There are two variables that indicate the interrupt type to be used
in the next test execution, global "irq_type" and test->irq_type.

The former is referenced from pci_endpoint_test_get_irq() to preserve
the current type for ioctl(PCITEST_GET_IRQTYPE).

In pci_endpoint_test_request_irq(), since this global variable is
referenced when an error occurs, the unintended error message is
displayed.

And the type set in pci_endpoint_test_set_irq() isn't reflected in
the global "irq_type", so ioctl(PCITEST_GET_IRQTYPE) returns the previous
type. As a result, the wrong type will be displayed in "pcitest".

This patch fixes these two issues.

Fixes: b2ba9225e031 ("misc: pci_endpoint_test: Avoid using module parameter to determine irqtype")
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
---
 drivers/misc/pci_endpoint_test.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
index e73b3078cdb6..854480921470 100644
--- a/drivers/misc/pci_endpoint_test.c
+++ b/drivers/misc/pci_endpoint_test.c
@@ -235,7 +235,7 @@ static bool pci_endpoint_test_request_irq(struct pci_endpoint_test *test)
 	return true;
 
 fail:
-	switch (irq_type) {
+	switch (test->irq_type) {
 	case IRQ_TYPE_INTX:
 		dev_err(dev, "Failed to request IRQ %d for Legacy\n",
 			pci_irq_vector(pdev, i));
@@ -739,6 +739,7 @@ static bool pci_endpoint_test_set_irq(struct pci_endpoint_test *test,
 	if (!pci_endpoint_test_request_irq(test))
 		goto err;
 
+	irq_type = test->irq_type;
 	return true;
 
 err:
-- 
2.25.1

On Thu, Jan 16, 2025 at 11:41:45AM +0900, Kunihiko Hayashi wrote:
> There are two variables that indicate the interrupt type to be used
> in the next test execution, global "irq_type" and test->irq_type.
> 
> The former is referenced from pci_endpoint_test_get_irq() to preserve
> the current type for ioctl(PCITEST_GET_IRQTYPE).
> 
> In pci_endpoint_test_request_irq(), since this global variable is
> referenced when an error occurs, the unintended error message is
> displayed.

Apparently this test fails (with an error message) when it shouldn't?
Please include the error message here.

"... since this global variable is referenced ..." is not quite enough
explanation of how this causes a spurious test failure or under what
circumstances the failure occurs.

> And the type set in pci_endpoint_test_set_irq() isn't reflected in
> the global "irq_type", so ioctl(PCITEST_GET_IRQTYPE) returns the previous
> type. As a result, the wrong type will be displayed in "pcitest".

The global "irq_type" seems a little suspect.  Is it possible to run
multiple tests concurrently?  If so, is this usage safe from races?

> This patch fixes these two issues.
> 
> Fixes: b2ba9225e031 ("misc: pci_endpoint_test: Avoid using module parameter to determine irqtype")
> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> ---
>  drivers/misc/pci_endpoint_test.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
> index e73b3078cdb6..854480921470 100644
> --- a/drivers/misc/pci_endpoint_test.c
> +++ b/drivers/misc/pci_endpoint_test.c
> @@ -235,7 +235,7 @@ static bool pci_endpoint_test_request_irq(struct pci_endpoint_test *test)
>  	return true;
>  
>  fail:
> -	switch (irq_type) {
> +	switch (test->irq_type) {
>  	case IRQ_TYPE_INTX:
>  		dev_err(dev, "Failed to request IRQ %d for Legacy\n",
>  			pci_irq_vector(pdev, i));
> @@ -739,6 +739,7 @@ static bool pci_endpoint_test_set_irq(struct pci_endpoint_test *test,
>  	if (!pci_endpoint_test_request_irq(test))
>  		goto err;
>  
> +	irq_type = test->irq_type;
>  	return true;
>  
>  err:
> -- 
> 2.25.1
>

Hi Bjorn,

Thank you for your comment.

On 2025/01/17 0:04, Bjorn Helgaas wrote:
> On Thu, Jan 16, 2025 at 11:41:45AM +0900, Kunihiko Hayashi wrote:
>> There are two variables that indicate the interrupt type to be used
>> in the next test execution, global "irq_type" and test->irq_type.
>>
>> The former is referenced from pci_endpoint_test_get_irq() to preserve
>> the current type for ioctl(PCITEST_GET_IRQTYPE).
>>
>> In pci_endpoint_test_request_irq(), since this global variable is
>> referenced when an error occurs, the unintended error message is
>> displayed.
> 
> Apparently this test fails (with an error message) when it shouldn't?
> Please include the error message here. >
> "... since this global variable is referenced ..." is not quite enough
> explanation of how this causes a spurious test failure or under what
> circumstances the failure occurs.

I see. This failure path is taken if devm_request_irq() returns with
an error. The message that causes an error in the third interrupt is for
example:

   pci-endpoint-test 0000:01:00.0: Failed to request IRQ 30 for MSI 3

Before this fix, this message will show "MSI" even if the current irq
type was "legacy" or "MSI-X".

I'll add such that description in the commit.

And I discovered that not releasing interrupt correctly caused WARN()
after displaying this message. I'll fix the issue additionally.

>> And the type set in pci_endpoint_test_set_irq() isn't reflected in
>> the global "irq_type", so ioctl(PCITEST_GET_IRQTYPE) returns the
> previous
>> type. As a result, the wrong type will be displayed in "pcitest".
> 
> The global "irq_type" seems a little suspect.  Is it possible to run
> multiple tests concurrently?  If so, is this usage safe from races?

The global "irq_type" is only changed in pci_endpoint_test_set_irq().
I think this function is protected by the ioctl's mutex even if running
multiple tests.

Thank you,

---
Best Regards
Kunihiko Hayashi

On Thu, Jan 16, 2025 at 11:41:45AM +0900, Kunihiko Hayashi wrote:
> There are two variables that indicate the interrupt type to be used
> in the next test execution, global "irq_type" and test->irq_type.
> 
> The former is referenced from pci_endpoint_test_get_irq() to preserve
> the current type for ioctl(PCITEST_GET_IRQTYPE).
> 
> In pci_endpoint_test_request_irq(), since this global variable is
> referenced when an error occurs, the unintended error message is
> displayed.
> 
> And the type set in pci_endpoint_test_set_irq() isn't reflected in
> the global "irq_type", so ioctl(PCITEST_GET_IRQTYPE) returns the previous
> type. As a result, the wrong type will be displayed in "pcitest".
> 
> This patch fixes these two issues.
> 
> Fixes: b2ba9225e031 ("misc: pci_endpoint_test: Avoid using module parameter to determine irqtype")
> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> ---
>  drivers/misc/pci_endpoint_test.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 

Hi,

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