From 5a63edf27896c8aee411bb17d322ce6f247eddce Mon Sep 17 00:00:00 2001
From: Slava Pestov <slava@slava-pestovs-macbook-pro.local>
Date: Thu, 22 Oct 2009 05:22:59 -0500
Subject: [PATCH] vm: clean up signal handling and add EXC_BAD_INSTRUCTION Mach
 exception handler for OS X, since signal handlers cannot change the stack
 pointer

---
 vm/mach_signal.cpp       | 12 ++++++--
 vm/os-freebsd-x86.32.hpp | 10 ++-----
 vm/os-freebsd-x86.64.hpp | 10 ++-----
 vm/os-genunix.hpp        |  5 ++++
 vm/os-linux-arm.hpp      | 12 ++------
 vm/os-linux-ppc.hpp      | 11 ++-----
 vm/os-linux-x86.32.hpp   | 11 ++-----
 vm/os-linux-x86.64.hpp   | 10 ++-----
 vm/os-macosx-ppc.hpp     |  2 +-
 vm/os-macosx-x86.32.hpp  |  2 +-
 vm/os-macosx-x86.64.hpp  |  2 +-
 vm/os-macosx.hpp         |  8 ++----
 vm/os-netbsd-x86.32.hpp  |  6 ++--
 vm/os-netbsd-x86.64.hpp  |  7 ++---
 vm/os-openbsd-x86.32.hpp | 14 +++------
 vm/os-openbsd-x86.64.hpp | 14 +++------
 vm/os-solaris-x86.32.hpp | 10 ++-----
 vm/os-solaris-x86.64.hpp | 10 ++-----
 vm/os-unix.cpp           | 62 +++++++++++++++-------------------------
 vm/vm.hpp                | 11 ++-----
 20 files changed, 79 insertions(+), 150 deletions(-)

diff --git a/vm/mach_signal.cpp b/vm/mach_signal.cpp
index 2d76b12c38..d05942ff7e 100644
--- a/vm/mach_signal.cpp
+++ b/vm/mach_signal.cpp
@@ -47,7 +47,7 @@ void factor_vm::call_fault_handler(
 	else
 		signal_callstack_top = NULL;
 
-	MACH_STACK_POINTER(thread_state) = fix_stack_pointer(MACH_STACK_POINTER(thread_state));
+	MACH_STACK_POINTER(thread_state) = align_stack_pointer(MACH_STACK_POINTER(thread_state));
 
 	/* Now we point the program counter at the right handler function. */
 	if(exception == EXC_BAD_ACCESS)
@@ -63,7 +63,13 @@ void factor_vm::call_fault_handler(
 	}
 	else
 	{
-		signal_number = (exception == EXC_ARITHMETIC ? SIGFPE : SIGABRT);
+		switch(exception)
+		{
+		case EXC_ARITHMETIC: signal_number = SIGFPE; break;
+		case EXC_BAD_INSTRUCTION: signal_number = SIGILL; break;
+		default: signal_number = SIGABRT; break;
+		}
+
 		MACH_PROGRAM_COUNTER(thread_state) = (cell)factor::misc_signal_handler_impl;
 	}
 }
@@ -226,7 +232,7 @@ void mach_initialize ()
 		fatal_error("mach_port_insert_right() failed",0);
 
 	/* The exceptions we want to catch. */
-	mask = EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC;
+	mask = EXC_MASK_BAD_ACCESS | EXC_MASK_BAD_INSTRUCTION | EXC_MASK_ARITHMETIC;
 
 	/* Create the thread listening on the exception port.  */
 	start_thread(mach_exception_thread,NULL);
diff --git a/vm/os-freebsd-x86.32.hpp b/vm/os-freebsd-x86.32.hpp
index e682fec13c..5ed5cf0e81 100644
--- a/vm/os-freebsd-x86.32.hpp
+++ b/vm/os-freebsd-x86.32.hpp
@@ -4,12 +4,6 @@
 namespace factor
 {
 
-inline static void *ucontext_stack_pointer(void *uap)
-{
-        ucontext_t *ucontext = (ucontext_t *)uap;
-        return (void *)ucontext->uc_mcontext.mc_esp;
-}
-
 inline static unsigned int uap_fpu_status(void *uap)
 {
         ucontext_t *ucontext = (ucontext_t *)uap;
@@ -43,6 +37,8 @@ inline static void uap_clear_fpu_status(void *uap)
         }
 }
 
-#define UAP_PROGRAM_COUNTER(ucontext) (((ucontext_t *)(ucontext))->uc_mcontext.mc_eip)
+
+#define UAP_STACK_POINTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.mc_esp)
+#define UAP_PROGRAM_COUNTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.mc_eip)
 
 }
diff --git a/vm/os-freebsd-x86.64.hpp b/vm/os-freebsd-x86.64.hpp
index 8f8d218a10..02f7fb3ad2 100644
--- a/vm/os-freebsd-x86.64.hpp
+++ b/vm/os-freebsd-x86.64.hpp
@@ -4,12 +4,6 @@
 namespace factor
 {
 
-inline static void *ucontext_stack_pointer(void *uap)
-{
-        ucontext_t *ucontext = (ucontext_t *)uap;
-        return (void *)ucontext->uc_mcontext.mc_rsp;
-}
-
 inline static unsigned int uap_fpu_status(void *uap)
 {
         ucontext_t *ucontext = (ucontext_t *)uap;
@@ -33,6 +27,8 @@ inline static void uap_clear_fpu_status(void *uap)
         }
 }
 
-#define UAP_PROGRAM_COUNTER(ucontext) (((ucontext_t *)(ucontext))->uc_mcontext.mc_rip)
+
+#define UAP_STACK_POINTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.mc_rsp)
+#define UAP_PROGRAM_COUNTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.mc_rip)
 
 }
diff --git a/vm/os-genunix.hpp b/vm/os-genunix.hpp
index 1972a728e6..626d399a27 100644
--- a/vm/os-genunix.hpp
+++ b/vm/os-genunix.hpp
@@ -10,4 +10,9 @@ void early_init();
 const char *vm_executable_path();
 const char *default_image_path();
 
+inline static cell align_stack_pointer(cell sp)
+{
+	return sp;
+}
+
 }
diff --git a/vm/os-linux-arm.hpp b/vm/os-linux-arm.hpp
index 70c3eb3ff6..3af92fda99 100644
--- a/vm/os-linux-arm.hpp
+++ b/vm/os-linux-arm.hpp
@@ -5,15 +5,9 @@
 namespace factor
 {
 
-inline static void *ucontext_stack_pointer(void *uap)
-{
-	ucontext_t *ucontext = (ucontext_t *)uap;
-	return (void *)ucontext->uc_mcontext.arm_sp;
-}
-
-#define UAP_PROGRAM_COUNTER(ucontext) \
-	(((ucontext_t *)(ucontext))->uc_mcontext.arm_pc)
-
 void flush_icache(cell start, cell len);
 
+#define UAP_STACK_POINTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.arm_sp)
+#define UAP_PROGRAM_COUNTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.arm_pc)
+
 }
diff --git a/vm/os-linux-ppc.hpp b/vm/os-linux-ppc.hpp
index 62671e5ded..51e017bdad 100644
--- a/vm/os-linux-ppc.hpp
+++ b/vm/os-linux-ppc.hpp
@@ -4,14 +4,7 @@ namespace factor
 {
 
 #define FRAME_RETURN_ADDRESS(frame,vm) *((void **)(vm->frame_successor(frame) + 1) + 1)
-
-inline static void *ucontext_stack_pointer(void *uap)
-{
-        ucontext_t *ucontext = (ucontext_t *)uap;
-        return (void *)ucontext->uc_mcontext.uc_regs->gregs[PT_R1];
-}
-
-#define UAP_PROGRAM_COUNTER(ucontext) \
-	(((ucontext_t *)(ucontext))->uc_mcontext.uc_regs->gregs[PT_NIP])
+#define UAP_STACK_POINTER(ucontext) ((ucontext_t *)ucontext)->uc_mcontext.uc_regs->gregs[PT_R1]
+#define UAP_PROGRAM_COUNTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.uc_regs->gregs[PT_NIP])
 
 }
diff --git a/vm/os-linux-x86.32.hpp b/vm/os-linux-x86.32.hpp
index bd2315ccef..53a93d17de 100644
--- a/vm/os-linux-x86.32.hpp
+++ b/vm/os-linux-x86.32.hpp
@@ -29,12 +29,6 @@ struct _fpstate {
 
 #define X86_FXSR_MAGIC          0x0000
 
-inline static void *ucontext_stack_pointer(void *uap)
-{
-	ucontext_t *ucontext = (ucontext_t *)uap;
-	return (void *)ucontext->uc_mcontext.gregs[7];
-}
-
 inline static unsigned int uap_fpu_status(void *uap)
 {
 	ucontext_t *ucontext = (ucontext_t *)uap;
@@ -54,7 +48,8 @@ inline static void uap_clear_fpu_status(void *uap)
 	    fpregs->mxcsr &= 0xffffffc0;
 }
 
-#define UAP_PROGRAM_COUNTER(ucontext) \
-	(((ucontext_t *)(ucontext))->uc_mcontext.gregs[14])
+
+#define UAP_STACK_POINTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.gregs[7])
+#define UAP_PROGRAM_COUNTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.gregs[14])
 
 }
diff --git a/vm/os-linux-x86.64.hpp b/vm/os-linux-x86.64.hpp
index 42adb3c6b8..14ba9fb002 100644
--- a/vm/os-linux-x86.64.hpp
+++ b/vm/os-linux-x86.64.hpp
@@ -3,12 +3,6 @@
 namespace factor
 {
 
-inline static void *ucontext_stack_pointer(void *uap)
-{
-        ucontext_t *ucontext = (ucontext_t *)uap;
-        return (void *)ucontext->uc_mcontext.gregs[15];
-}
-
 inline static unsigned int uap_fpu_status(void *uap)
 {
         ucontext_t *ucontext = (ucontext_t *)uap;
@@ -23,7 +17,7 @@ inline static void uap_clear_fpu_status(void *uap)
         ucontext->uc_mcontext.fpregs->mxcsr &= 0xffffffc0;
 }
 
-#define UAP_PROGRAM_COUNTER(ucontext) \
-	(((ucontext_t *)(ucontext))->uc_mcontext.gregs[16])
+#define UAP_STACK_POINTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.gregs[15])
+#define UAP_PROGRAM_COUNTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.gregs[16])
 
 }
diff --git a/vm/os-macosx-ppc.hpp b/vm/os-macosx-ppc.hpp
index 2bea926890..70fa18142a 100644
--- a/vm/os-macosx-ppc.hpp
+++ b/vm/os-macosx-ppc.hpp
@@ -62,7 +62,7 @@ inline static unsigned int uap_fpu_status(void *uap)
 	return mach_fpu_status(UAP_FS(uap));
 }
 
-inline static cell fix_stack_pointer(cell sp)
+inline static cell align_stack_pointer(cell sp)
 {
 	return sp;
 }
diff --git a/vm/os-macosx-x86.32.hpp b/vm/os-macosx-x86.32.hpp
index 89906cd9a4..4bdc68ff72 100644
--- a/vm/os-macosx-x86.32.hpp
+++ b/vm/os-macosx-x86.32.hpp
@@ -64,7 +64,7 @@ inline static unsigned int uap_fpu_status(void *uap)
 	return mach_fpu_status(UAP_FS(uap));
 }
 
-inline static cell fix_stack_pointer(cell sp)
+inline static cell align_stack_pointer(cell sp)
 {
 	return ((sp + 4) & ~15) - 4;
 }
diff --git a/vm/os-macosx-x86.64.hpp b/vm/os-macosx-x86.64.hpp
index fd6db4d68c..b923674cd1 100644
--- a/vm/os-macosx-x86.64.hpp
+++ b/vm/os-macosx-x86.64.hpp
@@ -62,7 +62,7 @@ inline static unsigned int uap_fpu_status(void *uap)
 	return mach_fpu_status(UAP_FS(uap));
 }
 
-inline static cell fix_stack_pointer(cell sp)
+inline static cell align_stack_pointer(cell sp)
 {
 	return ((sp + 8) & ~15) - 8;
 }
diff --git a/vm/os-macosx.hpp b/vm/os-macosx.hpp
index cdc0ff7b42..0d230f48e3 100644
--- a/vm/os-macosx.hpp
+++ b/vm/os-macosx.hpp
@@ -11,12 +11,8 @@ void early_init();
 const char *vm_executable_path();
 const char *default_image_path();
 
-inline static void *ucontext_stack_pointer(void *uap)
-{
-	ucontext_t *ucontext = (ucontext_t *)uap;
-	return ucontext->uc_stack.ss_sp;
-}
-
 void c_to_factor_toplevel(cell quot);
 
+#define UAP_STACK_POINTER(ucontext) (((ucontext_t *)ucontext)->uc_stack.ss_sp)
+
 }
diff --git a/vm/os-netbsd-x86.32.hpp b/vm/os-netbsd-x86.32.hpp
index f2f47ecf6c..21b3557239 100644
--- a/vm/os-netbsd-x86.32.hpp
+++ b/vm/os-netbsd-x86.32.hpp
@@ -3,9 +3,9 @@
 namespace factor
 {
 
-#define ucontext_stack_pointer(uap) ((void *)_UC_MACHINE_SP((ucontext_t *)uap))
-
 static inline unsigned int uap_fpu_status(void *uap) { return 0; }
-static inline void uap_clear_fpu_status(void *uap) {  }
+static inline void uap_clear_fpu_status(void *uap) {}
+
+#define UAP_STACK_POINTER(ucontext) (_UC_MACHINE_SP((ucontext_t *)ucontext))
 
 }
diff --git a/vm/os-netbsd-x86.64.hpp b/vm/os-netbsd-x86.64.hpp
index a9d52a6c2b..3e94998993 100644
--- a/vm/os-netbsd-x86.64.hpp
+++ b/vm/os-netbsd-x86.64.hpp
@@ -3,10 +3,9 @@
 namespace factor
 {
 
-#define ucontext_stack_pointer(uap) \
-	((void *)(((ucontext_t *)(uap))->uc_mcontext.__gregs[_REG_URSP]))
-
 static inline unsigned int uap_fpu_status(void *uap) { return 0; }
-static inline void uap_clear_fpu_status(void *uap) {  }
+static inline void uap_clear_fpu_status(void *uap) {}
+
+#define UAP_STACK_POINTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.__gregs[_REG_URSP])
 
 }
diff --git a/vm/os-openbsd-x86.32.hpp b/vm/os-openbsd-x86.32.hpp
index 0abd019219..34a641c235 100644
--- a/vm/os-openbsd-x86.32.hpp
+++ b/vm/os-openbsd-x86.32.hpp
@@ -3,16 +3,10 @@
 namespace factor
 {
 
-inline static void *openbsd_stack_pointer(void *uap)
-{
-	struct sigcontext *sc = (struct sigcontext*) uap;
-	return (void *)sc->sc_esp;
-}
-
-#define ucontext_stack_pointer openbsd_stack_pointer
-#define UAP_PROGRAM_COUNTER(uap) (((struct sigcontext*)(uap))->sc_eip)
-
 static inline unsigned int uap_fpu_status(void *uap) { return 0; }
-static inline void uap_clear_fpu_status(void *uap) {  }
+static inline void uap_clear_fpu_status(void *uap) {}
+
+#define UAP_STACK_POINTER(ucontext) (((struct sigcontext *)ucontext)->sc_esp)
+#define UAP_PROGRAM_COUNTER(ucontext) (((struct sigcontext *)ucontext)->sc_eip)
 
 }
diff --git a/vm/os-openbsd-x86.64.hpp b/vm/os-openbsd-x86.64.hpp
index 9dce48ee91..032e77b154 100644
--- a/vm/os-openbsd-x86.64.hpp
+++ b/vm/os-openbsd-x86.64.hpp
@@ -3,16 +3,10 @@
 namespace factor
 {
 
-inline static void *openbsd_stack_pointer(void *uap)
-{
-	struct sigcontext *sc = (struct sigcontext*) uap;
-	return (void *)sc->sc_rsp;
-}
-
-#define ucontext_stack_pointer openbsd_stack_pointer
-#define UAP_PROGRAM_COUNTER(uap) (((struct sigcontext*)(uap))->sc_rip)
-
 static inline unsigned int uap_fpu_status(void *uap) { return 0; }
-static inline void uap_clear_fpu_status(void *uap) {  }
+static inline void uap_clear_fpu_status(void *uap) {}
+
+#define UAP_STACK_POINTER(ucontext) (((struct sigcontext *)ucontext)->sc_rsp)
+#define UAP_PROGRAM_COUNTER(ucontext) (((struct sigcontext *)ucontext)->sc_rip)
 
 }
diff --git a/vm/os-solaris-x86.32.hpp b/vm/os-solaris-x86.32.hpp
index b89b8d541b..2ec8bc138f 100644
--- a/vm/os-solaris-x86.32.hpp
+++ b/vm/os-solaris-x86.32.hpp
@@ -3,13 +3,7 @@
 namespace factor
 {
 
-inline static void *ucontext_stack_pointer(void *uap)
-{
-        ucontext_t *ucontext = (ucontext_t *)uap;
-        return (void *)ucontext->uc_mcontext.gregs[ESP];
-}
-
-#define UAP_PROGRAM_COUNTER(ucontext) \
-	(((ucontext_t *)(ucontext))->uc_mcontext.gregs[EIP])
+#define UAP_STACK_POINTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.gregs[ESP])
+#define UAP_PROGRAM_COUNTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.gregs[EIP])
 
 }
diff --git a/vm/os-solaris-x86.64.hpp b/vm/os-solaris-x86.64.hpp
index 0d3a74e11d..72a7b5c2fd 100644
--- a/vm/os-solaris-x86.64.hpp
+++ b/vm/os-solaris-x86.64.hpp
@@ -3,13 +3,7 @@
 namespace factor
 {
 
-inline static void *ucontext_stack_pointer(void *uap)
-{
-        ucontext_t *ucontext = (ucontext_t *)uap;
-        return (void *)ucontext->uc_mcontext.gregs[RSP];
-}
-
-#define UAP_PROGRAM_COUNTER(ucontext) \
-	(((ucontext_t *)(ucontext))->uc_mcontext.gregs[RIP])
+#define UAP_STACK_POINTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.gregs[RSP])
+#define UAP_PROGRAM_COUNTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.gregs[RIP])
 
 }
diff --git a/vm/os-unix.cpp b/vm/os-unix.cpp
index 2f9d5a3c89..0f2570b183 100644
--- a/vm/os-unix.cpp
+++ b/vm/os-unix.cpp
@@ -115,63 +115,47 @@ segment::~segment()
 	if(retval)
 		fatal_error("Segment deallocation failed",0);
 }
-  
-stack_frame *factor_vm::uap_stack_pointer(void *uap)
+
+void factor_vm::dispatch_signal(void *uap, void (handler)())
 {
-	/* There is a race condition here, but in practice a signal
-	delivered during stack frame setup/teardown or while transitioning
-	from Factor to C is a sign of things seriously gone wrong, not just
-	a divide by zero or stack underflow in the listener */
 	if(in_code_heap_p(UAP_PROGRAM_COUNTER(uap)))
 	{
-		stack_frame *ptr = (stack_frame *)ucontext_stack_pointer(uap);
-		if(!ptr)
-			critical_error("Invalid uap",(cell)uap);
-		return ptr;
+		stack_frame *ptr = (stack_frame *)UAP_STACK_POINTER(uap);
+		assert(ptr);
+		signal_callstack_top = ptr;
 	}
 	else
-		return NULL;
-}
+		signal_callstack_top = NULL;
 
-void factor_vm::memory_signal_handler(int signal, siginfo_t *siginfo, void *uap)
-{
-	signal_fault_addr = (cell)siginfo->si_addr;
-	signal_callstack_top = uap_stack_pointer(uap);
-	UAP_PROGRAM_COUNTER(uap) = (cell)factor::memory_signal_handler_impl;
+	UAP_STACK_POINTER(uap) = (void *)align_stack_pointer((cell)UAP_STACK_POINTER(uap));
+	UAP_PROGRAM_COUNTER(uap) = (cell)handler;
 }
 
 void memory_signal_handler(int signal, siginfo_t *siginfo, void *uap)
 {
-	tls_vm()->memory_signal_handler(signal,siginfo,uap);
-}
-
-void factor_vm::misc_signal_handler(int signal, siginfo_t *siginfo, void *uap)
-{
-	signal_number = signal;
-	signal_callstack_top = uap_stack_pointer(uap);
-	UAP_PROGRAM_COUNTER(uap) = (cell)factor::misc_signal_handler_impl;
+	factor_vm *vm = tls_vm();
+	vm->signal_fault_addr = (cell)siginfo->si_addr;
+	vm->dispatch_signal(uap,factor::memory_signal_handler_impl);
 }
 
 void misc_signal_handler(int signal, siginfo_t *siginfo, void *uap)
 {
-	tls_vm()->misc_signal_handler(signal,siginfo,uap);
-}
-
-void factor_vm::fpe_signal_handler(int signal, siginfo_t *siginfo, void *uap)
-{
-	signal_number = signal;
-	signal_callstack_top = uap_stack_pointer(uap);
-	signal_fpu_status = fpu_status(uap_fpu_status(uap));
-	uap_clear_fpu_status(uap);
-	UAP_PROGRAM_COUNTER(uap) =
-		(siginfo->si_code == FPE_INTDIV || siginfo->si_code == FPE_INTOVF)
-		? (cell)factor::misc_signal_handler_impl
-		: (cell)factor::fp_signal_handler_impl;
+	factor_vm *vm = tls_vm();
+	vm->signal_number = signal;
+	vm->dispatch_signal(uap,factor::misc_signal_handler_impl);
 }
 
 void fpe_signal_handler(int signal, siginfo_t *siginfo, void *uap)
 {
-	tls_vm()->fpe_signal_handler(signal, siginfo, uap);
+	factor_vm *vm = tls_vm();
+	vm->signal_number = signal;
+	vm->signal_fpu_status = fpu_status(uap_fpu_status(uap));
+	uap_clear_fpu_status(uap);
+
+	vm->dispatch_signal(uap,
+		(siginfo->si_code == FPE_INTDIV || siginfo->si_code == FPE_INTOVF)
+		? factor::misc_signal_handler_impl
+		: factor::fp_signal_handler_impl);
 }
 
 static void sigaction_safe(int signum, const struct sigaction *act, struct sigaction *oldact)
diff --git a/vm/vm.hpp b/vm/vm.hpp
index 202996ce26..4b115ecd3f 100755
--- a/vm/vm.hpp
+++ b/vm/vm.hpp
@@ -689,17 +689,12 @@ struct factor_vm
 	void windows_image_path(vm_char *full_path, vm_char *temp_path, unsigned int length);
 	bool windows_stat(vm_char *path);
 
-   #if defined(WINNT)
+  #if defined(WINNT)
 	void open_console();
 	LONG exception_handler(PEXCEPTION_POINTERS pe);
- 	// next method here:
-   #endif
+  #endif
   #else  // UNIX
-	void memory_signal_handler(int signal, siginfo_t *siginfo, void *uap);
-	void misc_signal_handler(int signal, siginfo_t *siginfo, void *uap);
-	void fpe_signal_handler(int signal, siginfo_t *siginfo, void *uap);
-	stack_frame *uap_stack_pointer(void *uap);
-
+	void factor_vm::dispatch_signal(void *uap, void (handler)());
   #endif
 
   #ifdef __APPLE__