Re: 2.5.27: PREEMPT + DEBUG_SLAB = 100% reproducable oops

[george anzinger <george@mvista.com>]

Burton Windle wrote:
> 
> With kernel 2.5.26/27, if I compile in PREEMPT=y and CONFIG_DEBUG_SLAB=y,
> I can oops the machine at will by running a small shell script as a normal
> user. If I undef either of those, the machine is fine. It always oops in
> the same place.

Try running Ingo's latest "irqlock patch".  Should fix this.

-g
> 
> (gdb) list *0xc010e88f
> 0xc010e88f is in schedule
> (/biggie/kernel/linux-2.5.27/include/asm/bitops.h:39).
> 34       * Note that @nr may be almost arbitrarily large; this function is not
> 35       * restricted to acting on a single-word quantity.
> 36       */
> 37      static __inline__ void set_bit(int nr, volatile unsigned long * addr)
> 38      {
> 39              __asm__ __volatile__( LOCK_PREFIX
> 40                      "btsl %1,%0"
> 41                      :"=m" (ADDR)
> 42                      :"Ir" (nr));
> 43      }
> 
> Unable to handle kernel paging request at virtual address 5a5a5ace
> c010e88f
> *pde = 00000000
> Oops: 0002
> CPU:    0
> EIP:    0010:[<c010e88f>]    Not tainted
> Using defaults from ksymoops -t elf32-i386 -a i386
> EFLAGS: 00010813
> eax: c11ce000   ebx: c4b55580   ecx: c11d0040   edx: 5a5a5a5a
> esi: c4e51084   edi: c11d0040   ebp: c11cfed8   esp: c11cfec8
> ds: 0018   es: 0018   ss: 0018
> Stack: 7fffffff c4e560a4 c11cff60 c11d0040 c4e55000 c0119100 00000008 c4e560a4
>        00000000 00000246 c4e55980 c4e560a4 c01aefe4 c01af034 c4e55000 c4e560a4
>        c4e845e0 c4e560c4 c4e55bfc c4e55980 080df014 c4e55974 7fffffff 00000000
> Call Trace: [<c0119100>] [<c01aefe4>] [<c01af034>] [<c010e9c4>] [<c010e9c4>]
>    [<c01aada4>] [<c0132d40>] [<c0132ef6>] [<c0106c9f>]
> Code: 0f ba 6a 74 00 8b 42 0c 05 00 00 00 40 0f 22 d8 8b 8a 80 00
> 
> >>EIP; c010e88f <schedule+1b7/2b4>   <=====
> 
> >>eax; c11ce000 <END_OF_CODE+e8d604/????>
> >>ebx; c4b55580 <END_OF_CODE+4814b84/????>
> >>ecx; c11d0040 <END_OF_CODE+e8f644/????>
> >>edx; 5a5a5a5a Before first symbol
> >>esi; c4e51084 <END_OF_CODE+4b10688/????>
> >>edi; c11d0040 <END_OF_CODE+e8f644/????>
> >>ebp; c11cfed8 <END_OF_CODE+e8f4dc/????>
> >>esp; c11cfec8 <END_OF_CODE+e8f4cc/????>
> 
> Trace; c0119100 <schedule_timeout+14/a4>
> Trace; c01aefe4 <change_termios+90/180>
> Trace; c01af034 <change_termios+e0/180>
> Trace; c010e9c4 <default_wake_function+0/34>
> Trace; c010e9c4 <default_wake_function+0/34>
> Trace; c01aada4 <release_dev+16c/50c>
> Trace; c0132d40 <register_chrdev+54/dc>
> Trace; c0132ef6 <chrdev_open+7e/94>
> Trace; c0106c9f <syscall_call+7/b>
> 
> Code;  c010e88f <schedule+1b7/2b4>
> 00000000 <_EIP>:
> Code;  c010e88f <schedule+1b7/2b4>   <=====
>    0:   0f ba 6a 74 00            btsl   $0x0,0x74(%edx)   <=====
> Code;  c010e894 <schedule+1bc/2b4>
>    5:   8b 42 0c                  mov    0xc(%edx),%eax
> Code;  c010e897 <schedule+1bf/2b4>
>    8:   05 00 00 00 40            add    $0x40000000,%eax
> Code;  c010e89c <schedule+1c4/2b4>
>    d:   0f 22 d8                  mov    %eax,%cr3
> Code;  c010e89f <schedule+1c7/2b4>
>   10:   8b 8a 80 00 00 00         mov    0x80(%edx),%ecx
> 
> Oddily enough, running this on the command prompt won't cause problems,
> but running it at a shell script will causes an oops every single time.
> 
> #!/bin/sh
> start-stop-daemon --start --quiet --pidfile /tmp/xfs.pid --exec /home/bwindle/xfs-bin -- -daemon
> 
> Gnu C                  2.95.4
> Gnu make               3.79.1
> util-linux             2.11n
> mount                  2.11n
> modutils               2.4.15
> e2fsprogs              1.27
> Linux C Library        2.2.5
> Dynamic linker (ldd)   2.2.5
> Procps                 2.0.7
> Net-tools              1.60
> Console-tools          0.2.3
> Sh-utils               2.0.12
> 
> --
> Burton Windle                           burton@fint.org
> Linux: the "grim reaper of innocent orphaned children."
>           from /usr/src/linux-2.4.18/init/main.c:461
> 
> -
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-- 
George Anzinger   george@mvista.com
High-res-timers: 
http://sourceforge.net/projects/high-res-timers/
Real time sched:  http://sourceforge.net/projects/rtsched/
Preemption patch:
http://www.kernel.org/pub/linux/kernel/people/rml