On Wed, Dec 16, 2020 at 4:16 AM Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> wrote: > > Le 15/12/2020 à 20:35, Dan Carpenter a écrit : > > 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 > > Nice :) > I wasn't aware of it. > > > > > 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 > > > > The script I use to try to spot missing release function is: > /// > @@ > expression x, y; > identifier f, l; > @@ > > * x = irq_of_parse_and_map(...); > ... when any > * y = f(...); > ... when any > * if (<+... y ...+>) > { > ... > ( > * goto l; > | > * return ...; > ) > ... > } > ... when any > *l: > ... when != irq_dispose_mapping(...); > * return ...; > /// > > It is likely that some improvement can be made, but it works pretty well > for what I want. > > And I have a collection of alloc/free functions that I manually put in > place of irq_of_parse_and_map and irq_dispose_mapping. AFAICT the resource leak is likely larger in scope, as many drivers use platform_get_irq(), which eventually ends up calling irq_create_of_mapping() through of_irq_get() in the OF path. Same goes for platform_get_irq_byname(). ChenYu > Up to know, this list is: > > // alloc_etherdev/alloc_etherdev_mq/alloc_etherdev_mqs - free_netdev > // alloc_workqueue - destroy_workqueue > // class_register - class_unregister > // clk_get - clk_put > // clk_prepare - clk_unprepare > // create_workqueue - destroy_workqueue > // create_singlethread_workqueue - destroy_workqueue > // > dev_pm_domain_attach/dev_pm_domain_attach_by_id/dev_pm_domain_attach_by_name > - dev_pm_domain_detach > // devres_alloc - devres_free > // dma_alloc_coherent - dma_free_coherent > // dma_map_resource - dma_unmap_resource > // dma_map_single - dma_unmap_single > // dma_request_slave_channel - dma_release_channel > // dma_request_chan - dma_release_channel > // framebuffer_alloc - framebuffer_release > // get_device - put_device > // iio_channel_get - iio_channel_release > // ioremap - iounmap > // input_allocate_device - input_free_device > // input_register_handle - input_unregister_handle > // irq_of_parse_and_map / irq_create_of_mapping - irq_dispose_mapping > // kmalloc - kfree > // mempool_alloc - mempool_free > // of_node_get - of_node_put > // of_reserved_mem_device_init - of_reserved_mem_device_release > // pinctrl_register - pinctrl_unregister > // request_irq - free_irq > // request_region - release_region > // request_mem_region - release_mem_region > // reset_control_assert - reset_control_deassert > // scsi_host_alloc - scsi_host_put > > // pci_alloc_irq_vectors - pci_free_irq_vectors > // pci_dev_get - pci_dev_put > // pci_enable_device - pci_disable_device > // pci_iomap - pci_iounmap > // pci_request_region - pci_release_region > // pci_request_regions - pci_release_regions > > // alloc_skb/__alloc_skb - kfree_skb/__kfree_skb > // dev_alloc_skb - dev_kfree_skb > > // spi_dev_get - spi_dev_put > // spi_message_alloc - spi_message_free > // spi_register_master - spi_unregister_master > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
