[ofw] RE: Assert in checked ibbus driver?

[James Yang]

Fab,

 

I can see item's p_list pointer being cleared when it's removed from the
list. My guess is p_list is left over there when items are allocated
from free memory. I'm not familiar with the code enough to find all
these items and clear them during initialization. It's odd to see p_list
value was there but not p_prev and p_next.

 

If I ignore the assertion, it will be OK. However the assert will come
once again, especially during startup and shutdown.

 

Thanks,

James

 

________________________________

From: Fab Tillier [mailto:ftillier at windows.microsoft.com] 
Sent: Thursday, June 19, 2008 9:11 AM
To: James Yang; ofw at lists.openfabrics.org
Subject: RE: Assert in checked ibbus driver?

 

Hi James,

 

If you clear the p_list pointer does the assert go away?

 

-Fab

 

From: ofw-bounces at lists.openfabrics.org
[mailto:ofw-bounces at lists.openfabrics.org] On Behalf Of James Yang
Sent: Wednesday, June 18, 2008 6:05 PM
To: ofw at lists.openfabrics.org
Subject: [ofw] Assert in checked ibbus driver?

 

Can someone shed some light on the following assert I saw in checked
build driver?

 

It happened in the function cl_qlist_insert_head() when a new item is
added to the list. And the assertion happens because it thinks the item
is already in the list. However when checking the list item, I don't see
it is linked because its previous and next pointers are both NULL. The
item is also is not in the list by manually checking the list.

 

Is this because the item is not initialized properly as it's said in the
comments, or it's a true bug? 

 

Thanks,

James

 

----------------------

CL_INLINE void CL_API

cl_qlist_insert_head(

      IN    cl_qlist_t* const       p_list,

      IN    cl_list_item_t* const   p_list_item )

{

      /* CL_ASSERT that a non-null pointer is provided. */

      CL_ASSERT( p_list );

      /* CL_ASSERT that a non-null pointer is provided. */

      CL_ASSERT( p_list_item );

      /* CL_ASSERT that the list was initialized. */

      CL_ASSERT( p_list->state == CL_INITIALIZED );

 

      /*

       * The list item must not already be part of the list.  Note that
this

       * assertion may fail if an uninitialized list item happens to
have its

       * list pointer equal to the specified list.  The chances of this

       * happening are acceptable in light of the value of this check.

       */

      CL_ASSERT( p_list_item->p_list != p_list );

 

#if defined( _DEBUG_ )

      p_list_item->p_list = p_list;

#endif

 

      /* Insert before the head. */

      __cl_primitive_insert( cl_qlist_head( p_list ), p_list_item );

 

      p_list->count++;

}

 

 

1: kd> k

ChildEBP RetAddr  

f795e9fc 80873922 nt!DbgBreakPoint

f795ece4 f71588c4 nt!RtlAssert+0xba

f795ed0c f715a5df ibbus!cl_qlist_insert_head+0xb4
[k:\windows-openib\inc\complib\cl_qlist.h @ 782]

f795ed24 f71b08da ibbus!__cl_free_trk+0x6f
[k:\windows-openib\\core\complib\cl_memory.c @ 342]

f795ed38 f7218e8d ibbus!__pnp_reg_free+0xfa
[k:\windows-openib\\core\al\kernel\al_pnp.c @ 386]

f795ed70 f715c0e4 ibbus!async_destroy_cb+0x72d
[k:\windows-openib\\core\al\al_common.c @ 685]

f795ed8c f7162534 ibbus!__cl_async_proc_worker+0x94
[k:\windows-openib\core\complib\cl_async_proc.c @ 153]

f795eda0 f71645ec ibbus!__cl_thread_pool_routine+0x54
[k:\windows-openib\core\complib\cl_threadpool.c @ 67]

f795edac 80949b7c ibbus!__thread_callback+0x2c
[k:\windows-openib\core\complib\kernel\cl_thread.c @ 49]

f795eddc 8088e062 nt!PspSystemThreadStartup+0x2e

00000000 00000000 nt!KiThreadStartup+0x16

 

1: kd> dt 0x863416a0 _cl_qlist 

   +0x000 end              : _cl_list_item

   +0x00c count            : 0x29

   +0x010 state            : 2 ( CL_INITIALIZED )

1: kd> dt 0x85485268 _cl_list_item 

   +0x000 p_next           : (null) 

   +0x004 p_prev           : (null) 

   +0x008 p_list           : 0x863416a0 _cl_qlist

 

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