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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI"
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include "symint.h"
#include "debug.h"
/*
* symintFcns.c -- symbol information interface routines.
*
* these routines form a symbol information access
* interface, for the profilers to get at object file
* information. this interface was designed to aid
* in the COFF to ELF conversion of prof, lprof and friends.
*
*/
/*
* _symintOpen(aout_name)
* aout_name - char string file name of object file
* to open.
*
* returns PROF_FILE * - pointer to the PROF_FILE structure built,
* or NULL if fails.
*/
/*
*
* .H 3 "Executable File Open and Close"
*
* Under COFF, the routine ldopen, given a file name, returns a pointer to a
* structure called an LDFILE. This descriptor is then passed to each of
* the library routines (such as read header, read symbol table entry, etc)
* to access the information contained in the file. These calls are spread
* throughout the profiling code.
*
* Under ELF, the file must be opened using a system open call. The file
* descriptor is then passed to a routine which returns a pointer to an
* Elf structure. This pointer is then passed along to another routine which
* returns a different pointer which is in turn passed along to another
* routine. In an attempt to avoid disturbing the current format of the
* code (by having to pass around different types of pointers), we plan to
* build a PROF_FILE descriptor which will then be passed around in the
* same way as the pointer to LDFILE.
*
* Thus, for ELF, an open will consist of opening the file and extracting
* enough from it to fill in the PROF_FILE structure. The code for the
* open is as follows; the code for building the symbol table (extracting
* information from the sections to fill an array of PROF_SYMBOLS) has
* yet to be written.
*
*/
/*
* globals
*/
static char
*fail_open_s = "Unable to open file",
*fail_begin_s = "Unable to read (begin) file",
*fail_ehdr_s = "Unable to get elf header in",
*fail_sec_s = "Unable to get section",
*fail_shd_s = "Unable to get header for section",
*fail_dat_s = "Unable to get data for section",
*fail_sym_s = "Cannot find symbol table section in",
*fail_pfsym_s = "Unable to process symbols in",
*fail_buf_s = "Data buffer is null for section",
*fail_sym32_s = "Cannot handle more than 2^32 symbols"
;
/*
* this points at the name of the executable.
*/
static char *executableName;
/*
* section_data_p() - return ptr to section data,
* given section ptr and name of section.
*/
static Elf_Data *
section_data_p(Elf_Scn *sec_p, char *str)
{
Elf_Data *dat_p;
if ((dat_p = elf_getdata(sec_p, NULL)) == NULL)
_err_exit("%s %s in %s.", fail_dat_s, str, executableName);
return (dat_p);
}
PROF_FILE *
_symintOpen(char *aout_name)
{
/*
* Elf file open operation
*
* - point at executable's name, globally
* - open file
* - align to current version
* - read the elf descriptor and header
* - read header-names section descriptor, header, and data
* - allocate space for all the section hdrs (pf_shdarr_p).
* - set a pointer to the header-names buffer
* - search the section headers for
* - debug section header and data
* - line section header and data
* - symbol table header, data, strings, and number of symbols
* and copy each section hdr into our array.
* - populate the PROF_SYMBOL array and anchor it in (pf_symarr_p).
*/
PROF_FILE *pfile_p; /* PROF_FILE ptr to return. */
Elf *telf_p;
Elf_Scn *tscn_p;
Elf32_Shdr *tshd_p;
int k;
Elf64_Xword nsyms_pri = 0, nsyms_aux = 0;
executableName = aout_name;
DEBUG_LOC("_symintOpen: top");
if (aout_name == NULL) {
_err_exit("name of executable is null\n");
}
DEBUG_EXP(printf("Attempting to open %s\n", aout_name));
pfile_p = _Malloc(sizeof (PROF_FILE), 1);
if ((pfile_p->pf_fildes = open(aout_name, O_RDONLY)) == -1)
_err_exit("%s %s.", fail_open_s, aout_name);
if ((elf_version(EV_CURRENT)) == EV_NONE)
_err_exit("Elf library out of date");
if ((pfile_p->pf_elf_p = elf_begin(pfile_p->pf_fildes,
ELF_C_READ, (Elf *)NULL)) == NULL)
_err_exit("%s %s.", fail_begin_s, aout_name);
DEBUG_EXP(printf("elfkind = %d\n", elf_kind(pfile_p->pf_elf_p)));
if ((pfile_p->pf_elfhd_p = elf32_getehdr(pfile_p->pf_elf_p)) == NULL)
_err_exit("%s %s.", fail_ehdr_s, aout_name);
DEBUG_LOC("_symintOpen: after call to getehdr");
telf_p = pfile_p->pf_elf_p;
tscn_p = elf_getscn(telf_p, k = pfile_p->pf_elfhd_p->e_shstrndx);
if (tscn_p == NULL)
_err_exit("%s %d in %s.", fail_sec_s, k, aout_name);
if (elf32_getshdr(tscn_p) == NULL)
_err_exit("%s %s in %s.", fail_shd_s, "header names",
aout_name);
if ((pfile_p->pf_snmdat_p = elf_getdata(tscn_p, NULL)) == NULL)
_err_exit("%s %s in %s.", fail_dat_s, "header names",
aout_name);
DEBUG_EXP(printf("Address of data header = 0x%lx\n",
pfile_p->pf_snmdat_p));
DEBUG_EXP(printf("d_buf = 0x%lx\n",
pfile_p->pf_snmdat_p->d_buf));
DEBUG_EXP(printf("d_type = %d\n",
pfile_p->pf_snmdat_p->d_type));
DEBUG_EXP(printf("d_size = %d\n",
pfile_p->pf_snmdat_p->d_size));
DEBUG_EXP(printf("d_off = %d\n",
pfile_p->pf_snmdat_p->d_off));
DEBUG_EXP(printf("d_align = %d\n",
pfile_p->pf_snmdat_p->d_align));
DEBUG_EXP(printf("d_version = %d\n",
pfile_p->pf_snmdat_p->d_version));
if (pfile_p->pf_snmdat_p->d_buf == NULL)
_err_exit("%s %s in %s.", fail_buf_s, "header names",
aout_name);
DEBUG_LOC("_symintOpen: after call to getdata (for header names)");
pfile_p->pf_shdarr_p = _Malloc(pfile_p->pf_elfhd_p->e_shentsize,
pfile_p->pf_elfhd_p->e_shnum);
{
#ifdef DEBUG
char *shdnms_p = (char *)pfile_p->pf_snmdat_p->d_buf;
#endif
char *dest_p = (char *)pfile_p->pf_shdarr_p;
int shdsize = pfile_p->pf_elfhd_p->e_shentsize;
int i = 0;
int symtab_found = 0;
tscn_p = 0;
DEBUG_EXP(printf("Section header entry size = %d\n", shdsize));
DEBUG_EXP(printf("First section header name = %s\n", &shdnms_p[1]));
pfile_p->pf_symdat_aux_p = NULL;
/*
* Scan the section headers looking for a symbol table. Our
* preference is to use .symtab, because it contains the full
* set of symbols. If we find it, we stop looking immediately
* and use it. In the absence of a .symtab section, we are
* willing to use the dynamic symbol table (.dynsym), possibly
* augmented by the .SUNW_ldynsym, which contains local symbols.
*/
while ((tscn_p = elf_nextscn(telf_p, tscn_p)) != NULL) {
if ((tshd_p = elf32_getshdr(tscn_p)) == NULL)
_err_exit("%s %d in %s.", fail_shd_s, i, aout_name);
i++;
(void) memcpy(dest_p, tshd_p, shdsize);
dest_p += shdsize;
DEBUG_EXP(printf("index of section name = %d\n",
tshd_p->sh_name));
DEBUG_EXP(printf("_symintOpen: reading section %s\n",
&shdnms_p[tshd_p->sh_name]));
if (symtab_found)
continue;
switch (tshd_p->sh_type) {
case SHT_SYMTAB:
DEBUG_LOC("_symintOpen: found symbol section");
pfile_p->pf_symstr_ndx = tshd_p->sh_link;
pfile_p->pf_symdat_pri_p =
section_data_p(tscn_p, "symtab");
nsyms_pri = tshd_p->sh_size / tshd_p->sh_entsize;
/* Throw away .SUNW_ldynsym. It is for .dynsym only */
nsyms_aux = 0;
pfile_p->pf_symdat_aux_p = NULL;
/* We have found the best symbol table. Stop looking */
symtab_found = 1;
break;
case SHT_DYNSYM:
/* We will use .dynsym if no .symtab is found */
DEBUG_LOC("_symintOpen: found dynamic symbol section");
pfile_p->pf_symstr_ndx = tshd_p->sh_link;
pfile_p->pf_symdat_pri_p =
section_data_p(tscn_p, "dynsym");
nsyms_pri = tshd_p->sh_size / tshd_p->sh_entsize;
break;
case SHT_SUNW_LDYNSYM:
/* Auxiliary table, used with .dynsym */
DEBUG_LOC("_symintOpen: found dynamic symbol section");
pfile_p->pf_symdat_aux_p =
section_data_p(tscn_p, "SUNW_ldynsym");
nsyms_aux = tshd_p->sh_size / tshd_p->sh_entsize;
break;
}
}
}
if (pfile_p->pf_symdat_pri_p == NULL || pfile_p->pf_symstr_ndx == 0)
_err_exit("%s %s.", fail_sym_s, executableName);
pfile_p->pf_nstsyms = (int)(nsyms_pri + nsyms_aux);
pfile_p->pf_nstsyms_aux = (int)nsyms_aux;
if ((nsyms_pri + nsyms_aux) != (Elf64_Xword)pfile_p->pf_nstsyms)
_err_exit("%s %s.", fail_sym32_s, executableName);
DEBUG_LOC("_symintOpen: after for loop that reads the sections");
DEBUG_LOC("_symintOpen: before call to _symintLoad");
if ((pfile_p->pf_symarr_p = _symintLoad(pfile_p)) == NULL)
_err_exit("%s %s.", fail_pfsym_s, executableName);
DEBUG_LOC("_symintOpen: after call to _symintLoad");
/*
* At this point we might want to include some consistency
* checks to be sure all is well. For example, we can check
* symbol table consistency by comparing "the product of the
* number of symbols and the size of each symbol" to "the
* length of the symbol table data".
*
* Also, NULL may be a proper value (e.g., the debugger
* information when there is none) for some things that
* we cannot afford to be without. We should check these
* at this point also.
*/
DEBUG_LOC("_symintOpen: bottom");
return (pfile_p);
}
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