groups.c revision cce0e03bb2d07f0fe27cabb93acae9c23655859f
/*
* 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.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <stdio.h>
#include <string.h>
#include <link.h>
#include <debug.h>
#include "msg.h"
#include "_libld.h"
/*
* Define an AVL node for maintain group names, together with a compare function
* for the Grp_node AVL tree.
*/
typedef struct {
const char *gn_name; /* group name */
avl_node_t gn_avl; /* avl book-keeping (see SGSOFFSETOF) */
uint_t gn_hash; /* group name hash value */
} Grp_node;
static int
gnavl_compare(const void * n1, const void * n2)
{
uint_t hash1, hash2;
const char *st1, *st2;
int rc;
hash1 = ((Grp_node *)n1)->gn_hash;
hash2 = ((Grp_node *)n2)->gn_hash;
if (hash1 > hash2)
return (1);
if (hash1 < hash2)
return (-1);
st1 = ((Grp_node *)n1)->gn_name;
st2 = ((Grp_node *)n2)->gn_name;
rc = strcmp(st1, st2);
if (rc > 0)
return (1);
if (rc < 0)
return (-1);
return (0);
}
/*
* Determine whether a (COMDAT) group has already been encountered. If so,
* tag the new group having the same name as discardable.
*/
static uintptr_t
gpavl_loaded(Ofl_desc *ofl, Group_desc * gdp)
{
Grp_node gpn, *gpnp;
avl_tree_t *avlt;
avl_index_t where;
/*
* Create an avl tree if required.
*/
if ((avlt = ofl->ofl_groups) == 0) {
if ((avlt = calloc(sizeof (avl_tree_t), 1)) == NULL)
return (S_ERROR);
avl_create(avlt, gnavl_compare, sizeof (Grp_node),
SGSOFFSETOF(Grp_node, gn_avl));
ofl->ofl_groups = avlt;
}
gpn.gn_name = gdp->gd_symname;
gpn.gn_hash = sgs_str_hash(gdp->gd_symname);
if ((gpnp = avl_find(avlt, &gpn, &where)) != NULL) {
gdp->gd_flags |= GRP_FLG_DISCARD;
return (1);
}
/*
* This is a new group, save it.
*/
if ((gpnp = calloc(sizeof (Grp_node), 1)) == NULL)
return (S_ERROR);
gpnp->gn_name = gpn.gn_name;
gpnp->gn_hash = gpn.gn_hash;
avl_insert(avlt, gpnp, where);
return (0);
}
Group_desc *
ld_get_group(Ofl_desc *ofl, Is_desc *isp)
{
Ifl_desc *ifl = isp->is_file;
Elf *elf = ifl->ifl_elf;
uint_t scnndx = isp->is_scnndx;
Group_desc *gdp;
Aliste idx;
/*
* If this is the first SHF_GROUP section encountered for this file,
* establish what group sections exist.
*/
if (ifl->ifl_groups == NULL) {
Elf_Scn *scn = 0;
while (scn = elf_nextscn(elf, scn)) {
Shdr *shdr, *_shdr;
Sym *sym;
Elf_Scn *_scn;
Elf_Data *data;
Group_desc gd;
shdr = elf_getshdr(scn);
if (shdr->sh_type != SHT_GROUP)
continue;
/*
* Confirm that the sh_link points to a valid section.
*/
if ((shdr->sh_link == SHN_UNDEF) ||
(shdr->sh_link >= ifl->ifl_shnum)) {
eprintf(ofl->ofl_lml, ERR_FATAL,
MSG_INTL(MSG_FIL_INVSHLINK),
ifl->ifl_name, elf_strptr(elf,
ifl->ifl_shstrndx, shdr->sh_name),
EC_XWORD(shdr->sh_link));
ofl->ofl_flags |= FLG_OF_FATAL;
continue;
}
if (shdr->sh_entsize == 0) {
eprintf(ofl->ofl_lml, ERR_FATAL,
MSG_INTL(MSG_FIL_INVSHENTSIZE),
ifl->ifl_name, elf_strptr(elf,
ifl->ifl_shstrndx, shdr->sh_name),
EC_XWORD(shdr->sh_entsize));
ofl->ofl_flags |= FLG_OF_FATAL;
continue;
}
/*
* Get associated symbol table.
*/
_scn = elf_getscn(elf, shdr->sh_link);
_shdr = elf_getshdr(_scn);
/*
* Sanity check the sh_link field (which points to
* a symbol table entry) against the size of the
* symbol table.
*/
if ((shdr->sh_info == SHN_UNDEF) ||
(shdr->sh_info >= (Word)(_shdr->sh_size /
_shdr->sh_entsize))) {
eprintf(ofl->ofl_lml, ERR_FATAL,
MSG_INTL(MSG_FIL_INVSHINFO),
ifl->ifl_name, elf_strptr(elf,
ifl->ifl_shstrndx, shdr->sh_name),
EC_XWORD(shdr->sh_info));
ofl->ofl_flags |= FLG_OF_FATAL;
continue;
}
data = elf_getdata(_scn, 0);
sym = data->d_buf;
sym += shdr->sh_info;
data = elf_getdata(scn, 0);
gd.gd_gsectname =
elf_strptr(elf, ifl->ifl_shstrndx, shdr->sh_name);
gd.gd_symname =
elf_strptr(elf, _shdr->sh_link, sym->st_name);
gd.gd_scnndx = elf_ndxscn(scn);
gd.gd_data = data->d_buf;
gd.gd_cnt = data->d_size / sizeof (Word);
gd.gd_flags = 0;
/*
* If this group is a COMDAT group, determine whether
* this 'signature' symbol has already been detected.
*/
if ((gd.gd_data[0] & GRP_COMDAT) &&
(ELF_ST_BIND(sym->st_info) != STB_LOCAL) &&
(sym->st_shndx != SHN_UNDEF) &&
(gpavl_loaded(ofl, &gd) == S_ERROR))
return ((Group_desc *)S_ERROR);
if (alist_append(&(ifl->ifl_groups),
&gd, sizeof (Group_desc), AL_CNT_IFL_GROUPS) == 0)
return ((Group_desc *)S_ERROR);
}
}
/*
* Scan the GROUP sections associated with this file to find the
* matching group section.
*/
for (ALIST_TRAVERSE(ifl->ifl_groups, idx, gdp)) {
size_t ndx;
Word * data;
if (isp->is_shdr->sh_type == SHT_GROUP) {
if (isp->is_scnndx == gdp->gd_scnndx)
return (gdp);
continue;
}
data = gdp->gd_data;
for (ndx = 1; ndx < gdp->gd_cnt; ndx++) {
if (data[ndx] == scnndx)
return (gdp);
}
}
eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_ELF_NOGROUPSECT),
ifl->ifl_name, isp->is_name);
ofl->ofl_flags |= FLG_OF_FATAL;
return (0);
}