Hi, I am currently simulating a duplex voice traffic on a single SCO link. (two adapters connect with one single SCO user level socket). On each side, after connected, I fork another process to perform the write operations, and the parent process will perform the read operaions. The pseudo code looks like the following connect(sockfd); if (!fork()) { /* child process */ while (1) { if (write(sockfd) < 0) break; } close(sockfd); return 0; } /* parent process */ while(1) { if (read(sockfd) < 0) break; } close(sockfd); But after one side close the connection, the other side of the PC has this oops. BUG: unable to handle kernel NULL pointer dereference at virtual address 00000058 Call Trace: [memcpy_fromiovec+55/96] memcpy_fromiovec+0x37/0x60 [<f8bc6fa9>] sco_sock_sendmsg+0x119/0x160 [sco] [sock_aio_write+285/304] sock_aio_write+0x11d/0x130 [getnstimeofday+54/208] getnstimeofday+0x36/0xd0 [do_sync_write+213/288] do_sync_write+0xd5/0x120 [hrtimer_try_to_cancel+60/144] hrtimer_try_to_cancel+0x3c/0x90 [autoremove_wake_function+0/80] autoremove_wake_function+0x0/0x50 [hrtimer_wakeup+0/32] hrtimer_wakeup+0x0/0x20 [vfs_write+346/368] vfs_write+0x15a/0x170 [sys_write+65/112] sys_write+0x41/0x70 Is there any safe way to run two processes on a single SCO socket? Originally I use the following way, but actually these two direction traffic will block each other. while(1) { if (write(sockfd) < 0) break; if (read(sockfd) < 0) break; } close(sockfd); ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Bluez-devel mailing list Bluez-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/bluez-devel