On Tue, Dec 15, 2020 at 08:08:15PM +0100, Maxime Ripard wrote: > On Tue, Dec 15, 2020 at 07:18:48PM +0100, Christophe JAILLET wrote: > > Le 15/12/2020 à 12:37, Maxime Ripard a écrit : > > > On Tue, Dec 15, 2020 at 12:11:53PM +0300, Dan Carpenter wrote: > > > > On Tue, Dec 15, 2020 at 09:56:55AM +0100, Maxime Ripard wrote: > > > > > Hi, > > > > > > > > > > On Mon, Dec 14, 2020 at 09:21:17PM +0100, Christophe JAILLET wrote: > > > > > > 'irq_of_parse_and_map()' should be balanced by a corresponding > > > > > > 'irq_dispose_mapping()' call. Otherwise, there is some resources leaks. > > > > > > > > > > Do you have a source to back that? It's not clear at all from the > > > > > documentation for those functions, and couldn't find any user calling it > > > > > from the ten-or-so random picks I took. > > > > > > > > It looks like irq_create_of_mapping() needs to be freed with > > > > irq_dispose_mapping() so this is correct. > > > > > > The doc should be updated first to make that clear then, otherwise we're > > > going to fix one user while multiples will have poped up > > > > > > Maxime > > > > > > > Hi, > > > > as Dan explained, I think that 'irq_dispose_mapping()' is needed because of > > the 'irq_create_of_mapping()" within 'irq_of_parse_and_map()'. > > > > As you suggest, I'll propose a doc update to make it clear and more future > > proof. > > Thanks :) > > And if you feel like it, a coccinelle script would be awesome too so > that other users get fixed over time > > Maxime Smatch has a new check for resource leaks which hopefully people will find useful. https://github.com/error27/smatch/blob/master/check_unwind.c To check for these I would need to add the following lines to the table: { "irq_of_parse_and_map", ALLOC, -1, "$", &int_one, &int_max}, { "irq_create_of_mapping", ALLOC, -1, "$", &int_one, &int_max}, { "irq_dispose_mapping", RELEASE, 0, "$"}, The '-1, "$"' means the returned value. irq_of_parse_and_map() and irq_create_of_mapping() return positive int on success. The irq_dispose_mapping() frees its zeroth parameter so it's listed as '0, "$"'. We don't care about the returns from irq_dispose_mapping(). It doesn't apply in this case but if a function frees a struct member then that's listed as '0, "$->member_name"'. regards, dan carpenter
