The following patches added support for StandaloneMM using FF-A: 9da5ee116a28 ArmPkg: Allow FF-A calls to set memory region's attributes 0e43e02b9bd8 ArmPkg: Allow FF-A calls to get memory region's attributes
However, the error handling logic for the Get/Set Memory attributes introduced an issue wherein a status variable could be used without initialisation. This issue is reported by CLANG compiler and is not seen with GCC. The Get/Set Memory attributes operation is atomic and therefore an FFA_INTERRUPT or FFA_SUCCESS response is not expected in response to FFA_MSG_SEND_DIRECT_REQ. So the remaining cases that could occur are: - the target sends FFA_MSG_SEND_DIRECT_RESP with a success or failure code. or - FFA_MSG_SEND_DIRECT_REQ transmission failure. Therefore, reorder the error handling conditions such that the uninitialised variable issue is fixed. Signed-off-by: Sami Mujawar <sami.muja...@arm.com> --- The changes can be seen at: https://github.com/samimujawar/edk2/tree/1657_stmm_ffa_fix_unused_var_v1 ArmPkg/Library/StandaloneMmMmuLib/AArch64/ArmMmuStandaloneMmLib.c | 92 ++++++++++---------- 1 file changed, 45 insertions(+), 47 deletions(-) diff --git a/ArmPkg/Library/StandaloneMmMmuLib/AArch64/ArmMmuStandaloneMmLib.c b/ArmPkg/Library/StandaloneMmMmuLib/AArch64/ArmMmuStandaloneMmLib.c index a30369af9c91fb8045dfec7a68e2bd072706d101..73b63ca396e5395bdf2112709b0aa2ab871a2a07 100644 --- a/ArmPkg/Library/StandaloneMmMmuLib/AArch64/ArmMmuStandaloneMmLib.c +++ b/ArmPkg/Library/StandaloneMmMmuLib/AArch64/ArmMmuStandaloneMmLib.c @@ -57,36 +57,35 @@ GetMemoryPermissions ( // for other Direct Request calls which are not atomic // We therefore check only for Direct Response by the // callee. - if (GetMemoryPermissionsSvcArgs.Arg0 != + if (GetMemoryPermissionsSvcArgs.Arg0 == ARM_SVC_ID_FFA_MSG_SEND_DIRECT_RESP_AARCH64) { - // If Arg0 is not a Direct Response, that means we - // have an FF-A error. We need to check Arg2 for the - // FF-A error code. - Ret = GetMemoryPermissionsSvcArgs.Arg2; - switch (Ret) { - case ARM_FFA_SPM_RET_INVALID_PARAMETERS: - - return EFI_INVALID_PARAMETER; - - case ARM_FFA_SPM_RET_DENIED: - return EFI_NOT_READY; - - case ARM_FFA_SPM_RET_NOT_SUPPORTED: - return EFI_UNSUPPORTED; - - case ARM_FFA_SPM_RET_BUSY: - return EFI_NOT_READY; - - case ARM_FFA_SPM_RET_ABORTED: - return EFI_ABORTED; - } - } else if (GetMemoryPermissionsSvcArgs.Arg0 == - ARM_SVC_ID_FFA_MSG_SEND_DIRECT_RESP_AARCH64) { // A Direct Response means FF-A success // Now check the payload for errors // The callee sends back the return value // in Arg3 Ret = GetMemoryPermissionsSvcArgs.Arg3; + } else { + // If Arg0 is not a Direct Response, that means we + // have an FF-A error. We need to check Arg2 for the + // FF-A error code. + Ret = GetMemoryPermissionsSvcArgs.Arg2; + switch (Ret) { + case ARM_FFA_SPM_RET_INVALID_PARAMETERS: + + return EFI_INVALID_PARAMETER; + + case ARM_FFA_SPM_RET_DENIED: + return EFI_NOT_READY; + + case ARM_FFA_SPM_RET_NOT_SUPPORTED: + return EFI_UNSUPPORTED; + + case ARM_FFA_SPM_RET_BUSY: + return EFI_NOT_READY; + + case ARM_FFA_SPM_RET_ABORTED: + return EFI_ABORTED; + } } } else { Ret = GetMemoryPermissionsSvcArgs.Arg0; @@ -150,35 +149,34 @@ RequestMemoryPermissionChange ( // for other Direct Request calls which are not atomic // We therefore check only for Direct Response by the // callee. - if (ChangeMemoryPermissionsSvcArgs.Arg0 != + if (ChangeMemoryPermissionsSvcArgs.Arg0 == ARM_SVC_ID_FFA_MSG_SEND_DIRECT_RESP_AARCH64) { - // If Arg0 is not a Direct Response, that means we - // have an FF-A error. We need to check Arg2 for the - // FF-A error code. - Ret = ChangeMemoryPermissionsSvcArgs.Arg2; - switch (Ret) { - case ARM_FFA_SPM_RET_INVALID_PARAMETERS: - return EFI_INVALID_PARAMETER; - - case ARM_FFA_SPM_RET_DENIED: - return EFI_NOT_READY; - - case ARM_FFA_SPM_RET_NOT_SUPPORTED: - return EFI_UNSUPPORTED; - - case ARM_FFA_SPM_RET_BUSY: - return EFI_NOT_READY; - - case ARM_FFA_SPM_RET_ABORTED: - return EFI_ABORTED; - } - } else if (ChangeMemoryPermissionsSvcArgs.Arg0 == - ARM_SVC_ID_FFA_MSG_SEND_DIRECT_RESP_AARCH64) { // A Direct Response means FF-A success // Now check the payload for errors // The callee sends back the return value // in Arg3 Ret = ChangeMemoryPermissionsSvcArgs.Arg3; + } else { + // If Arg0 is not a Direct Response, that means we + // have an FF-A error. We need to check Arg2 for the + // FF-A error code. + Ret = ChangeMemoryPermissionsSvcArgs.Arg2; + switch (Ret) { + case ARM_FFA_SPM_RET_INVALID_PARAMETERS: + return EFI_INVALID_PARAMETER; + + case ARM_FFA_SPM_RET_DENIED: + return EFI_NOT_READY; + + case ARM_FFA_SPM_RET_NOT_SUPPORTED: + return EFI_UNSUPPORTED; + + case ARM_FFA_SPM_RET_BUSY: + return EFI_NOT_READY; + + case ARM_FFA_SPM_RET_ABORTED: + return EFI_ABORTED; + } } } else { Ret = ChangeMemoryPermissionsSvcArgs.Arg0; -- 'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)' -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#72152): https://edk2.groups.io/g/devel/message/72152 Mute This Topic: https://groups.io/mt/80885597/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
