[Crash-utility] [PATCH] Fix "net -a" option on Linux 6.13 and later kernels
From: Kazuhito Hagio <k-hagio-ab(a)nec.com>
Kernel commit e4e3fd0a99d5 ("Merge branch
'improve-neigh_flush_dev-performance'")
and its patch set, which are contained in Linux 6.13 and later kernels,
removed neigh_hash_table.hash_buckets and neighbour.next members, and
introduced neigh_hash_table.hash_heads and neighbour.hash members
instead with the hlist implementation.
Without the patch, the "net -a" option fails with the following error:
crash> net -a
net: invalid structure member offset: neigh_table_hash_buckets
FILE: net.c LINE: 701 FUNCTION: dump_arp()
...
Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com>
---
defs.h | 2 ++
net.c | 26 +++++++++++++++++++++-----
symbols.c | 2 ++
3 files changed, 25 insertions(+), 5 deletions(-)
diff --git a/defs.h b/defs.h
index d8d378ef94b1..8378cbab2f73 100644
--- a/defs.h
+++ b/defs.h
@@ -2269,6 +2269,8 @@ struct offset_table { /* stash of commonly-used
offsets */
long task_struct_thread_context_x26;
long task_struct_thread_context_x27;
long task_struct_thread_context_x28;
+ long neigh_table_hash_heads;
+ long neighbour_hash;
};
struct size_table { /* stash of commonly-used sizes */
diff --git a/net.c b/net.c
index 31d3f2bf7c2f..4e14f19fc097 100644
--- a/net.c
+++ b/net.c
@@ -169,6 +169,11 @@ net_init(void)
"neigh_hash_table", "hash_shift");
MEMBER_OFFSET_INIT(neigh_table_hash_buckets,
"neigh_hash_table", "hash_buckets");
+ /* Linux 6.13 and later */
+ if (INVALID_MEMBER(neigh_table_hash_buckets)) {
+ MEMBER_OFFSET_INIT(neigh_table_hash_heads, "neigh_hash_table",
"hash_heads");
+ MEMBER_OFFSET_INIT(neighbour_hash, "neighbour", "hash");
+ }
} else {
MEMBER_OFFSET_INIT(neigh_table_hash_buckets,
"neigh_table", "hash_buckets");
@@ -698,9 +703,13 @@ dump_arp(void)
"neigh_table key_len", FAULT_ON_ERROR);
if (VALID_MEMBER(neigh_table_nht_ptr)) {
- readmem(nht + OFFSET(neigh_table_hash_buckets),
- KVADDR, &hash, sizeof(hash),
- "neigh_hash_table hash_buckets ptr", FAULT_ON_ERROR);
+ /* Linux 6.13 and later */
+ if (VALID_MEMBER(neigh_table_hash_heads))
+ readmem(nht + OFFSET(neigh_table_hash_heads), KVADDR, &hash,
+ sizeof(hash), "neigh_hash_table hash_heads ptr", FAULT_ON_ERROR);
+ else
+ readmem(nht + OFFSET(neigh_table_hash_buckets), KVADDR, &hash,
+ sizeof(hash), "neigh_hash_table hash_buckets ptr", FAULT_ON_ERROR);
readmem(hash, KVADDR, hash_buckets, hash_bytes,
"neigh_hash_table hash_buckets", FAULT_ON_ERROR);
@@ -831,8 +840,15 @@ print_neighbour_q(ulong addr, int key_len)
arp_state_to_flags(state);
- readmem(addr + OFFSET(neighbour_next), KVADDR,
- &addr, sizeof(addr), "neighbour next", FAULT_ON_ERROR);
+ /* Linux 6.13 and later kernels use hlist. */
+ if (VALID_MEMBER(neighbour_hash)) {
+ readmem(addr + OFFSET(neighbour_hash), KVADDR, &addr,
+ sizeof(addr), "neighbour hash", FAULT_ON_ERROR);
+ if (addr)
+ addr -= OFFSET(neighbour_hash);
+ } else
+ readmem(addr + OFFSET(neighbour_next), KVADDR, &addr,
+ sizeof(addr), "neighbour next", FAULT_ON_ERROR);
}
FREEBUF(ha_buf);
diff --git a/symbols.c b/symbols.c
index a3cd0f3f6e1f..0b63e11fa567 100644
--- a/symbols.c
+++ b/symbols.c
@@ -11028,6 +11028,7 @@ dump_offset_table(char *spec, ulong makestruct)
fprintf(fp, " neighbour_next: %ld\n",
OFFSET(neighbour_next));
+ fprintf(fp, " neighbour_hash: %ld\n",
OFFSET(neighbour_hash));
fprintf(fp, " neighbour_primary_key: %ld\n",
OFFSET(neighbour_primary_key));
fprintf(fp, " neighbour_ha: %ld\n",
@@ -11038,6 +11039,7 @@ dump_offset_table(char *spec, ulong makestruct)
OFFSET(neighbour_nud_state));
fprintf(fp, " neigh_table_hash_buckets: %ld\n",
OFFSET(neigh_table_hash_buckets));
+ fprintf(fp, " neigh_table_hash_heads: %ld\n",
OFFSET(neigh_table_hash_heads));
fprintf(fp, " neigh_table_hash_mask: %ld\n",
OFFSET(neigh_table_hash_mask));
fprintf(fp, " neigh_table_hash_shift: %ld\n",
--
2.31.1