Re: [PATCH v3 1/5] misc: pci_endpoint_test: Avoid issue of interrupts remaining after request_irq error

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Mon, Feb 10, 2025 at 04:58:08PM +0900, Kunihiko Hayashi wrote:
> After devm_request_irq() fails with error in
> pci_endpoint_test_request_irq(), pci_endpoint_test_free_irq_vectors() is
> called assuming that all IRQs have been released.
> 
> However some requested IRQs remain unreleased, so there are still
> /proc/irq/* entries remaining and we encounters WARN() with the following

s/we encounters/this results in WARN()

> message:
> 
>     remove_proc_entry: removing non-empty directory 'irq/30', leaking at
>     least 'pci-endpoint-test.0'
>     WARNING: CPU: 0 PID: 202 at fs/proc/generic.c:719 remove_proc_entry
>     +0x190/0x19c
> 
> And show the call trace that led to this issue:

You can remove this backtrace.

> 
>     [   12.050005] Call trace:
>     [   12.051226]  remove_proc_entry+0x190/0x19c (P)
>     [   12.053448]  unregister_irq_proc+0xd0/0x104
>     [   12.055541]  free_desc+0x4c/0xd0
>     [   12.057155]  irq_free_descs+0x68/0x90
>     [   12.058984]  irq_domain_free_irqs+0x15c/0x1bc
>     [   12.061161]  msi_domain_free_locked.part.0+0x184/0x1d4
>     [   12.063728]  msi_domain_free_irqs_all_locked+0x64/0x8c
>     [   12.066296]  pci_msi_teardown_msi_irqs+0x48/0x54
>     [   12.068604]  pci_free_msi_irqs+0x18/0x38
>     [   12.070564]  pci_free_irq_vectors+0x64/0x8c
>     [   12.072654]  pci_endpoint_test_ioctl+0x870/0x1068
>     [   12.075006]  __arm64_sys_ioctl+0xb0/0xe8
>     [   12.076967]  invoke_syscall+0x48/0x110
>     [   12.078841]  el0_svc_common.constprop.0+0x40/0xe8
>     [   12.081192]  do_el0_svc+0x20/0x2c
>     [   12.082848]  el0_svc+0x30/0xd0
>     [   12.084376]  el0t_64_sync_handler+0x144/0x168
>     [   12.086553]  el0t_64_sync+0x198/0x19c
>     [   12.088383] ---[ end trace 0000000000000000 ]---
> 
> To solve this issue, set the number of remaining IRQs to test->num_irqs
> and release IRQs in advance by calling pci_endpoint_test_release_irq().
> 
> Cc: stable@vger.kernel.org
> Fixes: e03327122e2c ("pci_endpoint_test: Add 2 ioctl commands")
> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

- Mani

> ---
>  drivers/misc/pci_endpoint_test.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
> index d5ac71a49386..bbcccd425700 100644
> --- a/drivers/misc/pci_endpoint_test.c
> +++ b/drivers/misc/pci_endpoint_test.c
> @@ -259,6 +259,9 @@ static int pci_endpoint_test_request_irq(struct pci_endpoint_test *test)
>  		break;
>  	}
>  
> +	test->num_irqs = i;
> +	pci_endpoint_test_release_irq(test);
> +
>  	return ret;
>  }
>  
> -- 
> 2.25.1
> 

-- 
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