- 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>

sys/alpha/alpha/db_trace.c

@@ -47,7 +47,9 @@ __FBSDID("$FreeBSD$");
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/kdb.h>
+#include <sys/linker.h>
 #include <sys/proc.h>
+#include <sys/stack.h>
 #include <sys/sysent.h>
 
 #include <machine/db_machdep.h>
@@ -348,6 +350,45 @@ db_trace_thread(struct thread *thr, int count)
 		    count));
 }
 
+void
+stack_save(struct stack *st)
+{
+	struct prologue_info pi;
+	linker_symval_t symval;
+	c_linker_sym_t sym;
+	vm_offset_t callpc, frame;
+	long offset;
+	register_t pc, sp;
+
+	stack_zero(st);
+	__asm __volatile(
+		"	mov $30,%0 \n"
+		"	lda %1,1f \n"
+		"1:\n"
+		: "=r" (sp), "=r" (pc));
+	callpc = (vm_offset_t)pc;
+	frame = (vm_offset_t)sp;
+	while (1) {
+		/*
+		 * search_symbol/symbol_values are slow
+		 */
+		if (linker_ddb_search_symbol((caddr_t)callpc, &sym, &offset) != 0)
+			break;
+		if (linker_ddb_symbol_values(sym, &symval) != 0)
+			break;
+		if (callpc < (vm_offset_t)symval.value)
+			break;
+		if (stack_put(st, callpc) == -1)
+			break;
+		if (decode_prologue(callpc, (db_addr_t)symval.value, &pi))
+			break;
+		if ((pi.pi_regmask & (1 << 26)) == 0)
+			break;
+		callpc = *(vm_offset_t *)(frame + pi.pi_reg_offset[26]);
+		frame += pi.pi_frame_size;
+	}
+}
+
 int
 db_md_set_watchpoint(addr, size)
 	db_expr_t addr;

sys/arm/arm/db_trace.c

@@ -37,6 +37,7 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/proc.h>
 #include <sys/kdb.h>
+#include <sys/stack.h>
 #include <machine/armreg.h>
 #include <machine/asm.h>
 #include <machine/cpufunc.h>
@@ -219,3 +220,21 @@ db_trace_self(void)
 {
 	db_trace_thread(curthread, -1);
 }
+
+void
+stack_save(struct stack *st)
+{
+	vm_offset_t callpc;
+	u_int32_t *frame;
+
+	stack_zero(st);
+	frame = (u_int32_t *)__builtin_frame_address(0);
+	while (1) {
+		if (!INKERNEL(frame))
+			break;
+		callpc = frame[FR_SCP];
+		if (stack_put(st, callpc) == -1)
+			break;
+		frame = (u_int32_t *)(frame[FR_RFP]);
+	}
+}

sys/conf/files

@@ -1259,6 +1259,7 @@ kern/subr_sbuf.c		standard
 kern/subr_scanf.c		standard
 kern/subr_sleepqueue.c		standard
 kern/subr_smp.c			standard
+kern/subr_stack.c		optional ddb
 kern/subr_taskqueue.c		standard
 kern/subr_trap.c		standard
 kern/subr_turnstile.c		standard

sys/i386/i386/db_trace.c

@@ -31,6 +31,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/systm.h>
 #include <sys/kdb.h>
 #include <sys/proc.h>
+#include <sys/stack.h>
 #include <sys/sysent.h>
 
 #include <machine/cpu.h>
@@ -500,6 +501,28 @@ db_trace_thread(struct thread *thr, int count)
 		    ctx->pcb_eip, count));
 }
 
+void
+stack_save(struct stack *st)
+{
+	struct i386_frame *frame;
+	vm_offset_t callpc;
+	register_t ebp;
+
+	stack_zero(st);
+	__asm __volatile("movl %%ebp,%0" : "=r" (ebp));
+	frame = (struct i386_frame *)ebp;
+	while (1) {
+		if (!INKERNEL(frame))
+			break;
+		callpc = frame->f_retaddr;
+		if (!INKERNEL(callpc))
+			break;
+		if (stack_put(st, callpc) == -1)
+			break;
+		frame = frame->f_frame;
+	}
+}
+
 int
 i386_set_watch(watchnum, watchaddr, size, access, d)
 	int watchnum;

sys/ia64/ia64/db_trace.c

@@ -30,6 +30,7 @@
 #include <sys/param.h>
 #include <sys/kdb.h>
 #include <sys/proc.h>
+#include <sys/stack.h>
 
 #include <machine/db_machdep.h>
 #include <machine/frame.h>
@@ -148,6 +149,18 @@ db_trace_thread(struct thread *td, int count)
 	return (db_backtrace(td, ctx, count));
 }
 
+void
+stack_save(struct stack *st)
+{
+
+	stack_zero(st);
+	/*
+	 * Nothing for now.
+	 * Is libuwx reentrant?
+	 * Can unw_create* sleep?
+	 */
+}
+
 int
 db_md_set_watchpoint(addr, size)
 	db_expr_t addr;

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";
+}

sys/powerpc/powerpc/db_trace.c

@@ -32,6 +32,7 @@
 #include <sys/systm.h>
 #include <sys/kdb.h>
 #include <sys/proc.h>
+#include <sys/stack.h>
 
 #include <vm/vm.h>
 #include <vm/pmap.h>
@@ -287,3 +288,25 @@ db_trace_thread(struct thread *td, int count)
 	return (db_backtrace(td, (db_addr_t)ctx->pcb_sp, count));
 }
 
+void
+stack_save(struct stack *st)
+{
+	vm_offset_t callpc;
+	db_addr_t stackframe;
+
+	stack_zero(st);
+	stackframe = (db_addr_t)__builtin_frame_address(1);
+	if (stackframe < PAGE_SIZE)
+		return;
+	while (1) {
+		stackframe = *(db_addr_t *)stackframe;
+		if (stackframe < PAGE_SIZE)
+			break;
+		callpc = *(vm_offset_t *)(stackframe + 4) - 4;
+		if ((callpc & 3) || (callpc < 0x100))
+			break;
+		if (stack_put(st, callpc) == -1)
+			break;
+	}
+}
+

sys/sparc64/sparc64/db_trace.c

@@ -31,6 +31,7 @@
 #include <sys/kdb.h>
 #include <sys/linker_set.h>
 #include <sys/proc.h>
+#include <sys/stack.h>
 #include <sys/sysent.h>
 
 #include <vm/vm.h>
@@ -291,3 +292,23 @@ db_trace_thread(struct thread *td, int count)
 	ctx = kdb_thr_ctx(td);
 	return (db_backtrace(td, (struct frame*)(ctx->pcb_sp + SPOFF), count));
 }
+
+void
+stack_save(struct stack *st)
+{
+	struct frame *fp;
+	db_expr_t addr;
+	vm_offset_t callpc;
+
+	stack_zero(st);
+	addr = (db_expr_t)__builtin_frame_address(1);
+	fp = (struct frame *)(addr + SPOFF);
+	while (1) {
+		callpc = fp->fr_pc;
+		if (!INKERNEL(callpc))
+			break;
+		if (stack_put(st, callpc) == -1)
+			break;
+		fp = (struct frame *)(fp->fr_fp + SPOFF);
+	}
+}

sys/sys/stack.h

@@ -0,0 +1,62 @@
+/*-
+ * 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _SYS_STACK_H_
+#define	_SYS_STACK_H_
+
+#define	STACK_MAX	18	/* Don't change, stack_ktr relies on this. */
+
+struct sbuf;
+
+struct stack {
+	int		depth;
+	vm_offset_t	pcs[STACK_MAX];
+};
+
+/* MI Routines. */
+struct stack	*stack_create(void);
+void		 stack_destroy(struct stack *);
+int		 stack_put(struct stack *, vm_offset_t);
+void		 stack_copy(struct stack *, struct stack *);
+void		 stack_zero(struct stack *);
+void		 stack_print(struct stack *);
+void		 stack_sbuf_print(struct sbuf *, struct stack *);
+#ifdef KTR
+void		 stack_ktr(u_int, const char *, int, struct stack *, int);
+#define	CTRSTACK(m, st, cheap) do {					\
+	if (KTR_COMPILE & (m))						\
+		stack_ktr((m), __FILE__, __LINE__, st, cheap);		\
+	} while(0)
+#else
+#define	CTRSTACK(m, st, cheap)
+#endif
+
+/* MD Routine. */
+void		 stack_save(struct stack *);
+
+#endif