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elfdump.c
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elfdump.c
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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 2010 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Dump an elf file.
*/
#include <stddef.h>
#include <sys/elf_386.h>
#include <sys/elf_amd64.h>
#include <sys/elf_SPARC.h>
#include <_libelf.h>
#include <dwarf.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <strings.h>
#include <debug.h>
#include <conv.h>
#include <msg.h>
#include <_elfdump.h>
/*
* VERSYM_STATE is used to maintain information about the VERSYM section
* in the object being analyzed. It is filled in by versions(), and used
* by init_symtbl_state() when displaying symbol information.
*
* There are three forms of symbol versioning known to us:
*
* 1) The original form, introduced with Solaris 2.5, in which
* the Versym contains indexes to Verdef records, and the
* Versym values for UNDEF symbols resolved by other objects
* are all set to 0.
* 2) The GNU form, which is backward compatible with the original
* Solaris form, but which adds several extensions:
* - The Versym also contains indexes to Verneed records, recording
* which object/version contributed the external symbol at
* link time. These indexes start with the next value following
* the final Verdef index. The index is written to the previously
* reserved vna_other field of the ELF Vernaux structure.
* - The top bit of the Versym value is no longer part of the index,
* but is used as a "hidden bit" to prevent binding to the symbol.
* - Multiple implementations of a given symbol, contained in varying
* versions are allowed, using special assembler pseudo ops,
* and encoded in the symbol name using '@' characters.
* 3) Modified Solaris form, in which we adopt the first GNU extension
* (Versym indexes to Verneed records), but not the others.
*
* elfdump can handle any of these cases. The presence of a DT_VERSYM
* dynamic element indicates a full GNU object. An object that lacks
* a DT_VERSYM entry, but which has non-zero vna_other fields in the Vernaux
* structures is a modified Solaris object. An object that has neither of
* these uses the original form.
*
* max_verndx contains the largest version index that can appear
* in a Versym entry. This can never be less than 1: In the case where
* there is no verdef/verneed sections, the [0] index is reserved
* for local symbols, and the [1] index for globals. If the original
* Solaris versioning rules are in effect and there is a verdef section,
* then max_verndex is the number of defined versions. If one of the
* other versioning forms is in effect, then:
* 1) If there is no verneed section, it is the same as for
* original Solaris versioning.
* 2) If there is a verneed section, the vna_other field of the
* Vernaux structs contain versions, and max_verndx is the
* largest such index.
*
* If gnu_full is True, the object uses the full GNU form of versioning.
* The value of the gnu_full field is based on the presence of
* a DT_VERSYM entry in the dynamic section: GNU ld produces these, and
* Solaris ld does not.
*
* The gnu_needed field is True if the Versym contains indexes to
* Verneed records, as indicated by non-zero vna_other fields in the Verneed
* section. If gnu_full is True, then gnu_needed will always be true.
* However, gnu_needed can be true without gnu_full. This is the modified
* Solaris form.
*/
typedef struct {
Cache *cache; /* Pointer to cache entry for VERSYM */
Versym *data; /* Pointer to versym array */
int gnu_full; /* True if object uses GNU versioning rules */
int gnu_needed; /* True if object uses VERSYM indexes for */
/* VERNEED (subset of gnu_full) */
int max_verndx; /* largest versym index value */
} VERSYM_STATE;
/*
* SYMTBL_STATE is used to maintain information about a single symbol
* table section, for use by the routines that display symbol information.
*/
typedef struct {
const char *file; /* Name of file */
Ehdr *ehdr; /* ELF header for file */
Cache *cache; /* Cache of all section headers */
uchar_t osabi; /* OSABI to use */
Word shnum; /* # of sections in cache */
Cache *seccache; /* Cache of symbol table section hdr */
Word secndx; /* Index of symbol table section hdr */
const char *secname; /* Name of section */
uint_t flags; /* Command line option flags */
struct { /* Extended section index data */
int checked; /* TRUE if already checked for shxndx */
Word *data; /* NULL, or extended section index */
/* used for symbol table entries */
uint_t n; /* # items in shxndx.data */
} shxndx;
VERSYM_STATE *versym; /* NULL, or associated VERSYM section */
Sym *sym; /* Array of symbols */
Word symn; /* # of symbols */
} SYMTBL_STATE;
/*
* A variable of this type is used to track information related to
* .eh_frame and .eh_frame_hdr sections across calls to unwind_eh_frame().
*/
typedef struct {
Word frame_cnt; /* # .eh_frame sections seen */
Word frame_ndx; /* Section index of 1st .eh_frame */
Word hdr_cnt; /* # .eh_frame_hdr sections seen */
Word hdr_ndx; /* Section index of 1st .eh_frame_hdr */
uint64_t frame_ptr; /* Value of FramePtr field from first */
/* .eh_frame_hdr section */
uint64_t frame_base; /* Data addr of 1st .eh_frame */
} gnu_eh_state_t;
/*
* C++ .exception_ranges entries make use of the signed ptrdiff_t
* type to record self-relative pointer values. We need a type
* for this that is matched to the ELFCLASS being processed.
*/
#if defined(_ELF64)
typedef int64_t PTRDIFF_T;
#else
typedef int32_t PTRDIFF_T;
#endif
/*
* The Sun C++ ABI uses this struct to define each .exception_ranges
* entry. From the ABI:
*
* The field ret_addr is a self relative pointer to the start of the address
* range. The name was chosen because in the current implementation the range
* typically starts at the return address for a call site.
*
* The field length is the difference, in bytes, between the pc of the last
* instruction covered by the exception range and the first. When only a
* single call site is represented without optimization, this will equal zero.
*
* The field handler_addr is a relative pointer which stores the difference
* between the start of the exception range and the address of all code to
* catch exceptions and perform the cleanup for stack unwinding.
*
* The field type_block is a relative pointer which stores the difference
* between the start of the exception range and the address of an array used
* for storing a list of the types of exceptions which can be caught within
* the exception range.
*/
typedef struct {
PTRDIFF_T ret_addr;
Xword length;
PTRDIFF_T handler_addr;
PTRDIFF_T type_block;
Xword reserved;
} exception_range_entry;
/*
* Focal point for verifying symbol names.
*/
static const char *
string(Cache *refsec, Word ndx, Cache *strsec, const char *file, Word name)
{
/*
* If an error in this routine is due to a property of the string
* section, as opposed to a bad offset into the section (a property of
* the referencing section), then we will detect the same error on
* every call involving those sections. We use these static variables
* to retain the information needed to only issue each such error once.
*/
static Cache *last_refsec; /* Last referencing section seen */
static int strsec_err; /* True if error issued */
const char *strs;
Word strn;
if (strsec->c_data == NULL)
return (NULL);
strs = (char *)strsec->c_data->d_buf;
strn = strsec->c_data->d_size;
/*
* We only print a diagnostic regarding a bad string table once per
* input section being processed. If the refsec has changed, reset
* our retained error state.
*/
if (last_refsec != refsec) {
last_refsec = refsec;
strsec_err = 0;
}
/* Verify that strsec really is a string table */
if (strsec->c_shdr->sh_type != SHT_STRTAB) {
if (!strsec_err) {
(void) fprintf(stderr, MSG_INTL(MSG_ERR_NOTSTRTAB),
file, strsec->c_ndx, refsec->c_ndx);
strsec_err = 1;
}
return (MSG_INTL(MSG_STR_UNKNOWN));
}
/*
* Is the string table offset within range of the available strings?
*/
if (name >= strn) {
/*
* Do we have a empty string table?
*/
if (strs == NULL) {
if (!strsec_err) {
(void) fprintf(stderr, MSG_INTL(MSG_ERR_BADSZ),
file, strsec->c_name);
strsec_err = 1;
}
} else {
(void) fprintf(stderr, MSG_INTL(MSG_ERR_BADSTOFF),
file, refsec->c_name, EC_WORD(ndx), strsec->c_name,
EC_WORD(name), EC_WORD(strn - 1));
}
/*
* Return the empty string so that the calling function can
* continue it's output diagnostics.
*/
return (MSG_INTL(MSG_STR_UNKNOWN));
}
return (strs + name);
}
/*
* Relocations can reference section symbols and standard symbols. If the
* former, establish the section name.
*/
static const char *
relsymname(Cache *cache, Cache *csec, Cache *strsec, Word symndx, Word symnum,
Word relndx, Sym *syms, char *secstr, size_t secsz, const char *file)
{
Sym *sym;
const char *name;
if (symndx >= symnum) {
(void) fprintf(stderr, MSG_INTL(MSG_ERR_RELBADSYMNDX),
file, EC_WORD(symndx), EC_WORD(relndx));
return (MSG_INTL(MSG_STR_UNKNOWN));
}
sym = (Sym *)(syms + symndx);
name = string(csec, symndx, strsec, file, sym->st_name);
/*
* If the symbol represents a section offset construct an appropriate
* string. Note, although section symbol table entries typically have
* a NULL name pointer, entries do exist that point into the string
* table to their own NULL strings.
*/
if ((ELF_ST_TYPE(sym->st_info) == STT_SECTION) &&
((sym->st_name == 0) || (*name == '\0'))) {
(void) snprintf(secstr, secsz, MSG_INTL(MSG_STR_SECTION),
cache[sym->st_shndx].c_name);
return ((const char *)secstr);
}
return (name);
}
/*
* Focal point for establishing a string table section. Data such as the
* dynamic information simply points to a string table. Data such as
* relocations, reference a symbol table, which in turn is associated with a
* string table.
*/
static int
stringtbl(Cache *cache, int symtab, Word ndx, Word shnum, const char *file,
Word *symnum, Cache **symsec, Cache **strsec)
{
Shdr *shdr = cache[ndx].c_shdr;
if (symtab) {
/*
* Validate the symbol table section.
*/
if ((shdr->sh_link == 0) || (shdr->sh_link >= shnum)) {
(void) fprintf(stderr, MSG_INTL(MSG_ERR_BADSHLINK),
file, cache[ndx].c_name, EC_WORD(shdr->sh_link));
return (0);
}
if ((shdr->sh_entsize == 0) || (shdr->sh_size == 0)) {
(void) fprintf(stderr, MSG_INTL(MSG_ERR_BADSZ),
file, cache[ndx].c_name);
return (0);
}
/*
* Obtain, and verify the symbol table data.
*/
if ((cache[ndx].c_data == NULL) ||
(cache[ndx].c_data->d_buf == NULL)) {
(void) fprintf(stderr, MSG_INTL(MSG_ERR_BADSZ),
file, cache[ndx].c_name);
return (0);
}
/*
* Establish the string table index.
*/
ndx = shdr->sh_link;
shdr = cache[ndx].c_shdr;
/*
* Return symbol table information.
*/
if (symnum)
*symnum = (shdr->sh_size / shdr->sh_entsize);
if (symsec)
*symsec = &cache[ndx];
}
/*
* Validate the associated string table section.
*/
if ((shdr->sh_link == 0) || (shdr->sh_link >= shnum)) {
(void) fprintf(stderr, MSG_INTL(MSG_ERR_BADSHLINK),
file, cache[ndx].c_name, EC_WORD(shdr->sh_link));
return (0);
}
if (strsec)
*strsec = &cache[shdr->sh_link];
return (1);
}
/*
* Lookup a symbol and set Sym accordingly.
*
* entry:
* name - Name of symbol to lookup
* cache - Cache of all section headers
* shnum - # of sections in cache
* sym - Address of pointer to receive symbol
* target - NULL, or section to which the symbol must be associated.
* symtab - Symbol table to search for symbol
* file - Name of file
*
* exit:
* If the symbol is found, *sym is set to reference it, and True is
* returned. If target is non-NULL, the symbol must reference the given
* section --- otherwise the section is not checked.
*
* If no symbol is found, False is returned.
*/
static int
symlookup(const char *name, Cache *cache, Word shnum, Sym **sym,
Cache *target, Cache *symtab, const char *file)
{
Shdr *shdr;
Word symn, cnt;
Sym *syms;
if (symtab == 0)
return (0);
shdr = symtab->c_shdr;
/*
* Determine the symbol data and number.
*/
if ((shdr->sh_entsize == 0) || (shdr->sh_size == 0)) {
(void) fprintf(stderr, MSG_INTL(MSG_ERR_BADSZ),
file, symtab->c_name);
return (0);
}
if (symtab->c_data == NULL)
return (0);
/* LINTED */
symn = (Word)(shdr->sh_size / shdr->sh_entsize);
syms = (Sym *)symtab->c_data->d_buf;
/*
* Get the associated string table section.
*/
if ((shdr->sh_link == 0) || (shdr->sh_link >= shnum)) {
(void) fprintf(stderr, MSG_INTL(MSG_ERR_BADSHLINK),
file, symtab->c_name, EC_WORD(shdr->sh_link));
return (0);
}
/*
* Loop through the symbol table to find a match.
*/
*sym = NULL;
for (cnt = 0; cnt < symn; syms++, cnt++) {
const char *symname;
symname = string(symtab, cnt, &cache[shdr->sh_link], file,
syms->st_name);
if (symname && (strcmp(name, symname) == 0) &&
((target == NULL) || (target->c_ndx == syms->st_shndx))) {
/*
* It is possible, though rare, for a local and
* global symbol of the same name to exist, each
* contributed by a different input object. If the
* symbol just found is local, remember it, but
* continue looking.
*/
*sym = syms;
if (ELF_ST_BIND(syms->st_info) != STB_LOCAL)
break;
}
}
return (*sym != NULL);
}
/*
* Print section headers.
*/
static void
sections(const char *file, Cache *cache, Word shnum, Ehdr *ehdr, uchar_t osabi)
{
size_t seccnt;
for (seccnt = 1; seccnt < shnum; seccnt++) {
Cache *_cache = &cache[seccnt];
Shdr *shdr = _cache->c_shdr;
const char *secname = _cache->c_name;
/*
* Although numerous section header entries can be zero, it's
* usually a sign of trouble if the type is zero.
*/
if (shdr->sh_type == 0) {
(void) fprintf(stderr, MSG_INTL(MSG_ERR_BADSHTYPE),
file, secname, EC_WORD(shdr->sh_type));
}
if (!match(MATCH_F_ALL, secname, seccnt, shdr->sh_type))
continue;
/*
* Identify any sections that are suspicious. A .got section
* shouldn't exist in a relocatable object.
*/
if (ehdr->e_type == ET_REL) {
if (strncmp(secname, MSG_ORIG(MSG_ELF_GOT),
MSG_ELF_GOT_SIZE) == 0) {
(void) fprintf(stderr,
MSG_INTL(MSG_GOT_UNEXPECTED), file,
secname);
}
}
dbg_print(0, MSG_ORIG(MSG_STR_EMPTY));
dbg_print(0, MSG_INTL(MSG_ELF_SHDR), EC_WORD(seccnt), secname);
Elf_shdr(0, osabi, ehdr->e_machine, shdr);
}
}
/*
* Obtain a specified Phdr entry.
*/
static Phdr *
getphdr(Word phnum, Word *type_arr, Word type_cnt, const char *file, Elf *elf)
{
Word cnt, tcnt;
Phdr *phdr;
if ((phdr = elf_getphdr(elf)) == NULL) {
failure(file, MSG_ORIG(MSG_ELF_GETPHDR));
return (NULL);
}
for (cnt = 0; cnt < phnum; phdr++, cnt++) {
for (tcnt = 0; tcnt < type_cnt; tcnt++) {
if (phdr->p_type == type_arr[tcnt])
return (phdr);
}
}
return (NULL);
}
/*
* Display the contents of GNU/amd64 .eh_frame and .eh_frame_hdr
* sections.
*
* entry:
* cache - Cache of all section headers
* shndx - Index of .eh_frame or .eh_frame_hdr section to be displayed
* shnum - Total number of sections which exist
* uphdr - NULL, or unwind program header associated with
* the .eh_frame_hdr section.
* ehdr - ELF header for file
* eh_state - Data used across calls to this routine. The
* caller should zero it before the first call, and
* pass it on every call.
* osabi - OSABI to use in displaying information
* file - Name of file
* flags - Command line option flags
*/
static void
unwind_eh_frame(Cache *cache, Word shndx, Word shnum, Phdr *uphdr, Ehdr *ehdr,
gnu_eh_state_t *eh_state, uchar_t osabi, const char *file, uint_t flags)
{
#if defined(_ELF64)
#define MSG_UNW_BINSRTAB2 MSG_UNW_BINSRTAB2_64
#define MSG_UNW_BINSRTABENT MSG_UNW_BINSRTABENT_64
#else
#define MSG_UNW_BINSRTAB2 MSG_UNW_BINSRTAB2_32
#define MSG_UNW_BINSRTABENT MSG_UNW_BINSRTABENT_32
#endif
Cache *_cache = &cache[shndx];
Shdr *shdr = _cache->c_shdr;
uchar_t *data = (uchar_t *)(_cache->c_data->d_buf);
size_t datasize = _cache->c_data->d_size;
Conv_dwarf_ehe_buf_t dwarf_ehe_buf;
uint64_t ndx, frame_ptr, fde_cnt, tabndx;
uint_t vers, frame_ptr_enc, fde_cnt_enc, table_enc;
uint64_t initloc, initloc0;
uint64_t gotaddr = 0;
int cnt;
for (cnt = 1; cnt < shnum; cnt++) {
if (strncmp(cache[cnt].c_name, MSG_ORIG(MSG_ELF_GOT),
MSG_ELF_GOT_SIZE) == 0) {
gotaddr = cache[cnt].c_shdr->sh_addr;
break;
}
}
/*
* Is this a .eh_frame_hdr?
*/
if ((uphdr && (shdr->sh_addr == uphdr->p_vaddr)) ||
(strncmp(_cache->c_name, MSG_ORIG(MSG_SCN_FRMHDR),
MSG_SCN_FRMHDR_SIZE) == 0)) {
/*
* There can only be a single .eh_frame_hdr.
* Flag duplicates.
*/
if (++eh_state->hdr_cnt > 1)
(void) fprintf(stderr, MSG_INTL(MSG_ERR_MULTEHFRMHDR),
file, EC_WORD(shndx), _cache->c_name);
dbg_print(0, MSG_ORIG(MSG_UNW_FRMHDR));
ndx = 0;
vers = data[ndx++];
frame_ptr_enc = data[ndx++];
fde_cnt_enc = data[ndx++];
table_enc = data[ndx++];
dbg_print(0, MSG_ORIG(MSG_UNW_FRMVERS), vers);
frame_ptr = dwarf_ehe_extract(data, &ndx, frame_ptr_enc,
ehdr->e_ident, B_TRUE, shdr->sh_addr, ndx, gotaddr);
if (eh_state->hdr_cnt == 1) {
eh_state->hdr_ndx = shndx;
eh_state->frame_ptr = frame_ptr;
}
dbg_print(0, MSG_ORIG(MSG_UNW_FRPTRENC),
conv_dwarf_ehe(frame_ptr_enc, &dwarf_ehe_buf),
EC_XWORD(frame_ptr));
fde_cnt = dwarf_ehe_extract(data, &ndx, fde_cnt_enc,
ehdr->e_ident, B_TRUE, shdr->sh_addr, ndx, gotaddr);
dbg_print(0, MSG_ORIG(MSG_UNW_FDCNENC),
conv_dwarf_ehe(fde_cnt_enc, &dwarf_ehe_buf),
EC_XWORD(fde_cnt));
dbg_print(0, MSG_ORIG(MSG_UNW_TABENC),
conv_dwarf_ehe(table_enc, &dwarf_ehe_buf));
dbg_print(0, MSG_ORIG(MSG_UNW_BINSRTAB1));
dbg_print(0, MSG_ORIG(MSG_UNW_BINSRTAB2));
for (tabndx = 0; tabndx < fde_cnt; tabndx++) {
initloc = dwarf_ehe_extract(data, &ndx, table_enc,
ehdr->e_ident, B_TRUE, shdr->sh_addr, ndx, gotaddr);
/*LINTED:E_VAR_USED_BEFORE_SET*/
if ((tabndx != 0) && (initloc0 > initloc))
(void) fprintf(stderr,
MSG_INTL(MSG_ERR_BADSORT), file,
_cache->c_name, EC_WORD(tabndx));
dbg_print(0, MSG_ORIG(MSG_UNW_BINSRTABENT),
EC_XWORD(initloc),
EC_XWORD(dwarf_ehe_extract(data, &ndx,
table_enc, ehdr->e_ident, B_TRUE, shdr->sh_addr,
ndx, gotaddr)));
initloc0 = initloc;
}
} else { /* Display the .eh_frame section */
eh_state->frame_cnt++;
if (eh_state->frame_cnt == 1) {
eh_state->frame_ndx = shndx;
eh_state->frame_base = shdr->sh_addr;
} else if ((eh_state->frame_cnt > 1) &&
(ehdr->e_type != ET_REL)) {
Conv_inv_buf_t inv_buf;
(void) fprintf(stderr, MSG_INTL(MSG_WARN_MULTEHFRM),
file, EC_WORD(shndx), _cache->c_name,
conv_ehdr_type(osabi, ehdr->e_type, 0, &inv_buf));
}
dump_eh_frame(data, datasize, shdr->sh_addr,
ehdr->e_machine, ehdr->e_ident, gotaddr);
}
/*
* If we've seen the .eh_frame_hdr and the first .eh_frame section,
* compare the header frame_ptr to the address of the actual frame
* section to ensure the link-editor got this right. Note, this
* diagnostic is only produced when unwind information is explicitly
* asked for, as shared objects built with an older ld(1) may reveal
* this inconsistency. Although an inconsistency, it doesn't seem to
* have any adverse effect on existing tools.
*/
if (((flags & FLG_MASK_SHOW) != FLG_MASK_SHOW) &&
(eh_state->hdr_cnt > 0) && (eh_state->frame_cnt > 0) &&
(eh_state->frame_ptr != eh_state->frame_base))
(void) fprintf(stderr, MSG_INTL(MSG_ERR_BADEHFRMPTR),
file, EC_WORD(eh_state->hdr_ndx),
cache[eh_state->hdr_ndx].c_name,
EC_XWORD(eh_state->frame_ptr),
EC_WORD(eh_state->frame_ndx),
cache[eh_state->frame_ndx].c_name,
EC_XWORD(eh_state->frame_base));
#undef MSG_UNW_BINSRTAB2
#undef MSG_UNW_BINSRTABENT
}
/*
* Convert a self relative pointer into an address. A self relative
* pointer adds the address where the pointer resides to the offset
* contained in the pointer. The benefit is that the value of the
* pointer does not require relocation.
*
* entry:
* base_addr - Address of the pointer.
* delta - Offset relative to base_addr giving desired address
*
* exit:
* The computed address is returned.
*
* note:
* base_addr is an unsigned value, while ret_addr is signed. This routine
* used explicit testing and casting to explicitly control type
* conversion, and ensure that we handle the maximum possible range.
*/
static Addr
srelptr(Addr base_addr, PTRDIFF_T delta)
{
if (delta < 0)
return (base_addr - (Addr) (-delta));
return (base_addr + (Addr) delta);
}
/*
* Byte swap a PTRDIFF_T value.
*/
static PTRDIFF_T
swap_ptrdiff(PTRDIFF_T value)
{
PTRDIFF_T r;
uchar_t *dst = (uchar_t *)&r;
uchar_t *src = (uchar_t *)&value;
UL_ASSIGN_BSWAP_XWORD(dst, src);
return (r);
}
/*
* Display exception_range_entry items from the .exception_ranges section
* of a Sun C++ object.
*/
static void
unwind_exception_ranges(Cache *_cache, const char *file, int do_swap)
{
/*
* Translate a PTRDIFF_T self-relative address field of
* an exception_range_entry struct into an address.
*
* entry:
* exc_addr - Address of base of exception_range_entry struct
* cur_ent - Pointer to data in the struct to be translated
*
* _f - Field of struct to be translated
*/
#define SRELPTR(_f) \
srelptr(exc_addr + offsetof(exception_range_entry, _f), cur_ent->_f)
#if defined(_ELF64)
#define MSG_EXR_TITLE MSG_EXR_TITLE_64
#define MSG_EXR_ENTRY MSG_EXR_ENTRY_64
#else
#define MSG_EXR_TITLE MSG_EXR_TITLE_32
#define MSG_EXR_ENTRY MSG_EXR_ENTRY_32
#endif
exception_range_entry scratch, *ent, *cur_ent = &scratch;
char index[MAXNDXSIZE];
Word i, nelts;
Addr addr, addr0, offset = 0;
Addr exc_addr = _cache->c_shdr->sh_addr;
dbg_print(0, MSG_INTL(MSG_EXR_TITLE));
ent = (exception_range_entry *)(_cache->c_data->d_buf);
nelts = _cache->c_data->d_size / sizeof (exception_range_entry);
for (i = 0; i < nelts; i++, ent++) {
if (do_swap) {
/*
* Copy byte swapped values into the scratch buffer.
* The reserved field is not used, so we skip it.
*/
scratch.ret_addr = swap_ptrdiff(ent->ret_addr);
scratch.length = BSWAP_XWORD(ent->length);
scratch.handler_addr = swap_ptrdiff(ent->handler_addr);
scratch.type_block = swap_ptrdiff(ent->type_block);
} else {
cur_ent = ent;
}
/*
* The table is required to be sorted by the address
* derived from ret_addr, to allow binary searching. Ensure
* that addresses grow monotonically.
*/
addr = SRELPTR(ret_addr);
/*LINTED:E_VAR_USED_BEFORE_SET*/
if ((i != 0) && (addr0 > addr))
(void) fprintf(stderr, MSG_INTL(MSG_ERR_BADSORT),
file, _cache->c_name, EC_WORD(i));
(void) snprintf(index, MAXNDXSIZE, MSG_ORIG(MSG_FMT_INDEX),
EC_XWORD(i));
dbg_print(0, MSG_INTL(MSG_EXR_ENTRY), index, EC_ADDR(offset),
EC_ADDR(addr), EC_ADDR(cur_ent->length),
EC_ADDR(SRELPTR(handler_addr)),
EC_ADDR(SRELPTR(type_block)));
addr0 = addr;
exc_addr += sizeof (exception_range_entry);
offset += sizeof (exception_range_entry);
}
#undef SRELPTR
#undef MSG_EXR_TITLE
#undef MSG_EXR_ENTRY
}
/*
* Display information from unwind/exception sections:
*
* - GNU/amd64 .eh_frame and .eh_frame_hdr
* - Sun C++ .exception_ranges
*
*/
static void
unwind(Cache *cache, Word shnum, Word phnum, Ehdr *ehdr, uchar_t osabi,
const char *file, Elf *elf, uint_t flags)
{
static Word phdr_types[] = { PT_SUNW_UNWIND, PT_SUNW_EH_FRAME };
Word cnt;
Phdr *uphdr = NULL;
gnu_eh_state_t eh_state;
/*
* Historical background: .eh_frame and .eh_frame_hdr sections
* come from the GNU compilers (particularly C++), and are used
* under all architectures. Their format is based on DWARF. When
* the amd64 ABI was defined, these sections were adopted wholesale
* from the existing practice.
*
* When amd64 support was added to Solaris, support for these
* sections was added, using the SHT_AMD64_UNWIND section type
* to identify them. At first, we ignored them in objects for
* non-amd64 targets, but later broadened our support to include
* other architectures in order to better support gcc-generated
* objects.
*
* .exception_ranges implement the same basic concepts, but
* were invented at Sun for the Sun C++ compiler.
*
* We match these sections by name, rather than section type,
* because they can come in as either SHT_AMD64_UNWIND, or as
* SHT_PROGBITS, and because the type isn't enough to determine
* how they should be interpreted.
*/
/* Find the program header for .eh_frame_hdr if present */
if (phnum)
uphdr = getphdr(phnum, phdr_types,
sizeof (phdr_types) / sizeof (*phdr_types), file, elf);
/*
* eh_state is used to retain data used by unwind_eh_frame()
* across calls.
*/
bzero(&eh_state, sizeof (eh_state));
for (cnt = 1; cnt < shnum; cnt++) {
Cache *_cache = &cache[cnt];
Shdr *shdr = _cache->c_shdr;
int is_exrange;
/*
* Skip sections of the wrong type. On amd64, they
* can be SHT_AMD64_UNWIND. On all platforms, they
* can be SHT_PROGBITS (including amd64, if using
* the GNU compilers).
*
* Skip anything other than these two types. The name
* test below will thin out the SHT_PROGBITS that don't apply.
*/
if ((shdr->sh_type != SHT_PROGBITS) &&
(shdr->sh_type != SHT_AMD64_UNWIND))
continue;
/*
* Only sections with certain well known names are of interest.
* These are:
*
* .eh_frame - amd64/GNU-compiler unwind sections
* .eh_frame_hdr - Sorted table referencing .eh_frame
* .exception_ranges - Sun C++ unwind sections
*
* We do a prefix comparison, allowing for naming conventions
* like .eh_frame.foo, hence the use of strncmp() rather than
* strcmp(). This means that we only really need to test for
* .eh_frame, as it's a prefix of .eh_frame_hdr.
*/
is_exrange = strncmp(_cache->c_name,
MSG_ORIG(MSG_SCN_EXRANGE), MSG_SCN_EXRANGE_SIZE) == 0;
if ((strncmp(_cache->c_name, MSG_ORIG(MSG_SCN_FRM),
MSG_SCN_FRM_SIZE) != 0) && !is_exrange)
continue;
if (!match(MATCH_F_ALL, _cache->c_name, cnt, shdr->sh_type))
continue;
if (_cache->c_data == NULL)
continue;
dbg_print(0, MSG_ORIG(MSG_STR_EMPTY));
dbg_print(0, MSG_INTL(MSG_ELF_SCN_UNWIND), _cache->c_name);
if (is_exrange)
unwind_exception_ranges(_cache, file,
_elf_sys_encoding() != ehdr->e_ident[EI_DATA]);
else
unwind_eh_frame(cache, cnt, shnum, uphdr, ehdr,
&eh_state, osabi, file, flags);
}
}
/*
* Initialize a symbol table state structure
*
* entry:
* state - State structure to be initialized
* cache - Cache of all section headers
* shnum - # of sections in cache
* secndx - Index of symbol table section
* ehdr - ELF header for file
* versym - Information about versym section
* file - Name of file
* flags - Command line option flags
*/
static int
init_symtbl_state(SYMTBL_STATE *state, Cache *cache, Word shnum, Word secndx,
Ehdr *ehdr, uchar_t osabi, VERSYM_STATE *versym, const char *file,
uint_t flags)
{
Shdr *shdr;
state->file = file;
state->ehdr = ehdr;
state->cache = cache;
state->osabi = osabi;
state->shnum = shnum;
state->seccache = &cache[secndx];
state->secndx = secndx;
state->secname = state->seccache->c_name;
state->flags = flags;
state->shxndx.checked = 0;
state->shxndx.data = NULL;
state->shxndx.n = 0;
shdr = state->seccache->c_shdr;
/*
* Check the symbol data and per-item size.
*/
if ((shdr->sh_entsize == 0) || (shdr->sh_size == 0)) {
(void) fprintf(stderr, MSG_INTL(MSG_ERR_BADSZ),
file, state->secname);
return (0);
}
if (state->seccache->c_data == NULL)
return (0);
/* LINTED */
state->symn = (Word)(shdr->sh_size / shdr->sh_entsize);
state->sym = (Sym *)state->seccache->c_data->d_buf;
/*
* Check associated string table section.
*/
if ((shdr->sh_link == 0) || (shdr->sh_link >= shnum)) {
(void) fprintf(stderr, MSG_INTL(MSG_ERR_BADSHLINK),
file, state->secname, EC_WORD(shdr->sh_link));
return (0);
}
/*
* Determine if there is a associated Versym section
* with this Symbol Table.
*/
if (versym && versym->cache &&
(versym->cache->c_shdr->sh_link == state->secndx))
state->versym = versym;
else
state->versym = NULL;
return (1);
}
/*
* Determine the extended section index used for symbol tables entries.
*/
static void
symbols_getxindex(SYMTBL_STATE *state)
{
uint_t symn;
Word symcnt;
state->shxndx.checked = 1; /* Note that we've been called */
for (symcnt = 1; symcnt < state->shnum; symcnt++) {
Cache *_cache = &state->cache[symcnt];
Shdr *shdr = _cache->c_shdr;
if ((shdr->sh_type != SHT_SYMTAB_SHNDX) ||
(shdr->sh_link != state->secndx))
continue;
if ((shdr->sh_entsize) &&
/* LINTED */
((symn = (uint_t)(shdr->sh_size / shdr->sh_entsize)) == 0))
continue;
if (_cache->c_data == NULL)
continue;
state->shxndx.data = _cache->c_data->d_buf;
state->shxndx.n = symn;
return;
}
}
/*
* Produce a line of output for the given symbol
*