Re: [patch -rt] make gendev_rel_sem a compat_semaphore

From: Steven Rostedt
Date: Wed Nov 16 2005 - 10:35:00 EST


Crap! I sent this with my kihontech email. Please respond to this
instead. I'm still in the process of moving to my new machine, and the
email was messed up.

Thanks,

-- Steve


On Wed, 2005-11-16 at 10:31 -0500, Steven Rostedt wrote:
> Hi Ingo,
>
> I was getting the following:
>
> BUG: nonzero lock count 10 at exit time?
> modprobe: 2972 [ffff81007e1aaf70, 116]
>
> Call Trace:<ffffffff8014e2db>{printk_task+43} <ffffffff8015040f>{check_no_held_locks+111}
> <ffffffff80136d3c>{do_exit+3036} <ffffffff80136f5c>{do_group_exit+268}
> <ffffffff80136f72>{sys_exit_group+18} <ffffffff8011e471>{ia32_sysret+0}
>
> ---------------------------
> | preempt count: 00000000 ]
> | 0-level deep critical section nesting:
> ----------------------------------------
> hdc: ATAPI 40X DVD-ROM DVD-R CD-R/RW drive, 2048kB Cache, UDMA(33)
> Uniform CD-ROM driver Revision: 3.20
>
> BUG: modprobe/2972, lock held at task exit time!
> [ffffffff8809fd00] {(struct semaphore *)(&hwif->gendev_rel_sem)}
> .. held by: modprobe: 2972 [ffff81007e1aaf70, 116]
> ... acquired at: init_hwif_data+0xaf/0x1a0 [ide_core]
>
> [snipped to not be so annoying]
>
> Looking into this I see that gendev_rel_sem, which is only used when the
> device is unregistered, is defined as a semaphore. This patch changes
> this to be a compat_semaphore.
>
> -- Steve
>
> Index: linux-2.6.14-rt13/include/linux/ide.h
> ===================================================================
> --- linux-2.6.14-rt13.orig/include/linux/ide.h 2005-11-15 11:12:37.000000000 -0500
> +++ linux-2.6.14-rt13/include/linux/ide.h 2005-11-16 10:09:10.000000000 -0500
> @@ -910,7 +910,7 @@
> unsigned sg_mapped : 1; /* sg_table and sg_nents are ready */
>
> struct device gendev;
> - struct semaphore gendev_rel_sem; /* To deal with device release() */
> + struct compat_semaphore gendev_rel_sem; /* To deal with device release() */
>
> void *hwif_data; /* extra hwif data */
>
>

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