Hi Robert, On Sat, May 28, 2011 at 5:15 PM, Robert P. J. Day <[email protected]> wrote: > > from drivers/base/core.c, we have the fairly unambiguous advice: > > * NOTE: _Never_ directly free @dev after calling this function, even > * if it returned an error! Always use put_device() to give up the > * reference initialized in this function instead. > */ > int device_register(struct device *dev) > { > device_initialize(dev); > return device_add(dev); > } > > and yet, there appears to be driver code that does exactly that, > such as this snippet from drivers/w1/w1_int.c (line 86): > > ... snip ... > err = device_register(&dev->dev); > if (err) { > printk(KERN_ERR "Failed to register master device. err=%d\n", > err); > memset(dev, 0, sizeof(struct w1_master)); > kfree(dev); > dev = NULL; > } Free is for allocated dev not for struct device so it is OK. IMO thi snippet should look like: err = device_register(&dev->dev); if (err) { printk(KERN_ERR "Failed to register master device. err=%d\n", err); put_device(&dev->dev); memset(dev, 0, sizeof(struct w1_master)); kfree(dev); dev = NULL; }
> > return dev; > > isn't the above doing just that -- directly freeing the dev > structure without first calling put_device()? or am i misreading > something? > > rday > > -- > > ======================================================================== > Robert P. J. Day Ottawa, Ontario, CANADA > http://crashcourse.ca > > Twitter: http://twitter.com/rpjday > LinkedIn: http://ca.linkedin.com/in/rpjday > ======================================================================== > > > _______________________________________________ > Kernelnewbies mailing list > [email protected] > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > regards, marek -- as simple and primitive as possible ------------------------------------------------- Marek Belisko - OPEN-NANDRA Freelance Developer Ruska Nova Ves 219 | Presov, 08005 Slovak Republic Tel: +421 915 052 184 skype: marekwhite icq: 290551086 web: http://open-nandra.com _______________________________________________ Kernelnewbies mailing list [email protected] http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
