Re: [Crash-utility] [PATCH v2] Fix for XArray/radix_tree rework on linux-next

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 linux ibm com> --- bpf.c | 7 ++++++- filesys.c | 4 +++- ipcs.c | 5 ++++- kernel.c | 11 ++++++++--- task.c | 15 +++++++++++---- tools.c | 5 ++++- 6 files changed, 36 insertions(+), 11 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/filesys.c b/filesys.c index 9305627..6abba0b 100644 --- a/filesys.c +++ b/filesys.c @@ -2217,7 +2217,9 @@ dump_inode_page_cache_info(ulong inode) xarray = root_rnode = count = 0; if (MEMBER_EXISTS("address_space", "i_pages") && - STREQ(MEMBER_TYPE_NAME("address_space", "i_pages"), "xarray")) + (STREQ(MEMBER_TYPE_NAME("address_space", "i_pages"), "xarray") || + (STREQ(MEMBER_TYPE_NAME("address_space", "i_pages"), "radix_tree_root") && + MEMBER_EXISTS("radix_tree_root", "xa_head")))) xarray = i_mapping + OFFSET(address_space_page_tree); else root_rnode = i_mapping + OFFSET(address_space_page_tree); 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/kernel.c b/kernel.c index 9f5ba89..8080097 100644 --- a/kernel.c +++ b/kernel.c @@ -534,9 +534,14 @@ kernel_init() if (kernel_symbol_exists("irq_desc_tree")) { get_symbol_type("irq_desc_tree", NULL, &req); - kt->flags2 |= STREQ(req.type_tag_name, "xarray") ? - IRQ_DESC_TREE_XARRAY : IRQ_DESC_TREE_RADIX; - + if (STREQ(req.type_tag_name, "xarray")) { + kt->flags2 |= IRQ_DESC_TREE_XARRAY; + } else { + if (MEMBER_EXISTS("radix_tree_root", "xa_head")) + kt->flags2 |= IRQ_DESC_TREE_XARRAY; + else + kt->flags2 |= IRQ_DESC_TREE_RADIX; + } } STRUCT_SIZE_INIT(irq_data, "irq_data"); if (VALID_STRUCT(irq_data)) { 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")); diff --git a/tools.c b/tools.c index 72ec76a..43b838a 100644 --- a/tools.c +++ b/tools.c @@ -4241,7 +4241,10 @@ cmd_tree() } if (STRNEQ(optarg, "ra")) - type_flag = RADIXTREE_REQUEST; + if (MEMBER_EXISTS("radix_tree_root", "xa_head")) + type_flag = XARRAY_REQUEST; + else + type_flag = RADIXTREE_REQUEST; else if (STRNEQ(optarg, "rb")) type_flag = RBTREE_REQUEST; else if (STRNEQ(optarg, "x")) -- 2.16.4