On Tue, Feb 02, 2021 at 11:03:32AM +0100, Geert Uytterhoeven wrote:
> Kmemleak reports:
>
> unreferenced object 0xc328de40 (size 64):
> comm "kworker/1:1", pid 21, jiffies 4294938212 (age 1484.670s)
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 e0 d8 fc eb 00 00 00 00 ................
> 00 00 10 fe 00 00 00 00 00 00 00 00 00 00 00 00 ................
>
> backtrace:
> [<ad758d10>] pci_register_io_range+0x3c/0x80
> [<2c7f139e>] of_pci_range_to_resource+0x48/0xc0
> [<f079ecc8>]
> devm_of_pci_get_host_bridge_resources.constprop.0+0x2ac/0x3ac
> [<e999753b>] devm_of_pci_bridge_init+0x60/0x1b8
> [<a895b229>] devm_pci_alloc_host_bridge+0x54/0x64
> [<e451ddb0>] rcar_pcie_probe+0x2c/0x644
>
> In case a PCI host driver's probe is deferred, the same I/O range may be
> allocated again, and be ignored, causing a memory leak.
>
> Fix this by (a) letting logic_pio_register_range() return -EEXIST if the
> passed range already exists, so pci_register_io_range() will free it,
> and by (b) making pci_register_io_range() not consider -EEXIST an error
> condition.
>
> Signed-off-by: Geert Uytterhoeven <geert+rene...@glider.be>
Applied to pci/enumeration for v5.12, thanks!
> ---
> drivers/pci/pci.c | 4 ++++
> lib/logic_pio.c | 3 +++
> 2 files changed, 7 insertions(+)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 09b03cfba8894955..c651003e304a2b71 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -4037,6 +4037,10 @@ int pci_register_io_range(struct fwnode_handle
> *fwnode, phys_addr_t addr,
> ret = logic_pio_register_range(range);
> if (ret)
> kfree(range);
> +
> + /* Ignore duplicates due to deferred probing */
> + if (ret == -EEXIST)
> + ret = 0;
> #endif
>
> return ret;
> diff --git a/lib/logic_pio.c b/lib/logic_pio.c
> index f32fe481b4922bc1..07b4b9a1f54b6bf5 100644
> --- a/lib/logic_pio.c
> +++ b/lib/logic_pio.c
> @@ -28,6 +28,8 @@ static DEFINE_MUTEX(io_range_mutex);
> * @new_range: pointer to the IO range to be registered.
> *
> * Returns 0 on success, the error code in case of failure.
> + * If the range already exists, -EEXIST will be returned, which should be
> + * considered a success.
> *
> * Register a new IO range node in the IO range list.
> */
> @@ -51,6 +53,7 @@ int logic_pio_register_range(struct logic_pio_hwaddr
> *new_range)
> list_for_each_entry(range, &io_range_list, list) {
> if (range->fwnode == new_range->fwnode) {
> /* range already there */
> + ret = -EEXIST;
> goto end_register;
> }
> if (range->flags == LOGIC_PIO_CPU_MMIO &&
> --
> 2.25.1
>
