On Sat, Feb 08, 2025 at 07:31:08PM +0530, Anand Moon wrote:
> kmemleak reported following debug log
>
> $ sudo cat /sys/kernel/debug/kmemleak
> unreferenced object 0xffffffd6c47c2600 (size 128):
> comm "kworker/u16:2", pid 38, jiffies 4294942263
> hex dump (first 32 bytes):
> cc 7c 5a 8d ff ff ff ff 40 b0 47 c8 d6 ff ff ff .|Z.....@.G.....
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> backtrace (crc 4f07ff07):
> __create_object+0x2a/0xfc
> kmemleak_alloc+0x38/0x98
> __kmalloc_cache_noprof+0x296/0x444
> request_threaded_irq+0x168/0x284
> devm_request_threaded_irq+0xa8/0x13c
> plda_init_interrupts+0x46e/0x858
> plda_pcie_host_init+0x356/0x468
> starfive_pcie_probe+0x2f6/0x398
> platform_probe+0x106/0x150
> really_probe+0x30e/0x746
> __driver_probe_device+0x11c/0x2c2
> driver_probe_device+0x5e/0x316
> __device_attach_driver+0x296/0x3a4
> bus_for_each_drv+0x1d0/0x260
> __device_attach+0x1fa/0x2d6
> device_initial_probe+0x14/0x28
> unreferenced object 0xffffffd6c47c2900 (size 128):
> comm "kworker/u16:2", pid 38, jiffies 4294942281
>
> This patch addresses a kmemleak reported during StarFive PCIe driver
> initialization. The leak was observed with kmemleak reporting
> unreferenced objects related to IRQ handling. The backtrace pointed
> to the `request_threaded_irq` and related functions within the
> `plda_init_interrupts` path, indicating that some allocated memory
> related to IRQs was not being properly freed.
>
> The issue was that while the driver requested IRQs, it wasn't
> correctly handling the lifecycle of the associated resources.
What resources?
> This patch introduces an event IRQ handler and the necessary
> infrastructure to manage these IRQs, preventing the memory leak.
>
These handles appear pointless to me. What purpose are they serving?
- Mani
> Fixes: 647690479660 ("PCI: microchip: Add request_event_irq() callback function")
> Cc: Minda Chen <minda.chen@xxxxxxxxxxxxxxxx>
> Signed-off-by: Anand Moon <linux.amoon@xxxxxxxxx>
> ---
> drivers/pci/controller/plda/pcie-starfive.c | 39 +++++++++++++++++++++
> 1 file changed, 39 insertions(+)
>
> diff --git a/drivers/pci/controller/plda/pcie-starfive.c b/drivers/pci/controller/plda/pcie-starfive.c
> index e73c1b7bc8ef..a57177a8be8a 100644
> --- a/drivers/pci/controller/plda/pcie-starfive.c
> +++ b/drivers/pci/controller/plda/pcie-starfive.c
> @@ -381,7 +381,46 @@ static const struct plda_pcie_host_ops sf_host_ops = {
> .host_deinit = starfive_pcie_host_deinit,
> };
>
> +/* IRQ handler for PCIe events */
> +static irqreturn_t starfive_event_handler(int irq, void *dev_id)
> +{
> + struct plda_pcie_rp *port = dev_id;
> + struct irq_data *data;
> +
> + /* Retrieve IRQ data */
> + data = irq_domain_get_irq_data(port->event_domain, irq);
> +
> + if (data) {
> + dev_err_ratelimited(port->dev, "Event IRQ %ld triggered\n",
> + data->hwirq);
> + } else {
> + dev_err_ratelimited(port->dev, "Invalid event IRQ %d\n", irq);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +/* Request an IRQ for a specific event */
> +static int starfive_request_event_irq(struct plda_pcie_rp *plda, int event_irq,
> + int event)
> +{
> + int ret;
> +
> + /* Request the IRQ and associate it with the handler */
> + ret = devm_request_irq(plda->dev, event_irq, starfive_event_handler,
> + IRQF_SHARED, "starfivepcie", plda);
> +
> + if (ret) {
> + dev_err(plda->dev, "Failed to request IRQ %d: %d\n", event_irq,
> + ret);
> + return ret;
> + }
> +
> + return ret;
> +}
> +
> static const struct plda_event stf_pcie_event = {
> + .request_event_irq = starfive_request_event_irq,
> .intx_event = EVENT_PM_MSI_INT_INTX,
> .msi_event = EVENT_PM_MSI_INT_MSI
> };
>
> base-commit: bb066fe812d6fb3a9d01c073d9f1e2fd5a63403b
> --
> 2.48.1
>
--
மணிவண்ணன் சதாசிவம்
