- Add support for saving stack traces and displaying them via printf(9)

   and KTR.

Contributed by:		Antoine Brodin <antoine.brodin@laposte.net>
Concept code from:	Neal Fachan <neal@isilon.com>

1 files changed, 165 insertions, 0 deletions

diff --git a/sys/kern/subr_stack.c b/sys/kern/subr_stack.c
new file mode 100644
index 0000000..9b2be7b
--- /dev/null
+++ b/sys/kern/subr_stack.c
@@ -0,0 +1,165 @@
+/*-
+ * Copyright (c) 2005 Antoine Brodin
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#ifdef KTR
+#include <sys/ktr.h>
+#endif
+#include <sys/linker.h>
+#include <sys/malloc.h>
+#include <sys/sbuf.h>
+#include <sys/stack.h>
+#include <sys/systm.h>
+
+MALLOC_DEFINE(M_STACK, "stack", "Stack Traces");
+
+static void stack_symbol(vm_offset_t pc, const char **name, long *offset);
+
+struct stack *
+stack_create(void)
+{
+	struct stack *st;
+
+	st = malloc(sizeof *st, M_STACK, M_WAITOK | M_ZERO);
+	return (st);
+}
+
+void
+stack_destroy(struct stack *st)
+{
+
+	free(st, M_STACK);
+}
+
+int
+stack_put(struct stack *st, vm_offset_t pc)
+{
+
+	if (st->depth < STACK_MAX) {
+		st->pcs[st->depth++] = pc;
+		return (0);
+	} else
+		return (-1);
+}
+
+void
+stack_copy(struct stack *src, struct stack *dst)
+{
+
+	*dst = *src;
+}
+
+void
+stack_zero(struct stack *st)
+{
+
+	bzero(st, sizeof *st);
+}
+
+void
+stack_print(struct stack *st)
+{
+	const char *name;
+	long offset;
+	int i;
+
+	KASSERT(st->depth <= STACK_MAX, ("bogous stack"));
+	for (i = 0; i < st->depth; i++) {
+		stack_symbol(st->pcs[i], &name, &offset);
+		printf("#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
+		    name, offset);
+	}
+}
+
+void
+stack_sbuf_print(struct sbuf *sb, struct stack *st)
+{
+	const char *name;
+	long offset;
+	int i;
+
+	KASSERT(st->depth <= STACK_MAX, ("bogous stack"));
+	for (i = 0; i < st->depth; i++) {
+		stack_symbol(st->pcs[i], &name, &offset);
+		sbuf_printf(sb, "#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
+		    name, offset);
+	}
+}
+
+#ifdef KTR
+void
+stack_ktr(u_int mask, const char *file, int line, struct stack *st, int cheap)
+{
+	const char *name;
+	long offset;
+	int i;
+
+	KASSERT(st->depth <= STACK_MAX, ("bogous stack"));
+	if (cheap) {
+		ktr_tracepoint(mask, file, line, "#0 %p %p %p %p %p %p",
+		    st->pcs[0], st->pcs[1], st->pcs[2], st->pcs[3],
+		    st->pcs[4], st->pcs[5]);
+		if (st->depth <= 6)
+			return;
+		ktr_tracepoint(mask, file, line, "#1 %p %p %p %p %p %p",
+		    st->pcs[6], st->pcs[7], st->pcs[8], st->pcs[9],
+		    st->pcs[10], st->pcs[11]);
+		if (st->depth <= 12)
+			return;
+		ktr_tracepoint(mask, file, line, "#2 %p %p %p %p %p %p",
+		    st->pcs[12], st->pcs[13], st->pcs[14], st->pcs[15],
+		    st->pcs[16], st->pcs[17]);
+	} else
+		for (i = 0; i < st->depth; i++) {
+			stack_symbol(st->pcs[i], &name, &offset);
+			ktr_tracepoint(mask, file, line, "#%d %p at %s+%#lx",
+			    i, st->pcs[i], (u_long)name, offset, 0, 0);
+		}
+}
+#endif
+
+static void
+stack_symbol(vm_offset_t pc, const char **name, long *offset)
+{
+	linker_symval_t symval;
+	c_linker_sym_t sym;
+
+	if (linker_ddb_search_symbol((caddr_t)pc, &sym, offset) != 0)
+		goto out;
+	if (linker_ddb_symbol_values(sym, &symval) != 0)
+		goto out;
+	if (symval.name != NULL) {
+		*name = symval.name;
+		return;
+	}
+out:
+	*offset = 0;
+	*name = "Unknown func";
+}