runtime: Catch signals on altstack, disable splitstack signal blocking.

From-SVN: r182607

libgo/runtime/go-panic.c

@@ -24,13 +24,13 @@ __printpanics (struct __go_panic_stack *p)
   if (p->__next != NULL)
     {
       __printpanics (p->__next);
-      printf ("\t");
+      fprintf (stderr, "\t");
     }
-  printf ("panic: ");
+  fprintf (stderr, "panic: ");
   printany (p->__arg);
   if (p->__was_recovered)
-    printf (" [recovered]");
-  putchar ('\n');
+    fprintf (stderr, " [recovered]");
+  fputc ('\n', stderr);
 }
 
 /* This implements __go_panic which is used for the panic

libgo/runtime/mem.c

@@ -47,7 +47,7 @@ runtime_SysAlloc(uintptr n)
 	if (dev_zero == -1) {
 		dev_zero = open("/dev/zero", O_RDONLY);
 		if (dev_zero < 0) {
-			printf("open /dev/zero: errno=%d\n", errno);
+			runtime_printf("open /dev/zero: errno=%d\n", errno);
 			exit(2);
 		}
 	}
@@ -57,8 +57,8 @@ runtime_SysAlloc(uintptr n)
 	p = runtime_mmap(nil, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, fd, 0);
 	if (p == MAP_FAILED) {
 		if(errno == EACCES) {
-			printf("runtime: mmap: access denied\n");
-			printf("if you're running SELinux, enable execmem for this process.\n");
+			runtime_printf("runtime: mmap: access denied\n");
+			runtime_printf("if you're running SELinux, enable execmem for this process.\n");
 			exit(2);
 		}
 		return nil;
@@ -97,7 +97,7 @@ runtime_SysReserve(void *v, uintptr n)
 	if (dev_zero == -1) {
 		dev_zero = open("/dev/zero", O_RDONLY);
 		if (dev_zero < 0) {
-			printf("open /dev/zero: errno=%d\n", errno);
+			runtime_printf("open /dev/zero: errno=%d\n", errno);
 			exit(2);
 		}
 	}
@@ -123,7 +123,7 @@ runtime_SysMap(void *v, uintptr n)
 	if (dev_zero == -1) {
 		dev_zero = open("/dev/zero", O_RDONLY);
 		if (dev_zero < 0) {
-			printf("open /dev/zero: errno=%d\n", errno);
+			runtime_printf("open /dev/zero: errno=%d\n", errno);
 			exit(2);
 		}
 	}

libgo/runtime/proc.c

@@ -29,6 +29,11 @@ extern void * __splitstack_resetcontext(void *context[10], size_t *);
 extern void *__splitstack_find(void *, void *, size_t *, void **, void **,
 			       void **);
 
+extern void __splitstack_block_signals (int *, int *);
+
+extern void __splitstack_block_signals_context (void *context[10], int *,
+						int *);
+
 #endif
 
 #if defined(USING_SPLIT_STACK) && defined(LINKER_SUPPORTS_SPLIT_STACK)
@@ -862,6 +867,14 @@ runtime_mstart(void* mp)
 		*(int*)0x21 = 0x21;
 	}
 	runtime_minit();
+
+#ifdef USING_SPLIT_STACK
+	{
+	  int dont_block_signals = 0;
+	  __splitstack_block_signals(&dont_block_signals, nil);
+	}
+#endif
+
 	schedule(nil);
 	return nil;
 }
@@ -1142,9 +1155,13 @@ runtime_malg(int32 stacksize, byte** ret_stack, size_t* ret_stacksize)
 	newg = runtime_malloc(sizeof(G));
 	if(stacksize >= 0) {
 #if USING_SPLIT_STACK
+		int dont_block_signals = 0;
+
 		*ret_stack = __splitstack_makecontext(stacksize,
 						      &newg->stack_context[0],
 						      ret_stacksize);
+		__splitstack_block_signals_context(&newg->stack_context[0],
+						   &dont_block_signals, nil);
 #else
 		*ret_stack = runtime_mallocgc(stacksize, FlagNoProfiling|FlagNoGC, 0, 0);
 		*ret_stacksize = stacksize;
@@ -1186,8 +1203,12 @@ __go_go(void (*fn)(void*), void* arg)
 
 	if((newg = gfget()) != nil){
 #ifdef USING_SPLIT_STACK
+		int dont_block_signals = 0;
+
 		sp = __splitstack_resetcontext(&newg->stack_context[0],
 					       &spsize);
+		__splitstack_block_signals_context(&newg->stack_context[0],
+						   &dont_block_signals, nil);
 #else
 		sp = newg->gcinitial_sp;
 		spsize = newg->gcstack_size;

libgo/runtime/runtime.h

@@ -52,6 +52,7 @@ typedef	struct	G		G;
 typedef	union	Lock		Lock;
 typedef	struct	M		M;
 typedef	union	Note		Note;
+typedef	struct	SigTab		SigTab;
 typedef	struct	MCache		MCache;
 typedef struct	FixAlloc	FixAlloc;
 typedef	struct	Hchan		Hchan;
@@ -179,6 +180,20 @@ struct	M
 	uint32	waitsemalock;
 };
 
+struct	SigTab
+{
+	int32	sig;
+	int32	flags;
+};
+enum
+{
+	SigCatch = 1<<0,
+	SigIgnore = 1<<1,
+	SigRestart = 1<<2,
+	SigQueue = 1<<3,
+	SigPanic = 1<<4,
+};
+
 /* Macros.  */
 
 #ifdef __WINDOWS__
@@ -251,7 +266,7 @@ void	runtime_args(int32, byte**);
 void	runtime_osinit();
 void	runtime_goargs(void);
 void	runtime_goenvs(void);
-void	runtime_throw(const char*);
+void	runtime_throw(const char*) __attribute__ ((noreturn));
 void	runtime_panicstring(const char*) __attribute__ ((noreturn));
 void*	runtime_mal(uintptr);
 void	runtime_schedinit(void);

libgo/runtime/sigqueue.goc

@@ -110,6 +110,6 @@ func Signame(sig int32) (name String) {
 }
 
 func Siginit() {
-	runtime_initsig(1);
+	runtime_initsig(SigQueue);
 	sig.inuse = true;	// enable reception of signals; cannot disable
 }