Re: [PATCH v2 1/3] misc: pci_endpoint_test: Avoid issue of interrupts remaining after request_irq error

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Hi Manivannan,

On 2025/02/08 3:02, Manivannan Sadhasivam wrote:
On Wed, Jan 29, 2025 at 04:54:46PM +0900, Kunihiko Hayashi wrote:
Hi Manivannan,

On 2025/01/28 23:12, Manivannan Sadhasivam wrote:
On Wed, Jan 22, 2025 at 11:24:44AM +0900, Kunihiko Hayashi wrote:
After devm_request_irq() fails with error,
pci_endpoint_test_free_irq_vectors() is called to free allocated
vectors
with pci_free_irq_vectors().


You should mention the function name which you are referring to. Here it
is,
pci_endpoint_test_request_irq().

I see. I'll make the commit message more clear.

However some requested IRQs are still allocated, so there are still

This is confusing. Are you saying that the previously requested IRQs are
not
freed when an error happens during the for loop in
pci_endpoint_test_request_irq()?

Yes, after jumping to "fail:" label, it just prints an error message and
returns the function.

The pci_endpoint_test_request_irq() is called from the following
functions:
- pci_endpoint_test_probe()
- pci_endpoint_test_set_irq()

Both call pci_endpoint_test_free_irq_vectors() after the error, though,
requested IRQs are not freed anywhere.


You should not use the word 'allocated' since that has a different meaning
and the source of confusion.

Surely, 'allocated' means the vectors allocated with pci_irq_vectors(), not
the interrupts requested with request_irq().

I'll rewrite with a right description.

/proc/irq/* entries remaining and we encounters WARN() with the
following
message:

      remove_proc_entry: removing non-empty directory 'irq/30', leaking
at
      least 'pci-endpoint-test.0'
      WARNING: CPU: 0 PID: 80 at fs/proc/generic.c:717
remove_proc_entry
      +0x190/0x19c

When did you encounter this WARN?

Usually request_irq() can successfully get an interrupt.
If request_irq() returned an error, pci_endpoint_test_free_irq_vectors()
was
called and the following call-trace was obtained:

[   18.772522] Call trace:
[   18.773743]  remove_proc_entry+0x190/0x19c
[   18.775789]  unregister_irq_proc+0xd0/0x104
[   18.777881]  free_desc+0x4c/0xcc
[   18.779495]  irq_free_descs+0x68/0x8c
[   18.781325]  irq_domain_free_irqs+0x15c/0x1bc
[   18.783502]  msi_domain_free_locked.part.0+0x184/0x1d4
[   18.786069]  msi_domain_free_irqs_all_locked+0x64/0x8c
[   18.788637]  pci_msi_teardown_msi_irqs+0x48/0x54
[   18.790947]  pci_free_msi_irqs+0x18/0x38
[   18.792907]  pci_free_irq_vectors+0x64/0x8c
[   18.794997]  pci_endpoint_test_ioctl+0x7e8/0xf40
[   18.797304]  __arm64_sys_ioctl+0xa4/0xe8
[   18.799265]  invoke_syscall+0x48/0x110
[   18.801139]  el0_svc_common.constprop.0+0x40/0xe8
[   18.803489]  do_el0_svc+0x20/0x2c
[   18.805145]  el0_svc+0x30/0xd0
[   18.806673]  el0t_64_sync_handler+0x13c/0x158
[   18.808850]  el0t_64_sync+0x190/0x194
[   18.810680] ---[ end trace 0000000000000000 ]---


Please add this info to the patch description.

Okay, I'll add the call trace into the patch.

Thank you,

---
Best Regards
Kunihiko Hayashi




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