The offset of the field 'init_uts_ns.name' has changed
since commit 9a56493f6942 ("uts: Use generic ns_common::count").

Link: 
https://lore.kernel.org/r/159644978167.604812.1773586504374412107.stgit@localhost.localdomain

Read the offset from VMCOREINFO if present. This requires a linux version
which exports the requisite offset in VMCOREINFO.

Signed-off-by: Alexander Egorenkov <egore...@linux.ibm.com>
---

v1 -> v2:
 * Use offset from VMCOREINFO
 * Initialize corresponding entry in offset_table

 defs.h    |  1 +
 kernel.c  | 15 ++++++++++-----
 symbols.c |  3 +++
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/defs.h b/defs.h
index c899fe2..9a8030a 100644
--- a/defs.h
+++ b/defs.h
@@ -2104,6 +2104,7 @@ struct offset_table {                    /* stash of 
commonly-used offsets */
        long inode_i_sb_list;
        long irq_common_data_affinity;
        long irq_desc_irq_common_data;
+       long uts_namespace_name;
 };
 
 struct size_table {         /* stash of commonly-used sizes */
diff --git a/kernel.c b/kernel.c
index 5ae8cf1..9871637 100644
--- a/kernel.c
+++ b/kernel.c
@@ -230,16 +230,21 @@ kernel_init()
                fprintf(fp, "%s\n\n", ctime_tz(&kt->date.tv_sec));
                clean_exit(0);
        }
-       
+
+       MEMBER_OFFSET_INIT(uts_namespace_name, "uts_namespace", "name");
        if (symbol_exists("system_utsname"))
                readmem(symbol_value("system_utsname"), KVADDR, &kt->utsname,
                        sizeof(struct new_utsname), "system_utsname", 
                        RETURN_ON_ERROR);
-       else if (symbol_exists("init_uts_ns"))
-               readmem(symbol_value("init_uts_ns") + sizeof(int),
-                       KVADDR,  &kt->utsname, sizeof(struct new_utsname), 
+       else if (symbol_exists("init_uts_ns")) {
+               long offset = sizeof(int);
+               if (VALID_MEMBER(uts_namespace_name))
+                       offset = OFFSET(uts_namespace_name);
+
+               readmem(symbol_value("init_uts_ns") + offset,
+                       KVADDR,  &kt->utsname, sizeof(struct new_utsname),
                        "init_uts_ns", RETURN_ON_ERROR);
-       else
+       } else
                error(INFO, "cannot access utsname information\n\n");
 
        if (CRASHDEBUG(1)) {
diff --git a/symbols.c b/symbols.c
index d22fb1d..3dd5fa1 100644
--- a/symbols.c
+++ b/symbols.c
@@ -10585,6 +10585,9 @@ dump_offset_table(char *spec, ulong makestruct)
        fprintf(fp, "                 xa_node_shift: %ld\n",
                OFFSET(xa_node_shift));
 
+       fprintf(fp, "            uts_namespace_name: %ld\n",
+               OFFSET(uts_namespace_name));
+
        fprintf(fp, "\n                    size_table:\n");
        fprintf(fp, "                          page: %ld\n", SIZE(page));
        fprintf(fp, "                    page_flags: %ld\n", SIZE(page_flags));
-- 
2.26.2

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