From: Nabih Estefan <nabihestefan@google.com>

  ../tests/qtest/libqos/igb.c:106:5: runtime error: load of misaligned address 0x562040be8e33 for type 'uint32_t', which requires 4 byte alignment

Instead of straight casting the uint8_t array, we can use ldl_le_p and
lduw_l_p to assure the unaligned access working properly against
uint32_t and uint16_t.

Signed-off-by: Nabih Estefan <nabihestefan@google.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Tested-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250429155621.2028198-1-nabihestefan@google.com>
[AJB: fix commit message, remove unneeded casts]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

---
v2
  - change title to reflect test that failed
  - re-phrase ldl functions to assure unaligned works
  - remove excess ()'s
---
 tests/qtest/libqos/igb.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/qtest/libqos/igb.c b/tests/qtest/libqos/igb.c
index f40c4ec4cd..ab3ef6f0c3 100644
--- a/tests/qtest/libqos/igb.c
+++ b/tests/qtest/libqos/igb.c
@@ -104,10 +104,10 @@ static void igb_pci_start_hw(QOSGraphObject *obj)
     e1000e_macreg_write(&d->e1000e, E1000_RDT(0), 0);
     e1000e_macreg_write(&d->e1000e, E1000_RDH(0), 0);
     e1000e_macreg_write(&d->e1000e, E1000_RA,
-                        le32_to_cpu(*(uint32_t *)address));
+                        ldl_le_p(address));
     e1000e_macreg_write(&d->e1000e, E1000_RA + 4,
                         E1000_RAH_AV | E1000_RAH_POOL_1 |
-                        le16_to_cpu(*(uint16_t *)(address + 4)));
+                        lduw_le_p(address + 4));
 
     /* Set supported receive descriptor mode */
     e1000e_macreg_write(&d->e1000e,
-- 
2.39.5

On 2025/05/22 1:42, Alex Bennée wrote:
> From: Nabih Estefan <nabihestefan@google.com>
> 
>    ../tests/qtest/libqos/igb.c:106:5: runtime error: load of misaligned address 0x562040be8e33 for type 'uint32_t', which requires 4 byte alignment
> 
> Instead of straight casting the uint8_t array, we can use ldl_le_p and
> lduw_l_p to assure the unaligned access working properly against
> uint32_t and uint16_t.

I think the subject should mention the problem (the unaligned access) 
instead of the method used to detect it (UBSan).

On 22/5/25 06:19, Akihiko Odaki wrote:
> On 2025/05/22 1:42, Alex Bennée wrote:
>> From: Nabih Estefan <nabihestefan@google.com>
>>
>>    ../tests/qtest/libqos/igb.c:106:5: runtime error: load of 
>> misaligned address 0x562040be8e33 for type 'uint32_t', which requires 
>> 4 byte alignment
>>
>> Instead of straight casting the uint8_t array, we can use ldl_le_p and
>> lduw_l_p to assure the unaligned access working properly against
>> uint32_t and uint16_t.
> 
> I think the subject should mention the problem (the unaligned access) 
> instead of the method used to detect it (UBSan).

"tests/qtest: Avoid unaligned access in IGB test"

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>