linux/mm
Ben Greear d6543e3935 slub: Enable backtrace for create/delete points
This patch attempts to grab a backtrace for the creation
and deletion points of the slub object.  When a fault is
detected, we can then get a better idea of where the item
was deleted.

Example output from debugging some funky nfs/rpc behaviour:

=============================================================================
BUG kmalloc-64: Object is on free-list
-----------------------------------------------------------------------------

INFO: Allocated in rpcb_getport_async+0x39c/0x5a5 [sunrpc] age=381 cpu=3 pid=3750
       __slab_alloc+0x348/0x3ba
       kmem_cache_alloc_trace+0x67/0xe7
       rpcb_getport_async+0x39c/0x5a5 [sunrpc]
       call_bind+0x70/0x75 [sunrpc]
       __rpc_execute+0x78/0x24b [sunrpc]
       rpc_execute+0x3d/0x42 [sunrpc]
       rpc_run_task+0x79/0x81 [sunrpc]
       rpc_call_sync+0x3f/0x60 [sunrpc]
       rpc_ping+0x42/0x58 [sunrpc]
       rpc_create+0x4aa/0x527 [sunrpc]
       nfs_create_rpc_client+0xb1/0xf6 [nfs]
       nfs_init_client+0x3b/0x7d [nfs]
       nfs_get_client+0x453/0x5ab [nfs]
       nfs_create_server+0x10b/0x437 [nfs]
       nfs_fs_mount+0x4ca/0x708 [nfs]
       mount_fs+0x6b/0x152
INFO: Freed in rpcb_map_release+0x3f/0x44 [sunrpc] age=30 cpu=2 pid=29049
       __slab_free+0x57/0x150
       kfree+0x107/0x13a
       rpcb_map_release+0x3f/0x44 [sunrpc]
       rpc_release_calldata+0x12/0x14 [sunrpc]
       rpc_free_task+0x59/0x61 [sunrpc]
       rpc_final_put_task+0x82/0x8a [sunrpc]
       __rpc_execute+0x23c/0x24b [sunrpc]
       rpc_async_schedule+0x10/0x12 [sunrpc]
       process_one_work+0x230/0x41d
       worker_thread+0x133/0x217
       kthread+0x7d/0x85
       kernel_thread_helper+0x4/0x10
INFO: Slab 0xffffea00029aa470 objects=20 used=9 fp=0xffff8800be7830d8 flags=0x20000000004081
INFO: Object 0xffff8800be7830d8 @offset=4312 fp=0xffff8800be7827a8

Bytes b4 0xffff8800be7830c8:  87 a8 96 00 01 00 00 00 5a 5a 5a 5a 5a 5a 5a 5a .�......ZZZZZZZZ
 Object 0xffff8800be7830d8:  6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
 Object 0xffff8800be7830e8:  6b 6b 6b 6b 01 08 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkk..kkkkkkkkkk
 Object 0xffff8800be7830f8:  6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
 Object 0xffff8800be783108:  6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkkkkkkkkkk�
 Redzone 0xffff8800be783118:  bb bb bb bb bb bb bb bb                         �������������
 Padding 0xffff8800be783258:  5a 5a 5a 5a 5a 5a 5a 5a                         ZZZZZZZZ
Pid: 29049, comm: kworker/2:2 Not tainted 3.0.0-rc4+ #8
Call Trace:
 [<ffffffff811055c3>] print_trailer+0x131/0x13a
 [<ffffffff81105601>] object_err+0x35/0x3e
 [<ffffffff8110746f>] verify_mem_not_deleted+0x7a/0xb7
 [<ffffffffa02851b5>] rpcb_getport_done+0x23/0x126 [sunrpc]
 [<ffffffffa027d0ba>] rpc_exit_task+0x3f/0x6d [sunrpc]
 [<ffffffffa027d4ab>] __rpc_execute+0x78/0x24b [sunrpc]
 [<ffffffffa027d6c0>] ? rpc_execute+0x42/0x42 [sunrpc]
 [<ffffffffa027d6d0>] rpc_async_schedule+0x10/0x12 [sunrpc]
 [<ffffffff810611b7>] process_one_work+0x230/0x41d
 [<ffffffff81061102>] ? process_one_work+0x17b/0x41d
 [<ffffffff81063613>] worker_thread+0x133/0x217
 [<ffffffff810634e0>] ? manage_workers+0x191/0x191
 [<ffffffff81066e10>] kthread+0x7d/0x85
 [<ffffffff81485924>] kernel_thread_helper+0x4/0x10
 [<ffffffff8147eb18>] ? retint_restore_args+0x13/0x13
 [<ffffffff81066d93>] ? __init_kthread_worker+0x56/0x56
 [<ffffffff81485920>] ? gs_change+0x13/0x13

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-07 22:17:03 +03:00
..
backing-dev.c
bootmem.c
bounce.c
cleancache.c
compaction.c
debug-pagealloc.c
dmapool.c
fadvise.c
failslab.c
filemap.c
filemap_xip.c
fremap.c
highmem.c
huge_memory.c
hugetlb.c
hwpoison-inject.c
init-mm.c
internal.h
Kconfig
Kconfig.debug
kmemcheck.c
kmemleak-test.c
kmemleak.c
ksm.c
maccess.c
madvise.c
Makefile
memblock.c
memcontrol.c
memory-failure.c
memory.c
memory_hotplug.c
mempolicy.c
mempool.c
migrate.c
mincore.c
mlock.c
mm_init.c
mmap.c
mmu_context.c
mmu_notifier.c
mmzone.c
mprotect.c
mremap.c
msync.c
nobootmem.c
nommu.c
oom_kill.c
page-writeback.c
page_alloc.c
page_cgroup.c
page_io.c
page_isolation.c
pagewalk.c
percpu-km.c
percpu-vm.c
percpu.c
pgtable-generic.c
prio_tree.c
quicklist.c
readahead.c
rmap.c mm, rmap: Add yet more comments to page_get_anon_vma/page_lock_anon_vma 2011-05-29 09:25:48 -07:00
shmem.c tmpfs: fix race between truncate and writepage 2011-05-28 16:09:26 -07:00
slab.c
slob.c slob/lockdep: Fix gfp flags passed to lockdep 2011-06-07 21:38:07 +03:00
slub.c slub: Enable backtrace for create/delete points 2011-07-07 22:17:03 +03:00
sparse-vmemmap.c
sparse.c
swap.c
swap_state.c
swapfile.c
thrash.c
truncate.c
util.c
vmalloc.c
vmscan.c
vmstat.c