[Qemu-devel] [PATCH] hw/scsi/mptendian: Avoid taking address of fields in packed structs

[Peter Maydell]

Taking the address of a field in a packed struct is a bad idea, because
it might not be actually aligned enough for that pointer type (and
thus cause a crash on dereference on some host architectures). Newer
versions of clang warn about this. Avoid the bug by not using the
"modify in place" byte swapping functions.

This patch was produced with the following simple spatch script:
@@
expression E;
@@
-le16_to_cpus(&E);
+E = le16_to_cpu(E);
@@
expression E;
@@
-le32_to_cpus(&E);
+E = le32_to_cpu(E);
@@
expression E;
@@
-le64_to_cpus(&E);
+E = le64_to_cpu(E);
@@
expression E;
@@
-cpu_to_le16s(&E);
+E = cpu_to_le16(E);
@@
expression E;
@@
-cpu_to_le32s(&E);
+E = cpu_to_le32(E);
@@
expression E;
@@
-cpu_to_le64s(&E);
+E = cpu_to_le64(E);

followed by some minor tidying of overlong lines and bad indent.

Signed-off-by: Peter Maydell <address@hidden>
---
NB: tested with qemu-system-x86_64 -cpu host -enable-kvm -m 4096
 -device mptsas1068 -drive id=mydisk,if=none,file=harddisk.qcow2
 -device scsi-disk,drive=mydisk
which behaves no differently before or after the patch, though
the guest I have (an x86 ubuntu) seems to detect the controller
but not find any disks attached to it. Maybe my command line is wrong?

 hw/scsi/mptendian.c | 163 ++++++++++++++++++++++----------------------
 1 file changed, 83 insertions(+), 80 deletions(-)

diff --git a/hw/scsi/mptendian.c b/hw/scsi/mptendian.c
index 8ae39a76f42..79f99734d21 100644
--- a/hw/scsi/mptendian.c
+++ b/hw/scsi/mptendian.c
@@ -35,152 +35,155 @@
 
 static void mptsas_fix_sgentry_endianness(MPISGEntry *sge)
 {
-    le32_to_cpus(&sge->FlagsLength);
+    sge->FlagsLength = le32_to_cpu(sge->FlagsLength);
     if (sge->FlagsLength & MPI_SGE_FLAGS_64_BIT_ADDRESSING) {
-       le64_to_cpus(&sge->u.Address64);
+        sge->u.Address64 = le64_to_cpu(sge->u.Address64);
     } else {
-       le32_to_cpus(&sge->u.Address32);
+        sge->u.Address32 = le32_to_cpu(sge->u.Address32);
     }
 }
 
 static void mptsas_fix_sgentry_endianness_reply(MPISGEntry *sge)
 {
     if (sge->FlagsLength & MPI_SGE_FLAGS_64_BIT_ADDRESSING) {
-       cpu_to_le64s(&sge->u.Address64);
+        sge->u.Address64 = cpu_to_le64(sge->u.Address64);
     } else {
-       cpu_to_le32s(&sge->u.Address32);
+        sge->u.Address32 = cpu_to_le32(sge->u.Address32);
     }
-    cpu_to_le32s(&sge->FlagsLength);
+    sge->FlagsLength = cpu_to_le32(sge->FlagsLength);
 }
 
 void mptsas_fix_scsi_io_endianness(MPIMsgSCSIIORequest *req)
 {
-    le32_to_cpus(&req->MsgContext);
-    le32_to_cpus(&req->Control);
-    le32_to_cpus(&req->DataLength);
-    le32_to_cpus(&req->SenseBufferLowAddr);
+    req->MsgContext = le32_to_cpu(req->MsgContext);
+    req->Control = le32_to_cpu(req->Control);
+    req->DataLength = le32_to_cpu(req->DataLength);
+    req->SenseBufferLowAddr = le32_to_cpu(req->SenseBufferLowAddr);
 }
 
 void mptsas_fix_scsi_io_reply_endianness(MPIMsgSCSIIOReply *reply)
 {
-    cpu_to_le32s(&reply->MsgContext);
-    cpu_to_le16s(&reply->IOCStatus);
-    cpu_to_le32s(&reply->IOCLogInfo);
-    cpu_to_le32s(&reply->TransferCount);
-    cpu_to_le32s(&reply->SenseCount);
-    cpu_to_le32s(&reply->ResponseInfo);
-    cpu_to_le16s(&reply->TaskTag);
+    reply->MsgContext = cpu_to_le32(reply->MsgContext);
+    reply->IOCStatus = cpu_to_le16(reply->IOCStatus);
+    reply->IOCLogInfo = cpu_to_le32(reply->IOCLogInfo);
+    reply->TransferCount = cpu_to_le32(reply->TransferCount);
+    reply->SenseCount = cpu_to_le32(reply->SenseCount);
+    reply->ResponseInfo = cpu_to_le32(reply->ResponseInfo);
+    reply->TaskTag = cpu_to_le16(reply->TaskTag);
 }
 
 void mptsas_fix_scsi_task_mgmt_endianness(MPIMsgSCSITaskMgmt *req)
 {
-    le32_to_cpus(&req->MsgContext);
-    le32_to_cpus(&req->TaskMsgContext);
+    req->MsgContext = le32_to_cpu(req->MsgContext);
+    req->TaskMsgContext = le32_to_cpu(req->TaskMsgContext);
 }
 
 void mptsas_fix_scsi_task_mgmt_reply_endianness(MPIMsgSCSITaskMgmtReply *reply)
 {
-    cpu_to_le32s(&reply->MsgContext);
-    cpu_to_le16s(&reply->IOCStatus);
-    cpu_to_le32s(&reply->IOCLogInfo);
-    cpu_to_le32s(&reply->TerminationCount);
+    reply->MsgContext = cpu_to_le32(reply->MsgContext);
+    reply->IOCStatus = cpu_to_le16(reply->IOCStatus);
+    reply->IOCLogInfo = cpu_to_le32(reply->IOCLogInfo);
+    reply->TerminationCount = cpu_to_le32(reply->TerminationCount);
 }
 
 void mptsas_fix_ioc_init_endianness(MPIMsgIOCInit *req)
 {
-    le32_to_cpus(&req->MsgContext);
-    le16_to_cpus(&req->ReplyFrameSize);
-    le32_to_cpus(&req->HostMfaHighAddr);
-    le32_to_cpus(&req->SenseBufferHighAddr);
-    le32_to_cpus(&req->ReplyFifoHostSignalingAddr);
+    req->MsgContext = le32_to_cpu(req->MsgContext);
+    req->ReplyFrameSize = le16_to_cpu(req->ReplyFrameSize);
+    req->HostMfaHighAddr = le32_to_cpu(req->HostMfaHighAddr);
+    req->SenseBufferHighAddr = le32_to_cpu(req->SenseBufferHighAddr);
+    req->ReplyFifoHostSignalingAddr =
+        le32_to_cpu(req->ReplyFifoHostSignalingAddr);
     mptsas_fix_sgentry_endianness(&req->HostPageBufferSGE);
-    le16_to_cpus(&req->MsgVersion);
-    le16_to_cpus(&req->HeaderVersion);
+    req->MsgVersion = le16_to_cpu(req->MsgVersion);
+    req->HeaderVersion = le16_to_cpu(req->HeaderVersion);
 }
 
 void mptsas_fix_ioc_init_reply_endianness(MPIMsgIOCInitReply *reply)
 {
-    cpu_to_le32s(&reply->MsgContext);
-    cpu_to_le16s(&reply->IOCStatus);
-    cpu_to_le32s(&reply->IOCLogInfo);
+    reply->MsgContext = cpu_to_le32(reply->MsgContext);
+    reply->IOCStatus = cpu_to_le16(reply->IOCStatus);
+    reply->IOCLogInfo = cpu_to_le32(reply->IOCLogInfo);
 }
 
 void mptsas_fix_ioc_facts_endianness(MPIMsgIOCFacts *req)
 {
-    le32_to_cpus(&req->MsgContext);
+    req->MsgContext = le32_to_cpu(req->MsgContext);
 }
 
 void mptsas_fix_ioc_facts_reply_endianness(MPIMsgIOCFactsReply *reply)
 {
-    cpu_to_le16s(&reply->MsgVersion);
-    cpu_to_le16s(&reply->HeaderVersion);
-    cpu_to_le32s(&reply->MsgContext);
-    cpu_to_le16s(&reply->IOCExceptions);
-    cpu_to_le16s(&reply->IOCStatus);
-    cpu_to_le32s(&reply->IOCLogInfo);
-    cpu_to_le16s(&reply->ReplyQueueDepth);
-    cpu_to_le16s(&reply->RequestFrameSize);
-    cpu_to_le16s(&reply->ProductID);
-    cpu_to_le32s(&reply->CurrentHostMfaHighAddr);
-    cpu_to_le16s(&reply->GlobalCredits);
-    cpu_to_le32s(&reply->CurrentSenseBufferHighAddr);
-    cpu_to_le16s(&reply->CurReplyFrameSize);
-    cpu_to_le32s(&reply->FWImageSize);
-    cpu_to_le32s(&reply->IOCCapabilities);
-    cpu_to_le16s(&reply->HighPriorityQueueDepth);
+    reply->MsgVersion = cpu_to_le16(reply->MsgVersion);
+    reply->HeaderVersion = cpu_to_le16(reply->HeaderVersion);
+    reply->MsgContext = cpu_to_le32(reply->MsgContext);
+    reply->IOCExceptions = cpu_to_le16(reply->IOCExceptions);
+    reply->IOCStatus = cpu_to_le16(reply->IOCStatus);
+    reply->IOCLogInfo = cpu_to_le32(reply->IOCLogInfo);
+    reply->ReplyQueueDepth = cpu_to_le16(reply->ReplyQueueDepth);
+    reply->RequestFrameSize = cpu_to_le16(reply->RequestFrameSize);
+    reply->ProductID = cpu_to_le16(reply->ProductID);
+    reply->CurrentHostMfaHighAddr = cpu_to_le32(reply->CurrentHostMfaHighAddr);
+    reply->GlobalCredits = cpu_to_le16(reply->GlobalCredits);
+    reply->CurrentSenseBufferHighAddr =
+        cpu_to_le32(reply->CurrentSenseBufferHighAddr);
+    reply->CurReplyFrameSize = cpu_to_le16(reply->CurReplyFrameSize);
+    reply->FWImageSize = cpu_to_le32(reply->FWImageSize);
+    reply->IOCCapabilities = cpu_to_le32(reply->IOCCapabilities);
+    reply->HighPriorityQueueDepth = cpu_to_le16(reply->HighPriorityQueueDepth);
     mptsas_fix_sgentry_endianness_reply(&reply->HostPageBufferSGE);
-    cpu_to_le32s(&reply->ReplyFifoHostSignalingAddr);
+    reply->ReplyFifoHostSignalingAddr =
+        cpu_to_le32(reply->ReplyFifoHostSignalingAddr);
 }
 
 void mptsas_fix_config_endianness(MPIMsgConfig *req)
 {
-    le16_to_cpus(&req->ExtPageLength);
-    le32_to_cpus(&req->MsgContext);
-    le32_to_cpus(&req->PageAddress);
+    req->ExtPageLength = le16_to_cpu(req->ExtPageLength);
+    req->MsgContext = le32_to_cpu(req->MsgContext);
+    req->PageAddress = le32_to_cpu(req->PageAddress);
     mptsas_fix_sgentry_endianness(&req->PageBufferSGE);
 }
 
 void mptsas_fix_config_reply_endianness(MPIMsgConfigReply *reply)
 {
-    cpu_to_le16s(&reply->ExtPageLength);
-    cpu_to_le32s(&reply->MsgContext);
-    cpu_to_le16s(&reply->IOCStatus);
-    cpu_to_le32s(&reply->IOCLogInfo);
+    reply->ExtPageLength = cpu_to_le16(reply->ExtPageLength);
+    reply->MsgContext = cpu_to_le32(reply->MsgContext);
+    reply->IOCStatus = cpu_to_le16(reply->IOCStatus);
+    reply->IOCLogInfo = cpu_to_le32(reply->IOCLogInfo);
 }
 
 void mptsas_fix_port_facts_endianness(MPIMsgPortFacts *req)
 {
-    le32_to_cpus(&req->MsgContext);
+    req->MsgContext = le32_to_cpu(req->MsgContext);
 }
 
 void mptsas_fix_port_facts_reply_endianness(MPIMsgPortFactsReply *reply)
 {
-    cpu_to_le32s(&reply->MsgContext);
-    cpu_to_le16s(&reply->IOCStatus);
-    cpu_to_le32s(&reply->IOCLogInfo);
-    cpu_to_le16s(&reply->MaxDevices);
-    cpu_to_le16s(&reply->PortSCSIID);
-    cpu_to_le16s(&reply->ProtocolFlags);
-    cpu_to_le16s(&reply->MaxPostedCmdBuffers);
-    cpu_to_le16s(&reply->MaxPersistentIDs);
-    cpu_to_le16s(&reply->MaxLanBuckets);
+    reply->MsgContext = cpu_to_le32(reply->MsgContext);
+    reply->IOCStatus = cpu_to_le16(reply->IOCStatus);
+    reply->IOCLogInfo = cpu_to_le32(reply->IOCLogInfo);
+    reply->MaxDevices = cpu_to_le16(reply->MaxDevices);
+    reply->PortSCSIID = cpu_to_le16(reply->PortSCSIID);
+    reply->ProtocolFlags = cpu_to_le16(reply->ProtocolFlags);
+    reply->MaxPostedCmdBuffers = cpu_to_le16(reply->MaxPostedCmdBuffers);
+    reply->MaxPersistentIDs = cpu_to_le16(reply->MaxPersistentIDs);
+    reply->MaxLanBuckets = cpu_to_le16(reply->MaxLanBuckets);
 }
 
 void mptsas_fix_port_enable_endianness(MPIMsgPortEnable *req)
 {
-    le32_to_cpus(&req->MsgContext);
+    req->MsgContext = le32_to_cpu(req->MsgContext);
 }
 
 void mptsas_fix_port_enable_reply_endianness(MPIMsgPortEnableReply *reply)
 {
-    cpu_to_le32s(&reply->MsgContext);
-    cpu_to_le16s(&reply->IOCStatus);
-    cpu_to_le32s(&reply->IOCLogInfo);
+    reply->MsgContext = cpu_to_le32(reply->MsgContext);
+    reply->IOCStatus = cpu_to_le16(reply->IOCStatus);
+    reply->IOCLogInfo = cpu_to_le32(reply->IOCLogInfo);
 }
 
 void mptsas_fix_event_notification_endianness(MPIMsgEventNotify *req)
 {
-    le32_to_cpus(&req->MsgContext);
+    req->MsgContext = le32_to_cpu(req->MsgContext);
 }
 
 void mptsas_fix_event_notification_reply_endianness(MPIMsgEventNotifyReply 
*reply)
@@ -188,16 +191,16 @@ void 
mptsas_fix_event_notification_reply_endianness(MPIMsgEventNotifyReply *repl
     int length = reply->EventDataLength;
     int i;
 
-    cpu_to_le16s(&reply->EventDataLength);
-    cpu_to_le32s(&reply->MsgContext);
-    cpu_to_le16s(&reply->IOCStatus);
-    cpu_to_le32s(&reply->IOCLogInfo);
-    cpu_to_le32s(&reply->Event);
-    cpu_to_le32s(&reply->EventContext);
+    reply->EventDataLength = cpu_to_le16(reply->EventDataLength);
+    reply->MsgContext = cpu_to_le32(reply->MsgContext);
+    reply->IOCStatus = cpu_to_le16(reply->IOCStatus);
+    reply->IOCLogInfo = cpu_to_le32(reply->IOCLogInfo);
+    reply->Event = cpu_to_le32(reply->Event);
+    reply->EventContext = cpu_to_le32(reply->EventContext);
 
     /* Really depends on the event kind.  This will do for now.  */
     for (i = 0; i < length; i++) {
-        cpu_to_le32s(&reply->Data[i]);
+        reply->Data[i] = cpu_to_le32(reply->Data[i]);
     }
 }
 
-- 
2.19.0