Hello,
Sorry for the late rpely. I have a bit complicated acces to mail.
Here are some traces for the OOPS. I added following suggested patch:
--- linux-2.4.18-pre4/drivers/char/tty_io.c Tue Jan 15 15:08:24 2002
+++ linux-akpm-1/drivers/char/tty_io.c Mon Jan 21 15:23:32 2002
@@ -1266,8 +1266,14 @@ static void release_dev(struct file * fi
/*
* Make sure that the tty's task queue isn't activated.
*/
+ if (test_bit(TTY_DONT_FLIP, &tty->flags))
+ BUG();
run_task_queue(&tq_timer);
+ if (tty->flip.tqueue.sync)
+ BUG();
flush_scheduled_tasks();
+ if (tty->flip.tqueue.sync)
+ BUG();
and none of the bugs was triggered.
I also added printks to some functions to print argument values on entry (and
return from alloc_tty_struct). For every call to function tty_flip_buffer_push
I added a breakpoint to print full backrtrace.
This is backtrace in actual segfault:
Breakpoint 1, panic (fmt=0xa0146420 "Kernel mode fault at addr 0x%lx, ip 0x%lx") at panic.c:45
45 {
(gdb) bt
#0 panic (fmt=0xa0146420 "Kernel mode fault at addr 0x%lx, ip 0x%lx") at panic.c:45
#1 0xa00c578c in segv (address=0, ip=2684428006, is_write=0, is_user=0) at trap_kern.c:94
#2 0xa00c63ea in segv_handler (sig=11, sc=0xa0893ae0, usermode=0) at trap_user.c:369
#3 0xa00c6575 in sig_handler (sig=11, sc={gs = 0, __gsh = 0, fs = 0, __fsh = 0, es = 43, __esh = 0, ds = 43, __dsh = 0, edi = 2693587200, esi = 2693348808, ebp = 2693348816, esp = 2693348792, ebx = 0, edx = 0, ecx = 2693348576, eax = 0, trapno = 14, err = 4, eip = 2684428006, cs = 35, __csh = 0, eflags = 2163219, esp_at_signal = 2693348792, ss = 43, __ssh = 0, fpstate = 0xa0893b38, oldmask = 134217728, cr2 = 0}) at trap_user.c:428
#4 <signal handler called>
#5 __run_task_queue (list=0xa0169330) at softirq.c:352
#6 0xa00701d9 in release_dev (filp=0xa25d7340) at /usr/home/bulb/umlinux/include/linux/tqueue.h:122
#7 0xa0070629 in tty_release (inode=0xa08d1080, filp=0xa25d7340) at tty_io.c:1440
#8 0xa002aa25 in fput (file=0xa25d7340) at file_table.c:113
#9 0xa0029ac7 in filp_close (filp=0xa25d7340, id=0xa0171840) at open.c:838
#10 0xa0029b1c in sys_close (fd=0) at open.c:862
#11 0xa00c4575 in execute_syscall (regs={regs = {0, 2048, 1, 0, 2684353436, 2684353084, 4294967258, 43, 43, 0, 0, 6, 1074649757, 35, 2097799, 2684353040, 43}}) at syscall_kern.c:326
#12 0xa00c4671 in syscall_handler (unused=0x0) at syscall_user.c:70
I attach output on console (including debuging printks - each is first line
in named function except for alloc_tty_struct, where it's the last one.
The debugger output contains backtraces of all entries to tty_flip_buffer_push
for the same session. In the session I just waited for the shell to start
(it's started directly from inittab) and then quickly typed halt and <CR>.
The um-kernel was compiled with attached config. The host kernel was 2.4.13-ac8.
inittab, rc and rcS scripts used in the session are included. All binaries
(including /sbin/halt) are copied from debian (unstable) installation (last
updated about a month ago).
--------------------------------------------------------------------------------
- Jan Hudec `Bulb' <bulb@ucw.cz>
This archive was generated by hypermail 2b29 : Thu Jan 31 2002 - 21:00:20 EST