Hi Xiaolong,
I'm encountering some difficulties running the reproducer, see below.
Any help is very welcome!
On Tue, Apr 18 2017, kernel test robot wrote:
> [ 45.772683] BUG: unable to handle kernel NULL pointer dereference at
> 0000000000000010
<snip>
> [ 45.772697] IP: __debugfs_remove+0x5c/0xc0
> [ 45.772743] Call Trace:
> [ 45.772750] debugfs_remove_recursive+0xd4/0x1e0
> [ 45.772758] rpc_clnt_debugfs_unregister+0x19/0x30
> [ 45.772762] rpc_client_register+0x18a/0x1c0
> [ 45.772765] rpc_new_client+0x1de/0x2e0
> [ 45.772768] rpc_create_xprt+0x58/0x170
> [ 45.772769] rpc_create+0xea/0x1c0
> [ 45.772776] nfs_create_rpc_client+0xe8/0x130
> [ 45.772814] nfs4_init_client+0x7e/0x290 [nfsv4]
> [ 45.772820] ? __radix_tree_replace+0x8a/0x140
> [ 45.772823] ? radix_tree_iter_tag_clear+0x1c/0x20
> [ 45.772827] ? __rpc_init_priority_wait_queue+0x81/0xb0
> [ 45.772830] ? rpc_init_wait_queue+0x13/0x20
> [ 45.772847] ? nfs4_alloc_client+0x1d2/0x1e0 [nfsv4]
<snip>
> [ 45.772985] Code: 8b 7c 24 30 48 89 de e8 f3 28 e6 ff 48 89 df e8 3b
> 22 e5 ff 4c 8b 63 78 48 c7 c2 20 d7 3b 82 48 c7 c6 e0 9f c9 81 49 8d
> 7c 24 18 <41> c7 44 24 10 00 00 00 00 4d 8d 6c 24 10 e8 a1 b6 cc ff 49
> 8d
Ok, that's
41 c7 44 24 10 00 00 movl $0x0,0x10(%r12)
which is probably the init_completion() in __debugfs_remove_file():
fsd = dentry->d_fsdata;
init_completion(&fsd->active_users_drained);
This would mean that fsd == NULL and this can happen only if the dentry
in question isn't a regular file but a symlink or whatever. So, an
additional d_is_reg() is needed here. I'll fix this in the next
iteration once I got the reproducer working.
> To reproduce:
>
> git clone https://github.com/01org/lkp-tests.git
> cd lkp-tests
> bin/lkp qemu -k <bzImage> job-script # job-script is attached in
> this email
>
This gives
make: Entering directory '/home/nic/lkp-tests/bin/event'
gcc -c -o wakeup.o wakeup.c
gcc -o wakeup wakeup.o
rm -f wakeup.o
strip wakeup
make: Leaving directory '/home/nic/lkp-tests/bin/event'
cpio: root:lkp: invalid group
cpio: root:lkp: invalid group
cpio: root:lkp: invalid group
gzip: /home/nic/.lkp/cache/lkp-x86_64.cpio: No such file or directory
mv: cannot stat ‘/home/nic/.lkp/cache/lkp-x86_64.cpio.gz’: No such file or
directory
mv: cannot stat ‘/home/nic/.lkp/cache/lkp-x86_64.cgz’: No such file or
directory
result_root:
/home/nic/.lkp//result/boot/1/vm-lkp-nex04-8G/debian-x86_64-2016-08-31.cgz/x86_64-rhel-7.2/gcc-6/f3e7155d085591ab58f0993ce633fea58c082b35/3
downloading initrds ...
/usr/bin/wget -q --local-encoding=UTF-8 --retry-connrefused --waitretry 1000
--tries 1000
https://github.com/0day-ci/lkp-qemu/raw/master/osimage/debian/debian-x86_64-2016-08-31.cgz
-N -P /home/nic/.lkp/cache/osimage/debian
/usr/bin/wget -q --local-encoding=UTF-8 --retry-connrefused --waitretry 1000
--tries 1000
https://github.com/0day-ci/lkp-qemu/raw/master/osimage/deps/debian-x86_64-2016-08-31.cgz/lkp_2017-04-01.cgz
-N -P /home/nic/.lkp/cache/osimage/deps/debian-x86_64-2016-08-31.cgz
Failed to download
osimage/deps/debian-x86_64-2016-08-31.cgz/lkp_2017-04-01.cgz
Manual download of that very last lkp_2017-04-01.cgz file results in a 404
error. Please let me know if you need more details.
Thank you!
Nicolai
