On Fri, Jan 24, 2025 at 10:33:01AM +0100, Niklas Cassel wrote:
> Running 'pcitest -b 0' fails with "TEST FAILED" when the BAR0 size
> is e.g. 8 GB.
>
> The return value of the pci_resource_len() macro can be larger than that
> of a signed integer type. Thus, when using 'pcitest' with an 8 GB BAR,
> the bar_size of the integer type will overflow.
>
> Change bar_size from integer to resource_size_t to prevent integer
> overflow for large BAR sizes with 32-bit compilers.
>
> In order to handle 64-bit resource_type_t on 32-bit platforms, we would
> have needed to use a function like div_u64() or similar. Instead, change
> the code to use addition instead of division. This avoids the need for
> div_u64() or similar, while also simplifying the code.
>
> Co-developed-by: Hans Zhang <18255117159@xxxxxxx>
> Signed-off-by: Hans Zhang <18255117159@xxxxxxx>
> Signed-off-by: Niklas Cassel <cassel@xxxxxxxxxx>
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
> ---
> Changes since v1:
> -Add reason for why division was changed to addition in commit log.
>
> drivers/misc/pci_endpoint_test.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
> index d5ac71a49386..8e48a15100f1 100644
> --- a/drivers/misc/pci_endpoint_test.c
> +++ b/drivers/misc/pci_endpoint_test.c
> @@ -272,9 +272,9 @@ static const u32 bar_test_pattern[] = {
> };
>
> static int pci_endpoint_test_bar_memcmp(struct pci_endpoint_test *test,
> - enum pci_barno barno, int offset,
> - void *write_buf, void *read_buf,
> - int size)
> + enum pci_barno barno,
> + resource_size_t offset, void *write_buf,
> + void *read_buf, int size)
> {
> memset(write_buf, bar_test_pattern[barno], size);
> memcpy_toio(test->bar[barno] + offset, write_buf, size);
> @@ -287,10 +287,11 @@ static int pci_endpoint_test_bar_memcmp(struct pci_endpoint_test *test,
> static int pci_endpoint_test_bar(struct pci_endpoint_test *test,
> enum pci_barno barno)
> {
> - int j, bar_size, buf_size, iters;
> + resource_size_t bar_size, offset = 0;
> void *write_buf __free(kfree) = NULL;
> void *read_buf __free(kfree) = NULL;
> struct pci_dev *pdev = test->pdev;
> + int buf_size;
>
> if (!test->bar[barno])
> return -ENOMEM;
> @@ -314,11 +315,12 @@ static int pci_endpoint_test_bar(struct pci_endpoint_test *test,
> if (!read_buf)
> return -ENOMEM;
>
> - iters = bar_size / buf_size;
> - for (j = 0; j < iters; j++)
> - if (pci_endpoint_test_bar_memcmp(test, barno, buf_size * j,
> - write_buf, read_buf, buf_size))
> + while (offset < bar_size) {
> + if (pci_endpoint_test_bar_memcmp(test, barno, offset, write_buf,
> + read_buf, buf_size))
> return -EIO;
> + offset += buf_size;
> + }
>
> return 0;
> }
> --
> 2.48.1
>
