Since the following kernel commits split slab info from struct page
into struct slab, crash cannot get several slab related offsets from
struct page.

  d122019bf061 ("mm: Split slab into its own type")
  07f910f9b729 ("mm: Remove slab from struct page")

Without the patch, "kmem -s|-S" and "bt -F[F]" options cannot work
correctly with the following errors:

  crash> kmem -s kmem_cache
  CACHE             OBJSIZE  ALLOCATED     TOTAL  SLABS  SSIZE  NAME
  kmem: page_to_nid: invalid page: ffff9454afc35020
  kmem: kmem_cache: cannot gather relevant slab data
  ffff945140042000      216          ?         ?      ?     8k  kmem_cache

  crash> bt -F
  ...
  bt: invalid structure member offset: page_slab
      FILE: memory.c  LINE: 9477  FUNCTION: vaddr_to_kmem_cache()

Signed-by: Kazuhito Hagio <[email protected]>
---
 memory.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/memory.c b/memory.c
index e80c59ea4534..8448ddc3a16c 100644
--- a/memory.c
+++ b/memory.c
@@ -421,6 +421,8 @@ vm_init(void)
                MEMBER_OFFSET_INIT(page_prev, "page", "prev");
        if (INVALID_MEMBER(page_next))
                ANON_MEMBER_OFFSET_INIT(page_next, "page", "next");
+       if (INVALID_MEMBER(page_next))
+               MEMBER_OFFSET_INIT(page_next, "slab", "next");
 
        MEMBER_OFFSET_INIT(page_list, "page", "list");
        if (VALID_MEMBER(page_list)) {
@@ -747,11 +749,15 @@ vm_init(void)
                MEMBER_OFFSET_INIT(kmem_cache_random, "kmem_cache", "random");
                MEMBER_OFFSET_INIT(kmem_cache_cpu_freelist, "kmem_cache_cpu", 
"freelist");
                MEMBER_OFFSET_INIT(kmem_cache_cpu_page, "kmem_cache_cpu", 
"page");
+               if (INVALID_MEMBER(kmem_cache_cpu_page))
+                       MEMBER_OFFSET_INIT(kmem_cache_cpu_page, 
"kmem_cache_cpu", "slab");
                MEMBER_OFFSET_INIT(kmem_cache_cpu_node, "kmem_cache_cpu", 
"node");
                MEMBER_OFFSET_INIT(kmem_cache_cpu_partial, "kmem_cache_cpu", 
"partial");
                MEMBER_OFFSET_INIT(page_inuse, "page", "inuse");
                if (INVALID_MEMBER(page_inuse))
                        ANON_MEMBER_OFFSET_INIT(page_inuse, "page", "inuse");
+               if (INVALID_MEMBER(page_inuse))
+                       MEMBER_OFFSET_INIT(page_inuse, "slab", "inuse");
                MEMBER_OFFSET_INIT(page_offset, "page", "offset");
                if (INVALID_MEMBER(page_offset))
                        ANON_MEMBER_OFFSET_INIT(page_offset, "page", "offset");
@@ -763,6 +769,9 @@ vm_init(void)
                        if (INVALID_MEMBER(page_slab))
                                ANON_MEMBER_OFFSET_INIT(page_slab, "page", 
"slab_cache");
                }
+               if (INVALID_MEMBER(page_slab))
+                       MEMBER_OFFSET_INIT(page_slab, "slab", "slab_cache");
+
                MEMBER_OFFSET_INIT(page_slab_page, "page", "slab_page");
                if (INVALID_MEMBER(page_slab_page))
                        ANON_MEMBER_OFFSET_INIT(page_slab_page, "page", 
"slab_page");
@@ -772,10 +781,14 @@ vm_init(void)
                MEMBER_OFFSET_INIT(page_freelist, "page", "freelist");
                if (INVALID_MEMBER(page_freelist))
                        ANON_MEMBER_OFFSET_INIT(page_freelist, "page", 
"freelist");
+               if (INVALID_MEMBER(page_freelist))
+                       MEMBER_OFFSET_INIT(page_freelist, "slab", "freelist");
                if (INVALID_MEMBER(kmem_cache_objects)) {
                        MEMBER_OFFSET_INIT(kmem_cache_oo, "kmem_cache", "oo");
                        /* NOTE: returns offset of containing bitfield */
                        ANON_MEMBER_OFFSET_INIT(page_objects, "page", 
"objects");
+                       if (INVALID_MEMBER(page_objects))
+                               ANON_MEMBER_OFFSET_INIT(page_objects, "slab", 
"objects");
                }
                if (VALID_MEMBER(kmem_cache_node)) {
                        ARRAY_LENGTH_INIT(len, NULL, "kmem_cache.node", NULL, 
0);
-- 
2.27.0


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