Add stack_getbounds() and thr_stksegment() interfaces

zfs/lib/libspl/include/sys/frame.h

@@ -0,0 +1,8 @@
+/*
+ * This header file distributed under the terms of the CDDL.
+ * Portions Copyright 2008 Sun Microsystems, Inc. All Rights reserved.
+ */
+#ifndef _SYS_FRAME_H
+#define _SYS_FRAME_H
+
+#endif /* _SYS_FRAME_H */

zfs/lib/libspl/include/sys/stack.h

@@ -0,0 +1,58 @@
+/*
+ * This header file distributed under the terms of the CDDL.
+ * Portions Copyright 2008 Sun Microsystems, Inc. All Rights reserved.
+ */
+#ifndef _SYS_STACK_H
+#define _SYS_STACK_H
+
+#include <pthread.h>
+
+#define STACK_BIAS	0
+
+typedef struct {
+	void    *ss_sp;
+	size_t  ss_size;
+	int     ss_flags;
+} stack_t;
+
+#ifdef __USE_GNU
+
+static inline int
+stack_getbounds(stack_t *sp)
+{
+	pthread_attr_t attr;
+	int rc;
+
+	rc = pthread_getattr_np(pthread_self(), &attr);
+	if (rc)
+		return rc;
+
+	rc = pthread_attr_getstack(&attr, &sp->ss_sp, &sp->ss_size);
+	if (rc == 0)
+		sp->ss_flags = 0;
+
+	pthread_attr_destroy(&attr);
+
+	return rc;
+}
+
+static inline int
+thr_stksegment(stack_t *sp)
+{
+	int rc;
+
+	rc = stack_getbounds(sp);
+	if (rc)
+		return rc;
+
+         /* thr_stksegment() is expected to set sp.ss_sp to the high stack
+	  * address, but the stack_getbounds() interface is expected to
+	  * set sp.ss_sp to the low address.  Adjust accordingly. */
+	sp->ss_sp = (void *)(((uintptr_t)sp->ss_sp) + sp->ss_size);
+	sp->ss_flags = 0;
+
+	return rc;
+}
+
+#endif /* __USE_GNU */
+#endif /* _SYS_STACK_H */