misc: pci_endpoint_test: Handle BAR sizes larger than INT_MAX

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.

Fixes: cda370ec6d1f ("misc: pci_endpoint_test: Avoid using hard-coded BAR sizes")
Co-developed-by: Hans Zhang <18255117159@163.com>
Signed-off-by: Hans Zhang <18255117159@163.com>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250124093300.3629624-2-cassel@kernel.org
[mani: added fixes tag]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>

diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
index 705659f5f0e96399bd87428eccc3069058c0a072..a3d2caa7a6bbea975a215893dd48fbf7eaa30e35 100644 (file)
--- 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;
 
        bar_size = pci_resource_len(pdev, barno);
        if (!bar_size)
@@ -316,11 +317,12 @@ 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;
 }