From 206daeabdae89fa8c405b426fc1359d779ce87bb Mon Sep 17 00:00:00 2001
From: Robert Griesemer <gri@golang.org>
Date: Tue, 24 Jun 2008 16:48:54 -0700
Subject: [PATCH] - added access to thread state info from the signal handler

SVN=124404
---
 src/runtime/rt1_amd64_darwin.c | 120 ++++++++++++++++++++++++++++-----
 1 file changed, 105 insertions(+), 15 deletions(-)

diff --git a/src/runtime/rt1_amd64_darwin.c b/src/runtime/rt1_amd64_darwin.c
index 94d27ee70e..f9bc30570d 100644
--- a/src/runtime/rt1_amd64_darwin.c
+++ b/src/runtime/rt1_amd64_darwin.c
@@ -5,6 +5,99 @@
 #include "runtime.h"
 #include "signals.h"
 
+
+typedef uint64 __uint64_t;
+
+// From /usr/include/mach/i386/_structs.h
+#define	_STRUCT_X86_THREAD_STATE64	struct __darwin_x86_thread_state64
+_STRUCT_X86_THREAD_STATE64
+{
+	__uint64_t	__rax;
+	__uint64_t	__rbx;
+	__uint64_t	__rcx;
+	__uint64_t	__rdx;
+	__uint64_t	__rdi;
+	__uint64_t	__rsi;
+	__uint64_t	__rbp;
+	__uint64_t	__rsp;
+	__uint64_t	__r8;
+	__uint64_t	__r9;
+	__uint64_t	__r10;
+	__uint64_t	__r11;
+	__uint64_t	__r12;
+	__uint64_t	__r13;
+	__uint64_t	__r14;
+	__uint64_t	__r15;
+	__uint64_t	__rip;
+	__uint64_t	__rflags;
+	__uint64_t	__cs;
+	__uint64_t	__fs;
+	__uint64_t	__gs;
+};
+
+
+void
+print_thread_state(_STRUCT_X86_THREAD_STATE64* ss)
+{
+	prints("\nrax     0x");  sys_printpointer((void*)ss->__rax);
+	prints("\nrbx     0x");  sys_printpointer((void*)ss->__rbx);
+	prints("\nrcx     0x");  sys_printpointer((void*)ss->__rcx);
+	prints("\nrdx     0x");  sys_printpointer((void*)ss->__rdx);
+	prints("\nrdi     0x");  sys_printpointer((void*)ss->__rdi);
+	prints("\nrsi     0x");  sys_printpointer((void*)ss->__rsi);
+	prints("\nrbp     0x");  sys_printpointer((void*)ss->__rbp);
+	prints("\nrsp     0x");  sys_printpointer((void*)ss->__rsp);
+	prints("\nr8      0x");  sys_printpointer((void*)ss->__r8 );
+	prints("\nr9      0x");  sys_printpointer((void*)ss->__r9 );
+	prints("\nr10     0x");  sys_printpointer((void*)ss->__r10);
+	prints("\nr11     0x");  sys_printpointer((void*)ss->__r11);
+	prints("\nr12     0x");  sys_printpointer((void*)ss->__r12);
+	prints("\nr13     0x");  sys_printpointer((void*)ss->__r13);
+	prints("\nr14     0x");  sys_printpointer((void*)ss->__r14);
+	prints("\nr15     0x");  sys_printpointer((void*)ss->__r15);
+	prints("\nrip     0x");  sys_printpointer((void*)ss->__rip);
+	prints("\nrflags  0x");  sys_printpointer((void*)ss->__rflags);
+	prints("\ncs      0x");  sys_printpointer((void*)ss->__cs);
+	prints("\nfs      0x");  sys_printpointer((void*)ss->__fs);
+	prints("\ngs      0x");  sys_printpointer((void*)ss->__gs);
+	prints("\n");
+}
+
+
+/* Code generated via: g++ -m64 signals.cc && a.out */
+
+static void *adr_at(void *ptr, int32 offs) {
+  return (void *)((uint8 *)ptr + offs);
+}
+
+static void *ptr_at(void *ptr, int32 offs) {
+  return *(void **)((uint8 *)ptr + offs);
+}
+
+typedef void ucontext_t;
+typedef void _STRUCT_MCONTEXT64;
+typedef void _STRUCT_X86_EXCEPTION_STATE64;
+typedef void _STRUCT_X86_FLOAT_STATE64;
+
+static _STRUCT_MCONTEXT64 *get_uc_mcontext(ucontext_t *ptr) {
+  return (_STRUCT_MCONTEXT64 *)ptr_at(ptr, 48);
+}
+
+static _STRUCT_X86_EXCEPTION_STATE64 *get___es(_STRUCT_MCONTEXT64 *ptr) {
+  return (_STRUCT_X86_EXCEPTION_STATE64 *)adr_at(ptr, 0);
+}
+
+static _STRUCT_X86_THREAD_STATE64 *get___ss(_STRUCT_MCONTEXT64 *ptr) {
+  return (_STRUCT_X86_THREAD_STATE64 *)adr_at(ptr, 16);
+}
+
+static _STRUCT_X86_FLOAT_STATE64 *get___fs(_STRUCT_MCONTEXT64 *ptr) {
+  return (_STRUCT_X86_FLOAT_STATE64 *)adr_at(ptr, 184);
+}
+
+/* End of generated code */
+
+
 /*
  * This assembler routine takes the args from registers, puts them on the stack,
  * and calls sighandler().
@@ -37,10 +130,8 @@ typedef struct  sigaction {
 } sigaction;
 
 void
-sighandler(int32 sig, siginfo* info, void** context) {
-	int32 i;
-	void *pc, *sp;
-
+sighandler(int32 sig, siginfo *info, void *context)
+{
 	if(sig < 0 || sig >= NSIG){
 		prints("Signal ");
 		sys_printint(sig);
@@ -48,17 +139,16 @@ sighandler(int32 sig, siginfo* info, void** context) {
 		prints(sigtab[sig].name);
 	}
 
-	prints("\nFaulting address: 0x");
-	sys_printpointer(info->si_addr);
-	prints("\nPC: 0x");
-	pc = ((void**)((&sig)+1))[22];
-	sys_printpointer(pc);
-	prints("\nSP: 0x");
-	sp = ((void**)((&sig)+1))[13];
-	sys_printpointer(sp);
-	prints("\n");
-	if (pc != 0 && sp != 0)
-		traceback(pc, sp);	/* empirically discovered locations */
+        _STRUCT_MCONTEXT64 *uc_mcontext = get_uc_mcontext(context);
+        _STRUCT_X86_THREAD_STATE64 *ss = get___ss(uc_mcontext);
+
+	prints("\nFaulting address: 0x");  sys_printpointer(info->si_addr);
+        prints("\npc: 0x");  sys_printpointer((void *)ss->__rip);
+        prints("\n\n");
+        
+	traceback((void *)ss->__rip, (void *)ss->__rsp);
+        print_thread_state(ss);
+        
 	sys_exit(2);
 }