Add DDB symbol support for ELF and KLD. The KLD support only supports global

symbols so its not too useful.  Changes to the kernel linker to allow it to
supply DDB with symbols will come later.

2 files changed, 539 insertions, 0 deletions

diff --git a/sys/ddb/db_elf.c b/sys/ddb/db_elf.c
new file mode 100644
index 0000000..c887aa8
--- /dev/null
+++ b/sys/ddb/db_elf.c
@@ -0,0 +1,402 @@
+/* $Id$ */
+/*	$NetBSD: db_elf.c,v 1.4 1998/05/03 18:49:54 thorpej Exp $	*/
+
+/*-
+ * Copyright (c) 1997 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
+ * NASA Ames Research Center.
+ *
+ * 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the NetBSD
+ *	Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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 "opt_ddb.h"
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/systm.h>  
+#include <sys/proc.h>
+
+#include <machine/db_machdep.h>
+
+#include <ddb/db_sym.h>
+#include <ddb/db_output.h>
+
+#ifdef DB_ELF_SYMBOLS
+
+#ifndef DB_ELFSIZE
+#error Must define DB_ELFSIZE!
+#endif
+
+#define	ELFSIZE		DB_ELFSIZE
+
+#include <machine/elf.h>
+
+#define	CONCAT(x,y)	__CONCAT(x,y)
+#define	ELFDEFNAME(x)	CONCAT(Elf,CONCAT(ELFSIZE,CONCAT(_,x)))
+
+static char *db_elf_find_strtab __P((db_symtab_t *));
+
+#define	STAB_TO_SYMSTART(stab)	((Elf_Sym *)((stab)->start))
+#define	STAB_TO_SYMEND(stab)	((Elf_Sym *)((stab)->end))
+#define	STAB_TO_EHDR(stab)	((Elf_Ehdr *)((stab)->private))
+#define	STAB_TO_SHDR(stab, e)	((Elf_Shdr *)((stab)->private + (e)->e_shoff))
+
+#define Elf_Ehdr	ELFDEFNAME(Ehdr)
+#define Elf_Shdr	ELFDEFNAME(Shdr)
+#define Elf_Sym		ELFDEFNAME(Sym)
+
+#if ELFSIZE == 64
+#define ELF_ST_TYPE(x)	ELF64_ST_TYPE(x)
+#define ELF_ST_BIND(x)	ELF64_ST_BIND(x)
+#else
+#define ELF_ST_TYPE(x)	ELF32_ST_TYPE(x)
+#define ELF_ST_BIND(x)	ELF32_ST_BIND(x)
+#endif
+
+void X_db_sym_init(void *symtab, void *esymtab, char *name);
+
+/*
+ * Find the symbol table and strings; tell ddb about them.
+ */
+void
+X_db_sym_init(symtab, esymtab, name)
+	void *symtab;		/* pointer to start of symbol table */
+	void *esymtab;		/* pointer to end of string table,
+				   for checking - rounded up to integer
+				   boundary */
+	char *name;
+{
+	Elf_Ehdr *elf;
+	Elf_Shdr *shp;
+	Elf_Sym *symp, *symtab_start, *symtab_end;
+	char *strtab_start, *strtab_end;
+	int i;
+
+	if (ALIGNED_POINTER(symtab, long) == 0) {
+		printf("DDB: bad symbol table start address %p\n", symtab);
+		return;
+	}
+
+	symtab_start = symtab_end = NULL;
+	strtab_start = strtab_end = NULL;
+
+	/*
+	 * The format of the symbols loaded by the boot program is:
+	 *
+	 *	Elf exec header
+	 *	first section header
+	 *	. . .
+	 *	. . .
+	 *	last section header
+	 *	first symbol or string table section
+	 *	. . .
+	 *	. . .
+	 *	last symbol or string table section
+	 */
+
+	/*
+	 * Validate the Elf header.
+	 */
+	elf = (Elf_Ehdr *)symtab;
+	if (elf->e_ident[EI_MAG0] != ELFMAG0
+	    || elf->e_ident[EI_MAG1] != ELFMAG1
+	    || elf->e_ident[EI_MAG2] != ELFMAG2
+	    || elf->e_ident[EI_MAG3] != ELFMAG3)
+		goto badheader;
+
+	if (!ELF_MACHINE_OK(elf->e_machine))
+		goto badheader;
+
+	/*
+	 * We need to avoid the section header string table (small string
+	 * table which names the sections).  We do this by assuming that
+	 * the following two conditions will be true:
+	 *
+	 *	(1) .shstrtab will be smaller than one page.
+	 *	(2) .strtab will be larger than one page.
+	 *
+	 * When we encounter what we think is the .shstrtab, we change
+	 * its section type Elf_sht_null so that it will be ignored
+	 * later.
+	 */
+	shp = (Elf_Shdr *)((char*)symtab + elf->e_shoff);
+	for (i = 0; i < elf->e_shnum; i++) {
+		if (shp[i].sh_addr || i == elf->e_shstrndx)
+			continue;
+		switch (shp[i].sh_type) {
+		case SHT_STRTAB:
+			if (shp[i].sh_size < PAGE_SIZE) {
+				shp[i].sh_type = SHT_NULL;
+				continue;
+			}
+			if (strtab_start != NULL)
+				goto multiple_strtab;
+			strtab_start = (char *)symtab + shp[i].sh_offset;
+			strtab_end = (char *)symtab + shp[i].sh_offset +
+			    shp[i].sh_size;
+			break;
+		
+		case SHT_SYMTAB:
+			if (symtab_start != NULL)
+				goto multiple_symtab;
+			symtab_start = (Elf_Sym *)((char*)symtab + shp[i].sh_offset);
+			symtab_end = (Elf_Sym *)((char*)symtab + shp[i].sh_offset +
+			    shp[i].sh_size);
+			break;
+
+		default:
+			/* Ignore all other sections. */
+			break;
+		}
+	}
+
+	/*
+	 * Now, sanity check the symbols against the string table.
+	 */
+	if (symtab_start == NULL || strtab_start == NULL ||
+	    ALIGNED_POINTER(symtab_start, long) == 0 ||
+	    ALIGNED_POINTER(strtab_start, long) == 0)
+		goto badheader;
+	for (symp = symtab_start; symp < symtab_end; symp++)
+		if (symp->st_name + strtab_start > strtab_end)
+			goto badheader;
+
+	/*
+	 * Link the symbol table into the debugger.
+	 */
+	db_add_symbol_table((char *)symtab_start,
+			    (char *)symtab_end, name, (char *)symtab);
+	printf("[ preserving %lu bytes of %s symbol table ]\n",
+	       (u_long)roundup(((char*)esymtab - (char*)symtab), sizeof(u_long)), name);
+	return;
+
+ badheader:
+	printf("[ %s symbol table not valid ]\n", name);
+	return;
+
+ multiple_strtab:
+	printf("[ %s has multiple string tables ]\n", name);
+	return;
+
+ multiple_symtab:
+	printf("[ %s has multiple symbol tables ]\n", name);
+	return;
+}
+
+/*
+ * Internal helper function - return a pointer to the string table
+ * for the current symbol table.
+ */
+static char *
+db_elf_find_strtab(stab)
+	db_symtab_t *stab;
+{
+	Elf_Ehdr *elf = STAB_TO_EHDR(stab);
+	Elf_Shdr *shp = STAB_TO_SHDR(stab, elf);
+	int i;
+
+	for (i = 0; i < elf->e_shnum; i++) {
+		if (shp[i].sh_type == SHT_STRTAB
+		    && !shp[i].sh_addr && i != elf->e_shstrndx)
+			return (stab->private + shp[i].sh_offset);
+	}
+
+	return (NULL);
+}
+
+/*
+ * Lookup the symbol with the given name.
+ */
+db_sym_t
+X_db_lookup(stab, symstr)
+	db_symtab_t *stab;
+	char *symstr;
+{
+	Elf_Sym *symp, *symtab_start, *symtab_end;
+	char *strtab;
+
+	symtab_start = STAB_TO_SYMSTART(stab);
+	symtab_end = STAB_TO_SYMEND(stab);
+
+	strtab = db_elf_find_strtab(stab);
+	if (strtab == NULL)
+		return ((db_sym_t)0);
+
+	for (symp = symtab_start; symp < symtab_end; symp++) {
+		if (symp->st_name != 0 &&
+		    db_eqname(strtab + symp->st_name, symstr, 0))
+			return ((db_sym_t)symp);
+	}
+
+	return ((db_sym_t)0);
+}
+
+/*
+ * Search for the symbol with the given address (matching within the
+ * provided threshold).
+ */
+db_sym_t
+X_db_search_symbol(symtab, off, strategy, diffp)
+	db_symtab_t *symtab;
+	db_addr_t off;
+	db_strategy_t strategy;
+	db_expr_t *diffp;		/* in/out */
+{
+	Elf_Sym *rsymp, *symp, *symtab_start, *symtab_end;
+	db_expr_t diff = *diffp;
+
+	symtab_start = STAB_TO_SYMSTART(symtab);
+	symtab_end = STAB_TO_SYMEND(symtab);
+
+	rsymp = NULL;
+
+	for (symp = symtab_start; symp < symtab_end; symp++) {
+		if (symp->st_name == 0)
+			continue;
+		if (ELF_ST_TYPE(symp->st_info) != STT_OBJECT &&
+		    ELF_ST_TYPE(symp->st_info) != STT_FUNC)
+			continue;
+
+		if (off >= symp->st_value) {
+			if ((off - symp->st_value) < diff) {
+				diff = off - symp->st_value;
+				rsymp = symp;
+				if (diff == 0) {
+					if (strategy == DB_STGY_PROC &&
+					    ELF_ST_TYPE(symp->st_info) ==
+					      STT_FUNC &&
+					    ELF_ST_BIND(symp->st_info) !=
+					      STB_LOCAL)
+						break;
+					if (strategy == DB_STGY_ANY &&
+					    ELF_ST_BIND(symp->st_info) !=
+					      STB_LOCAL)
+						break;
+				}
+			} else if ((off - symp->st_value) == diff) {
+				if (rsymp == NULL)
+					rsymp = symp;
+				else if (ELF_ST_BIND(rsymp->st_info) ==
+				      STB_LOCAL &&
+				    ELF_ST_BIND(symp->st_info) !=
+				      STB_LOCAL) {
+					/* pick the external symbol */
+					rsymp = symp;
+				}
+			}
+		}
+	}
+
+	if (rsymp == NULL)
+		*diffp = off;
+	else
+		*diffp = diff;
+
+	return ((db_sym_t)rsymp);
+}
+
+/*
+ * Return the name and value for a symbol.
+ */
+void
+X_db_symbol_values(symtab, sym, namep, valuep)
+	db_symtab_t *symtab;
+	db_sym_t sym;
+	char **namep;
+	db_expr_t *valuep;
+{
+	Elf_Sym *symp = (Elf_Sym *)sym;
+	char *strtab;
+
+	if (namep) {
+		strtab = db_elf_find_strtab(symtab);
+		if (strtab == NULL)
+			*namep = NULL;
+		else
+			*namep = strtab + symp->st_name;
+	}
+
+	if (valuep)
+		*valuep = symp->st_value;
+}
+
+/*
+ * Return the file and line number of the current program counter
+ * if we can find the appropriate debugging symbol.
+ */
+boolean_t
+X_db_line_at_pc(symtab, cursym, filename, linenum, off)
+	db_symtab_t *symtab;
+	db_sym_t cursym;
+	char **filename;
+	int *linenum;
+	db_expr_t off;
+{
+
+	/*
+	 * XXX We don't support this (yet).
+	 */
+	return (FALSE);
+}
+
+/*
+ * Returns the number of arguments to a function and their
+ * names if we can find the appropriate debugging symbol.
+ */
+boolean_t
+X_db_sym_numargs(symtab, cursym, nargp, argnamep)
+	db_symtab_t *symtab;
+	db_sym_t cursym;
+	int *nargp;
+	char **argnamep;
+{
+
+	/*
+	 * XXX We don't support this (yet).
+	 */
+	return (FALSE);
+}
+
+/*
+ * Initialization routine for Elf files.
+ */
+extern void *ksym_start, *ksym_end;
+
+void
+kdb_init()
+{
+
+	if (ksym_end > ksym_start)
+		X_db_sym_init(ksym_start, ksym_end, "kernel");
+}
+
+#endif /* DB_ELF_SYMBOLS */
diff --git a/sys/ddb/db_kld.c b/sys/ddb/db_kld.c
new file mode 100644
index 0000000..48ba135
--- /dev/null
+++ b/sys/ddb/db_kld.c
@@ -0,0 +1,137 @@
+/*
+ * Mach Operating System
+ * Copyright (c) 1991,1990 Carnegie Mellon University
+ * All Rights Reserved.
+ *
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ *
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * Carnegie Mellon requests users of this software to return to
+ *
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ *
+ * any improvements or extensions that they make and grant Carnegie the
+ * rights to redistribute these changes.
+ *
+ *	$Id$
+ *	from db_aout.c,v 1.20 1998/06/07 17:09:36 dfr Exp
+ */
+
+/*
+ *	Author: David B. Golub, Carnegie Mellon University
+ *	Date:	7/90
+ */
+/*
+ * Symbol table routines for a.out format files.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/linker.h>
+
+#include <machine/bootinfo.h>
+
+#include <ddb/ddb.h>
+#include <ddb/db_sym.h>
+
+extern linker_file_t linker_kernel_file;
+
+#define KF linker_kernel_file
+
+db_sym_t
+X_db_lookup(stab, symstr)
+	db_symtab_t	*stab;
+	char *		symstr;
+{
+	linker_sym_t sym;
+
+	if (!KF)
+		return 0;
+
+	if (KF->ops->lookup_symbol(KF, symstr, &sym) == 0)
+	    return (db_sym_t) sym;
+	else
+	    return (db_sym_t) 0;
+}
+
+db_sym_t
+X_db_search_symbol(symtab, off, strategy, diffp)
+	db_symtab_t *	symtab;
+	register
+	db_addr_t	off;
+	db_strategy_t	strategy;
+	db_expr_t	*diffp;		/* in/out */
+{
+	linker_sym_t sym;
+	long diff;
+
+	if (!KF)
+		return 0;
+
+	if (KF->ops->search_symbol(KF, (caddr_t) off, &sym, &diff) == 0) {
+		*diffp = (db_expr_t) diff;
+		return (db_sym_t) sym;
+	}
+
+	return 0;
+}
+
+/*
+ * Return the name and value for a symbol.
+ */
+void
+X_db_symbol_values(dbsym, namep, valuep)
+	db_sym_t	dbsym;
+	char		**namep;
+	db_expr_t	*valuep;
+{
+	linker_sym_t sym = (linker_sym_t) dbsym;
+	linker_symval_t symval;
+
+	KF->ops->symbol_values(KF, sym, &symval);
+	if (namep)
+	    *namep = (char*) symval.name;
+	if (valuep)
+	    *valuep = (db_expr_t) symval.value;
+}
+
+
+boolean_t
+X_db_line_at_pc(symtab, cursym, filename, linenum, off)
+	db_symtab_t *	symtab;
+	db_sym_t	cursym;
+	char 		**filename;
+	int 		*linenum;
+	db_expr_t	off;
+{
+	return FALSE;
+}
+
+boolean_t
+X_db_sym_numargs(symtab, cursym, nargp, argnamep)
+	db_symtab_t *	symtab;
+	db_sym_t	cursym;
+	int		*nargp;
+	char		**argnamep;
+{
+	return FALSE;
+}
+
+/*
+ * Initialization routine for a.out files.
+ */
+void
+kdb_init()
+{
+	db_add_symbol_table(0, 0, "kernel", 0);
+}