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nasm/output/outelf32.c
Cyrill Gorcunov 2e6297ff1b out: Zeroify temp buffer before use 
This is a a buffer on stack big enough to hold
bigger object we might need (address, number and
etc) but it's defined as an array of bytes and
we treat it as different types depending on context,
which may lead to situation where data from stack
been treated as meaningful.

In particular in commit 5b730a197 we've fixed such
problem simply using a "big" write to zeroify stack
data before use.

Lets simply zeroify this buffer explicitly to escape
such problems in future.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
2015-07-19 14:24:26 +03:00

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/* ----------------------------------------------------------------------- *
*
* Copyright 1996-2013 The NASM Authors - All Rights Reserved
* See the file AUTHORS included with the NASM distribution for
* the specific copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following
* conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* ----------------------------------------------------------------------- */
/*
* outelf32.c output routines for the Netwide Assembler to produce
* ELF32 (i386 of course) object file format
*/
#include "compiler.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <inttypes.h>
#include <limits.h>
#include "nasm.h"
#include "nasmlib.h"
#include "saa.h"
#include "raa.h"
#include "stdscan.h"
#include "eval.h"
#include "output/outform.h"
#include "output/outlib.h"
#include "rbtree.h"
#include "output/dwarf.h"
#include "output/stabs.h"
#include "output/outelf.h"
#ifdef OF_ELF32
#define SECT_DELTA 32
static struct elf_section **sects;
static int nsects, sectlen;
#define SHSTR_DELTA 256
static char *shstrtab;
static int shstrtablen, shstrtabsize;
static struct SAA *syms;
static uint32_t nlocals, nglobs, ndebugs; /* Symbol counts */
static int32_t def_seg;
static struct RAA *bsym;
static struct SAA *strs;
static uint32_t strslen;
static struct elf_symbol *fwds;
static char elf_module[FILENAME_MAX];
extern struct ofmt of_elf32;
static struct ELF_SECTDATA {
void *data;
int32_t len;
bool is_saa;
} *elf_sects;
static int elf_nsect, nsections;
static int32_t elf_foffs;
static void elf_write(void);
static void elf_sect_write(struct elf_section *, const uint8_t *,
uint32_t);
static void elf_section_header(int, int, int, void *, bool, int32_t, int, int,
int, int);
static void elf_write_sections(void);
static struct SAA *elf_build_symtab(int32_t *, int32_t *);
static struct SAA *elf_build_reltab(uint64_t *, struct elf_reloc *);
static void add_sectname(char *, char *);
struct erel {
int offset, info;
};
struct symlininfo {
int offset;
int section; /* section index */
char *name; /* shallow-copied pointer of section name */
};
struct linelist {
struct linelist *next;
struct linelist *last;
struct symlininfo info;
char *filename;
int line;
};
struct sectlist {
struct SAA *psaa;
int section;
int line;
int offset;
int file;
struct sectlist *next;
struct sectlist *last;
};
/* common debug variables */
static int currentline = 1;
static int debug_immcall = 0;
/* stabs debug variables */
static struct linelist *stabslines = 0;
static int numlinestabs = 0;
static char *stabs_filename = 0;
static uint8_t *stabbuf = 0, *stabstrbuf = 0, *stabrelbuf = 0;
static int stablen, stabstrlen, stabrellen;
/* dwarf debug variables */
static struct linelist *dwarf_flist = 0, *dwarf_clist = 0, *dwarf_elist = 0;
static struct sectlist *dwarf_fsect = 0, *dwarf_csect = 0, *dwarf_esect = 0;
static int dwarf_numfiles = 0, dwarf_nsections;
static uint8_t *arangesbuf = 0, *arangesrelbuf = 0, *pubnamesbuf = 0, *infobuf = 0, *inforelbuf = 0,
*abbrevbuf = 0, *linebuf = 0, *linerelbuf = 0, *framebuf = 0, *locbuf = 0;
static int8_t line_base = -5, line_range = 14, opcode_base = 13;
static int arangeslen, arangesrellen, pubnameslen, infolen, inforellen,
abbrevlen, linelen, linerellen, framelen, loclen;
static int32_t dwarf_infosym, dwarf_abbrevsym, dwarf_linesym;
static struct dfmt df_dwarf;
static struct dfmt df_stabs;
static struct elf_symbol *lastsym;
/* common debugging routines */
static void debug32_typevalue(int32_t);
static void debug32_deflabel(char *, int32_t, int64_t, int, char *);
static void debug32_directive(const char *, const char *);
/* stabs debugging routines */
static void stabs32_linenum(const char *filename, int32_t linenumber, int32_t);
static void stabs32_output(int, void *);
static void stabs32_generate(void);
static void stabs32_cleanup(void);
/* dwarf debugging routines */
static void dwarf32_init(void);
static void dwarf32_linenum(const char *filename, int32_t linenumber, int32_t);
static void dwarf32_output(int, void *);
static void dwarf32_generate(void);
static void dwarf32_cleanup(void);
static void dwarf32_findfile(const char *);
static void dwarf32_findsect(const int);
/*
* Special NASM section numbers which are used to define ELF special
* symbols, which can be used with WRT to provide PIC and TLS
* relocation types.
*/
static int32_t elf_gotpc_sect, elf_gotoff_sect;
static int32_t elf_got_sect, elf_plt_sect;
static int32_t elf_sym_sect, elf_tlsie_sect;
static void elf_init(void)
{
sects = NULL;
nsects = sectlen = 0;
syms = saa_init((int32_t)sizeof(struct elf_symbol));
nlocals = nglobs = ndebugs = 0;
bsym = raa_init();
strs = saa_init(1L);
saa_wbytes(strs, "\0", 1L);
saa_wbytes(strs, elf_module, strlen(elf_module)+1);
strslen = 2 + strlen(elf_module);
shstrtab = NULL;
shstrtablen = shstrtabsize = 0;;
add_sectname("", "");
fwds = NULL;
elf_gotpc_sect = seg_alloc();
define_label("..gotpc", elf_gotpc_sect + 1, 0L, NULL, false, false);
elf_gotoff_sect = seg_alloc();
define_label("..gotoff", elf_gotoff_sect + 1, 0L, NULL, false, false);
elf_got_sect = seg_alloc();
define_label("..got", elf_got_sect + 1, 0L, NULL, false, false);
elf_plt_sect = seg_alloc();
define_label("..plt", elf_plt_sect + 1, 0L, NULL, false, false);
elf_sym_sect = seg_alloc();
define_label("..sym", elf_sym_sect + 1, 0L, NULL, false, false);
elf_tlsie_sect = seg_alloc();
define_label("..tlsie", elf_tlsie_sect + 1, 0L, NULL, false, false);
def_seg = seg_alloc();
}
static void elf_cleanup(int debuginfo)
{
struct elf_reloc *r;
int i;
(void)debuginfo;
elf_write();
for (i = 0; i < nsects; i++) {
if (sects[i]->type != SHT_NOBITS)
saa_free(sects[i]->data);
if (sects[i]->head)
saa_free(sects[i]->rel);
while (sects[i]->head) {
r = sects[i]->head;
sects[i]->head = sects[i]->head->next;
nasm_free(r);
}
}
nasm_free(sects);
saa_free(syms);
raa_free(bsym);
saa_free(strs);
if (of_elf32.current_dfmt) {
of_elf32.current_dfmt->cleanup();
}
}
static void add_sectname(char *firsthalf, char *secondhalf)
{
int len = strlen(firsthalf) + strlen(secondhalf);
while (shstrtablen + len + 1 > shstrtabsize)
shstrtab = nasm_realloc(shstrtab, (shstrtabsize += SHSTR_DELTA));
strcpy(shstrtab + shstrtablen, firsthalf);
strcat(shstrtab + shstrtablen, secondhalf);
shstrtablen += len + 1;
}
static int elf_make_section(char *name, int type, int flags, int align)
{
struct elf_section *s;
s = nasm_zalloc(sizeof(*s));
if (type != SHT_NOBITS)
s->data = saa_init(1L);
s->tail = &s->head;
if (!strcmp(name, ".text"))
s->index = def_seg;
else
s->index = seg_alloc();
add_sectname("", name);
s->name = nasm_strdup(name);
s->type = type;
s->flags = flags;
s->align = align;
if (nsects >= sectlen)
sects = nasm_realloc(sects, (sectlen += SECT_DELTA) * sizeof(*sects));
sects[nsects++] = s;
return nsects - 1;
}
static int32_t elf_section_names(char *name, int pass, int *bits)
{
char *p;
uint32_t flags, flags_and, flags_or;
uint64_t align;
int type, i;
/*
* Default is 32 bits.
*/
if (!name) {
*bits = 32;
return def_seg;
}
p = nasm_skip_word(name);
if (*p)
*p++ = '\0';
flags_and = flags_or = type = align = 0;
elf_section_attrib(name, p, pass, &flags_and,
&flags_or, &align, &type);
if (!strcmp(name, ".shstrtab") ||
!strcmp(name, ".symtab") ||
!strcmp(name, ".strtab")) {
nasm_error(ERR_NONFATAL, "attempt to redefine reserved section"
"name `%s'", name);
return NO_SEG;
}
for (i = 0; i < nsects; i++)
if (!strcmp(name, sects[i]->name))
break;
if (i == nsects) {
const struct elf_known_section *ks = elf_known_sections;
while (ks->name) {
if (!strcmp(name, ks->name))
break;
ks++;
}
type = type ? type : ks->type;
align = align ? align : ks->align;
flags = (ks->flags & ~flags_and) | flags_or;
i = elf_make_section(name, type, flags, align);
} else if (pass == 1) {
if ((type && sects[i]->type != type)
|| (align && sects[i]->align != align)
|| (flags_and && ((sects[i]->flags & flags_and) != flags_or)))
nasm_error(ERR_WARNING, "incompatible section attributes ignored on"
" redeclaration of section `%s'", name);
}
return sects[i]->index;
}
static void elf_deflabel(char *name, int32_t segment, int64_t offset,
int is_global, char *special)
{
int pos = strslen;
struct elf_symbol *sym;
bool special_used = false;
#if defined(DEBUG) && DEBUG>2
nasm_error(ERR_DEBUG,
" elf_deflabel: %s, seg=%"PRIx32", off=%"PRIx64", is_global=%d, %s\n",
name, segment, offset, is_global, special);
#endif
if (name[0] == '.' && name[1] == '.' && name[2] != '@') {
/*
* This is a NASM special symbol. We never allow it into
* the ELF symbol table, even if it's a valid one. If it
* _isn't_ a valid one, we should barf immediately.
*/
if (strcmp(name, "..gotpc") && strcmp(name, "..gotoff") &&
strcmp(name, "..got") && strcmp(name, "..plt") &&
strcmp(name, "..sym") && strcmp(name, "..tlsie"))
nasm_error(ERR_NONFATAL, "unrecognised special symbol `%s'", name);
return;
}
if (is_global == 3) {
struct elf_symbol **s;
/*
* Fix up a forward-reference symbol size from the first
* pass.
*/
for (s = &fwds; *s; s = &(*s)->nextfwd)
if (!strcmp((*s)->name, name)) {
struct tokenval tokval;
expr *e;
char *p = nasm_skip_spaces(nasm_skip_word(special));
stdscan_reset();
stdscan_set(p);
tokval.t_type = TOKEN_INVALID;
e = evaluate(stdscan, NULL, &tokval, NULL, 1, nasm_error, NULL);
if (e) {
if (!is_simple(e))
nasm_error(ERR_NONFATAL, "cannot use relocatable"
" expression as symbol size");
else
(*s)->size = reloc_value(e);
}
/*
* Remove it from the list of unresolved sizes.
*/
nasm_free((*s)->name);
*s = (*s)->nextfwd;
return;
}
return; /* it wasn't an important one */
}
saa_wbytes(strs, name, (int32_t)(1 + strlen(name)));
strslen += 1 + strlen(name);
lastsym = sym = saa_wstruct(syms);
memset(&sym->symv, 0, sizeof(struct rbtree));
sym->strpos = pos;
sym->type = is_global ? SYM_GLOBAL : SYM_LOCAL;
sym->other = STV_DEFAULT;
sym->size = 0;
if (segment == NO_SEG)
sym->section = SHN_ABS;
else {
int i;
sym->section = SHN_UNDEF;
if (segment == def_seg) {
/* we have to be sure at least text section is there */
int tempint;
if (segment != elf_section_names(".text", 2, &tempint))
nasm_error(ERR_PANIC, "strange segment conditions in ELF driver");
}
for (i = 0; i < nsects; i++) {
if (segment == sects[i]->index) {
sym->section = i + 1;
break;
}
}
}
if (is_global == 2) {
sym->size = offset;
sym->symv.key = 0;
sym->section = SHN_COMMON;
/*
* We have a common variable. Check the special text to see
* if it's a valid number and power of two; if so, store it
* as the alignment for the common variable.
*/
if (special) {
bool err;
sym->symv.key = readnum(special, &err);
if (err)
nasm_error(ERR_NONFATAL, "alignment constraint `%s' is not a"
" valid number", special);
else if ((sym->symv.key | (sym->symv.key - 1)) != 2 * sym->symv.key - 1)
nasm_error(ERR_NONFATAL, "alignment constraint `%s' is not a"
" power of two", special);
}
special_used = true;
} else
sym->symv.key = (sym->section == SHN_UNDEF ? 0 : offset);
if (sym->type == SYM_GLOBAL) {
/*
* If sym->section == SHN_ABS, then the first line of the
* else section would cause a core dump, because its a reference
* beyond the end of the section array.
* This behaviour is exhibited by this code:
* GLOBAL crash_nasm
* crash_nasm equ 0
* To avoid such a crash, such requests are silently discarded.
* This may not be the best solution.
*/
if (sym->section == SHN_UNDEF || sym->section == SHN_COMMON) {
bsym = raa_write(bsym, segment, nglobs);
} else if (sym->section != SHN_ABS) {
/*
* This is a global symbol; so we must add it to the rbtree
* of global symbols in its section.
*
* In addition, we check the special text for symbol
* type and size information.
*/
sects[sym->section-1]->gsyms =
rb_insert(sects[sym->section-1]->gsyms, &sym->symv);
if (special) {
int n = strcspn(special, " \t");
if (!nasm_strnicmp(special, "function", n))
sym->type |= STT_FUNC;
else if (!nasm_strnicmp(special, "data", n) ||
!nasm_strnicmp(special, "object", n))
sym->type |= STT_OBJECT;
else if (!nasm_strnicmp(special, "notype", n))
sym->type |= STT_NOTYPE;
else
nasm_error(ERR_NONFATAL, "unrecognised symbol type `%.*s'",
n, special);
special += n;
special = nasm_skip_spaces(special);
if (*special) {
n = strcspn(special, " \t");
if (!nasm_strnicmp(special, "default", n))
sym->other = STV_DEFAULT;
else if (!nasm_strnicmp(special, "internal", n))
sym->other = STV_INTERNAL;
else if (!nasm_strnicmp(special, "hidden", n))
sym->other = STV_HIDDEN;
else if (!nasm_strnicmp(special, "protected", n))
sym->other = STV_PROTECTED;
else
n = 0;
special += n;
}
if (*special) {
struct tokenval tokval;
expr *e;
int fwd = 0;
char *saveme = stdscan_get();
while (special[n] && nasm_isspace(special[n]))
n++;
/*
* We have a size expression; attempt to
* evaluate it.
*/
stdscan_reset();
stdscan_set(special + n);
tokval.t_type = TOKEN_INVALID;
e = evaluate(stdscan, NULL, &tokval, &fwd, 0, nasm_error,
NULL);
if (fwd) {
sym->nextfwd = fwds;
fwds = sym;
sym->name = nasm_strdup(name);
} else if (e) {
if (!is_simple(e))
nasm_error(ERR_NONFATAL, "cannot use relocatable"
" expression as symbol size");
else
sym->size = reloc_value(e);
}
stdscan_set(saveme);
}
special_used = true;
}
/*
* If TLS segment, mark symbol accordingly.
*/
if (sects[sym->section - 1]->flags & SHF_TLS) {
sym->type &= 0xf0;
sym->type |= STT_TLS;
}
}
sym->globnum = nglobs;
nglobs++;
} else
nlocals++;
if (special && !special_used)
nasm_error(ERR_NONFATAL, "no special symbol features supported here");
}
static void elf_add_reloc(struct elf_section *sect, int32_t segment, int type)
{
struct elf_reloc *r;
r = *sect->tail = nasm_zalloc(sizeof(struct elf_reloc));
sect->tail = &r->next;
r->address = sect->len;
if (segment != NO_SEG) {
int i;
for (i = 0; i < nsects; i++)
if (segment == sects[i]->index)
r->symbol = i + 2;
if (!r->symbol)
r->symbol = GLOBAL_TEMP_BASE + raa_read(bsym, segment);
}
r->type = type;
sect->nrelocs++;
}
/*
* This routine deals with ..got and ..sym relocations: the more
* complicated kinds. In shared-library writing, some relocations
* with respect to global symbols must refer to the precise symbol
* rather than referring to an offset from the base of the section
* _containing_ the symbol. Such relocations call to this routine,
* which searches the symbol list for the symbol in question.
*
* R_386_GOT32 references require the _exact_ symbol address to be
* used; R_386_32 references can be at an offset from the symbol.
* The boolean argument `exact' tells us this.
*
* Return value is the adjusted value of `addr', having become an
* offset from the symbol rather than the section. Should always be
* zero when returning from an exact call.
*
* Limitation: if you define two symbols at the same place,
* confusion will occur.
*
* Inefficiency: we search, currently, using a linked list which
* isn't even necessarily sorted.
*/
static int32_t elf_add_gsym_reloc(struct elf_section *sect,
int32_t segment, uint32_t offset,
int type, bool exact)
{
struct elf_reloc *r;
struct elf_section *s;
struct elf_symbol *sym;
struct rbtree *srb;
int i;
/*
* First look up the segment/offset pair and find a global
* symbol corresponding to it. If it's not one of our segments,
* then it must be an external symbol, in which case we're fine
* doing a normal elf_add_reloc after first sanity-checking
* that the offset from the symbol is zero.
*/
s = NULL;
for (i = 0; i < nsects; i++)
if (segment == sects[i]->index) {
s = sects[i];
break;
}
if (!s) {
if (exact && offset)
nasm_error(ERR_NONFATAL, "unable to find a suitable global symbol"
" for this reference");
else
elf_add_reloc(sect, segment, type);
return offset;
}
srb = rb_search(s->gsyms, offset);
if (!srb || (exact && srb->key != offset)) {
nasm_error(ERR_NONFATAL, "unable to find a suitable global symbol"
" for this reference");
return 0;
}
sym = container_of(srb, struct elf_symbol, symv);
r = *sect->tail = nasm_malloc(sizeof(struct elf_reloc));
sect->tail = &r->next;
r->next = NULL;
r->address = sect->len;
r->symbol = GLOBAL_TEMP_BASE + sym->globnum;
r->type = type;
sect->nrelocs++;
return offset - sym->symv.key;
}
static void elf_out(int32_t segto, const void *data,
enum out_type type, uint64_t size,
int32_t segment, int32_t wrt)
{
struct elf_section *s;
int32_t addr;
uint8_t mydata[8], *p;
int reltype, bytes;
int i;
static struct symlininfo sinfo;
/*
* handle absolute-assembly (structure definitions)
*/
if (segto == NO_SEG) {
if (type != OUT_RESERVE)
nasm_error(ERR_NONFATAL, "attempt to assemble code in [ABSOLUTE]"
" space");
return;
}
s = NULL;
for (i = 0; i < nsects; i++)
if (segto == sects[i]->index) {
s = sects[i];
break;
}
if (!s) {
int tempint; /* ignored */
if (segto != elf_section_names(".text", 2, &tempint))
nasm_error(ERR_PANIC, "strange segment conditions in ELF driver");
else {
s = sects[nsects - 1];
i = nsects - 1;
}
}
/* again some stabs debugging stuff */
if (of_elf32.current_dfmt) {
sinfo.offset = s->len;
sinfo.section = i;
sinfo.name = s->name;
of_elf32.current_dfmt->debug_output(TY_STABSSYMLIN, &sinfo);
}
/* end of debugging stuff */
if (s->type == SHT_NOBITS && type != OUT_RESERVE) {
nasm_error(ERR_WARNING, "attempt to initialize memory in"
" BSS section `%s': ignored", s->name);
s->len += realsize(type, size);
return;
}
memset(mydata, 0, sizeof(mydata));
switch (type) {
case OUT_RESERVE:
if (s->type == SHT_PROGBITS) {
nasm_error(ERR_WARNING, "uninitialized space declared in"
" non-BSS section `%s': zeroing", s->name);
elf_sect_write(s, NULL, size);
} else
s->len += size;
break;
case OUT_RAWDATA:
if (segment != NO_SEG)
nasm_error(ERR_PANIC, "OUT_RAWDATA with other than NO_SEG");
elf_sect_write(s, data, size);
break;
case OUT_ADDRESS:
{
bool gnu16 = false;
int asize = abs(size);
addr = *(int64_t *)data;
if (segment != NO_SEG) {
if (segment % 2) {
nasm_error(ERR_NONFATAL, "ELF format does not support"
" segment base references");
} else {
if (wrt == NO_SEG) {
/*
* The if() is a hack to deal with compilers which
* don't handle switch() statements with 64-bit
* expressions.
*/
switch (asize) {
case 1:
gnu16 = true;
elf_add_reloc(s, segment, R_386_8);
break;
case 2:
gnu16 = true;
elf_add_reloc(s, segment, R_386_16);
break;
case 4:
elf_add_reloc(s, segment, R_386_32);
break;
default: /* Error issued further down */
break;
}
} else if (wrt == elf_gotpc_sect + 1) {
/*
* The user will supply GOT relative to $$. ELF
* will let us have GOT relative to $. So we
* need to fix up the data item by $-$$.
*/
addr += s->len;
elf_add_reloc(s, segment, R_386_GOTPC);
} else if (wrt == elf_gotoff_sect + 1) {
elf_add_reloc(s, segment, R_386_GOTOFF);
} else if (wrt == elf_tlsie_sect + 1) {
addr = elf_add_gsym_reloc(s, segment, addr,
R_386_TLS_IE, true);
} else if (wrt == elf_got_sect + 1) {
addr = elf_add_gsym_reloc(s, segment, addr,
R_386_GOT32, true);
} else if (wrt == elf_sym_sect + 1) {
switch (asize) {
case 1:
gnu16 = true;
addr = elf_add_gsym_reloc(s, segment, addr,
R_386_8, false);
break;
case 2:
gnu16 = true;
addr = elf_add_gsym_reloc(s, segment, addr,
R_386_16, false);
break;
case 4:
addr = elf_add_gsym_reloc(s, segment, addr,
R_386_32, false);
break;
default:
break;
}
} else if (wrt == elf_plt_sect + 1) {
nasm_error(ERR_NONFATAL, "ELF format cannot produce non-PC-"
"relative PLT references");
} else {
nasm_error(ERR_NONFATAL, "ELF format does not support this"
" use of WRT");
wrt = NO_SEG; /* we can at least _try_ to continue */
}
}
}
p = mydata;
if (gnu16) {
nasm_error(ERR_WARNING | ERR_WARN_GNUELF,
"8- or 16-bit relocations in ELF32 is a GNU extension");
} else if (asize != 4 && segment != NO_SEG) {
nasm_error(ERR_NONFATAL, "Unsupported non-32-bit ELF relocation");
}
WRITEADDR(p, addr, asize);
elf_sect_write(s, mydata, asize);
break;
}
case OUT_REL1ADR:
bytes = 1;
reltype = R_386_PC8;
goto rel12adr;
case OUT_REL2ADR:
bytes = 2;
reltype = R_386_PC16;
goto rel12adr;
rel12adr:
nasm_assert(segment != segto);
if (segment != NO_SEG && segment % 2) {
nasm_error(ERR_NONFATAL, "ELF format does not support"
" segment base references");
} else {
if (wrt == NO_SEG) {
nasm_error(ERR_WARNING | ERR_WARN_GNUELF,
"8- or 16-bit relocations in ELF is a GNU extension");
elf_add_reloc(s, segment, reltype);
} else {
nasm_error(ERR_NONFATAL,
"Unsupported non-32-bit ELF relocation");
}
}
p = mydata;
WRITESHORT(p, *(int64_t *)data - size);
elf_sect_write(s, mydata, bytes);
break;
case OUT_REL4ADR:
if (segment == segto)
nasm_error(ERR_PANIC, "intra-segment OUT_REL4ADR");
if (segment != NO_SEG && segment % 2) {
nasm_error(ERR_NONFATAL, "ELF format does not support"
" segment base references");
} else {
if (wrt == NO_SEG) {
elf_add_reloc(s, segment, R_386_PC32);
} else if (wrt == elf_plt_sect + 1) {
elf_add_reloc(s, segment, R_386_PLT32);
} else if (wrt == elf_gotpc_sect + 1 ||
wrt == elf_gotoff_sect + 1 ||
wrt == elf_got_sect + 1) {
nasm_error(ERR_NONFATAL, "ELF format cannot produce PC-"
"relative GOT references");
} else {
nasm_error(ERR_NONFATAL, "ELF format does not support this"
" use of WRT");
wrt = NO_SEG; /* we can at least _try_ to continue */
}
}
p = mydata;
WRITELONG(p, *(int64_t *)data - size);
elf_sect_write(s, mydata, 4L);
break;
case OUT_REL8ADR:
nasm_error(ERR_NONFATAL,
"32-bit ELF format does not support 64-bit relocations");
p = mydata;
WRITEDLONG(p, 0);
elf_sect_write(s, mydata, 8L);
break;
}
}
static void elf_write(void)
{
int align;
char *p;
int i;
struct SAA *symtab;
int32_t symtablen, symtablocal;
/*
* Work out how many sections we will have. We have SHN_UNDEF,
* then the flexible user sections, then the fixed sections
* `.shstrtab', `.symtab' and `.strtab', then optionally
* relocation sections for the user sections.
*/
nsections = sec_numspecial + 1;
if (of_elf32.current_dfmt == &df_stabs)
nsections += 3;
else if (of_elf32.current_dfmt == &df_dwarf)
nsections += 10;
add_sectname("", ".shstrtab");
add_sectname("", ".symtab");
add_sectname("", ".strtab");
for (i = 0; i < nsects; i++) {
nsections++; /* for the section itself */
if (sects[i]->head) {
nsections++; /* for its relocations */
add_sectname(".rel", sects[i]->name);
}
}
if (of_elf32.current_dfmt == &df_stabs) {
/* in case the debug information is wanted, just add these three sections... */
add_sectname("", ".stab");
add_sectname("", ".stabstr");
add_sectname(".rel", ".stab");
} else if (of_elf32.current_dfmt == &df_dwarf) {
/* the dwarf debug standard specifies the following ten sections,
not all of which are currently implemented,
although all of them are defined. */
add_sectname("", ".debug_aranges");
add_sectname(".rela", ".debug_aranges");
add_sectname("", ".debug_pubnames");
add_sectname("", ".debug_info");
add_sectname(".rela", ".debug_info");
add_sectname("", ".debug_abbrev");
add_sectname("", ".debug_line");
add_sectname(".rela", ".debug_line");
add_sectname("", ".debug_frame");
add_sectname("", ".debug_loc");
}
/*
* Output the ELF header.
*/
nasm_write("\177ELF\1\1\1", 7, ofile);
fputc(elf_osabi, ofile);
fputc(elf_abiver, ofile);
fwritezero(7, ofile);
fwriteint16_t(1, ofile); /* ET_REL relocatable file */
fwriteint16_t(3, ofile); /* EM_386 processor ID */
fwriteint32_t(1L, ofile); /* EV_CURRENT file format version */
fwriteint32_t(0L, ofile); /* no entry point */
fwriteint32_t(0L, ofile); /* no program header table */
fwriteint32_t(0x40L, ofile); /* section headers straight after
* ELF header plus alignment */
fwriteint32_t(0L, ofile); /* 386 defines no special flags */
fwriteint16_t(0x34, ofile); /* size of ELF header */
fwriteint16_t(0, ofile); /* no program header table, again */
fwriteint16_t(0, ofile); /* still no program header table */
fwriteint16_t(0x28, ofile); /* size of section header */
fwriteint16_t(nsections, ofile); /* number of sections */
fwriteint16_t(sec_shstrtab, ofile); /* string table section index for
* section header table */
fwriteint32_t(0L, ofile); /* align to 0x40 bytes */
fwriteint32_t(0L, ofile);
fwriteint32_t(0L, ofile);
/*
* Build the symbol table and relocation tables.
*/
symtab = elf_build_symtab(&symtablen, &symtablocal);
for (i = 0; i < nsects; i++)
if (sects[i]->head)
sects[i]->rel = elf_build_reltab(&sects[i]->rellen,
sects[i]->head);
/*
* Now output the section header table.
*/
elf_foffs = 0x40 + 0x28 * nsections;
align = ALIGN(elf_foffs, SEC_FILEALIGN) - elf_foffs;
elf_foffs += align;
elf_nsect = 0;
elf_sects = nasm_malloc(sizeof(*elf_sects) * nsections);
/* SHN_UNDEF */
elf_section_header(0, SHT_NULL, 0, NULL, false, 0, SHN_UNDEF, 0, 0, 0);
p = shstrtab + 1;
/* The normal sections */
for (i = 0; i < nsects; i++) {
elf_section_header(p - shstrtab, sects[i]->type, sects[i]->flags,
(sects[i]->type == SHT_PROGBITS ?
sects[i]->data : NULL), true,
sects[i]->len, 0, 0, sects[i]->align, 0);
p += strlen(p) + 1;
}
/* .shstrtab */
elf_section_header(p - shstrtab, SHT_STRTAB, 0, shstrtab, false,
shstrtablen, 0, 0, 1, 0);
p += strlen(p) + 1;
/* .symtab */
elf_section_header(p - shstrtab, SHT_SYMTAB, 0, symtab, true,
symtablen, sec_strtab, symtablocal, 4, 16);
p += strlen(p) + 1;
/* .strtab */
elf_section_header(p - shstrtab, SHT_STRTAB, 0, strs, true,
strslen, 0, 0, 1, 0);
p += strlen(p) + 1;
/* The relocation sections */
for (i = 0; i < nsects; i++)
if (sects[i]->head) {
elf_section_header(p - shstrtab, SHT_REL, 0, sects[i]->rel, true,
sects[i]->rellen, sec_symtab, i + 1, 4, 8);
p += strlen(p) + 1;
}
if (of_elf32.current_dfmt == &df_stabs) {
/* for debugging information, create the last three sections
which are the .stab , .stabstr and .rel.stab sections respectively */
/* this function call creates the stab sections in memory */
stabs32_generate();
if (stabbuf && stabstrbuf && stabrelbuf) {
elf_section_header(p - shstrtab, SHT_PROGBITS, 0, stabbuf, false,
stablen, sec_stabstr, 0, 4, 12);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_STRTAB, 0, stabstrbuf, false,
stabstrlen, 0, 0, 4, 0);
p += strlen(p) + 1;
/* link -> symtable info -> section to refer to */
elf_section_header(p - shstrtab, SHT_REL, 0, stabrelbuf, false,
stabrellen, sec_symtab, sec_stab, 4, 8);
p += strlen(p) + 1;
}
} else if (of_elf32.current_dfmt == &df_dwarf) {
/* for dwarf debugging information, create the ten dwarf sections */
/* this function call creates the dwarf sections in memory */
if (dwarf_fsect)
dwarf32_generate();
elf_section_header(p - shstrtab, SHT_PROGBITS, 0, arangesbuf, false,
arangeslen, 0, 0, 1, 0);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_RELA, 0, arangesrelbuf, false,
arangesrellen, sec_symtab, sec_debug_aranges,
1, 12);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_PROGBITS, 0, pubnamesbuf,
false, pubnameslen, 0, 0, 1, 0);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_PROGBITS, 0, infobuf, false,
infolen, 0, 0, 1, 0);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_RELA, 0, inforelbuf, false,
inforellen, sec_symtab, sec_debug_info, 1, 12);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_PROGBITS, 0, abbrevbuf, false,
abbrevlen, 0, 0, 1, 0);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_PROGBITS, 0, linebuf, false,
linelen, 0, 0, 1, 0);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_RELA, 0, linerelbuf, false,
linerellen, sec_symtab, sec_debug_line, 1, 12);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_PROGBITS, 0, framebuf, false,
framelen, 0, 0, 8, 0);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_PROGBITS, 0, locbuf, false,
loclen, 0, 0, 1, 0);
p += strlen(p) + 1;
}
fwritezero(align, ofile);
/*
* Now output the sections.
*/
elf_write_sections();
nasm_free(elf_sects);
saa_free(symtab);
}
static struct SAA *elf_build_symtab(int32_t *len, int32_t *local)
{
struct SAA *s = saa_init(1L);
struct elf_symbol *sym;
uint8_t entry[16], *p;
int i;
*len = *local = 0;
/*
* First, an all-zeros entry, required by the ELF spec.
*/
saa_wbytes(s, NULL, 16L); /* null symbol table entry */
*len += 16;
(*local)++;
/*
* Next, an entry for the file name.
*/
p = entry;
WRITELONG(p, 1); /* we know it's 1st entry in strtab */
WRITELONG(p, 0); /* no value */
WRITELONG(p, 0); /* no size either */
WRITESHORT(p, STT_FILE); /* type FILE */
WRITESHORT(p, SHN_ABS);
saa_wbytes(s, entry, 16L);
*len += 16;
(*local)++;
/*
* Now some standard symbols defining the segments, for relocation
* purposes.
*/
for (i = 1; i <= nsects; i++) {
p = entry;
WRITELONG(p, 0); /* no symbol name */
WRITELONG(p, 0); /* offset zero */
WRITELONG(p, 0); /* size zero */
WRITESHORT(p, STT_SECTION); /* type, binding, and visibility */
WRITESHORT(p, i); /* section id */
saa_wbytes(s, entry, 16L);
*len += 16;
(*local)++;
}
/*
* Now the other local symbols.
*/
saa_rewind(syms);
while ((sym = saa_rstruct(syms))) {
if (sym->type & SYM_GLOBAL)
continue;
p = entry;
WRITELONG(p, sym->strpos);
WRITELONG(p, sym->symv.key);
WRITELONG(p, sym->size);
WRITECHAR(p, sym->type); /* type and binding */
WRITECHAR(p, sym->other); /* visibility */
WRITESHORT(p, sym->section);
saa_wbytes(s, entry, 16L);
*len += 16;
(*local)++;
}
/*
* dwarf needs symbols for debug sections
* which are relocation targets.
*/
//*** fix for 32 bit
if (of_elf32.current_dfmt == &df_dwarf) {
dwarf_infosym = *local;
p = entry;
WRITELONG(p, 0); /* no symbol name */
WRITELONG(p, (uint32_t) 0); /* offset zero */
WRITELONG(p, (uint32_t) 0); /* size zero */
WRITESHORT(p, STT_SECTION); /* type, binding, and visibility */
WRITESHORT(p, sec_debug_info); /* section id */
saa_wbytes(s, entry, 16L);
*len += 16;
(*local)++;
dwarf_abbrevsym = *local;
p = entry;
WRITELONG(p, 0); /* no symbol name */
WRITELONG(p, (uint32_t) 0); /* offset zero */
WRITELONG(p, (uint32_t) 0); /* size zero */
WRITESHORT(p, STT_SECTION); /* type, binding, and visibility */
WRITESHORT(p, sec_debug_abbrev); /* section id */
saa_wbytes(s, entry, 16L);
*len += 16;
(*local)++;
dwarf_linesym = *local;
p = entry;
WRITELONG(p, 0); /* no symbol name */
WRITELONG(p, (uint32_t) 0); /* offset zero */
WRITELONG(p, (uint32_t) 0); /* size zero */
WRITESHORT(p, STT_SECTION); /* type, binding, and visibility */
WRITESHORT(p, sec_debug_line); /* section id */
saa_wbytes(s, entry, 16L);
*len += 16;
(*local)++;
}
/*
* Now the global symbols.
*/
saa_rewind(syms);
while ((sym = saa_rstruct(syms))) {
if (!(sym->type & SYM_GLOBAL))
continue;
p = entry;
WRITELONG(p, sym->strpos);
WRITELONG(p, sym->symv.key);
WRITELONG(p, sym->size);
WRITECHAR(p, sym->type); /* type and binding */
WRITECHAR(p, sym->other); /* visibility */
WRITESHORT(p, sym->section);
saa_wbytes(s, entry, 16L);
*len += 16;
}
return s;
}
static struct SAA *elf_build_reltab(uint64_t *len, struct elf_reloc *r)
{
struct SAA *s;
uint8_t *p, entry[8];
int32_t global_offset;
if (!r)
return NULL;
s = saa_init(1L);
*len = 0;
/*
* How to onvert from a global placeholder to a real symbol index;
* the +2 refers to the two special entries, the null entry and
* the filename entry.
*/
global_offset = -GLOBAL_TEMP_BASE + nsects + nlocals + ndebugs + 2;
while (r) {
int32_t sym = r->symbol;
if (sym >= GLOBAL_TEMP_BASE)
sym += global_offset;
p = entry;
WRITELONG(p, r->address);
WRITELONG(p, (sym << 8) + r->type);
saa_wbytes(s, entry, 8L);
*len += 8;
r = r->next;
}
return s;
}
static void elf_section_header(int name, int type, int flags,
void *data, bool is_saa, int32_t datalen,
int link, int info, int align, int eltsize)
{
elf_sects[elf_nsect].data = data;
elf_sects[elf_nsect].len = datalen;
elf_sects[elf_nsect].is_saa = is_saa;
elf_nsect++;
fwriteint32_t((int32_t)name, ofile);
fwriteint32_t((int32_t)type, ofile);
fwriteint32_t((int32_t)flags, ofile);
fwriteint32_t(0L, ofile); /* no address, ever, in object files */
fwriteint32_t(type == 0 ? 0L : elf_foffs, ofile);
fwriteint32_t(datalen, ofile);
if (data)
elf_foffs += ALIGN(datalen, SEC_FILEALIGN);
fwriteint32_t((int32_t)link, ofile);
fwriteint32_t((int32_t)info, ofile);
fwriteint32_t((int32_t)align, ofile);
fwriteint32_t((int32_t)eltsize, ofile);
}
static void elf_write_sections(void)
{
int i;
for (i = 0; i < elf_nsect; i++)
if (elf_sects[i].data) {
int32_t len = elf_sects[i].len;
int32_t reallen = ALIGN(len, SEC_FILEALIGN);
int32_t align = reallen - len;
if (elf_sects[i].is_saa)
saa_fpwrite(elf_sects[i].data, ofile);
else
nasm_write(elf_sects[i].data, len, ofile);
fwritezero(align, ofile);
}
}
static void elf_sect_write(struct elf_section *sect,
const uint8_t *data, uint32_t len)
{
saa_wbytes(sect->data, data, len);
sect->len += len;
}
static void elf_sectalign(int32_t seg, unsigned int value)
{
struct elf_section *s = NULL;
int i;
for (i = 0; i < nsects; i++) {
if (sects[i]->index == seg) {
s = sects[i];
break;
}
}
if (!s || !is_power2(value))
return;
if (value > s->align)
s->align = value;
}
static int32_t elf_segbase(int32_t segment)
{
return segment;
}
static void elf_filename(char *inname, char *outname)
{
strcpy(elf_module, inname);
standard_extension(inname, outname, ".o");
}
extern macros_t elf_stdmac[];
static int elf_set_info(enum geninfo type, char **val)
{
(void)type;
(void)val;
return 0;
}
static struct dfmt df_dwarf = {
"ELF32 (i386) dwarf debug format for Linux/Unix",
"dwarf",
dwarf32_init,
dwarf32_linenum,
debug32_deflabel,
debug32_directive,
debug32_typevalue,
dwarf32_output,
dwarf32_cleanup
};
static struct dfmt df_stabs = {
"ELF32 (i386) stabs debug format for Linux/Unix",
"stabs",
null_debug_init,
stabs32_linenum,
debug32_deflabel,
debug32_directive,
debug32_typevalue,
stabs32_output,
stabs32_cleanup
};
struct dfmt *elf32_debugs_arr[3] = { &df_dwarf, &df_stabs, NULL };
struct ofmt of_elf32 = {
"ELF32 (i386) object files (e.g. Linux)",
"elf32",
0,
elf32_debugs_arr,
&df_stabs,
elf_stdmac,
elf_init,
elf_set_info,
elf_out,
elf_deflabel,
elf_section_names,
elf_sectalign,
elf_segbase,
elf_directive,
elf_filename,
elf_cleanup
};
/* again, the stabs debugging stuff (code) */
static void stabs32_linenum(const char *filename, int32_t linenumber,
int32_t segto)
{
(void)segto;
if (!stabs_filename) {
stabs_filename = (char *)nasm_malloc(strlen(filename) + 1);
strcpy(stabs_filename, filename);
} else {
if (strcmp(stabs_filename, filename)) {
/*
* yep, a memory leak...this program is one-shot anyway, so who cares...
* in fact, this leak comes in quite handy to maintain a list of files
* encountered so far in the symbol lines...
*/
/* why not nasm_free(stabs_filename); we're done with the old one */
stabs_filename = (char *)nasm_malloc(strlen(filename) + 1);
strcpy(stabs_filename, filename);
}
}
debug_immcall = 1;
currentline = linenumber;
}
static void debug32_deflabel(char *name, int32_t segment, int64_t offset, int is_global,
char *special)
{
(void)name;
(void)segment;
(void)offset;
(void)is_global;
(void)special;
}
static void debug32_directive(const char *directive, const char *params)
{
(void)directive;
(void)params;
}
static void debug32_typevalue(int32_t type)
{
int32_t stype, ssize;
switch (TYM_TYPE(type)) {
case TY_LABEL:
ssize = 0;
stype = STT_NOTYPE;
break;
case TY_BYTE:
ssize = 1;
stype = STT_OBJECT;
break;
case TY_WORD:
ssize = 2;
stype = STT_OBJECT;
break;
case TY_DWORD:
ssize = 4;
stype = STT_OBJECT;
break;
case TY_FLOAT:
ssize = 4;
stype = STT_OBJECT;
break;
case TY_QWORD:
ssize = 8;
stype = STT_OBJECT;
break;
case TY_TBYTE:
ssize = 10;
stype = STT_OBJECT;
break;
case TY_OWORD:
ssize = 16;
stype = STT_OBJECT;
break;
case TY_YWORD:
ssize = 32;
stype = STT_OBJECT;
break;
case TY_COMMON:
ssize = 0;
stype = STT_COMMON;
break;
case TY_SEG:
ssize = 0;
stype = STT_SECTION;
break;
case TY_EXTERN:
ssize = 0;
stype = STT_NOTYPE;
break;
case TY_EQU:
ssize = 0;
stype = STT_NOTYPE;
break;
default:
ssize = 0;
stype = STT_NOTYPE;
break;
}
if (stype == STT_OBJECT && lastsym && !lastsym->type) {
lastsym->size = ssize;
lastsym->type = stype;
}
}
static void stabs32_output(int type, void *param)
{
struct symlininfo *s;
struct linelist *el;
if (type == TY_STABSSYMLIN) {
if (debug_immcall) {
s = (struct symlininfo *)param;
if (!(sects[s->section]->flags & SHF_EXECINSTR))
return; /* line info is only collected for executable sections */
numlinestabs++;
el = (struct linelist *)nasm_malloc(sizeof(struct linelist));
el->info.offset = s->offset;
el->info.section = s->section;
el->info.name = s->name;
el->line = currentline;
el->filename = stabs_filename;
el->next = 0;
if (stabslines) {
stabslines->last->next = el;
stabslines->last = el;
} else {
stabslines = el;
stabslines->last = el;
}
}
}
debug_immcall = 0;
}
/* for creating the .stab , .stabstr and .rel.stab sections in memory */
static void stabs32_generate(void)
{
int i, numfiles, strsize, numstabs = 0, currfile, mainfileindex;
uint8_t *sbuf, *ssbuf, *rbuf, *sptr, *rptr;
char **allfiles;
int *fileidx;
struct linelist *ptr;
ptr = stabslines;
allfiles = (char **)nasm_malloc(numlinestabs * sizeof(char *));
for (i = 0; i < numlinestabs; i++)
allfiles[i] = 0;
numfiles = 0;
while (ptr) {
if (numfiles == 0) {
allfiles[0] = ptr->filename;
numfiles++;
} else {
for (i = 0; i < numfiles; i++) {
if (!strcmp(allfiles[i], ptr->filename))
break;
}
if (i >= numfiles) {
allfiles[i] = ptr->filename;
numfiles++;
}
}
ptr = ptr->next;
}
strsize = 1;
fileidx = (int *)nasm_malloc(numfiles * sizeof(int));
for (i = 0; i < numfiles; i++) {
fileidx[i] = strsize;
strsize += strlen(allfiles[i]) + 1;
}
mainfileindex = 0;
for (i = 0; i < numfiles; i++) {
if (!strcmp(allfiles[i], elf_module)) {
mainfileindex = i;
break;
}
}
/*
* worst case size of the stab buffer would be:
* the sourcefiles changes each line, which would mean 1 SOL, 1 SYMLIN per line
* plus one "ending" entry
*/
sbuf = (uint8_t *)nasm_malloc((numlinestabs * 2 + 4) *
sizeof(struct stabentry));
ssbuf = (uint8_t *)nasm_malloc(strsize);
rbuf = (uint8_t *)nasm_malloc(numlinestabs * 8 * (2 + 3));
rptr = rbuf;
for (i = 0; i < numfiles; i++)
strcpy((char *)ssbuf + fileidx[i], allfiles[i]);
ssbuf[0] = 0;
stabstrlen = strsize; /* set global variable for length of stab strings */
sptr = sbuf;
ptr = stabslines;
numstabs = 0;
if (ptr) {
/*
* this is the first stab, its strx points to the filename of the
* the source-file, the n_desc field should be set to the number
* of remaining stabs
*/
WRITE_STAB(sptr, fileidx[0], 0, 0, 0, strlen(allfiles[0] + 12));
/* this is the stab for the main source file */
WRITE_STAB(sptr, fileidx[mainfileindex], N_SO, 0, 0, 0);
/* relocation table entry */
/*
* Since the symbol table has two entries before
* the section symbols, the index in the info.section
* member must be adjusted by adding 2
*/
WRITELONG(rptr, (sptr - sbuf) - 4);
WRITELONG(rptr, ((ptr->info.section + 2) << 8) | R_386_32);
numstabs++;
currfile = mainfileindex;
}
while (ptr) {
if (strcmp(allfiles[currfile], ptr->filename)) {
/* oops file has changed... */
for (i = 0; i < numfiles; i++)
if (!strcmp(allfiles[i], ptr->filename))
break;
currfile = i;
WRITE_STAB(sptr, fileidx[currfile], N_SOL, 0, 0,
ptr->info.offset);
numstabs++;
/* relocation table entry */
WRITELONG(rptr, (sptr - sbuf) - 4);
WRITELONG(rptr, ((ptr->info.section + 2) << 8) | R_386_32);
}
WRITE_STAB(sptr, 0, N_SLINE, 0, ptr->line, ptr->info.offset);
numstabs++;
/* relocation table entry */
WRITELONG(rptr, (sptr - sbuf) - 4);
WRITELONG(rptr, ((ptr->info.section + 2) << 8) | R_386_32);
ptr = ptr->next;
}
/* this is an "ending" token */
WRITE_STAB(sptr, 0, N_SO, 0, 0, 0);
numstabs++;
((struct stabentry *)sbuf)->n_desc = numstabs;
nasm_free(allfiles);
nasm_free(fileidx);
stablen = (sptr - sbuf);
stabrellen = (rptr - rbuf);
stabrelbuf = rbuf;
stabbuf = sbuf;
stabstrbuf = ssbuf;
}
static void stabs32_cleanup(void)
{
struct linelist *ptr, *del;
if (!stabslines)
return;
ptr = stabslines;
while (ptr) {
del = ptr;
ptr = ptr->next;
nasm_free(del);
}
nasm_free(stabbuf);
nasm_free(stabrelbuf);
nasm_free(stabstrbuf);
}
/* dwarf routines */
static void dwarf32_init(void)
{
ndebugs = 3; /* 3 debug symbols */
}
static void dwarf32_linenum(const char *filename, int32_t linenumber,
int32_t segto)
{
(void)segto;
dwarf32_findfile(filename);
debug_immcall = 1;
currentline = linenumber;
}
/* called from elf_out with type == TY_DEBUGSYMLIN */
static void dwarf32_output(int type, void *param)
{
int ln, aa, inx, maxln, soc;
struct symlininfo *s;
struct SAA *plinep;
(void)type;
s = (struct symlininfo *)param;
/* line number info is only gathered for executable sections */
if (!(sects[s->section]->flags & SHF_EXECINSTR))
return;
/* Check if section index has changed */
if (!(dwarf_csect && (dwarf_csect->section) == (s->section)))
dwarf32_findsect(s->section);
/* do nothing unless line or file has changed */
if (!debug_immcall)
return;
ln = currentline - dwarf_csect->line;
aa = s->offset - dwarf_csect->offset;
inx = dwarf_clist->line;
plinep = dwarf_csect->psaa;
/* check for file change */
if (!(inx == dwarf_csect->file)) {
saa_write8(plinep,DW_LNS_set_file);
saa_write8(plinep,inx);
dwarf_csect->file = inx;
}
/* check for line change */
if (ln) {
/* test if in range of special op code */
maxln = line_base + line_range;
soc = (ln - line_base) + (line_range * aa) + opcode_base;
if (ln >= line_base && ln < maxln && soc < 256) {
saa_write8(plinep,soc);
} else {
saa_write8(plinep,DW_LNS_advance_line);
saa_wleb128s(plinep,ln);
if (aa) {
saa_write8(plinep,DW_LNS_advance_pc);
saa_wleb128u(plinep,aa);
}
}
dwarf_csect->line = currentline;
dwarf_csect->offset = s->offset;
}
/* show change handled */
debug_immcall = 0;
}
static void dwarf32_generate(void)
{
uint8_t *pbuf;
int indx;
struct linelist *ftentry;
struct SAA *paranges, *ppubnames, *pinfo, *pabbrev, *plines, *plinep;
struct SAA *parangesrel, *plinesrel, *pinforel;
struct sectlist *psect;
size_t saalen, linepoff, totlen, highaddr;
/* write epilogues for each line program range */
/* and build aranges section */
paranges = saa_init(1L);
parangesrel = saa_init(1L);
saa_write16(paranges,2); /* dwarf version */
saa_write32(parangesrel, paranges->datalen+4);
saa_write32(parangesrel, (dwarf_infosym << 8) + R_386_32); /* reloc to info */
saa_write32(parangesrel, 0);
saa_write32(paranges,0); /* offset into info */
saa_write8(paranges,4); /* pointer size */
saa_write8(paranges,0); /* not segmented */
saa_write32(paranges,0); /* padding */
/* iterate though sectlist entries */
psect = dwarf_fsect;
totlen = 0;
highaddr = 0;
for (indx = 0; indx < dwarf_nsections; indx++) {
plinep = psect->psaa;
/* Line Number Program Epilogue */
saa_write8(plinep,2); /* std op 2 */
saa_write8(plinep,(sects[psect->section]->len)-psect->offset);
saa_write8(plinep,DW_LNS_extended_op);
saa_write8(plinep,1); /* operand length */
saa_write8(plinep,DW_LNE_end_sequence);
totlen += plinep->datalen;
/* range table relocation entry */
saa_write32(parangesrel, paranges->datalen + 4);
saa_write32(parangesrel, ((uint32_t) (psect->section + 2) << 8) + R_386_32);
saa_write32(parangesrel, (uint32_t) 0);
/* range table entry */
saa_write32(paranges,0x0000); /* range start */
saa_write32(paranges,sects[psect->section]->len); /* range length */
highaddr += sects[psect->section]->len;
/* done with this entry */
psect = psect->next;
}
saa_write32(paranges,0); /* null address */
saa_write32(paranges,0); /* null length */
saalen = paranges->datalen;
arangeslen = saalen + 4;
arangesbuf = pbuf = nasm_malloc(arangeslen);
WRITELONG(pbuf,saalen); /* initial length */
saa_rnbytes(paranges, pbuf, saalen);
saa_free(paranges);
/* build rela.aranges section */
arangesrellen = saalen = parangesrel->datalen;
arangesrelbuf = pbuf = nasm_malloc(arangesrellen);
saa_rnbytes(parangesrel, pbuf, saalen);
saa_free(parangesrel);
/* build pubnames section */
ppubnames = saa_init(1L);
saa_write16(ppubnames,3); /* dwarf version */
saa_write32(ppubnames,0); /* offset into info */
saa_write32(ppubnames,0); /* space used in info */
saa_write32(ppubnames,0); /* end of list */
saalen = ppubnames->datalen;
pubnameslen = saalen + 4;
pubnamesbuf = pbuf = nasm_malloc(pubnameslen);
WRITELONG(pbuf,saalen); /* initial length */
saa_rnbytes(ppubnames, pbuf, saalen);
saa_free(ppubnames);
/* build info section */
pinfo = saa_init(1L);
pinforel = saa_init(1L);
saa_write16(pinfo,2); /* dwarf version */
saa_write32(pinforel, pinfo->datalen + 4);
saa_write32(pinforel, (dwarf_abbrevsym << 8) + R_386_32); /* reloc to abbrev */
saa_write32(pinforel, 0);
saa_write32(pinfo,0); /* offset into abbrev */
saa_write8(pinfo,4); /* pointer size */
saa_write8(pinfo,1); /* abbrviation number LEB128u */
saa_write32(pinforel, pinfo->datalen + 4);
saa_write32(pinforel, ((dwarf_fsect->section + 2) << 8) + R_386_32);
saa_write32(pinforel, 0);
saa_write32(pinfo,0); /* DW_AT_low_pc */
saa_write32(pinforel, pinfo->datalen + 4);
saa_write32(pinforel, ((dwarf_fsect->section + 2) << 8) + R_386_32);
saa_write32(pinforel, 0);
saa_write32(pinfo,highaddr); /* DW_AT_high_pc */
saa_write32(pinforel, pinfo->datalen + 4);
saa_write32(pinforel, (dwarf_linesym << 8) + R_386_32); /* reloc to line */
saa_write32(pinforel, 0);
saa_write32(pinfo,0); /* DW_AT_stmt_list */
saa_wbytes(pinfo, elf_module, strlen(elf_module)+1);
saa_wbytes(pinfo, nasm_signature, strlen(nasm_signature)+1);
saa_write16(pinfo,DW_LANG_Mips_Assembler);
saa_write8(pinfo,2); /* abbrviation number LEB128u */
saa_write32(pinforel, pinfo->datalen + 4);
saa_write32(pinforel, ((dwarf_fsect->section + 2) << 8) + R_386_32);
saa_write32(pinforel, 0);
saa_write32(pinfo,0); /* DW_AT_low_pc */
saa_write32(pinfo,0); /* DW_AT_frame_base */
saa_write8(pinfo,0); /* end of entries */
saalen = pinfo->datalen;
infolen = saalen + 4;
infobuf = pbuf = nasm_malloc(infolen);
WRITELONG(pbuf,saalen); /* initial length */
saa_rnbytes(pinfo, pbuf, saalen);
saa_free(pinfo);
/* build rela.info section */
inforellen = saalen = pinforel->datalen;
inforelbuf = pbuf = nasm_malloc(inforellen);
saa_rnbytes(pinforel, pbuf, saalen);
saa_free(pinforel);
/* build abbrev section */
pabbrev = saa_init(1L);
saa_write8(pabbrev,1); /* entry number LEB128u */
saa_write8(pabbrev,DW_TAG_compile_unit); /* tag LEB128u */
saa_write8(pabbrev,1); /* has children */
/* the following attributes and forms are all LEB128u values */
saa_write8(pabbrev,DW_AT_low_pc);
saa_write8(pabbrev,DW_FORM_addr);
saa_write8(pabbrev,DW_AT_high_pc);
saa_write8(pabbrev,DW_FORM_addr);
saa_write8(pabbrev,DW_AT_stmt_list);
saa_write8(pabbrev,DW_FORM_data4);
saa_write8(pabbrev,DW_AT_name);
saa_write8(pabbrev,DW_FORM_string);
saa_write8(pabbrev,DW_AT_producer);
saa_write8(pabbrev,DW_FORM_string);
saa_write8(pabbrev,DW_AT_language);
saa_write8(pabbrev,DW_FORM_data2);
saa_write16(pabbrev,0); /* end of entry */
/* LEB128u usage same as above */
saa_write8(pabbrev,2); /* entry number */
saa_write8(pabbrev,DW_TAG_subprogram);
saa_write8(pabbrev,0); /* no children */
saa_write8(pabbrev,DW_AT_low_pc);
saa_write8(pabbrev,DW_FORM_addr);
saa_write8(pabbrev,DW_AT_frame_base);
saa_write8(pabbrev,DW_FORM_data4);
saa_write16(pabbrev,0); /* end of entry */
abbrevlen = saalen = pabbrev->datalen;
abbrevbuf = pbuf = nasm_malloc(saalen);
saa_rnbytes(pabbrev, pbuf, saalen);
saa_free(pabbrev);
/* build line section */
/* prolog */
plines = saa_init(1L);
saa_write8(plines,1); /* Minimum Instruction Length */
saa_write8(plines,1); /* Initial value of 'is_stmt' */
saa_write8(plines,line_base); /* Line Base */
saa_write8(plines,line_range); /* Line Range */
saa_write8(plines,opcode_base); /* Opcode Base */
/* standard opcode lengths (# of LEB128u operands) */
saa_write8(plines,0); /* Std opcode 1 length */
saa_write8(plines,1); /* Std opcode 2 length */
saa_write8(plines,1); /* Std opcode 3 length */
saa_write8(plines,1); /* Std opcode 4 length */
saa_write8(plines,1); /* Std opcode 5 length */
saa_write8(plines,0); /* Std opcode 6 length */
saa_write8(plines,0); /* Std opcode 7 length */
saa_write8(plines,0); /* Std opcode 8 length */
saa_write8(plines,1); /* Std opcode 9 length */
saa_write8(plines,0); /* Std opcode 10 length */
saa_write8(plines,0); /* Std opcode 11 length */
saa_write8(plines,1); /* Std opcode 12 length */
/* Directory Table */
saa_write8(plines,0); /* End of table */
/* File Name Table */
ftentry = dwarf_flist;
for (indx = 0; indx < dwarf_numfiles; indx++) {
saa_wbytes(plines, ftentry->filename, (int32_t)(strlen(ftentry->filename) + 1));
saa_write8(plines,0); /* directory LEB128u */
saa_write8(plines,0); /* time LEB128u */
saa_write8(plines,0); /* size LEB128u */
ftentry = ftentry->next;
}
saa_write8(plines,0); /* End of table */
linepoff = plines->datalen;
linelen = linepoff + totlen + 10;
linebuf = pbuf = nasm_malloc(linelen);
WRITELONG(pbuf,linelen-4); /* initial length */
WRITESHORT(pbuf,3); /* dwarf version */
WRITELONG(pbuf,linepoff); /* offset to line number program */
/* write line header */
saalen = linepoff;
saa_rnbytes(plines, pbuf, saalen); /* read a given no. of bytes */
pbuf += linepoff;
saa_free(plines);
/* concatonate line program ranges */
linepoff += 13;
plinesrel = saa_init(1L);
psect = dwarf_fsect;
for (indx = 0; indx < dwarf_nsections; indx++) {
saa_write32(plinesrel, linepoff);
saa_write32(plinesrel, ((uint32_t) (psect->section + 2) << 8) + R_386_32);
saa_write32(plinesrel, (uint32_t) 0);
plinep = psect->psaa;
saalen = plinep->datalen;
saa_rnbytes(plinep, pbuf, saalen);
pbuf += saalen;
linepoff += saalen;
saa_free(plinep);
/* done with this entry */
psect = psect->next;
}
/* build rela.lines section */
linerellen =saalen = plinesrel->datalen;
linerelbuf = pbuf = nasm_malloc(linerellen);
saa_rnbytes(plinesrel, pbuf, saalen);
saa_free(plinesrel);
/* build frame section */
framelen = 4;
framebuf = pbuf = nasm_malloc(framelen);
WRITELONG(pbuf,framelen-4); /* initial length */
/* build loc section */
loclen = 16;
locbuf = pbuf = nasm_malloc(loclen);
WRITELONG(pbuf,0); /* null beginning offset */
WRITELONG(pbuf,0); /* null ending offset */
}
static void dwarf32_cleanup(void)
{
nasm_free(arangesbuf);
nasm_free(arangesrelbuf);
nasm_free(pubnamesbuf);
nasm_free(infobuf);
nasm_free(inforelbuf);
nasm_free(abbrevbuf);
nasm_free(linebuf);
nasm_free(linerelbuf);
nasm_free(framebuf);
nasm_free(locbuf);
}
static void dwarf32_findfile(const char * fname)
{
int finx;
struct linelist *match;
/* return if fname is current file name */
if (dwarf_clist && !(strcmp(fname, dwarf_clist->filename)))
return;
/* search for match */
match = 0;
if (dwarf_flist) {
match = dwarf_flist;
for (finx = 0; finx < dwarf_numfiles; finx++) {
if (!(strcmp(fname, match->filename))) {
dwarf_clist = match;
return;
}
}
}
/* add file name to end of list */
dwarf_clist = (struct linelist *)nasm_malloc(sizeof(struct linelist));
dwarf_numfiles++;
dwarf_clist->line = dwarf_numfiles;
dwarf_clist->filename = nasm_malloc(strlen(fname) + 1);
strcpy(dwarf_clist->filename,fname);
dwarf_clist->next = 0;
if (!dwarf_flist) { /* if first entry */
dwarf_flist = dwarf_elist = dwarf_clist;
dwarf_clist->last = 0;
} else { /* chain to previous entry */
dwarf_elist->next = dwarf_clist;
dwarf_elist = dwarf_clist;
}
}
static void dwarf32_findsect(const int index)
{
int sinx;
struct sectlist *match;
struct SAA *plinep;
/* return if index is current section index */
if (dwarf_csect && (dwarf_csect->section == index))
return;
/* search for match */
match = 0;
if (dwarf_fsect) {
match = dwarf_fsect;
for (sinx = 0; sinx < dwarf_nsections; sinx++) {
if (match->section == index) {
dwarf_csect = match;
return;
}
match = match->next;
}
}
/* add entry to end of list */
dwarf_csect = (struct sectlist *)nasm_malloc(sizeof(struct sectlist));
dwarf_nsections++;
dwarf_csect->psaa = plinep = saa_init(1L);
dwarf_csect->line = 1;
dwarf_csect->offset = 0;
dwarf_csect->file = 1;
dwarf_csect->section = index;
dwarf_csect->next = 0;
/* set relocatable address at start of line program */
saa_write8(plinep,DW_LNS_extended_op);
saa_write8(plinep,5); /* operand length */
saa_write8(plinep,DW_LNE_set_address);
saa_write32(plinep,0); /* Start Address */
if (!dwarf_fsect) { /* if first entry */
dwarf_fsect = dwarf_esect = dwarf_csect;
dwarf_csect->last = 0;
} else { /* chain to previous entry */
dwarf_esect->next = dwarf_csect;
dwarf_esect = dwarf_csect;
}
}
#endif /* OF_ELF */
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