Stress test for tty. :) You can use this program for debug new tty changes. Use with caution. In any case(with/without Peter's patches) I have BUG(): BUG: unable to handle kernel NULL pointer dereference at 000000000000004c IP: [<ffffffff81116650>] devpts_pty_kill+0x17/0x81 PGD 48696067 PUD a79c5067 PMD 0 Oops: 0000 [#1] SMP Pid: 7877, comm: a.out Tainted: P O 3.7.0-next-20121214-tty.1+ #9 System manufacturer P5K Premium/P5K Premium RIP: 0010:[<ffffffff81116650>] [<ffffffff81116650>] devpts_pty_kill+0x17/0x81 RSP: 0018:ffff8800484a3aa8 EFLAGS: 00010292 RAX: ffff88012f0385a0 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000282 RDI: 0000000000000000 RBP: ffff8800484a3ac8 R08: 0000000000000000 R09: ffff880046f26d40 R10: ffffffff81426ec8 R11: 0000000000000246 R12: ffff8800486a6c00 R13: ffff8800484c7180 R14: ffff880046ec4890 R15: 00000000fffffffb FS: 00007f9a64345700(0000) GS:ffff88012fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 000000000000004c CR3: 00000000a7a01000 CR4: 00000000000407e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process a.out (pid: 7877, threadinfo ffff8800484a2000, task ffff88007576d220) Stack: ffff880000000001 ffff88004854a400 ffff8800486a6c00 ffff8800484c7180 ffff8800484a3ae8 ffffffff811e0c1b ffff8800484c7180 ffff88004854a400 ffff8800484a3bd8 ffffffff811d83aa ffff880046f26d78 0000000000000009 Call Trace: [<ffffffff811e0c1b>] pty_close+0x123/0x14f [<ffffffff811d83aa>] tty_release+0x17a/0x53d [<ffffffff812e7442>] ? __mutex_unlock_slowpath+0x15/0x39 [<ffffffff811e1003>] ptmx_open+0x12c/0x161 [<ffffffff810c6d4b>] chrdev_open+0x12a/0x14b [<ffffffff810c6c21>] ? cdev_put+0x23/0x23 [<ffffffff810c27a9>] do_dentry_open+0x170/0x217 [<ffffffff810c2933>] finish_open+0x34/0x40 [<ffffffff810ce069>] do_last+0x8c4/0xa72 [<ffffffff810ce2ed>] ? path_init+0xd6/0x2fe [<ffffffff810ceaf4>] path_openat+0xcb/0x363 [<ffffffff81051033>] ? __dequeue_entity+0x2e/0x33 [<ffffffff810cee91>] do_filp_open+0x38/0x84 [<ffffffff810d9846>] ? __alloc_fd+0x51/0x110 [<ffffffff810c24ed>] do_sys_open+0x6d/0xff [<ffffffff810c25ac>] sys_open+0x1c/0x1e [<ffffffff812ee652>] system_call_fastpath+0x16/0x1b Code: 08 02 00 00 48 89 c7 e8 6c f3 fb ff 5b 4c 89 e0 41 5c c9 c3 55 48 89 e5 41 55 41 54 53 48 89 fb 48 83 ec 08 48 8b 05 80 43 71 00 <81> 7f 4c 02 00 50 00 48 8b 40 08 4c 8b 60 60 75 04 0f 0b eb fe RIP [<ffffffff81116650>] devpts_pty_kill+0x17/0x81 RSP <ffff8800484a3aa8> CR2: 000000000000004c Without Peter's patches I have WARN(): 7388:Dec 18 22:43:12 bm kernel: [ 2484.054010] WARNING: at drivers/tty/tty_buffer.c:476 flush_to_ldisc+0x52/0x1b2() 7389-Dec 18 22:43:12 bm kernel: [ 2484.054011] Hardware name: P5K Premium 7390-Dec 18 22:43:12 bm kernel: [ 2484.054012] tty is NULL 7392-Dec 18 22:43:12 bm kernel: [ 2484.054042] Pid: 3030, comm: kworker/0:0 Tainted: P W O 3.7.0-next-20121214-tty.1 #8 7393-Dec 18 22:43:12 bm kernel: [ 2484.054044] Call Trace: 7394-Dec 18 22:43:12 bm kernel: [ 2484.054047] [<ffffffff8102ce58>] warn_slowpath_common+0x80/0x98 7395-Dec 18 22:43:12 bm kernel: [ 2484.054049] [<ffffffff8102cf04>] warn_slowpath_fmt+0x41/0x43 7396-Dec 18 22:43:12 bm kernel: [ 2484.054051] [<ffffffff811df175>] flush_to_ldisc+0x52/0x1b2 7397-Dec 18 22:43:12 bm kernel: [ 2484.054053] [<ffffffff812e81a9>] ? __schedule+0x5d1/0x613 7398-Dec 18 22:43:12 bm kernel: [ 2484.054056] [<ffffffff8103ee42>] process_one_work+0x1c1/0x279 7399-Dec 18 22:43:12 bm kernel: [ 2484.054058] [<ffffffff811df123>] ? tty_buffer_free_all+0x4d/0x4d 7400-Dec 18 22:43:12 bm kernel: [ 2484.054060] [<ffffffff81040d47>] worker_thread+0x154/0x24e 7401-Dec 18 22:43:12 bm kernel: [ 2484.054062] [<ffffffff81040bf3>] ? manage_workers+0x26c/0x26c 7402-Dec 18 22:43:12 bm kernel: [ 2484.054064] [<ffffffff810443eb>] kthread+0xb0/0xb8 7403-Dec 18 22:43:12 bm kernel: [ 2484.054066] [<ffffffff8104433b>] ? kthread_parkme+0x1f/0x1f 7404-Dec 18 22:43:12 bm kernel: [ 2484.054068] [<ffffffff812ee46c>] ret_from_fork+0x7c/0xb0 7405-Dec 18 22:43:12 bm kernel: [ 2484.054070] [<ffffffff8104433b>] ? kthread_parkme+0x1f/0x1f With Peter's patches I have WARN(): WARNING: at drivers/tty/n_tty.c:160 n_tty_set_room+0xe7/0xf8() Hardware name: P5K Premium scheduling buffer work for halted ldisc Pid: 3127, comm: a.out Tainted: P W O 3.7.0-next-20121214-tty.1+ #9 Call Trace: [<ffffffff8102ce58>] warn_slowpath_common+0x80/0x98 [<ffffffff8102cf04>] warn_slowpath_fmt+0x41/0x43 [<ffffffff811dae01>] n_tty_set_room+0xe7/0xf8 [<ffffffff811db2cf>] reset_buffer_flags+0xad/0xb6 [<ffffffff811dd01b>] n_tty_open+0xca/0x11f [<ffffffff811de4c9>] tty_ldisc_open+0x4e/0x5f [<ffffffff811ded14>] tty_ldisc_hangup+0x1f5/0x292 [<ffffffff810d0289>] ? fasync_helper+0x22/0x6c [<ffffffff811d7a03>] __tty_hangup+0x102/0x30e [<ffffffff810d52ad>] ? d_delete+0x12d/0x136 [<ffffffff811d7c2a>] tty_vhangup+0x9/0xb [<ffffffff811e0c3b>] pty_close+0x143/0x14f [<ffffffff811d83aa>] tty_release+0x17a/0x53d [<ffffffff8104b9f7>] ? __wake_up+0x3f/0x48 [<ffffffff810efb55>] ? fsnotify+0x21d/0x244 [<ffffffff810c4bc5>] __fput+0xf9/0x1bd [<ffffffff810c4ccf>] ____fput+0x9/0xb [<ffffffff81041cd4>] task_work_run+0x80/0x98 [<ffffffff810025bd>] do_notify_resume+0x58/0x69 [<ffffffff812ee8da>] int_signal+0x12/0x17 --- /* * stress_test_tty.c * * Created on: Dec, 2012 * Copyright (C) 2012 Ilya Zykov * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <stdio.h> #include <fcntl.h> #include <sys/ioctl.h> #include <termios.h> #include <stdlib.h> #include <pthread.h> #include <signal.h> #define BUF_SIZE 2 #define ERROR_EXIT_CODE 1 #define parent child_id static int mfd=-1, sfd=-1, parent=1; static pthread_t pth_id; static char pty_name[24], buf[]={ '1', '\n' }; static void pty_exit(int ret, char * exit_message){ if (sfd >= 0) close(sfd); if (mfd >= 0) close(mfd); printf("%s %s %s exit. \n",exit_message?exit_message:"", ret?"Error":"Normal", parent?"parent":"child"); exit(ret); } static void pty_init(void){ int ptn; if( (mfd=open("/dev/ptmx", O_RDWR )) < 0 ) pty_exit(ERROR_EXIT_CODE,"Couldn't open /dev/ptmx. \n"); if (ioctl(mfd, TIOCGPTN, &ptn) < 0 ) pty_exit(ERROR_EXIT_CODE,"Couldn't get pty number. \n"); snprintf(pty_name, sizeof(pty_name), "/dev/pts/%d", ptn); //printf("Slave pty name = %s.\n",pty_name); ptn=0; if (ioctl(mfd, TIOCSPTLCK, &ptn) < 0 ) pty_exit(ERROR_EXIT_CODE,"Couldn't unlock pty slave. \n"); if ( (sfd=open(pty_name, O_RDWR )) < 0 ) pty_exit(ERROR_EXIT_CODE, "Couldn't open pty slave. \n"); } static void * pty_thread_open(void * arg) { static char ret[]="Thread open has been created.\n"; printf(ret); do { close(open(pty_name, O_RDWR )); } while(1); return ret; } static void * pty_thread_read(void * arg) { static char ret[]="Thread read has been created.\n"; printf(ret); do { read(sfd, buf, BUF_SIZE); } while(1); return ret; } static void * pty_thread_write(void * arg) { static char ret[]="Thread write has been created.\n"; printf(ret); do { write(mfd, buf, BUF_SIZE); } while(1); return ret; } int main(int argc,char *argv[]) { pty_init(); child_id=fork(); if(parent) { sleep(100); kill(child_id, SIGINT); pty_exit(0,"Parent normal exit\n"); } pthread_create(&pth_id, NULL, &pty_thread_open, 0); /* For WARNINGS. pthread_create(&pth_id, NULL, &pty_thread_write, 0); pthread_create(&pth_id, NULL, &pty_thread_read, 0); */ do { close(sfd); close(mfd); pty_init(); } while(1); return 0; } -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
