Save major/minor opcodes in ClientRec for RecordAReply

The record extension needs the major and minor opcodes in the reply
hook, but the request buffer may have been freed by the time the hook
is invoked. Saving the request major and minor codes as the request is
executed avoids fetching from the defunct request buffer.

This patch also eliminates the public MinorOpcodeOfRequest function,
inlining it into Dispatch. Usages of that function have been replaced
with direct access to the new ClientRec field.

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Jamey Sharp <jamey@minilop.net>

7 files changed, 20 insertions, 36 deletions

diff --git a/Xext/security.c b/Xext/security.c
index 0a63aa280..6fc1eafdd 100644
--- a/Xext/security.c
+++ b/Xext/security.c
@@ -148,9 +148,7 @@ SecurityLabelInitial(void)
 static _X_INLINE const char *
 SecurityLookupRequestName(ClientPtr client)
 {
-    int major = ((xReq *)client->requestBuffer)->reqType;
-    int minor = MinorOpcodeOfRequest(client);
-    return LookupRequestName(major, minor);
+    return LookupRequestName(client->majorOp, client->minorOp);
 }
 
 
diff --git a/Xext/xselinux_hooks.c b/Xext/xselinux_hooks.c
index f1d8e5d2f..0d4c9ab11 100644
--- a/Xext/xselinux_hooks.c
+++ b/Xext/xselinux_hooks.c
@@ -263,8 +263,8 @@ SELinuxAudit(void *auditdata,
     if (client) {
 	REQUEST(xReq);
 	if (stuff) {
-	    major = stuff->reqType;
-	    minor = MinorOpcodeOfRequest(client);
+	    major = client->majorOp;
+	    minor = client->minorOp;
 	}
     }
     if (audit->id)
diff --git a/dix/dispatch.c b/dix/dispatch.c
index 6e3361573..b39271fd9 100644
--- a/dix/dispatch.c
+++ b/dix/dispatch.c
@@ -337,8 +337,6 @@ DisableLimitedSchedulingLatency(void)
 	SmartScheduleLatencyLimited = 0;
 }
 
-#define MAJOROP ((xReq *)client->requestBuffer)->reqType
-
 void
 Dispatch(void)
 {
@@ -419,21 +417,28 @@ Dispatch(void)
 	        }
 
 		client->sequence++;
+		client->majorOp = ((xReq *)client->requestBuffer)->reqType;
+		client->minorOp = 0;
+		if (client->majorOp >= EXTENSION_BASE) {
+		    ExtensionEntry *ext = GetExtensionEntry(client->majorOp);
+		    if (ext)
+			client->minorOp = ext->MinorOpcode(client);
+		}
 #ifdef XSERVER_DTRACE
-		XSERVER_REQUEST_START(LookupMajorName(MAJOROP), MAJOROP,
+		XSERVER_REQUEST_START(LookupMajorName(client->majorOp), client->majorOp,
 			      ((xReq *)client->requestBuffer)->length,
 			      client->index, client->requestBuffer);
 #endif
 		if (result > (maxBigRequestSize << 2))
 		    result = BadLength;
 		else {
-		    result = XaceHookDispatch(client, MAJOROP);
+		    result = XaceHookDispatch(client, client->majorOp);
 		    if (result == Success)
-			result = (* client->requestVector[MAJOROP])(client);
+			result = (* client->requestVector[client->majorOp])(client);
 		    XaceHookAuditEnd(client, result);
 		}
 #ifdef XSERVER_DTRACE
-		XSERVER_REQUEST_DONE(LookupMajorName(MAJOROP), MAJOROP,
+		XSERVER_REQUEST_DONE(LookupMajorName(client->majorOp), client->majorOp,
 			      client->sequence, client->index, result);
 #endif
 
@@ -444,8 +449,8 @@ Dispatch(void)
 		}
 		else if (result != Success)
 		{
-		    SendErrorToClient(client, MAJOROP,
-				      MinorOpcodeOfRequest(client),
+		    SendErrorToClient(client, client->majorOp,
+				      client->minorOp,
 				      client->errorValue, result);
 		    break;
 		}
@@ -466,8 +471,6 @@ Dispatch(void)
     SmartScheduleLatencyLimited = 0;
 }
 
-#undef MAJOROP
-
 static int  VendorRelease = VENDOR_RELEASE;
 static char *VendorString = VENDOR_NAME;
 
diff --git a/dix/extension.c b/dix/extension.c
index 53aaf051f..cc516b6ba 100644
--- a/dix/extension.c
+++ b/dix/extension.c
@@ -228,20 +228,6 @@ StandardMinorOpcode(ClientPtr client)
     return ((xReq *)client->requestBuffer)->data;
 }
 
-unsigned short
-MinorOpcodeOfRequest(ClientPtr client)
-{
-    unsigned char major;
-
-    major = ((xReq *)client->requestBuffer)->reqType;
-    if (major < EXTENSION_BASE)
-	return 0;
-    major -= EXTENSION_BASE;
-    if (major >= NumExtensions)
-	return 0;
-    return (*extensions[major]->MinorOpcode)(client);
-}
-
 void
 CloseDownExtensions(void)
 {
diff --git a/include/dixstruct.h b/include/dixstruct.h
index 6cc961478..0a85f40b6 100644
--- a/include/dixstruct.h
+++ b/include/dixstruct.h
@@ -122,6 +122,7 @@ typedef struct _Client {
     
     DeviceIntPtr clientPtr;
     ClientIdPtr  clientIds;
+    unsigned short majorOp, minorOp;
 }           ClientRec;
 
 /*
diff --git a/include/extension.h b/include/extension.h
index ee6260eb5..17accafd9 100644
--- a/include/extension.h
+++ b/include/extension.h
@@ -52,8 +52,6 @@ _XFUNCPROTOBEGIN
 
 extern _X_EXPORT unsigned short StandardMinorOpcode(ClientPtr /*client*/);
 
-extern _X_EXPORT unsigned short MinorOpcodeOfRequest(ClientPtr /*client*/);
-
 extern _X_EXPORT Bool EnableDisableExtension(const char *name, Bool enable);
 
 extern _X_EXPORT void EnableDisableExtensionError(const char *name, Bool enable);
diff --git a/record/record.c b/record/record.c
index db77b64f5..b956b4ab8 100644
--- a/record/record.c
+++ b/record/record.c
@@ -552,7 +552,7 @@ RecordARequest(ClientPtr client)
 	    }
 	    else /* extension, check minor opcode */
 	    {
-		int minorop = MinorOpcodeOfRequest(client);
+		int minorop = client->minorOp;
 		int numMinOpInfo;
 		RecordMinorOpPtr pMinorOpInfo = pRCAP->pRequestMinOpInfo;
 
@@ -609,12 +609,9 @@ RecordAReply(CallbackListPtr *pcbl, pointer nulldata, pointer calldata)
     RecordContextPtr pContext;
     RecordClientsAndProtocolPtr pRCAP;
     int eci;
-    int majorop;
     ReplyInfoRec *pri = (ReplyInfoRec *)calldata;
     ClientPtr client = pri->client;
-    REQUEST(xReq);
 
-    majorop = stuff->reqType;
     for (eci = 0; eci < numEnabledContexts; eci++)
     {
 	pContext = ppAllContexts[eci];
@@ -622,6 +619,7 @@ RecordAReply(CallbackListPtr *pcbl, pointer nulldata, pointer calldata)
 					  NULL);
 	if (pRCAP)
 	{
+	    int majorop = client->majorOp;
 	    if (pContext->continuedReply)
 	    {
 		RecordAProtocolElement(pContext, client, XRecordFromServer,
@@ -642,7 +640,7 @@ RecordAReply(CallbackListPtr *pcbl, pointer nulldata, pointer calldata)
 		}
 		else /* extension, check minor opcode */
 		{
-		    int minorop = MinorOpcodeOfRequest(client);
+		    int minorop = client->minorOp;
 		    int numMinOpInfo;
 		    RecordMinorOpPtr pMinorOpInfo = pRCAP->pReplyMinOpInfo;
 		    		    assert (pMinorOpInfo);