Implement runtime suspension for OSX

This change implements runtime suspension for OSX using activation
injection, the same mechanism as Linux uses.
I have modified the activation injection mechanism by adding a new
function that CoreCLR registers with PAL and PAL calls it to check
if an instruction address is safe for injection. The injection is
performed only if this new function returns true.
The activation on OSX is performed by suspending the target thread,
checking the instruction address in the suspended thread's context
using the above mentioned function and modifying the context to
perform the injection only at injection safe place.

CMakeLists.txt

@@ -545,9 +545,7 @@ if(WIN32)
 endif(WIN32)
 add_definitions(-DFEATURE_EXCEPTIONDISPATCHINFO)
 add_definitions(-DFEATURE_FRAMEWORK_INTERNAL)
-if(WIN32 OR (CLR_CMAKE_PLATFORM_LINUX AND CLR_CMAKE_PLATFORM_UNIX_TARGET_AMD64))
-    add_definitions(-DFEATURE_HIJACK)
-endif(WIN32 OR (CLR_CMAKE_PLATFORM_LINUX AND CLR_CMAKE_PLATFORM_UNIX_TARGET_AMD64))
+add_definitions(-DFEATURE_HIJACK)
 add_definitions(-DFEATURE_HOST_ASSEMBLY_RESOLVER)
 add_definitions(-DFEATURE_HOSTED_BINDER)
 if(WIN32)

src/pal/inc/pal.h

@@ -5446,12 +5446,14 @@ PALAPI
 FlushProcessWriteBuffers();
 
 typedef void (*PAL_ActivationFunction)(CONTEXT *context);
+typedef BOOL (*PAL_SafeActivationCheckFunction)(SIZE_T ip);
 
 PALIMPORT
 VOID
 PALAPI
 PAL_SetActivationFunction(
-    IN PAL_ActivationFunction pActivationFunction);
+    IN PAL_ActivationFunction pActivationFunction,
+    IN PAL_SafeActivationCheckFunction pSafeActivationCheckFunction);
 
 PALIMPORT
 BOOL

src/pal/src/CMakeLists.txt

@@ -40,6 +40,7 @@ endif()
 if(CMAKE_SYSTEM_NAME STREQUAL Darwin)
   add_definitions(-D_TARGET_MAC64)
   set(PLATFORM_SOURCES
+    arch/i386/activationhandlerwrapper.S
     arch/i386/context.S
     arch/i386/dispatchexceptionwrapper.S
     exception/machexception.cpp

src/pal/src/arch/i386/activationhandlerwrapper.S

@@ -0,0 +1,31 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+.intel_syntax noprefix
+#include "unixasmmacros.inc"
+#include "asmconstants.h"
+
+#ifdef BIT64
+// Offset of the return address from the ActivationHandler in the ActivationHandlerWrapper
+.globl C_FUNC(ActivationHandlerReturnOffset)
+C_FUNC(ActivationHandlerReturnOffset):
+    .int LOCAL_LABEL(ActivationHandlerReturn)-C_FUNC(ActivationHandlerWrapper)
+
+NESTED_ENTRY ActivationHandlerWrapper, _TEXT, NoHandler
+    push_nonvol_reg rbp
+    mov     rbp, rsp
+    set_cfa_register rbp, 0
+    alloc_stack (CONTEXT_Size)
+    mov     rdi, rsp
+    int3
+    call    C_FUNC(ActivationHandler)
+LOCAL_LABEL(ActivationHandlerReturn):
+    int3
+    free_stack (CONTEXT_Size)
+    pop_nonvol_reg rbp
+    ret
+NESTED_END ActivationHandlerWrapper, _TEXT
+
+#endif // BIT64

src/pal/src/arch/i386/asmconstants.h

@@ -0,0 +1,105 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+#ifdef BIT64
+
+#define CONTEXT_AMD64   0x100000
+
+#define CONTEXT_CONTROL 1 // SegSs, Rsp, SegCs, Rip, and EFlags
+#define CONTEXT_INTEGER 2 // Rax, Rcx, Rdx, Rbx, Rbp, Rsi, Rdi, R8-R15
+#define CONTEXT_SEGMENTS 4 // SegDs, SegEs, SegFs, SegGs
+#define CONTEXT_FLOATING_POINT 8
+#define CONTEXT_DEBUG_REGISTERS 16 // Dr0-Dr3 and Dr6-Dr7
+
+#define CONTEXT_FULL (CONTEXT_CONTROL | CONTEXT_INTEGER | CONTEXT_FLOATING_POINT)
+
+#define CONTEXT_ContextFlags 6*8
+#define CONTEXT_SegCs CONTEXT_ContextFlags+8
+#define CONTEXT_SegDs CONTEXT_SegCs+2
+#define CONTEXT_SegEs CONTEXT_SegDs+2
+#define CONTEXT_SegFs CONTEXT_SegEs+2
+#define CONTEXT_SegGs CONTEXT_SegFs+2
+#define CONTEXT_SegSs CONTEXT_SegGs+2
+#define CONTEXT_EFlags CONTEXT_SegSs+2
+#define CONTEXT_Dr0 CONTEXT_EFlags+4
+#define CONTEXT_Dr1 CONTEXT_Dr0+8
+#define CONTEXT_Dr2 CONTEXT_Dr1+8
+#define CONTEXT_Dr3 CONTEXT_Dr2+8
+#define CONTEXT_Dr6 CONTEXT_Dr3+8
+#define CONTEXT_Dr7 CONTEXT_Dr6+8
+#define CONTEXT_Rax CONTEXT_Dr7+8
+#define CONTEXT_Rcx CONTEXT_Rax+8
+#define CONTEXT_Rdx CONTEXT_Rcx+8
+#define CONTEXT_Rbx CONTEXT_Rdx+8
+#define CONTEXT_Rsp CONTEXT_Rbx+8
+#define CONTEXT_Rbp CONTEXT_Rsp+8
+#define CONTEXT_Rsi CONTEXT_Rbp+8
+#define CONTEXT_Rdi CONTEXT_Rsi+8
+#define CONTEXT_R8 CONTEXT_Rdi+8
+#define CONTEXT_R9 CONTEXT_R8+8
+#define CONTEXT_R10 CONTEXT_R9+8
+#define CONTEXT_R11 CONTEXT_R10+8
+#define CONTEXT_R12 CONTEXT_R11+8
+#define CONTEXT_R13 CONTEXT_R12+8
+#define CONTEXT_R14 CONTEXT_R13+8
+#define CONTEXT_R15 CONTEXT_R14+8
+#define CONTEXT_Rip CONTEXT_R15+8
+#define CONTEXT_FltSave CONTEXT_Rip+8
+#define FLOATING_SAVE_AREA_SIZE 4*8+24*16+96
+#define CONTEXT_Xmm0 CONTEXT_FltSave+FLOATING_SAVE_AREA_SIZE // was 10*16
+#define CONTEXT_Xmm1 CONTEXT_Xmm0+16
+#define CONTEXT_Xmm2 CONTEXT_Xmm1+16
+#define CONTEXT_Xmm3 CONTEXT_Xmm2+16
+#define CONTEXT_Xmm4 CONTEXT_Xmm3+16
+#define CONTEXT_Xmm5 CONTEXT_Xmm4+16
+#define CONTEXT_Xmm6 CONTEXT_Xmm5+16
+#define CONTEXT_Xmm7 CONTEXT_Xmm6+16
+#define CONTEXT_Xmm8 CONTEXT_Xmm7+16
+#define CONTEXT_Xmm9 CONTEXT_Xmm8+16
+#define CONTEXT_Xmm10 CONTEXT_Xmm9+16
+#define CONTEXT_Xmm11 CONTEXT_Xmm10+16
+#define CONTEXT_Xmm12 CONTEXT_Xmm11+16
+#define CONTEXT_Xmm13 CONTEXT_Xmm12+16
+#define CONTEXT_Xmm14 CONTEXT_Xmm13+16
+#define CONTEXT_Xmm15 CONTEXT_Xmm14+16
+#define CONTEXT_VectorRegister CONTEXT_Xmm15+16
+#define CONTEXT_VectorControl CONTEXT_VectorRegister+16*26
+#define CONTEXT_DebugControl CONTEXT_VectorControl+8
+#define CONTEXT_LastBranchToRip CONTEXT_DebugControl+8
+#define CONTEXT_LastBranchFromRip CONTEXT_LastBranchToRip+8
+#define CONTEXT_LastExceptionToRip CONTEXT_LastBranchFromRip+8
+#define CONTEXT_LastExceptionFromRip CONTEXT_LastExceptionToRip+8
+#define CONTEXT_Size CONTEXT_LastExceptionFromRip+8
+
+#else // BIT64
+
+#define CONTEXT_ContextFlags 0
+#define CONTEXT_FLOATING_POINT 8
+#define CONTEXT_FloatSave 7*4
+#define FLOATING_SAVE_AREA_SIZE 8*4+80
+#define CONTEXT_Edi CONTEXT_FloatSave + FLOATING_SAVE_AREA_SIZE + 4*4
+#define CONTEXT_Esi CONTEXT_Edi+4
+#define CONTEXT_Ebx CONTEXT_Esi+4
+#define CONTEXT_Edx CONTEXT_Ebx+4
+#define CONTEXT_Ecx CONTEXT_Edx+4
+#define CONTEXT_Eax CONTEXT_Ecx+4
+#define CONTEXT_Ebp CONTEXT_Eax+4
+#define CONTEXT_Eip CONTEXT_Ebp+4
+#define CONTEXT_SegCs CONTEXT_Eip+4
+#define CONTEXT_EFlags CONTEXT_SegCs+4
+#define CONTEXT_Esp CONTEXT_EFlags+4
+#define CONTEXT_SegSs CONTEXT_Esp+4
+#define CONTEXT_EXTENDED_REGISTERS 32
+#define CONTEXT_ExtendedRegisters CONTEXT_SegSs+4
+#define CONTEXT_Xmm0 CONTEXT_ExtendedRegisters+160
+#define CONTEXT_Xmm1 CONTEXT_Xmm0+16
+#define CONTEXT_Xmm2 CONTEXT_Xmm1+16
+#define CONTEXT_Xmm3 CONTEXT_Xmm2+16
+#define CONTEXT_Xmm4 CONTEXT_Xmm3+16
+#define CONTEXT_Xmm5 CONTEXT_Xmm4+16
+#define CONTEXT_Xmm6 CONTEXT_Xmm5+16
+#define CONTEXT_Xmm7 CONTEXT_Xmm6+16
+
+#endif // BIT64

src/pal/src/arch/i386/context2.S

@@ -10,76 +10,10 @@
 
 .intel_syntax noprefix
 #include "unixasmmacros.inc"
+#include "asmconstants.h"
 
 #ifdef BIT64
 
-#define CONTEXT_AMD64   0x100000
-
-#define CONTEXT_CONTROL 1 // SegSs, Rsp, SegCs, Rip, and EFlags
-#define CONTEXT_INTEGER 2 // Rax, Rcx, Rdx, Rbx, Rbp, Rsi, Rdi, R8-R15
-#define CONTEXT_SEGMENTS 4 // SegDs, SegEs, SegFs, SegGs
-#define CONTEXT_FLOATING_POINT 8
-#define CONTEXT_DEBUG_REGISTERS 16 // Dr0-Dr3 and Dr6-Dr7
-
-#define CONTEXT_FULL (CONTEXT_CONTROL | CONTEXT_INTEGER | CONTEXT_FLOATING_POINT)
-
-#define CONTEXT_ContextFlags 6*8
-#define CONTEXT_SegCs CONTEXT_ContextFlags+8
-#define CONTEXT_SegDs CONTEXT_SegCs+2
-#define CONTEXT_SegEs CONTEXT_SegDs+2
-#define CONTEXT_SegFs CONTEXT_SegEs+2
-#define CONTEXT_SegGs CONTEXT_SegFs+2
-#define CONTEXT_SegSs CONTEXT_SegGs+2
-#define CONTEXT_EFlags CONTEXT_SegSs+2
-#define CONTEXT_Dr0 CONTEXT_EFlags+4
-#define CONTEXT_Dr1 CONTEXT_Dr0+8
-#define CONTEXT_Dr2 CONTEXT_Dr1+8
-#define CONTEXT_Dr3 CONTEXT_Dr2+8
-#define CONTEXT_Dr6 CONTEXT_Dr3+8
-#define CONTEXT_Dr7 CONTEXT_Dr6+8
-#define CONTEXT_Rax CONTEXT_Dr7+8
-#define CONTEXT_Rcx CONTEXT_Rax+8
-#define CONTEXT_Rdx CONTEXT_Rcx+8
-#define CONTEXT_Rbx CONTEXT_Rdx+8
-#define CONTEXT_Rsp CONTEXT_Rbx+8
-#define CONTEXT_Rbp CONTEXT_Rsp+8
-#define CONTEXT_Rsi CONTEXT_Rbp+8
-#define CONTEXT_Rdi CONTEXT_Rsi+8
-#define CONTEXT_R8 CONTEXT_Rdi+8
-#define CONTEXT_R9 CONTEXT_R8+8
-#define CONTEXT_R10 CONTEXT_R9+8
-#define CONTEXT_R11 CONTEXT_R10+8
-#define CONTEXT_R12 CONTEXT_R11+8
-#define CONTEXT_R13 CONTEXT_R12+8
-#define CONTEXT_R14 CONTEXT_R13+8
-#define CONTEXT_R15 CONTEXT_R14+8
-#define CONTEXT_Rip CONTEXT_R15+8
-#define CONTEXT_FltSave CONTEXT_Rip+8
-#define FLOATING_SAVE_AREA_SIZE 4*8+24*16+96
-#define CONTEXT_Xmm0 CONTEXT_FltSave+10*16
-#define CONTEXT_Xmm1 CONTEXT_Xmm0+16
-#define CONTEXT_Xmm2 CONTEXT_Xmm1+16
-#define CONTEXT_Xmm3 CONTEXT_Xmm2+16
-#define CONTEXT_Xmm4 CONTEXT_Xmm3+16
-#define CONTEXT_Xmm5 CONTEXT_Xmm4+16
-#define CONTEXT_Xmm6 CONTEXT_Xmm5+16
-#define CONTEXT_Xmm7 CONTEXT_Xmm6+16
-#define CONTEXT_Xmm8 CONTEXT_Xmm7+16
-#define CONTEXT_Xmm9 CONTEXT_Xmm8+16
-#define CONTEXT_Xmm10 CONTEXT_Xmm9+16
-#define CONTEXT_Xmm11 CONTEXT_Xmm10+16
-#define CONTEXT_Xmm12 CONTEXT_Xmm11+16
-#define CONTEXT_Xmm13 CONTEXT_Xmm12+16
-#define CONTEXT_Xmm14 CONTEXT_Xmm13+16
-#define CONTEXT_Xmm15 CONTEXT_Xmm14+16
-#define CONTEXT_VectorRegister CONTEXT_Xmm15+16
-#define CONTEXT_VectorControl CONTEXT_VectorRegister+16*26
-#define CONTEXT_DebugControl CONTEXT_VectorControl+8
-#define CONTEXT_LastBranchToRip CONTEXT_DebugControl+8
-#define CONTEXT_LastBranchFromRip CONTEXT_LastBranchToRip+8
-#define CONTEXT_LastExceptionToRip CONTEXT_LastBranchFromRip+8
-#define CONTEXT_LastExceptionFromRip CONTEXT_LastExceptionToRip+8
-
 #define IRETFRAME_Rip 0
 #define IRETFRAME_SegCs IRETFRAME_Rip+8
 #define IRETFRAME_EFlags IRETFRAME_SegCs+8
@@ -198,7 +132,16 @@ LOCAL_LABEL(Done_Restore_CONTEXT_FLOATING_POINT):
 
     // The control registers are restored via the iret instruction
     // so we build the frame for the iret on the stack.
+#ifdef __APPLE__
+.att_syntax 
+    // On OSX, we cannot read SS via the thread_get_context and RtlRestoreContext
+    // needs to be used on context extracted by thread_get_context. So we 
+    // don't change the SS.
+    mov     %ss, %ax
+.intel_syntax noprefix
+#else    
     mov     ax, [rdi + CONTEXT_SegSs]
+#endif    
     mov     [rsp + IRETFRAME_SegSs], ax
     mov     rax, [rdi + CONTEXT_Rsp]
     mov     [rsp + IRETFRAME_Rsp], rax
@@ -249,33 +192,6 @@ LEAF_END RtlRestoreContext, _TEXT
 
 #else
 
-#define CONTEXT_ContextFlags 0
-#define CONTEXT_FLOATING_POINT 8
-#define CONTEXT_FloatSave 7*4
-#define FLOATING_SAVE_AREA_SIZE 8*4+80
-#define CONTEXT_Edi CONTEXT_FloatSave + FLOATING_SAVE_AREA_SIZE + 4*4
-#define CONTEXT_Esi CONTEXT_Edi+4
-#define CONTEXT_Ebx CONTEXT_Esi+4
-#define CONTEXT_Edx CONTEXT_Ebx+4
-#define CONTEXT_Ecx CONTEXT_Edx+4
-#define CONTEXT_Eax CONTEXT_Ecx+4
-#define CONTEXT_Ebp CONTEXT_Eax+4
-#define CONTEXT_Eip CONTEXT_Ebp+4
-#define CONTEXT_SegCs CONTEXT_Eip+4
-#define CONTEXT_EFlags CONTEXT_SegCs+4
-#define CONTEXT_Esp CONTEXT_EFlags+4
-#define CONTEXT_SegSs CONTEXT_Esp+4
-#define CONTEXT_EXTENDED_REGISTERS 32
-#define CONTEXT_ExtendedRegisters CONTEXT_SegSs+4
-#define CONTEXT_Xmm0 CONTEXT_ExtendedRegisters+160
-#define CONTEXT_Xmm1 CONTEXT_Xmm0+16
-#define CONTEXT_Xmm2 CONTEXT_Xmm1+16
-#define CONTEXT_Xmm3 CONTEXT_Xmm2+16
-#define CONTEXT_Xmm4 CONTEXT_Xmm3+16
-#define CONTEXT_Xmm5 CONTEXT_Xmm4+16
-#define CONTEXT_Xmm6 CONTEXT_Xmm5+16
-#define CONTEXT_Xmm7 CONTEXT_Xmm6+16
-
     .globl C_FUNC(CONTEXT_CaptureContext)
 C_FUNC(CONTEXT_CaptureContext):
     push %eax