* gc.c (ruby_stack_check): no check if using sigaltstack.

* signal.c (register_sigaltstack): minimum size is insufficient for
  method calls.

* signal.c (sigsegv): handles stack overflow if possible.

* thread.c (ruby_thread_stack_overflow): helper function to raise
  sysstack_error.

* thread_pthread.c (ruby_stack_overflowed_p): checks for stack
  overflow.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@20372 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

gc.c

@@ -1050,6 +1050,9 @@ ruby_stack_length(VALUE **p)
 int
 ruby_stack_check(void)
 {
+#if defined(POSIX_SIGNAL) && defined(SIGSEGV) && defined(HAVE_SIGALTSTACK)
+    return 0;
+#else
     int ret;
     rb_thread_t *th = GET_THREAD();
     SET_STACK_END;
@@ -1061,6 +1064,7 @@ ruby_stack_check(void)
     }
 #endif
     return ret;
+#endif
 }
 
 static void

signal.c

@@ -415,6 +415,7 @@ typedef RETSIGTYPE (*sighandler_t)(int);
 #endif
 
 #ifdef USE_SIGALTSTACK
+#define SIGINFO_ARG , siginfo_t *info, void *ctx
 #ifdef SIGSTKSZ
 #define ALT_STACK_SIZE SIGSTKSZ
 #else
@@ -430,7 +431,7 @@ register_sigaltstack()
     if (is_altstack_defined)
       return;
 
-    newSS.ss_sp = malloc(ALT_STACK_SIZE);
+    newSS.ss_sp = malloc(ALT_STACK_SIZE * 2);
     if (newSS.ss_sp == NULL)
       /* should handle error */
        rb_bug("register_sigaltstack. malloc error\n");
@@ -441,6 +442,8 @@ register_sigaltstack()
         rb_bug("register_sigaltstack. error\n");
     is_altstack_defined = 1;
 }
+#else
+#define SIGINFO_ARG
 #endif
 
 static sighandler_t
@@ -570,8 +573,16 @@ sigbus(int sig)
 #ifdef SIGSEGV
 static int segv_received = 0;
 static RETSIGTYPE
-sigsegv(int sig)
+sigsegv(int sig SIGINFO_ARG)
 {
+#ifdef USE_SIGALTSTACK
+    int ruby_stack_overflowed_p(const rb_thread_t *, const void *);
+    NORETURN(void ruby_thread_stack_overflow(rb_thread_t *th));
+    rb_thread_t *th = GET_THREAD();
+    if (ruby_stack_overflowed_p(th, info->si_addr)) {
+	ruby_thread_stack_overflow(th);
+    }
+#endif
     if (segv_received) {
 	fprintf(stderr, "SEGV recieved in SEGV handler\n");
 	exit(EXIT_FAILURE);
@@ -700,7 +711,7 @@ default_handler(int sig)
 #endif
 #ifdef SIGSEGV
       case SIGSEGV:
-        func = sigsegv;
+        func = (sighandler_t)sigsegv;
 #ifdef USE_SIGALTSTACK
         register_sigaltstack();
 #endif
@@ -1114,7 +1125,7 @@ Init_signal(void)
 #ifdef USE_SIGALTSTACK
     register_sigaltstack();
 #endif
-    install_sighandler(SIGSEGV, sigsegv);
+    install_sighandler(SIGSEGV, (sighandler_t)sigsegv);
 #endif
     }
 #ifdef SIGPIPE

thread.c

@@ -1184,6 +1184,14 @@ rb_thread_signal_exit(void *thptr)
     rb_thread_raise(2, argv, th->vm->main_thread);
 }
 
+void
+ruby_thread_stack_overflow(rb_thread_t *th)
+{
+    th->errinfo = sysstack_error;
+    th->raised_flag = 0;
+    TH_JUMP_TAG(th, TAG_RAISE);
+}
+
 int
 rb_thread_set_raised(rb_thread_t *th)
 {

thread_pthread.c

@@ -180,6 +180,75 @@ native_thread_destroy(rb_thread_t *th)
 
 #define USE_THREAD_CACHE 0
 
+#if STACK_GROW_DIRECTION
+#define STACK_GROW_DIR_DETECTION
+#define STACK_DIR_UPPER(a,b) STACK_UPPER(0, a, b)
+#else
+#define STACK_GROW_DIR_DETECTION VALUE stack_grow_dir_detection
+#define STACK_DIR_UPPER(a,b) STACK_UPPER(&stack_grow_dir_detection, a, b)
+#endif
+
+#if defined HAVE_PTHREAD_GETATTR_NP || defined HAVE_PTHREAD_ATTR_GET_NP
+#define STACKADDR_AVAILABLE 1
+#elif defined HAVE_PTHREAD_GET_STACKADDR_NP && defined HAVE_PTHREAD_GET_STACKSIZE_NP
+#define STACKADDR_AVAILABLE 1
+#elif defined HAVE_THR_STKSEGMENT || defined HAVE_PTHREAD_STACKSEG_NP
+#define STACKADDR_AVAILABLE 1
+#endif
+
+#ifdef STACKADDR_AVAILABLE
+static int
+get_stack(void **addr, size_t *size)
+{
+#define CHECK_ERR(expr)				\
+    {int err = (expr); if (err) return err;}
+#if defined HAVE_PTHREAD_GETATTR_NP || defined HAVE_PTHREAD_ATTR_GET_NP
+    pthread_attr_t attr;
+    size_t guard = 0;
+
+# ifdef HAVE_PTHREAD_GETATTR_NP
+    CHECK_ERR(pthread_getattr_np(pthread_self(), &attr));
+#   ifdef HAVE_PTHREAD_ATTR_GETSTACK
+    CHECK_ERR(pthread_attr_getstack(&attr, addr, size));
+#   else
+    CHECK_ERR(pthread_attr_getstackaddr(&attr, addr));
+    CHECK_ERR(pthread_attr_getstacksize(&attr, size));
+#   endif
+    if (pthread_attr_getguardsize(&attr, &guard) == 0) {
+	STACK_GROW_DIR_DETECTION;
+	STACK_DIR_UPPER((void)0, *addr = (char *)*addr + guard);
+	*size -= guard;
+    }
+# else
+    CHECK_ERR(pthread_attr_init(&attr));
+    CHECK_ERR(pthread_attr_get_np(pthread_self(), &attr));
+    CHECK_ERR(pthread_attr_getstackaddr(&attr, addr));
+    CHECK_ERR(pthread_attr_getstacksize(&attr, size));
+# endif
+    CHECK_ERR(pthread_attr_getguardsize(&attr, &guard));
+# ifndef HAVE_PTHREAD_GETATTR_NP
+    pthread_attr_destroy(&attr);
+# endif
+    size -= guard;
+#elif defined HAVE_PTHREAD_GET_STACKADDR_NP && defined HAVE_PTHREAD_GET_STACKSIZE_NP
+    pthread_t th = pthread_self();
+    *addr = pthread_get_stackaddr_np(th);
+    *size = pthread_get_stacksize_np(th);
+#elif defined HAVE_THR_STKSEGMENT || defined HAVE_PTHREAD_STACKSEG_NP
+    stack_t stk;
+# if defined HAVE_THR_STKSEGMENT
+    CHECK_ERR(thr_stksegment(&stk));
+# else
+    CHECK_ERR(pthread_stackseg_np(pthread_self(), &stk));
+# endif
+    *addr = stk.ss_sp;
+    *size = stk.ss_size;
+#endif
+    return 0;
+#undef CHECK_ERR
+}
+#endif
+
 static struct {
     rb_thread_id_t id;
     size_t stack_maxsize;
@@ -742,4 +811,39 @@ native_stop_timer_thread(void)
     return stopped;
 }
 
+#ifdef HAVE_SIGALTSTACK
+int
+ruby_stack_overflowed_p(const rb_thread_t *th, const void *addr)
+{
+    void *base;
+    size_t size;
+    const size_t water_mark = 1024 * 1024;
+    STACK_GROW_DIR_DETECTION;
+
+    if (th) {
+	size = th->machine_stack_maxsize;
+	base = (char *)th->machine_stack_start - STACK_DIR_UPPER(0, size);
+    }
+#ifdef STACKADDR_AVAILABLE
+    else if (get_stack(&base, &size) == 0) {
+	STACK_DIR_UPPER(base = (char *)base + size, (void)0);
+    }
+#endif
+    else {
+	return 0;
+    }
+    size /= 5;
+    if (size > water_mark) size = water_mark;
+    if (STACK_DIR_UPPER(1, 0)) {
+	if (size > ~(size_t)base+1) size = ~(size_t)base+1;
+	if (addr > base && addr <= (void *)((char *)base + size)) return 1;
+    }
+    else {
+	if (size > (size_t)base) size = (size_t)base;
+	if (addr > (void *)((char *)base - size) && addr <= base) return 1;
+    }
+    return 0;
+}
+#endif
+
 #endif /* THREAD_SYSTEM_DEPENDENT_IMPLEMENTATION */