936 lines
24 KiB
C
936 lines
24 KiB
C
/* $NetBSD: kern_ksyms.c,v 1.51 2009/03/15 17:14:40 cegger Exp $ */
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/*-
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* Copyright (c) 2008 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software developed for The NetBSD Foundation
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* by Andrew Doran.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Copyright (c) 2001, 2003 Anders Magnusson (ragge@ludd.luth.se).
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Code to deal with in-kernel symbol table management + /dev/ksyms.
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*
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* For each loaded module the symbol table info is kept track of by a
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* struct, placed in a circular list. The first entry is the kernel
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* symbol table.
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*/
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/*
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* TODO:
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*
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* Add support for mmap, poll.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: kern_ksyms.c,v 1.51 2009/03/15 17:14:40 cegger Exp $");
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#if defined(_KERNEL) && defined(_KERNEL_OPT)
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#include "opt_ddb.h"
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#include "opt_ddbparam.h" /* for SYMTAB_SPACE */
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#endif
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#define _KSYMS_PRIVATE
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#include <sys/param.h>
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#include <sys/queue.h>
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#include <sys/exec.h>
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#include <sys/systm.h>
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#include <sys/conf.h>
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#include <sys/kmem.h>
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#include <sys/proc.h>
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#include <sys/atomic.h>
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#include <sys/ksyms.h>
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#include <uvm/uvm_extern.h>
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#ifdef DDB
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#include <ddb/db_output.h>
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#endif
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#include "ksyms.h"
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static int ksyms_maxlen;
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static bool ksyms_isopen;
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static bool ksyms_initted;
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static struct ksyms_hdr ksyms_hdr;
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static kmutex_t ksyms_lock;
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void ksymsattach(int);
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static void ksyms_hdr_init(void *);
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static void ksyms_sizes_calc(void);
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#ifdef KSYMS_DEBUG
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#define FOLLOW_CALLS 1
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#define FOLLOW_MORE_CALLS 2
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#define FOLLOW_DEVKSYMS 4
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static int ksyms_debug;
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#endif
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#ifdef SYMTAB_SPACE
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#define SYMTAB_FILLER "|This is the symbol table!"
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char db_symtab[SYMTAB_SPACE] = SYMTAB_FILLER;
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int db_symtabsize = SYMTAB_SPACE;
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#endif
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int ksyms_symsz;
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int ksyms_strsz;
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TAILQ_HEAD(, ksyms_symtab) ksyms_symtabs =
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TAILQ_HEAD_INITIALIZER(ksyms_symtabs);
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static struct ksyms_symtab kernel_symtab;
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static int
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ksyms_verify(void *symstart, void *strstart)
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{
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#if defined(DIAGNOSTIC) || defined(DEBUG)
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if (symstart == NULL)
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printf("ksyms: Symbol table not found\n");
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if (strstart == NULL)
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printf("ksyms: String table not found\n");
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if (symstart == NULL || strstart == NULL)
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printf("ksyms: Perhaps the kernel is stripped?\n");
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#endif
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if (symstart == NULL || strstart == NULL)
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return 0;
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KASSERT(symstart <= strstart);
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return 1;
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}
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/*
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* Finds a certain symbol name in a certain symbol table.
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*/
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static Elf_Sym *
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findsym(const char *name, struct ksyms_symtab *table, int type)
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{
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Elf_Sym *sym, *maxsym;
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int low, mid, high, nglob;
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char *str, *cmp;
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sym = table->sd_symstart;
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str = table->sd_strstart - table->sd_usroffset;
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nglob = table->sd_nglob;
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low = 0;
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high = nglob;
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/*
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* Start with a binary search of all global symbols in this table.
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* Global symbols must have unique names.
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*/
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while (low < high) {
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mid = (low + high) >> 1;
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cmp = sym[mid].st_name + str;
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if (cmp[0] < name[0] || strcmp(cmp, name) < 0) {
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low = mid + 1;
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} else {
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high = mid;
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}
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}
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KASSERT(low == high);
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if (__predict_true(low < nglob &&
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strcmp(sym[low].st_name + str, name) == 0)) {
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KASSERT(ELF_ST_BIND(sym[low].st_info) == STB_GLOBAL);
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return &sym[low];
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}
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/*
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* Perform a linear search of local symbols (rare). Many local
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* symbols with the same name can exist so are not included in
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* the binary search.
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*/
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if (type != KSYMS_EXTERN) {
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maxsym = sym + table->sd_symsize / sizeof(Elf_Sym);
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for (sym += nglob; sym < maxsym; sym++) {
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if (strcmp(name, sym->st_name + str) == 0) {
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return sym;
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}
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}
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}
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return NULL;
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}
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/*
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* The "attach" is in reality done in ksyms_init().
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*/
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void
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ksymsattach(int arg)
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{
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}
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void
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ksyms_init(void)
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{
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#ifdef SYMTAB_SPACE
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if (!ksyms_initted &&
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strncmp(db_symtab, SYMTAB_FILLER, sizeof(SYMTAB_FILLER))) {
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ksyms_addsyms_elf(db_symtabsize, db_symtab,
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db_symtab + db_symtabsize);
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}
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#endif
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mutex_init(&ksyms_lock, MUTEX_DEFAULT, IPL_NONE);
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}
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/*
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* Add a symbol table.
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* This is intended for use when the symbol table and its corresponding
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* string table are easily available. If they are embedded in an ELF
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* image, use addsymtab_elf() instead.
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*
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* name - Symbol's table name.
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* symstart, symsize - Address and size of the symbol table.
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* strstart, strsize - Address and size of the string table.
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* tab - Symbol table to be updated with this information.
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* newstart - Address to which the symbol table has to be copied during
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* shrinking. If NULL, it is not moved.
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*/
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static const char *addsymtab_strstart;
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static int
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addsymtab_compar(const void *a, const void *b)
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{
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const Elf_Sym *sa, *sb;
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sa = a;
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sb = b;
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/*
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* Split the symbol table into two, with globals at the start
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* and locals at the end.
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*/
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if (ELF_ST_BIND(sa->st_info) != ELF_ST_BIND(sb->st_info)) {
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if (ELF_ST_BIND(sa->st_info) == STB_GLOBAL) {
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return -1;
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}
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if (ELF_ST_BIND(sb->st_info) == STB_GLOBAL) {
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return 1;
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}
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}
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/* Within each band, sort by name. */
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return strcmp(sa->st_name + addsymtab_strstart,
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sb->st_name + addsymtab_strstart);
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}
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static void
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addsymtab(const char *name, void *symstart, size_t symsize,
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void *strstart, size_t strsize, struct ksyms_symtab *tab,
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void *newstart)
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{
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Elf_Sym *sym, *nsym, ts;
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int i, j, n, nglob;
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char *str;
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tab->sd_symstart = symstart;
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tab->sd_symsize = symsize;
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tab->sd_strstart = strstart;
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tab->sd_strsize = strsize;
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tab->sd_name = name;
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tab->sd_minsym = UINTPTR_MAX;
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tab->sd_maxsym = 0;
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tab->sd_usroffset = 0;
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tab->sd_gone = false;
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#ifdef KSYMS_DEBUG
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printf("newstart %p sym %p ksyms_symsz %d str %p strsz %d send %p\n",
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newstart, symstart, symsize, strstart, strsize,
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tab->sd_strstart + tab->sd_strsize);
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#endif
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/* Pack symbol table by removing all file name references. */
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sym = tab->sd_symstart;
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nsym = (Elf_Sym *)newstart;
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str = tab->sd_strstart;
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nglob = 0;
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for (i = n = 0; i < tab->sd_symsize/sizeof(Elf_Sym); i++) {
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/*
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* Remove useless symbols.
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* Should actually remove all typeless symbols.
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*/
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if (sym[i].st_name == 0)
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continue; /* Skip nameless entries */
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if (sym[i].st_shndx == SHN_UNDEF)
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continue; /* Skip external references */
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if (ELF_ST_TYPE(sym[i].st_info) == STT_FILE)
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continue; /* Skip filenames */
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if (ELF_ST_TYPE(sym[i].st_info) == STT_NOTYPE &&
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sym[i].st_value == 0 &&
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strcmp(str + sym[i].st_name, "*ABS*") == 0)
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continue; /* XXX */
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if (ELF_ST_TYPE(sym[i].st_info) == STT_NOTYPE &&
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strcmp(str + sym[i].st_name, "gcc2_compiled.") == 0)
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continue; /* XXX */
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/* Save symbol. Set it as an absolute offset */
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nsym[n] = sym[i];
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nsym[n].st_shndx = SHBSS;
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j = strlen(nsym[n].st_name + str) + 1;
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if (j > ksyms_maxlen)
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ksyms_maxlen = j;
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nglob += (ELF_ST_BIND(nsym[n].st_info) == STB_GLOBAL);
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/* Compute min and max symbols. */
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if (nsym[n].st_value < tab->sd_minsym) {
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tab->sd_minsym = nsym[n].st_value;
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}
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if (nsym[n].st_value > tab->sd_maxsym) {
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tab->sd_maxsym = nsym[n].st_value;
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}
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n++;
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}
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/* Fill the rest of the record, and sort the symbols. */
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tab->sd_symstart = nsym;
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tab->sd_symsize = n * sizeof(Elf_Sym);
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tab->sd_nglob = nglob;
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addsymtab_strstart = str;
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if (kheapsort(nsym, n, sizeof(Elf_Sym), addsymtab_compar, &ts) != 0)
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panic("addsymtab");
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/* ksymsread() is unlocked, so membar. */
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membar_producer();
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TAILQ_INSERT_TAIL(&ksyms_symtabs, tab, sd_queue);
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ksyms_sizes_calc();
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ksyms_initted = true;
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}
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/*
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* Setup the kernel symbol table stuff.
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*/
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void
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ksyms_addsyms_elf(int symsize, void *start, void *end)
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{
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int i, j;
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Elf_Shdr *shdr;
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char *symstart = NULL, *strstart = NULL;
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size_t strsize = 0;
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Elf_Ehdr *ehdr;
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if (symsize <= 0) {
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printf("[ Kernel symbol table missing! ]\n");
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return;
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}
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/* Sanity check */
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if (ALIGNED_POINTER(start, long) == 0) {
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printf("[ Kernel symbol table has bad start address %p ]\n",
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start);
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return;
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}
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ehdr = (Elf_Ehdr *)start;
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/* check if this is a valid ELF header */
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/* No reason to verify arch type, the kernel is actually running! */
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if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) ||
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ehdr->e_ident[EI_CLASS] != ELFCLASS ||
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ehdr->e_version > 1) {
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printf("[ Kernel symbol table invalid! ]\n");
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return; /* nothing to do */
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}
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/* Loaded header will be scratched in addsymtab */
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ksyms_hdr_init(start);
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/* Find the symbol table and the corresponding string table. */
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shdr = (Elf_Shdr *)((uint8_t *)start + ehdr->e_shoff);
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for (i = 1; i < ehdr->e_shnum; i++) {
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if (shdr[i].sh_type != SHT_SYMTAB)
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continue;
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if (shdr[i].sh_offset == 0)
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continue;
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symstart = (uint8_t *)start + shdr[i].sh_offset;
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symsize = shdr[i].sh_size;
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j = shdr[i].sh_link;
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if (shdr[j].sh_offset == 0)
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continue; /* Can this happen? */
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strstart = (uint8_t *)start + shdr[j].sh_offset;
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strsize = shdr[j].sh_size;
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break;
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}
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if (!ksyms_verify(symstart, strstart))
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return;
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addsymtab("netbsd", symstart, symsize, strstart, strsize,
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&kernel_symtab, start);
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#ifdef DEBUG
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printf("Loaded initial symtab at %p, strtab at %p, # entries %ld\n",
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kernel_symtab.sd_symstart, kernel_symtab.sd_strstart,
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(long)kernel_symtab.sd_symsize/sizeof(Elf_Sym));
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#endif
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}
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/*
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* Setup the kernel symbol table stuff.
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* Use this when the address of the symbol and string tables are known;
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* otherwise use ksyms_init with an ELF image.
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* We need to pass a minimal ELF header which will later be completed by
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* ksyms_hdr_init and handed off to userland through /dev/ksyms. We use
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* a void *rather than a pointer to avoid exposing the Elf_Ehdr type.
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*/
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void
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ksyms_addsyms_explicit(void *ehdr, void *symstart, size_t symsize,
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void *strstart, size_t strsize)
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{
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if (!ksyms_verify(symstart, strstart))
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return;
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ksyms_hdr_init(ehdr);
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addsymtab("netbsd", symstart, symsize, strstart, strsize,
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&kernel_symtab, symstart);
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}
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/*
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* Get the value associated with a symbol.
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* "mod" is the module name, or null if any module.
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* "sym" is the symbol name.
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* "val" is a pointer to the corresponding value, if call succeeded.
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* Returns 0 if success or ENOENT if no such entry.
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*
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* Call with ksyms_lock, unless known that the symbol table can't change.
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*/
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int
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ksyms_getval_unlocked(const char *mod, const char *sym, unsigned long *val,
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int type)
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{
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struct ksyms_symtab *st;
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Elf_Sym *es;
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#ifdef KSYMS_DEBUG
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if (ksyms_debug & FOLLOW_CALLS)
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printf("ksyms_getval_unlocked: mod %s sym %s valp %p\n",
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mod, sym, val);
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#endif
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TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) {
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if (__predict_false(st->sd_gone))
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continue;
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if (mod != NULL && strcmp(st->sd_name, mod))
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continue;
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if ((es = findsym(sym, st, type)) != NULL) {
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*val = es->st_value;
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return 0;
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}
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}
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return ENOENT;
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}
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int
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ksyms_getval(const char *mod, const char *sym, unsigned long *val, int type)
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{
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int rc;
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if (!ksyms_initted)
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return ENOENT;
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mutex_enter(&ksyms_lock);
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rc = ksyms_getval_unlocked(mod, sym, val, type);
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mutex_exit(&ksyms_lock);
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return rc;
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}
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/*
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* Get "mod" and "symbol" associated with an address.
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* Returns 0 if success or ENOENT if no such entry.
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*
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* Call with ksyms_lock, unless known that the symbol table can't change.
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*/
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int
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ksyms_getname(const char **mod, const char **sym, vaddr_t v, int f)
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{
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struct ksyms_symtab *st;
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Elf_Sym *les, *es = NULL;
|
|
vaddr_t laddr = 0;
|
|
const char *lmod = NULL;
|
|
char *stable = NULL;
|
|
int type, i, sz;
|
|
|
|
if (!ksyms_initted)
|
|
return ENOENT;
|
|
|
|
TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) {
|
|
if (st->sd_gone)
|
|
continue;
|
|
if (v < st->sd_minsym || v > st->sd_maxsym)
|
|
continue;
|
|
sz = st->sd_symsize/sizeof(Elf_Sym);
|
|
for (i = 0; i < sz; i++) {
|
|
les = st->sd_symstart + i;
|
|
type = ELF_ST_TYPE(les->st_info);
|
|
|
|
if ((f & KSYMS_PROC) && (type != STT_FUNC))
|
|
continue;
|
|
|
|
if (type == STT_NOTYPE)
|
|
continue;
|
|
|
|
if (((f & KSYMS_ANY) == 0) &&
|
|
(type != STT_FUNC) && (type != STT_OBJECT))
|
|
continue;
|
|
|
|
if ((les->st_value <= v) && (les->st_value > laddr)) {
|
|
laddr = les->st_value;
|
|
es = les;
|
|
lmod = st->sd_name;
|
|
stable = st->sd_strstart - st->sd_usroffset;
|
|
}
|
|
}
|
|
}
|
|
if (es == NULL)
|
|
return ENOENT;
|
|
if ((f & KSYMS_EXACT) && (v != es->st_value))
|
|
return ENOENT;
|
|
if (mod)
|
|
*mod = lmod;
|
|
if (sym)
|
|
*sym = stable + es->st_name;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Add a symbol table from a loadable module.
|
|
*/
|
|
void
|
|
ksyms_modload(const char *name, void *symstart, vsize_t symsize,
|
|
char *strstart, vsize_t strsize)
|
|
{
|
|
struct ksyms_symtab *st;
|
|
|
|
st = kmem_zalloc(sizeof(*st), KM_SLEEP);
|
|
mutex_enter(&ksyms_lock);
|
|
addsymtab(name, symstart, symsize, strstart, strsize, st, symstart);
|
|
mutex_exit(&ksyms_lock);
|
|
}
|
|
|
|
/*
|
|
* Remove a symbol table from a loadable module.
|
|
*/
|
|
void
|
|
ksyms_modunload(const char *name)
|
|
{
|
|
struct ksyms_symtab *st;
|
|
|
|
mutex_enter(&ksyms_lock);
|
|
TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) {
|
|
if (st->sd_gone)
|
|
continue;
|
|
if (strcmp(name, st->sd_name) != 0)
|
|
continue;
|
|
st->sd_gone = true;
|
|
if (!ksyms_isopen) {
|
|
TAILQ_REMOVE(&ksyms_symtabs, st, sd_queue);
|
|
ksyms_sizes_calc();
|
|
kmem_free(st, sizeof(*st));
|
|
}
|
|
break;
|
|
}
|
|
mutex_exit(&ksyms_lock);
|
|
KASSERT(st != NULL);
|
|
}
|
|
|
|
#ifdef DDB
|
|
/*
|
|
* Keep sifting stuff here, to avoid export of ksyms internals.
|
|
*
|
|
* Systems is expected to be quiescent, so no locking done.
|
|
*/
|
|
int
|
|
ksyms_sift(char *mod, char *sym, int mode)
|
|
{
|
|
struct ksyms_symtab *st;
|
|
char *sb;
|
|
int i, sz;
|
|
|
|
if (!ksyms_initted)
|
|
return ENOENT;
|
|
|
|
TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) {
|
|
if (st->sd_gone)
|
|
continue;
|
|
if (mod && strcmp(mod, st->sd_name))
|
|
continue;
|
|
sb = st->sd_strstart - st->sd_usroffset;
|
|
|
|
sz = st->sd_symsize/sizeof(Elf_Sym);
|
|
for (i = 0; i < sz; i++) {
|
|
Elf_Sym *les = st->sd_symstart + i;
|
|
char c;
|
|
|
|
if (strstr(sb + les->st_name, sym) == NULL)
|
|
continue;
|
|
|
|
if (mode == 'F') {
|
|
switch (ELF_ST_TYPE(les->st_info)) {
|
|
case STT_OBJECT:
|
|
c = '+';
|
|
break;
|
|
case STT_FUNC:
|
|
c = '*';
|
|
break;
|
|
case STT_SECTION:
|
|
c = '&';
|
|
break;
|
|
case STT_FILE:
|
|
c = '/';
|
|
break;
|
|
default:
|
|
c = ' ';
|
|
break;
|
|
}
|
|
db_printf("%s%c ", sb + les->st_name, c);
|
|
} else
|
|
db_printf("%s ", sb + les->st_name);
|
|
}
|
|
}
|
|
return ENOENT;
|
|
}
|
|
#endif /* DDB */
|
|
|
|
/*
|
|
* In case we exposing the symbol table to the userland using the pseudo-
|
|
* device /dev/ksyms, it is easier to provide all the tables as one.
|
|
* However, it means we have to change all the st_name fields for the
|
|
* symbols so they match the ELF image that the userland will read
|
|
* through the device.
|
|
*
|
|
* The actual (correct) value of st_name is preserved through a global
|
|
* offset stored in the symbol table structure.
|
|
*
|
|
* Call with ksyms_lock held.
|
|
*/
|
|
static void
|
|
ksyms_sizes_calc(void)
|
|
{
|
|
struct ksyms_symtab *st;
|
|
int i, delta;
|
|
|
|
ksyms_symsz = ksyms_strsz = 0;
|
|
TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) {
|
|
delta = ksyms_strsz - st->sd_usroffset;
|
|
if (delta != 0) {
|
|
for (i = 0; i < st->sd_symsize/sizeof(Elf_Sym); i++)
|
|
st->sd_symstart[i].st_name += delta;
|
|
st->sd_usroffset = ksyms_strsz;
|
|
}
|
|
ksyms_symsz += st->sd_symsize;
|
|
ksyms_strsz += st->sd_strsize;
|
|
}
|
|
}
|
|
|
|
static void
|
|
ksyms_hdr_init(void *hdraddr)
|
|
{
|
|
|
|
/* Copy the loaded elf exec header */
|
|
memcpy(&ksyms_hdr.kh_ehdr, hdraddr, sizeof(Elf_Ehdr));
|
|
|
|
/* Set correct program/section header sizes, offsets and numbers */
|
|
ksyms_hdr.kh_ehdr.e_phoff = offsetof(struct ksyms_hdr, kh_phdr[0]);
|
|
ksyms_hdr.kh_ehdr.e_phentsize = sizeof(Elf_Phdr);
|
|
ksyms_hdr.kh_ehdr.e_phnum = NPRGHDR;
|
|
ksyms_hdr.kh_ehdr.e_shoff = offsetof(struct ksyms_hdr, kh_shdr[0]);
|
|
ksyms_hdr.kh_ehdr.e_shentsize = sizeof(Elf_Shdr);
|
|
ksyms_hdr.kh_ehdr.e_shnum = NSECHDR;
|
|
ksyms_hdr.kh_ehdr.e_shstrndx = SHSTRTAB;
|
|
|
|
/* Text/data - fake */
|
|
ksyms_hdr.kh_phdr[0].p_type = PT_LOAD;
|
|
ksyms_hdr.kh_phdr[0].p_memsz = (unsigned long)-1L;
|
|
ksyms_hdr.kh_phdr[0].p_flags = PF_R | PF_X | PF_W;
|
|
|
|
/* First section is null */
|
|
|
|
/* Second section header; ".symtab" */
|
|
ksyms_hdr.kh_shdr[SYMTAB].sh_name = 1; /* Section 3 offset */
|
|
ksyms_hdr.kh_shdr[SYMTAB].sh_type = SHT_SYMTAB;
|
|
ksyms_hdr.kh_shdr[SYMTAB].sh_offset = sizeof(struct ksyms_hdr);
|
|
/* ksyms_hdr.kh_shdr[SYMTAB].sh_size = filled in at open */
|
|
ksyms_hdr.kh_shdr[SYMTAB].sh_link = 2; /* Corresponding strtab */
|
|
ksyms_hdr.kh_shdr[SYMTAB].sh_addralign = sizeof(long);
|
|
ksyms_hdr.kh_shdr[SYMTAB].sh_entsize = sizeof(Elf_Sym);
|
|
|
|
/* Third section header; ".strtab" */
|
|
ksyms_hdr.kh_shdr[STRTAB].sh_name = 9; /* Section 3 offset */
|
|
ksyms_hdr.kh_shdr[STRTAB].sh_type = SHT_STRTAB;
|
|
/* ksyms_hdr.kh_shdr[STRTAB].sh_offset = filled in at open */
|
|
/* ksyms_hdr.kh_shdr[STRTAB].sh_size = filled in at open */
|
|
ksyms_hdr.kh_shdr[STRTAB].sh_addralign = sizeof(char);
|
|
|
|
/* Fourth section, ".shstrtab" */
|
|
ksyms_hdr.kh_shdr[SHSTRTAB].sh_name = 17; /* This section name offset */
|
|
ksyms_hdr.kh_shdr[SHSTRTAB].sh_type = SHT_STRTAB;
|
|
ksyms_hdr.kh_shdr[SHSTRTAB].sh_offset =
|
|
offsetof(struct ksyms_hdr, kh_strtab);
|
|
ksyms_hdr.kh_shdr[SHSTRTAB].sh_size = SHSTRSIZ;
|
|
ksyms_hdr.kh_shdr[SHSTRTAB].sh_addralign = sizeof(char);
|
|
|
|
/* Fifth section, ".bss". All symbols reside here. */
|
|
ksyms_hdr.kh_shdr[SHBSS].sh_name = 27; /* This section name offset */
|
|
ksyms_hdr.kh_shdr[SHBSS].sh_type = SHT_NOBITS;
|
|
ksyms_hdr.kh_shdr[SHBSS].sh_offset = 0;
|
|
ksyms_hdr.kh_shdr[SHBSS].sh_size = (unsigned long)-1L;
|
|
ksyms_hdr.kh_shdr[SHBSS].sh_addralign = PAGE_SIZE;
|
|
ksyms_hdr.kh_shdr[SHBSS].sh_flags = SHF_ALLOC | SHF_EXECINSTR;
|
|
|
|
/* Set section names */
|
|
strlcpy(&ksyms_hdr.kh_strtab[1], ".symtab",
|
|
sizeof(ksyms_hdr.kh_strtab) - 1);
|
|
strlcpy(&ksyms_hdr.kh_strtab[9], ".strtab",
|
|
sizeof(ksyms_hdr.kh_strtab) - 9);
|
|
strlcpy(&ksyms_hdr.kh_strtab[17], ".shstrtab",
|
|
sizeof(ksyms_hdr.kh_strtab) - 17);
|
|
strlcpy(&ksyms_hdr.kh_strtab[27], ".bss",
|
|
sizeof(ksyms_hdr.kh_strtab) - 27);
|
|
}
|
|
|
|
static int
|
|
ksymsopen(dev_t dev, int oflags, int devtype, struct lwp *l)
|
|
{
|
|
|
|
if (minor(dev) != 0 || !ksyms_initted)
|
|
return ENXIO;
|
|
|
|
/*
|
|
* Create a "snapshot" of the kernel symbol table. Setting
|
|
* ksyms_isopen will prevent symbol tables from being freed.
|
|
*/
|
|
mutex_enter(&ksyms_lock);
|
|
ksyms_hdr.kh_shdr[SYMTAB].sh_size = ksyms_symsz;
|
|
ksyms_hdr.kh_shdr[SYMTAB].sh_info = ksyms_symsz / sizeof(Elf_Sym);
|
|
ksyms_hdr.kh_shdr[STRTAB].sh_offset = ksyms_symsz +
|
|
ksyms_hdr.kh_shdr[SYMTAB].sh_offset;
|
|
ksyms_hdr.kh_shdr[STRTAB].sh_size = ksyms_strsz;
|
|
ksyms_isopen = true;
|
|
mutex_exit(&ksyms_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
ksymsclose(dev_t dev, int oflags, int devtype, struct lwp *l)
|
|
{
|
|
struct ksyms_symtab *st, *next;
|
|
bool resize;
|
|
|
|
/* Discard refernces to symbol tables. */
|
|
mutex_enter(&ksyms_lock);
|
|
ksyms_isopen = false;
|
|
resize = false;
|
|
for (st = TAILQ_FIRST(&ksyms_symtabs); st != NULL; st = next) {
|
|
next = TAILQ_NEXT(st, sd_queue);
|
|
if (st->sd_gone) {
|
|
TAILQ_REMOVE(&ksyms_symtabs, st, sd_queue);
|
|
kmem_free(st, sizeof(*st));
|
|
resize = true;
|
|
}
|
|
}
|
|
if (resize)
|
|
ksyms_sizes_calc();
|
|
mutex_exit(&ksyms_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
ksymsread(dev_t dev, struct uio *uio, int ioflag)
|
|
{
|
|
struct ksyms_symtab *st;
|
|
size_t filepos, inpos, off;
|
|
int error;
|
|
|
|
/*
|
|
* First: Copy out the ELF header. XXX Lose if ksymsopen()
|
|
* occurs during read of the header.
|
|
*/
|
|
off = uio->uio_offset;
|
|
if (off < sizeof(struct ksyms_hdr)) {
|
|
error = uiomove((char *)&ksyms_hdr + off,
|
|
sizeof(struct ksyms_hdr) - off, uio);
|
|
if (error != 0)
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Copy out the symbol table.
|
|
*/
|
|
filepos = sizeof(struct ksyms_hdr);
|
|
TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) {
|
|
if (uio->uio_resid == 0)
|
|
return 0;
|
|
if (uio->uio_offset <= st->sd_symsize + filepos) {
|
|
inpos = uio->uio_offset - filepos;
|
|
error = uiomove((char *)st->sd_symstart + inpos,
|
|
st->sd_symsize - inpos, uio);
|
|
if (error != 0)
|
|
return error;
|
|
}
|
|
filepos += st->sd_symsize;
|
|
}
|
|
|
|
/*
|
|
* Copy out the string table
|
|
*/
|
|
KASSERT(filepos == sizeof(struct ksyms_hdr) +
|
|
ksyms_hdr.kh_shdr[SYMTAB].sh_size);
|
|
TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) {
|
|
if (uio->uio_resid == 0)
|
|
return 0;
|
|
if (uio->uio_offset <= st->sd_strsize + filepos) {
|
|
inpos = uio->uio_offset - filepos;
|
|
error = uiomove((char *)st->sd_strstart + inpos,
|
|
st->sd_strsize - inpos, uio);
|
|
if (error != 0)
|
|
return error;
|
|
}
|
|
filepos += st->sd_strsize;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
ksymswrite(dev_t dev, struct uio *uio, int ioflag)
|
|
{
|
|
|
|
return EROFS;
|
|
}
|
|
|
|
static int
|
|
ksymsioctl(dev_t dev, u_long cmd, void *data, int fflag, struct lwp *l)
|
|
{
|
|
struct ksyms_gsymbol *kg = (struct ksyms_gsymbol *)data;
|
|
struct ksyms_symtab *st;
|
|
Elf_Sym *sym = NULL, copy;
|
|
unsigned long val;
|
|
int error = 0;
|
|
char *str = NULL;
|
|
int len;
|
|
|
|
/* Read ksyms_maxlen only once while not holding the lock. */
|
|
len = ksyms_maxlen;
|
|
|
|
if (cmd == KIOCGVALUE || cmd == KIOCGSYMBOL) {
|
|
str = kmem_alloc(len, KM_SLEEP);
|
|
if ((error = copyinstr(kg->kg_name, str, len, NULL)) != 0) {
|
|
kmem_free(str, len);
|
|
return error;
|
|
}
|
|
}
|
|
|
|
switch (cmd) {
|
|
case KIOCGVALUE:
|
|
/*
|
|
* Use the in-kernel symbol lookup code for fast
|
|
* retreival of a value.
|
|
*/
|
|
error = ksyms_getval(NULL, str, &val, KSYMS_EXTERN);
|
|
if (error == 0)
|
|
error = copyout(&val, kg->kg_value, sizeof(long));
|
|
kmem_free(str, len);
|
|
break;
|
|
|
|
case KIOCGSYMBOL:
|
|
/*
|
|
* Use the in-kernel symbol lookup code for fast
|
|
* retreival of a symbol.
|
|
*/
|
|
mutex_enter(&ksyms_lock);
|
|
TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) {
|
|
if (st->sd_gone)
|
|
continue;
|
|
if ((sym = findsym(str, st, KSYMS_ANY)) == NULL)
|
|
continue;
|
|
#ifdef notdef
|
|
/* Skip if bad binding */
|
|
if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL) {
|
|
sym = NULL;
|
|
continue;
|
|
}
|
|
#endif
|
|
break;
|
|
}
|
|
if (sym != NULL) {
|
|
memcpy(©, sym, sizeof(copy));
|
|
mutex_exit(&ksyms_lock);
|
|
error = copyout(©, kg->kg_sym, sizeof(Elf_Sym));
|
|
} else {
|
|
mutex_exit(&ksyms_lock);
|
|
error = ENOENT;
|
|
}
|
|
kmem_free(str, len);
|
|
break;
|
|
|
|
case KIOCGSIZE:
|
|
/*
|
|
* Get total size of symbol table.
|
|
*/
|
|
mutex_enter(&ksyms_lock);
|
|
*(int *)data = ksyms_strsz + ksyms_symsz +
|
|
sizeof(struct ksyms_hdr);
|
|
mutex_exit(&ksyms_lock);
|
|
break;
|
|
|
|
default:
|
|
error = ENOTTY;
|
|
break;
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
const struct cdevsw ksyms_cdevsw = {
|
|
ksymsopen, ksymsclose, ksymsread, ksymswrite, ksymsioctl,
|
|
nullstop, notty, nopoll, nommap, nullkqfilter, D_OTHER | D_MPSAFE
|
|
};
|