On Tue, 5 Jan 2016, kbuild test robot wrote: > Hi Dan, > > [auto build test WARNING on balbi-usb/next] > [also build test WARNING on v4.4-rc8 next-20160105] > [if your patch is applied to the wrong git tree, please drop us a note to help improving the system] > > url: https://github.com/0day-ci/linux/commits/Dan-Carpenter/usb-gadget-f_midi-missing-unlock-on-error-path/20160105-183115 > base: https://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git next > > > coccinelle warnings: (new ones prefixed by >>) > > >> drivers/usb/gadget/function/f_midi.c:1233:14-21: ERROR: midi is NULL but dereferenced. It's a false positive for coccinelle, but I wonder if avoiding duplicating the mutex_lock is really worth it? There is a slightly subtle interaction between the possibility of midi being NULL and the value of i that make it all work. julia > > vim +1233 drivers/usb/gadget/function/f_midi.c > > e1e3d7ec Felipe F. Tonello 2015-12-01 1217 > 6f1de344 Andrzej Pietrasiewicz 2014-10-16 1218 ++opts->refcnt; > 6f1de344 Andrzej Pietrasiewicz 2014-10-16 1219 mutex_unlock(&opts->lock); > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1220 > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1221 midi->func.name = "gmidi function"; > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1222 midi->func.bind = f_midi_bind; > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1223 midi->func.unbind = f_midi_unbind; > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1224 midi->func.set_alt = f_midi_set_alt; > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1225 midi->func.disable = f_midi_disable; > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1226 midi->func.free_func = f_midi_free; > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1227 > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1228 return &midi->func; > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1229 > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1230 setup_fail: > 39920a18 Dan Carpenter 2016-01-05 1231 mutex_unlock(&opts->lock); > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1232 for (--i; i >= 0; i--) > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 @1233 kfree(midi->in_port[i]); > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1234 kfree(midi); > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1235 return ERR_PTR(status); > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1236 } > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1237 > b85e9de9 Andrzej Pietrasiewicz 2014-10-16 1238 DECLARE_USB_FUNCTION_INIT(midi, f_midi_alloc_inst, f_midi_alloc); > > :::::: The code at line 1233 was first introduced by commit > :::::: b85e9de9e818de0dcbc50b7b4242192eb6194855 usb: gadget: f_midi: convert to new function interface with backward compatibility > > :::::: TO: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxx> > :::::: CC: Felipe Balbi <balbi@xxxxxx> > > --- > 0-DAY kernel test infrastructure Open Source Technology Center > https://lists.01.org/pipermail/kbuild-all Intel Corporation > -- > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
