Messages in this thread | | | Subject | Re: [PATCH][ATM] add reference counting to atm_dev | Date | Fri, 16 May 2003 11:39:21 -0400 | From | chas williams <> |
| |
In message <200305161640.43804.baldrick@wanadoo.fr>,Duncan Sands writes: >I was wondering about ioctl and proc calls. Can the ATM layer call >a driver's ioctl routine before opening a vcc? If so, does it take a
yes
>reference to the module first (I didn't spot anything)? Also, are
the original atm code used atm_dev_lock to keep the device from disappearing during the ioctl. atm_dev_lock was being used to protect sections of code, like ioctl and atm device (de)registry. the 2.5 code is getting changes that should improve matters. atm_dev will now have a reference count to keep a device from being unregistered while someone holds a reference (ioctl or otherwise).
>calls to a driver's proc_read routine protected against module >unloading races (I confess I didn't take the time to look into this, >because my own driver does not sleep in proc_read)?
i believe proc has always been a troublesome child. it has never had any protection (via atm_dev_lock or otherwise). you can sleep in the proc function (since it would in user mode). i have added some locking to proc in the 2.5 that should make proc safer (but not very elegant--perhaps elegance with come with the seq conversion). - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |