Linux PCI subsystem development
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* [PATCH v2] misc: pci_endpoint_test: Handle BAR sizes larger than INT_MAX
@ 2025-01-24  9:33 Niklas Cassel
  2025-01-24 15:43 ` Frank Li
                   ` (3 more replies)
  0 siblings, 4 replies; 7+ messages in thread
From: Niklas Cassel @ 2025-01-24  9:33 UTC (permalink / raw)
  To: Manivannan Sadhasivam, Krzysztof Wilczyński,
	Kishon Vijay Abraham I, Arnd Bergmann, Greg Kroah-Hartman
  Cc: Jon Hunter, Frank Li, Niklas Cassel, Hans Zhang, linux-pci

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@163.com>
Signed-off-by: Hans Zhang <18255117159@163.com>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
---
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


^ permalink raw reply related	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2025-02-14 17:48 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-01-24  9:33 [PATCH v2] misc: pci_endpoint_test: Handle BAR sizes larger than INT_MAX Niklas Cassel
2025-01-24 15:43 ` Frank Li
2025-01-27 13:37 ` Jon Hunter
2025-02-01 16:01 ` Manivannan Sadhasivam
2025-02-01 17:39   ` Niklas Cassel
2025-02-07 17:42     ` Manivannan Sadhasivam
2025-02-14 17:48 ` Manivannan Sadhasivam

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