[Crash-utility] Re: [PATCH] Fix "net -a" option on Linux 6.13 and later kernels

From: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; 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&gt; --- 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 -- Crash-utility mailing list -- devel(a)lists.crash-utility.osci.io To unsubscribe send an email to devel-leave(a)lists.crash-utility.osci.io https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/ Contribution Guidelines: https://github.com/crash-utility/crash/wiki