On Wed, Apr 05, 2017 at 10:28:22AM +0800, Jeffy Chen wrote: > Currently we only free the allocated resource struct when error. > This would cause memory leak after pci_free_resource_list. I think I see the problem here. The release path is this: pci_release_host_bridge_dev pci_free_resource_list resource_list_free list_for_each_entry_safe(entry, tmp, head, node) resource_list_destroy_entry resource_list_del resource_list_free_entry kfree(entry) but that frees only the struct resource_entry, not the struct resource pointed to by entry->res. Is that right? And this patch solves it for of_pci_get_host_bridge_resources() by always making entry->res point to entry->__res, which is an element in struct resource_entry, so it's sufficient to free the resource_entry. The memory management here is pretty tangled. I wonder if there's some way to simplify it so it's easier to make sure everybody does it correctly. For example, could we remove the entry->res pointer completely and force everybody to use entry->__res? > Signed-off-by: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx> > --- > > Changes in v5: > Fix some careless compile errors. > > Changes in v4: > Use IORESOURCE_AUTO to mark struct resources which could be copied. > > Changes in v3: > Add some comments. > > Changes in v2: > Don't change the resource_list_create_entry's behavior. > > drivers/of/of_pci.c | 51 ++++++++++++++++++--------------------------------- > drivers/pci/bus.c | 7 ++++++- > 2 files changed, 24 insertions(+), 34 deletions(-) > > diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c > index 0ee42c3..49233bf 100644 > --- a/drivers/of/of_pci.c > +++ b/drivers/of/of_pci.c > @@ -189,9 +189,7 @@ int of_pci_get_host_bridge_resources(struct device_node *dev, > unsigned char busno, unsigned char bus_max, > struct list_head *resources, resource_size_t *io_base) > { > - struct resource_entry *window; > - struct resource *res; > - struct resource *bus_range; > + struct resource res; > struct of_pci_range range; > struct of_pci_range_parser parser; > char range_type[4]; > @@ -200,24 +198,21 @@ int of_pci_get_host_bridge_resources(struct device_node *dev, > if (io_base) > *io_base = (resource_size_t)OF_BAD_ADDR; > > - bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL); > - if (!bus_range) > - return -ENOMEM; > - > pr_info("host bridge %s ranges:\n", dev->full_name); > > - err = of_pci_parse_bus_range(dev, bus_range); > + err = of_pci_parse_bus_range(dev, &res); > if (err) { > - bus_range->start = busno; > - bus_range->end = bus_max; > - bus_range->flags = IORESOURCE_BUS; > - pr_info(" No bus range found for %s, using %pR\n", > - dev->full_name, bus_range); > + res.start = busno; > + res.end = bus_max; > + res.flags = IORESOURCE_BUS; > + pr_info(" No bus range found for %s\n", dev->full_name); > } else { > - if (bus_range->end > bus_range->start + bus_max) > - bus_range->end = bus_range->start + bus_max; > + if (res.end > res.start + bus_max) > + res.end = res.start + bus_max; > } > - pci_add_resource(resources, bus_range); > + > + res.flags |= IORESOURCE_AUTO; > + pci_add_resource(resources, &res); > > /* Check for ranges property */ > err = of_pci_range_parser_init(&parser, dev); > @@ -244,24 +239,16 @@ int of_pci_get_host_bridge_resources(struct device_node *dev, > if (range.cpu_addr == OF_BAD_ADDR || range.size == 0) > continue; > > - res = kzalloc(sizeof(struct resource), GFP_KERNEL); > - if (!res) { > - err = -ENOMEM; > - goto parse_failed; > - } > - > - err = of_pci_range_to_resource(&range, dev, res); > - if (err) { > - kfree(res); > + err = of_pci_range_to_resource(&range, dev, &res); > + if (err) > continue; > - } > > - if (resource_type(res) == IORESOURCE_IO) { > + if (resource_type(&res) == IORESOURCE_IO) { > if (!io_base) { > pr_err("I/O range found for %s. Please provide an io_base pointer to save CPU base address\n", > dev->full_name); > err = -EINVAL; > - goto conversion_failed; > + goto parse_failed; > } > if (*io_base != (resource_size_t)OF_BAD_ADDR) > pr_warn("More than one I/O resource converted for %s. CPU base address for old range lost!\n", > @@ -269,16 +256,14 @@ int of_pci_get_host_bridge_resources(struct device_node *dev, > *io_base = range.cpu_addr; > } > > - pci_add_resource_offset(resources, res, res->start - range.pci_addr); > + res.flags |= IORESOURCE_AUTO; > + pci_add_resource_offset(resources, &res, > + res.start - range.pci_addr); > } > > return 0; > > -conversion_failed: > - kfree(res); > parse_failed: > - resource_list_for_each_entry(window, resources) > - kfree(window->res); > pci_free_resource_list(resources); > return err; > } > diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > index bc56cf1..3dbcb95 100644 > --- a/drivers/pci/bus.c > +++ b/drivers/pci/bus.c > @@ -22,12 +22,17 @@ void pci_add_resource_offset(struct list_head *resources, struct resource *res, > { > struct resource_entry *entry; > > - entry = resource_list_create_entry(res, 0); > + entry = resource_list_create_entry(NULL, 0); If we make this change, there are no callers of resource_list_create_entry() that supply a non-NULL "res", so we could remove that argument completely. > if (!entry) { > printk(KERN_ERR "PCI: can't add host bridge window %pR\n", res); > return; > } > > + if (res->flags & IORESOURCE_AUTO) > + *entry->res = *res; > + else > + entry->res = res; > + > entry->offset = offset; > resource_list_add_tail(entry, resources); > } > -- > 2.1.4 > > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html