6.14-stable review patch. If anyone has any objections, please let me know.
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From: Sudeep Holla sudeep.holla@arm.com
[ Upstream commit 3e282f41585c4dd49b688bd6395fd6f21a57c9f7 ]
The return value ret.a2 is of type unsigned long and FFA_RET_NO_DATA is a negative value.
Since the return value from the firmware can be just 32-bit even on 64-bit systems as FFA specification mentions it as int32 error code in w0 register, explicitly casting to s32 ensures correct sign interpretation when comparing against a signed error code FFA_RET_NO_DATA.
Without casting, comparison between unsigned long and a negative constant could lead to unintended results due to type promotions.
Fixes: 3522be48d82b ("firmware: arm_ffa: Implement the NOTIFICATION_INFO_GET interface") Reported-by: Andrei Homescu ahomescu@google.com Message-Id: 20250221095633.506678-2-sudeep.holla@arm.com Signed-off-by: Sudeep Holla sudeep.holla@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/firmware/arm_ffa/driver.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c index ce1ec015e076b..25b52acae4662 100644 --- a/drivers/firmware/arm_ffa/driver.c +++ b/drivers/firmware/arm_ffa/driver.c @@ -899,7 +899,7 @@ static void ffa_notification_info_get(void) }, &ret);
if (ret.a0 != FFA_FN_NATIVE(SUCCESS) && ret.a0 != FFA_SUCCESS) { - if (ret.a2 != FFA_RET_NO_DATA) + if ((s32)ret.a2 != FFA_RET_NO_DATA) pr_err("Notification Info fetch failed: 0x%lx (0x%lx)", ret.a0, ret.a2); return;