Roll third_party/mach_override to 87f491f8acef924d2ba90dd55fc23ad64f9d5bbd.

BUG=none
TEST=none


Review URL: http://codereview.chromium.org/7693006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@97582 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 29 insertions, 14 deletions

diff --git a/third_party/mach_override/README.chromium b/third_party/mach_override/README.chromium
index fad7a93..0e7e394 100644
--- a/third_party/mach_override/README.chromium
+++ b/third_party/mach_override/README.chromium
@@ -2,8 +2,8 @@ Name: mach_override
 Short Name: Part of the mach_star project
 Version: Unknown
 URL: https://github.com/rentzsch/mach_star
-Date: 07/22/2011
-Revision: 51ae3d199463fa84548f466d649f0821d579fdaf
+Date: 08/19/2011
+Revision: 87f491f8acef924d2ba90dd55fc23ad64f9d5bbd
 License: MIT
 Security Critical: Yes
 
@@ -11,7 +11,7 @@ Security Critical: Yes
 Description:
 This is the mach_override part of mach_star, namely:
 
-  https://github.com/rentzsch/mach_star/tree/51ae3d199463fa84548f466d649f0821d579fdaf
+  https://github.com/rentzsch/mach_star/tree/87f491f8acef924d2ba90dd55fc23ad64f9d5bbd
 
 This package is used to replace framework functions with different
 implementations at run time.
@@ -19,7 +19,4 @@ implementations at run time.
 
 Local Modifications:
 
-Added the instructions to |possibleInstructions| for the very short
-malloc_error_break() on 10.5 so that it can be overriden on that platform.
-
-Print errors using fprintf() to stderr, rather than printf() to stdout.
+None. All local changes have been upstreamed.
diff --git a/third_party/mach_override/mach_override.c b/third_party/mach_override/mach_override.c
index 3920026..8a4cf95 100644
--- a/third_party/mach_override/mach_override.c
+++ b/third_party/mach_override/mach_override.c
@@ -170,6 +170,23 @@ mach_override_ptr(
 	assert( originalFunctionAddress );
 	assert( overrideFunctionAddress );
 	
+	// this addresses overriding such functions as AudioOutputUnitStart()
+	// test with modified DefaultOutputUnit project
+#if defined(__x86_64__) || defined(__i386__)
+    for(;;){
+        if(*(unsigned char*)originalFunctionAddress==0xE9)      // jmp .+0x????????
+            originalFunctionAddress=(void*)((char*)originalFunctionAddress+5+*(int32_t *)((char*)originalFunctionAddress+1));
+#if defined(__x86_64__)
+        else if(*(uint16_t*)originalFunctionAddress==0x25FF)    // jmp qword near [rip+0x????????]
+            originalFunctionAddress=*(void**)((char*)originalFunctionAddress+6+*(int32_t *)((uint16_t*)originalFunctionAddress+1));
+#elif defined(__i386__)
+        else if(*(uint16_t*)originalFunctionAddress==0x25FF)    // jmp *0x????????
+            originalFunctionAddress=**(void***)((uint16_t*)originalFunctionAddress+1);
+#endif
+        else break;
+    }
+#endif
+
 	long	*originalFunctionPtr = (long*) originalFunctionAddress;
 	mach_error_t	err = err_none;
 	
@@ -296,18 +313,18 @@ mach_override_ptr(
 		if( reentryIsland )
 			err = setBranchIslandTarget_i386( reentryIsland,
 										 (void*) ((char *)originalFunctionPtr+eatenCount), originalInstructions );
+		// try making islands executable before planting the jmp
+#if defined(__x86_64__) || defined(__i386__)
+        if( !err )
+            err = makeIslandExecutable(escapeIsland);
+        if( !err && reentryIsland )
+            err = makeIslandExecutable(reentryIsland);
+#endif
 		if ( !err )
 			atomic_mov64((uint64_t *)originalFunctionPtr, jumpRelativeInstruction);
 	}
 #endif
 	
-#if defined(__i386__) || defined(__x86_64__)
-	if ( !err )
-	        err = makeIslandExecutable( escapeIsland );
-	if ( !err && reentryIsland )
-	        err = makeIslandExecutable( reentryIsland );
-#endif
-	
 	//	Clean up on error.
 	if( err ) {
 		if( reentryIsland )
@@ -604,6 +621,7 @@ eatKnownInstructions(
 		// if all instruction matches failed, we don't know current instruction then, stop here
 		if (!curInstructionKnown) { 
 			allInstructionsKnown = false;
+			fprintf(stderr, "mach_override: some instructions unknown! Need to update mach_override.c\n");
 			break;
 		}