diff options
| author | Sudeep Holla <sudeep.holla@arm.com> | 2025-02-21 09:56:31 +0000 |
|---|---|---|
| committer | Sudeep Holla <sudeep.holla@arm.com> | 2025-02-21 11:40:24 +0000 |
| commit | cecf6a504137aa238d768ae440a1f6488cb2f436 (patch) | |
| tree | 004ae0c38e277a53674ea46da0f423b534234e1e | |
| parent | 9472fe20d3968743e683bd48dace02b4accd7736 (diff) | |
firmware: arm_ffa: Explicitly cast return value from FFA_VERSION before comparison
The return value ver.a0 is unsigned long type and FFA_RET_NOT_SUPPORTED
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_NOT_SUPPORTED.
Without casting, comparison between unsigned long and a negative
constant could lead to unintended results due to type promotions.
Fixes: 3bbfe9871005 ("firmware: arm_ffa: Add initial Arm FFA driver support")
Reported-by: Andrei Homescu <ahomescu@google.com>
Message-Id: <20250221095633.506678-1-sudeep.holla@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
| -rw-r--r-- | drivers/firmware/arm_ffa/driver.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c index f3ca703a4441..7c288ae74f97 100644 --- a/drivers/firmware/arm_ffa/driver.c +++ b/drivers/firmware/arm_ffa/driver.c @@ -144,7 +144,7 @@ static int ffa_version_check(u32 *version) .a0 = FFA_VERSION, .a1 = FFA_DRIVER_VERSION, }, &ver); - if (ver.a0 == FFA_RET_NOT_SUPPORTED) { + if ((s32)ver.a0 == FFA_RET_NOT_SUPPORTED) { pr_info("FFA_VERSION returned not supported\n"); return -EOPNOTSUPP; } |