresh_task_table = refresh_radix_tree_task_table;
+ tt->pid_radix_tree = symbol_value("init_pid_ns") +
+ OFFSET(pid_namespace_idr) + OFFSET(idr_idr_rt);
+ tt->flags |= PID_RADIX_TREE;
+ } else if (MEMBER_EXISTS("radix_tree_root", "xa_head")) {
+ tt->refresh_task_table = refresh_xarray_task_table;
+ tt->pid_xarray = symbol_value("init_pid_ns") +
+ OFFSET(pid_namespace_idr) + OFFSET(idr_idr_rt);
+ tt->flags |= PID_XARRAY;
+ }
} else
error(FATAL, "unknown pid_namespace.idr type: %s\n",
MEMBER_TYPE_NAME("idr", "idr_rt"));
--
2.16.4