xserver: Branch 'master'

[Eamon Walsh]

 Xext/xace.c    |   47 +++++++++++++++++++++--------------------------
 Xext/xace.h    |    9 +++++++++
 dix/dispatch.c |    4 ++--
 3 files changed, 32 insertions(+), 28 deletions(-)

New commits:
commit d7c5e8bfc1aecbd23a4cbb2eab08656587aac2e8
Author: Eamon Walsh <ewalsh at tycho.nsa.gov>
Date:   Tue Nov 6 16:26:09 2007 -0500

    Modified performance patches from Arjan van de Ven <arjan at infradead.org>
    
    Subject: [PATCH] fix some performance gaps in Xace
    
    The XaceHook function is used in several hotpaths.
    The problem with it (performance wise) is twofold:
     * The XaceHook function has a big switch() statement for the hook number in it
     * The XaceHook function uses varargs to reassemble the final dispatch arguments again
    
    Both are expensive operations... for something that is known at compile time
    
    This patch turns the hotpath XaceHook call into a direct call to avoid
    the switch and varargs; this gives me over 10% performance gain
    on the x11perf benchmark.

diff --git a/Xext/xace.c b/Xext/xace.c
index 00c3b8f..b4e0eee 100644
--- a/Xext/xace.c
+++ b/Xext/xace.c
@@ -44,6 +44,22 @@ static int (*SwappedUntrustedProcVector[256])(
     ClientPtr /*client*/
 );
 
+/* Special-cased hook functions.  Called by Xserver.
+ */
+void XaceHookAuditBegin(ClientPtr ptr)
+{
+    XaceAuditRec rec = { ptr, 0 };
+    /* call callbacks, there is no return value. */
+    CallCallbacks(&XaceHooks[XACE_AUDIT_BEGIN], &rec);
+}
+
+void XaceHookAuditEnd(ClientPtr ptr, int result)
+{
+    XaceAuditRec rec = { ptr, result };
+    /* call callbacks, there is no return value. */
+    CallCallbacks(&XaceHooks[XACE_AUDIT_END], &rec);
+}
+
 /* Entry point for hook functions.  Called by Xserver.
  */
 int XaceHook(int hook, ...)
@@ -60,15 +76,6 @@ int XaceHook(int hook, ...)
      */
     switch (hook)
     {
-	case XACE_CORE_DISPATCH: {
-	    XaceCoreDispatchRec rec = {
-		va_arg(ap, ClientPtr),
-		TRUE	/* default allow */
-	    };
-	    calldata = &rec;
-	    prv = &rec.rval;
-	    break;
-	}
 	case XACE_RESOURCE_ACCESS: {
 	    XaceResourceAccessRec rec = {
 		va_arg(ap, ClientPtr),
@@ -190,22 +197,6 @@ int XaceHook(int hook, ...)
 	    calldata = &rec;
 	    break;
 	}
-	case XACE_AUDIT_BEGIN: {
-	    XaceAuditRec rec = {
-		va_arg(ap, ClientPtr),
-		0
-	    };
-	    calldata = &rec;
-	    break;
-	}
-	case XACE_AUDIT_END: {
-	    XaceAuditRec rec = {
-		va_arg(ap, ClientPtr),
-		va_arg(ap, int)
-	    };
-	    calldata = &rec;
-	    break;
-	}
 	default: {
 	    va_end(ap);
 	    return 0;	/* unimplemented hook number */
@@ -271,11 +262,15 @@ XaceCatchDispatchProc(ClientPtr client)
 {
     REQUEST(xReq);
     int major = stuff->reqType;
+    XaceCoreDispatchRec rec = { client, TRUE /* default allow */ };
 
     if (!ProcVector[major])
 	return (BadRequest);
 
-    if (!XaceHook(XACE_CORE_DISPATCH, client))
+    /* call callbacks and return result, if any. */
+    CallCallbacks(&XaceHooks[XACE_CORE_DISPATCH], &rec);
+
+    if (!rec.rval)
 	return (BadAccess);
 
     return client->swapped ? 
diff --git a/Xext/xace.h b/Xext/xace.h
index 4143cd4..273635c 100644
--- a/Xext/xace.h
+++ b/Xext/xace.h
@@ -68,6 +68,11 @@ extern int XaceHook(
     ... /*appropriate args for hook*/
     ); 
 
+/* Special-cased hook functions
+ */
+extern void XaceHookAuditEnd(ClientPtr ptr, int result);
+extern void XaceHookAuditBegin(ClientPtr ptr);
+
 /* Register a callback for a given hook.
  */
 #define XaceRegisterCallback(hook,callback,data) \
@@ -98,9 +103,13 @@ extern void XaceCensorImage(
 
 #ifdef __GNUC__
 #define XaceHook(args...) XaceAllowOperation
+#define XaceHookAuditEnd(args...) { ; }
+#define XaceHookAuditBegin(args...) { ; }
 #define XaceCensorImage(args...) { ; }
 #else
 #define XaceHook(...) XaceAllowOperation
+#define XaceHookAuditEnd(...) { ; }
+#define XaceHookAuditBegin(...) { ; }
 #define XaceCensorImage(...) { ; }
 #endif
 
diff --git a/dix/dispatch.c b/dix/dispatch.c
index 5c4f8e4..8c76eb1 100644
--- a/dix/dispatch.c
+++ b/dix/dispatch.c
@@ -498,9 +498,9 @@ Dispatch(void)
 		if (result > (maxBigRequestSize << 2))
 		    result = BadLength;
 		else {
-		    XaceHook(XACE_AUDIT_BEGIN, client);
+		    XaceHookAuditBegin(client);
 		    result = (* client->requestVector[MAJOROP])(client);
-		    XaceHook(XACE_AUDIT_END, client, result);
+		    XaceHookAuditEnd(client, result);
 		}
 #ifdef XSERVER_DTRACE
 		XSERVER_REQUEST_DONE(GetRequestName(MAJOROP), MAJOROP,