Проблема появляется при вызове функции wait_event_interruptible() в доморощенной функции read_wbuffs() при работе с tcp протоколом. Передача идет по защищенному каналу ipsec.
Функция wait_event_interruptible() используется для синхронизации с приемным буфером.
static ssize_t read_wbuffs(char *buf, size_t count, int fuser)
{
int flags;
printk(KERN_INFO "======myrnd_read================\n");
if(!atomic_read(&(buff_data.buff_full)))
{
printk(KERN_ERR "sizeBuf empty wait\n");
if(wait_event_interruptible(buff_data.waitQueue,atomic_read(& (buff_data.rsrc))))
{
atomic_set(&(buff_data.rsrc),0);
return -ERESTARTSYS; // signal (tell to handle it)
}
atomic_set(&(buff_data.rsrc),0);
}
memcpy(buf, data_wbuf, count);
atomic_set(&(buff_data.buff_full),0);
atomic_set(&(buff_data.wsrc),1);
wake_up_interruptible_all(&(buff_data.waitQueue));
wake_up_interruptible(&msk_sleep);
return count;
}
Проявляется при работе с tcp протоколом, с udp всё ок!
На передающей стороне (проблемная) запускаю команду:
#nc -q1 10.1.101.125 6789 < ./text_out (стек вызовов tcp см. ниже), которая по протоколу tcp передает файл text_out
на приемной стороне, команда записывает его в файл text_in:
#nc -l -p 6789 > ./text_in
С udp:
#nc -u -q1 10.1.101.125 6789 < ./text_out (стек вызовов udp см. ниже).
#nc -u -l -p 6789 > ./text_in
[ 124.220724] Call Trace:
[ 124.217139] ===========myrnd_read========================
[ 124.217143] sizeBuf empty wait
[ 124.218839] BUG: scheduling while atomic: nc/2271/0x00000200
[ 124.220640] Modules linked in: my myiv myrndm loop snd_hda_codec_realtek snd_hda_intel snd_hda_codec i915 drm_kms_helper snd_hwdep drm snd_pcm snd_timer i2c_algo_bit i2c_i801 psmouse snd parport_pc evdev i2c_core serio_raw pcspkr parport soundcore rng_core video button processor snd_page_alloc output ext3 jbd mbcache sd_mod crc_t10dif ata_generic 8139too r8169 uhci_hcd ata_piix 8139cp ehci_hcd thermal mii libata scsi_mod usbcore nls_base thermal_sys [last unloaded: scsi_wait_scan]
[ 124.220719] Pid: 2271, comm: nc Not tainted 2.6.32-debug #2
[ 124.220724] Call Trace:
[ 124.220737] [<c102ab3a>] ? printk+0x18/0x1a
[ 124.220746] [<c1023492>] __schedule_bug+0x58/0x5e
[ 124.220755] [<c12c4559>] schedule+0x44/0x3f4
[ 124.220766] [<f80fe2ca>] read_wbuffs+0x8b/0x11b [myrndm]
[ 124.220775] [<c104045d>] ? autoremove_wake_function+0x0/0x3d
[ 124.220784] [<f80fe3b8>] my_rndg+0x2a/0x34 [myrndm]
[ 124.220793] [<f81d11fc>] myiv_aead_givencrypt+0xe0/0x139 [myiv]
[ 124.220803] [<c1267c33>] esp_output+0x2a1/0x2db
[ 124.220812] [<c127587c>] xfrm_output_resume+0x249/0x2d6
[ 124.220822] [<c1220f91>] ? sch_direct_xmit+0x45/0x12c
[ 124.220830] [<c1275916>] xfrm_output2+0xd/0xf
[ 124.220837] [<c12759bc>] xfrm_output+0xa4/0xb8
[ 124.220845] [<c126c7f0>] xfrm4_output_finish+0x24/0x26
[ 124.220852] [<c126c8ef>] xfrm4_output+0x59/0x6a
[ 124.220859] [<c126f8c5>] ? xfrm_dst_check+0x12/0x28
[ 124.220867] [<c12347fb>] ip_local_out+0x18/0x1b
[ 124.220874] [<c1234a83>] ip_queue_xmit+0x285/0x2fb
[ 124.220883] [<c10b68d2>] ? __slab_free+0x4d/0x20b
[ 124.220892] [<c1231877>] ? ip_local_deliver+0x78/0x7e
[ 124.220900] [<c1248b5b>] ? tcp_v4_md5_lookup+0xe/0x10
[ 124.220909] [<c124641f>] tcp_transmit_skb+0x5a8/0x5e8
[ 124.220917] [<c1246f61>] tcp_write_xmit+0x73c/0x81b
[ 124.220926] [<c12470a6>] __tcp_push_pending_frames+0x30/0x81
[ 124.220934] [<c12447ee>] tcp_rcv_established+0xe6/0x660
[ 124.220943] [<c124a842>] tcp_v4_do_rcv+0x154/0x2e5
[ 124.220953] [<c1202ae3>] release_sock+0x3a/0x99
[ 124.220960] [<c123c6f4>] tcp_sendmsg+0x85b/0x923
[ 124.220969] [<c1146fd8>] ? __generic_unplug_device+0x26/0x29
[ 124.220979] [<c101c472>] ? kmap_atomic_prot+0xa8/0xc8
[ 124.220988] [<c11ffe9d>] sock_aio_write+0xfc/0x10b
[ 124.220996] [<c10bb0f1>] do_sync_write+0xaf/0xeb
[ 124.221004] [<c12012d1>] ? sys_connect+0x88/0xc3
[ 124.221013] [<c1047664>] ? ktime_get+0x6b/0xdf
[ 124.221021] [<c104045d>] ? autoremove_wake_function+0x0/0x3d
[ 124.221029] [<c11136b0>] ? security_file_permission+0xf/0x11
[ 124.221037] [<c10bb412>] ? rw_verify_area+0xb0/0xe4
[ 124.221044] [<c10bb6ef>] vfs_write+0xa0/0x174
[ 124.221052] [<c10bb9d2>] sys_write+0x38/0x63
[ 124.221060] [<c100343b>] sysenter_do_call+0x12/0x28
Стек вызовов для UDP:
sys_write
vfs_write
do_sync_write
sock_aio_write
do_sock_write
__sock_sendmsg
inet_sendmsg
udp_sendmsg
release_sock
udp_push_pending_frames
ip_push_pending_frames
ip_local_out
dst_output
xfrm4_output
xfrm4_output_finish
xfrm_output
xfrm_output2
xfrm_output_one
esp_output
myiv_aead_givencrypt
my_rndg
read_wbuffs
sys_write
vfs_write
do_sync_write
sock_aio_write
do_sock_write
__sock_sendmsg
tcp_sendmsg
release_sock
__release_sock
sk_backlog_rcv
tcp_v4_do_rcv
tcp_rcv_established
tcp_data_snd_check
tcp_push_pending_frames
_tcp_push_pending_frames
tcp_write_xmit
tcp_transmit_skb
ip_queue_xmit
ip_local_out
dst_output
xfrm4_output
xfrm4_output_finish
xfrm_output
xfrm_output2
xfrm_output_resume
xfrm_output_one
esp_output
myiv_aead_givencrypt
my_rndg
read_wbuff
