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ftmemsim-valgrind/coregrind/vg_symtab2.c
Julian Seward 72a784f3b1 Initial revision 
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@2
2002-03-22 01:27:54 +00:00

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/*--------------------------------------------------------------------*/
/*--- Management of symbols and debugging information. ---*/
/*--- vg_symtab2.c ---*/
/*--------------------------------------------------------------------*/
/*
This file is part of Valgrind, an x86 protected-mode emulator
designed for debugging and profiling binaries on x86-Unixes.
Copyright (C) 2000-2002 Julian Seward
jseward@acm.org
Julian_Seward@muraroa.demon.co.uk
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307, USA.
The GNU General Public License is contained in the file LICENSE.
*/
#include "vg_include.h"
#include "vg_unsafe.h"
#include <elf.h> /* ELF defns */
#include <a.out.h> /* stabs defns */
/* Majorly rewritten Sun 3 Feb 02 to enable loading symbols from
dlopen()ed libraries, which is something that KDE3 does a lot.
Still kludgey, though less than before:
* we don't check whether we should throw away some symbol tables
when munmap() happens
* symbol table reading code for ELF binaries is a shambles.
Use GHC's fptools/ghc/rts/Linker.c as the basis for something better.
*/
/*------------------------------------------------------------*/
/*--- Structs n stuff ---*/
/*------------------------------------------------------------*/
/* A structure to hold an ELF symbol (very crudely). */
typedef
struct {
Addr addr; /* lowest address of entity */
UInt size; /* size in bytes */
Int nmoff; /* offset of name in this SegInfo's str tab */
}
RiSym;
/* A structure to hold addr-to-source info for a single line. */
typedef
struct {
Addr addr; /* lowest address for this line */
Int fnmoff; /* source filename; offset in this SegInfo's str tab */
UShort lineno; /* source line number, or zero */
UShort size; /* size in bytes; we go to a bit of trouble to
catch overflows of this */
}
RiLoc;
/* A structure which contains information pertaining to one mapped
text segment. */
typedef
struct _SegInfo {
struct _SegInfo* next;
/* Description of the mapped segment. */
Addr start;
UInt size;
UChar* filename; /* in mallocville */
UInt foffset;
/* An expandable array of symbols. */
RiSym* symtab;
UInt symtab_used;
UInt symtab_size;
/* An expandable array of locations. */
RiLoc* loctab;
UInt loctab_used;
UInt loctab_size;
/* An expandable array of characters -- the string table. */
Char* strtab;
UInt strtab_used;
UInt strtab_size;
/* offset is what we need to add to symbol table entries
to get the real location of that symbol in memory.
For executables, offset is zero.
For .so's, offset == base_addr.
This seems like a giant kludge to me.
*/
UInt offset;
}
SegInfo;
/* -- debug helper -- */
static void ppSegInfo ( SegInfo* si )
{
VG_(printf)("name: %s\n"
"start %p, size %d, foffset %d\n",
si->filename?si->filename : (UChar*)"NULL",
si->start, si->size, si->foffset );
}
static void freeSegInfo ( SegInfo* si )
{
vg_assert(si != NULL);
if (si->filename) VG_(free)(VG_AR_SYMTAB, si->filename);
if (si->symtab) VG_(free)(VG_AR_SYMTAB, si->symtab);
if (si->loctab) VG_(free)(VG_AR_SYMTAB, si->loctab);
if (si->strtab) VG_(free)(VG_AR_SYMTAB, si->strtab);
VG_(free)(VG_AR_SYMTAB, si);
}
/*------------------------------------------------------------*/
/*--- Adding stuff ---*/
/*------------------------------------------------------------*/
/* Add a str to the string table, including terminating zero, and
return offset of the string in vg_strtab. */
static __inline__
Int addStr ( SegInfo* si, Char* str )
{
Char* new_tab;
Int new_sz, i, space_needed;
space_needed = 1 + VG_(strlen)(str);
if (si->strtab_used + space_needed > si->strtab_size) {
new_sz = 2 * si->strtab_size;
if (new_sz == 0) new_sz = 5000;
new_tab = VG_(malloc)(VG_AR_SYMTAB, new_sz);
if (si->strtab != NULL) {
for (i = 0; i < si->strtab_used; i++)
new_tab[i] = si->strtab[i];
VG_(free)(VG_AR_SYMTAB, si->strtab);
}
si->strtab = new_tab;
si->strtab_size = new_sz;
}
for (i = 0; i < space_needed; i++)
si->strtab[si->strtab_used+i] = str[i];
si->strtab_used += space_needed;
vg_assert(si->strtab_used <= si->strtab_size);
return si->strtab_used - space_needed;
}
/* Add a symbol to the symbol table. */
static __inline__
void addSym ( SegInfo* si, RiSym* sym )
{
Int new_sz, i;
RiSym* new_tab;
/* Ignore zero-sized syms. */
if (sym->size == 0) return;
if (si->symtab_used == si->symtab_size) {
new_sz = 2 * si->symtab_size;
if (new_sz == 0) new_sz = 500;
new_tab = VG_(malloc)(VG_AR_SYMTAB, new_sz * sizeof(RiSym) );
if (si->symtab != NULL) {
for (i = 0; i < si->symtab_used; i++)
new_tab[i] = si->symtab[i];
VG_(free)(VG_AR_SYMTAB, si->symtab);
}
si->symtab = new_tab;
si->symtab_size = new_sz;
}
si->symtab[si->symtab_used] = *sym;
si->symtab_used++;
vg_assert(si->symtab_used <= si->symtab_size);
}
/* Add a location to the location table. */
static __inline__
void addLoc ( SegInfo* si, RiLoc* loc )
{
Int new_sz, i;
RiLoc* new_tab;
/* Ignore zero-sized locs. */
if (loc->size == 0) return;
if (si->loctab_used == si->loctab_size) {
new_sz = 2 * si->loctab_size;
if (new_sz == 0) new_sz = 500;
new_tab = VG_(malloc)(VG_AR_SYMTAB, new_sz * sizeof(RiLoc) );
if (si->loctab != NULL) {
for (i = 0; i < si->loctab_used; i++)
new_tab[i] = si->loctab[i];
VG_(free)(VG_AR_SYMTAB, si->loctab);
}
si->loctab = new_tab;
si->loctab_size = new_sz;
}
si->loctab[si->loctab_used] = *loc;
si->loctab_used++;
vg_assert(si->loctab_used <= si->loctab_size);
}
/*------------------------------------------------------------*/
/*--- Helpers ---*/
/*------------------------------------------------------------*/
/* Non-fatal -- use vg_panic if terminal. */
static
void vg_symerr ( Char* msg )
{
if (VG_(clo_verbosity) > 1)
VG_(message)(Vg_UserMsg,"%s", msg );
}
/* Print a symbol. */
static
void printSym ( SegInfo* si, Int i )
{
VG_(printf)( "%5d: %8p .. %8p (%d) %s\n",
i,
si->symtab[i].addr,
si->symtab[i].addr + si->symtab[i].size - 1, si->symtab[i].size,
&si->strtab[si->symtab[i].nmoff] );
}
#if 0
/* Print the entire sym tab. */
static __attribute__ ((unused))
void printSymtab ( void )
{
Int i;
VG_(printf)("\n------ BEGIN vg_symtab ------\n");
for (i = 0; i < vg_symtab_used; i++)
printSym(i);
VG_(printf)("------ BEGIN vg_symtab ------\n");
}
#endif
#if 0
/* Paranoid strcat. */
static
void safeCopy ( UChar* dst, UInt maxlen, UChar* src )
{
UInt i = 0, j = 0;
while (True) {
if (i >= maxlen) return;
if (dst[i] == 0) break;
i++;
}
while (True) {
if (i >= maxlen) return;
dst[i] = src[j];
if (src[j] == 0) return;
i++; j++;
}
}
#endif
/*------------------------------------------------------------*/
/*--- Canonicalisers ---*/
/*------------------------------------------------------------*/
/* Sort the symtab by starting address, and emit warnings if any
symbols have overlapping address ranges. We use that old chestnut,
shellsort. Mash the table around so as to establish the property
that addresses are in order and the ranges to not overlap. This
facilitates using binary search to map addresses to symbols when we
come to query the table.
*/
static
void canonicaliseSymtab ( SegInfo* si )
{
/* Magic numbers due to Janet Incerpi and Robert Sedgewick. */
Int incs[16] = { 1, 3, 7, 21, 48, 112, 336, 861, 1968,
4592, 13776, 33936, 86961, 198768,
463792, 1391376 };
Int lo = 0;
Int hi = si->symtab_used-1;
Int i, j, h, bigN, hp, n_merged, n_truncated;
RiSym v;
Addr s1, s2, e1, e2;
# define SWAP(ty,aa,bb) \
do { ty tt = (aa); (aa) = (bb); (bb) = tt; } while (0)
bigN = hi - lo + 1; if (bigN < 2) return;
hp = 0; while (hp < 16 && incs[hp] < bigN) hp++; hp--;
vg_assert(0 <= hp && hp < 16);
for (; hp >= 0; hp--) {
h = incs[hp];
i = lo + h;
while (1) {
if (i > hi) break;
v = si->symtab[i];
j = i;
while (si->symtab[j-h].addr > v.addr) {
si->symtab[j] = si->symtab[j-h];
j = j - h;
if (j <= (lo + h - 1)) break;
}
si->symtab[j] = v;
i++;
}
}
cleanup_more:
/* If two symbols have identical address ranges, favour the
one with the longer name.
*/
do {
n_merged = 0;
j = si->symtab_used;
si->symtab_used = 0;
for (i = 0; i < j; i++) {
if (i < j-1
&& si->symtab[i].addr == si->symtab[i+1].addr
&& si->symtab[i].size == si->symtab[i+1].size) {
n_merged++;
/* merge the two into one */
if (VG_(strlen)(&si->strtab[si->symtab[i].nmoff])
> VG_(strlen)(&si->strtab[si->symtab[i+1].nmoff])) {
si->symtab[si->symtab_used++] = si->symtab[i];
} else {
si->symtab[si->symtab_used++] = si->symtab[i+1];
}
i++;
} else {
si->symtab[si->symtab_used++] = si->symtab[i];
}
}
if (VG_(clo_trace_symtab))
VG_(printf)( "%d merged\n", n_merged);
}
while (n_merged > 0);
/* Detect and "fix" overlapping address ranges. */
n_truncated = 0;
for (i = 0; i < si->symtab_used-1; i++) {
vg_assert(si->symtab[i].addr <= si->symtab[i+1].addr);
/* Check for common (no overlap) case. */
if (si->symtab[i].addr + si->symtab[i].size
<= si->symtab[i+1].addr)
continue;
/* There's an overlap. Truncate one or the other. */
if (VG_(clo_trace_symtab)) {
VG_(printf)("overlapping address ranges in symbol table\n\t");
printSym(si,i);
VG_(printf)("\t");
printSym(si,i+1);
VG_(printf)("\n");
}
/* Truncate one or the other. */
s1 = si->symtab[i].addr;
s2 = si->symtab[i+1].addr;
e1 = s1 + si->symtab[i].size - 1;
e2 = s2 + si->symtab[i+1].size - 1;
if (s1 < s2) {
e1 = s2-1;
} else {
vg_assert(s1 == s2);
if (e1 > e2) {
s1 = e2+1; SWAP(Addr,s1,s2); SWAP(Addr,e1,e2);
} else
if (e1 < e2) {
s2 = e1+1;
} else {
/* e1 == e2. Identical addr ranges. We'll eventually wind
up back at cleanup_more, which will take care of it. */
}
}
si->symtab[i].addr = s1;
si->symtab[i+1].addr = s2;
si->symtab[i].size = e1 - s1 + 1;
si->symtab[i+1].size = e2 - s2 + 1;
vg_assert(s1 <= s2);
vg_assert(si->symtab[i].size > 0);
vg_assert(si->symtab[i+1].size > 0);
/* It may be that the i+1 entry now needs to be moved further
along to maintain the address order requirement. */
j = i+1;
while (j < si->symtab_used-1
&& si->symtab[j].addr > si->symtab[j+1].addr) {
SWAP(RiSym,si->symtab[j],si->symtab[j+1]);
j++;
}
n_truncated++;
}
if (n_truncated > 0) goto cleanup_more;
/* Ensure relevant postconditions hold. */
for (i = 0; i < si->symtab_used-1; i++) {
/* No zero-sized symbols. */
vg_assert(si->symtab[i].size > 0);
/* In order. */
vg_assert(si->symtab[i].addr < si->symtab[i+1].addr);
/* No overlaps. */
vg_assert(si->symtab[i].addr + si->symtab[i].size - 1
< si->symtab[i+1].addr);
}
# undef SWAP
}
/* Sort the location table by starting address. Mash the table around
so as to establish the property that addresses are in order and the
ranges do not overlap. This facilitates using binary search to map
addresses to locations when we come to query the table. */
static
void canonicaliseLoctab ( SegInfo* si )
{
/* Magic numbers due to Janet Incerpi and Robert Sedgewick. */
Int incs[16] = { 1, 3, 7, 21, 48, 112, 336, 861, 1968,
4592, 13776, 33936, 86961, 198768,
463792, 1391376 };
Int lo = 0;
Int hi = si->loctab_used-1;
Int i, j, h, bigN, hp;
RiLoc v;
# define SWAP(ty,aa,bb) \
do { ty tt = (aa); (aa) = (bb); (bb) = tt; } while (0);
/* Sort by start address. */
bigN = hi - lo + 1; if (bigN < 2) return;
hp = 0; while (hp < 16 && incs[hp] < bigN) hp++; hp--;
vg_assert(0 <= hp && hp < 16);
for (; hp >= 0; hp--) {
h = incs[hp];
i = lo + h;
while (1) {
if (i > hi) break;
v = si->loctab[i];
j = i;
while (si->loctab[j-h].addr > v.addr) {
si->loctab[j] = si->loctab[j-h];
j = j - h;
if (j <= (lo + h - 1)) break;
}
si->loctab[j] = v;
i++;
}
}
/* If two adjacent entries overlap, truncate the first. */
for (i = 0; i < si->loctab_used-1; i++) {
vg_assert(si->loctab[i].size < 10000);
if (si->loctab[i].addr + si->loctab[i].size > si->loctab[i+1].addr) {
/* Do this in signed int32 because the actual .size fields
are unsigned 16s. */
Int new_size = si->loctab[i+1].addr - si->loctab[i].addr;
if (new_size < 0) {
si->loctab[i].size = 0;
} else
if (new_size >= 65536) {
si->loctab[i].size = 65535;
} else {
si->loctab[i].size = (UShort)new_size;
}
}
}
/* Zap any zero-sized entries resulting from the truncation
process. */
j = 0;
for (i = 0; i < si->loctab_used; i++) {
if (si->loctab[i].size > 0) {
si->loctab[j] = si->loctab[i];
j++;
}
}
si->loctab_used = j;
/* Ensure relevant postconditions hold. */
for (i = 0; i < si->loctab_used-1; i++) {
/*
VG_(printf)("%d (%d) %d 0x%x\n",
i, si->loctab[i+1].confident,
si->loctab[i+1].size, si->loctab[i+1].addr );
*/
/* No zero-sized symbols. */
vg_assert(si->loctab[i].size > 0);
/* In order. */
vg_assert(si->loctab[i].addr < si->loctab[i+1].addr);
/* No overlaps. */
vg_assert(si->loctab[i].addr + si->loctab[i].size - 1
< si->loctab[i+1].addr);
}
# undef SWAP
}
/*------------------------------------------------------------*/
/*--- Read info from a .so/exe file. ---*/
/*------------------------------------------------------------*/
static __inline__
void addLineInfo ( SegInfo* si,
Int fnmoff,
Addr start,
Addr end,
UInt lineno )
{
RiLoc loc;
UInt size = end - start + 1;
# if 0
if (size > 10000)
VG_(printf)( "line %4d: %p .. %p, in %s\n",
lineno, start, end,
&si->strtab[fnmoff] );
# endif
/* Sanity ... */
if (size > 10000) return;
if (start >= si->start+si->size
|| end < si->start) return;
loc.addr = start;
loc.size = (UShort)size;
loc.lineno = lineno;
loc.fnmoff = fnmoff;
addLoc ( si, &loc );
}
/* Read the symbols from the object/exe specified by the SegInfo into
the tables within the supplied SegInfo. */
static
void vg_read_lib_symbols ( SegInfo* si )
{
Elf32_Ehdr* ehdr; /* The ELF header */
Elf32_Shdr* shdr; /* The section table */
UChar* sh_strtab; /* The section table's string table */
struct nlist* stab; /* The .stab table */
UChar* stabstr; /* The .stab string table */
Int stab_sz; /* Size in bytes of the .stab table */
Int stabstr_sz; /* Size in bytes of the .stab string table */
Int fd;
Int i;
Bool ok;
Addr oimage;
Int n_oimage;
struct stat stat_buf;
/* for the .stabs reader */
Int curr_filenmoff;
Addr curr_fnbaseaddr;
Addr range_startAddr;
Int range_lineno;
oimage = (Addr)NULL;
if (VG_(clo_verbosity) > 1)
VG_(message)(Vg_UserMsg, "Reading syms from %s",
si->filename );
/* mmap the object image aboard, so that we can read symbols and
line number info out of it. It will be munmapped immediately
thereafter; it is only aboard transiently. */
i = stat(si->filename, &stat_buf);
if (i != 0) {
vg_symerr("Can't stat .so/.exe (to determine its size)?!");
return;
}
n_oimage = stat_buf.st_size;
fd = VG_(open_read)(si->filename);
if (fd == -1) {
vg_symerr("Can't open .so/.exe to read symbols?!");
return;
}
oimage = (Addr)VG_(mmap)( NULL, n_oimage, PROT_READ, MAP_PRIVATE, fd, 0 );
if (oimage == ((Addr)(-1))) {
VG_(message)(Vg_UserMsg,
"mmap failed on %s", si->filename );
VG_(close)(fd);
return;
}
VG_(close)(fd);
/* Ok, the object image is safely in oimage[0 .. n_oimage-1].
Now verify that it is a valid ELF .so or executable image.
*/
ok = (n_oimage >= sizeof(Elf32_Ehdr));
ehdr = (Elf32_Ehdr*)oimage;
if (ok) {
ok &= (ehdr->e_ident[EI_MAG0] == 0x7F
&& ehdr->e_ident[EI_MAG1] == 'E'
&& ehdr->e_ident[EI_MAG2] == 'L'
&& ehdr->e_ident[EI_MAG3] == 'F');
ok &= (ehdr->e_ident[EI_CLASS] == ELFCLASS32
&& ehdr->e_ident[EI_DATA] == ELFDATA2LSB
&& ehdr->e_ident[EI_VERSION] == EV_CURRENT);
ok &= (ehdr->e_type == ET_EXEC || ehdr->e_type == ET_DYN);
ok &= (ehdr->e_machine == EM_386);
ok &= (ehdr->e_version == EV_CURRENT);
ok &= (ehdr->e_shstrndx != SHN_UNDEF);
ok &= (ehdr->e_shoff != 0 && ehdr->e_shnum != 0);
}
if (!ok) {
vg_symerr("Invalid ELF header, or missing stringtab/sectiontab.");
VG_(munmap) ( (void*)oimage, n_oimage );
return;
}
if (VG_(clo_trace_symtab))
VG_(printf)(
"shoff = %d, shnum = %d, size = %d, n_vg_oimage = %d\n",
ehdr->e_shoff, ehdr->e_shnum, sizeof(Elf32_Shdr), n_oimage );
if (ehdr->e_shoff + ehdr->e_shnum*sizeof(Elf32_Shdr) > n_oimage) {
vg_symerr("ELF section header is beyond image end?!");
VG_(munmap) ( (void*)oimage, n_oimage );
return;
}
shdr = (Elf32_Shdr*)(oimage + ehdr->e_shoff);
sh_strtab = (UChar*)(oimage + shdr[ehdr->e_shstrndx].sh_offset);
/* try and read the object's symbol table */
{
UChar* o_strtab = NULL;
Elf32_Sym* o_symtab = NULL;
UInt o_strtab_sz = 0;
UInt o_symtab_sz = 0;
UChar* o_got = NULL;
UChar* o_plt = NULL;
UInt o_got_sz = 0;
UInt o_plt_sz = 0;
Bool snaffle_it;
Addr sym_addr;
/* find the .stabstr and .stab sections */
for (i = 0; i < ehdr->e_shnum; i++) {
if (0 == VG_(strcmp)(".symtab",sh_strtab + shdr[i].sh_name)) {
o_symtab = (Elf32_Sym*)(oimage + shdr[i].sh_offset);
o_symtab_sz = shdr[i].sh_size;
vg_assert((o_symtab_sz % sizeof(Elf32_Sym)) == 0);
/* check image overrun here */
}
if (0 == VG_(strcmp)(".strtab",sh_strtab + shdr[i].sh_name)) {
o_strtab = (UChar*)(oimage + shdr[i].sh_offset);
o_strtab_sz = shdr[i].sh_size;
/* check image overrun here */
}
/* find out where the .got and .plt sections will be in the
executable image, not in the object image transiently loaded.
*/
if (0 == VG_(strcmp)(".got",sh_strtab + shdr[i].sh_name)) {
o_got = (UChar*)(si->offset
+ shdr[i].sh_offset);
o_got_sz = shdr[i].sh_size;
/* check image overrun here */
}
if (0 == VG_(strcmp)(".plt",sh_strtab + shdr[i].sh_name)) {
o_plt = (UChar*)(si->offset
+ shdr[i].sh_offset);
o_plt_sz = shdr[i].sh_size;
/* check image overrun here */
}
}
if (VG_(clo_trace_symtab)) {
if (o_plt) VG_(printf)( "PLT: %p .. %p\n",
o_plt, o_plt + o_plt_sz - 1 );
if (o_got) VG_(printf)( "GOT: %p .. %p\n",
o_got, o_got + o_got_sz - 1 );
}
if (o_strtab == NULL || o_symtab == NULL) {
vg_symerr(" object doesn't have a symbol table");
} else {
/* Perhaps should start at i = 1; ELF docs suggest that entry
0 always denotes `unknown symbol'. */
for (i = 1; i < o_symtab_sz/sizeof(Elf32_Sym); i++){
# if 0
VG_(printf)("raw symbol: ");
switch (ELF32_ST_BIND(o_symtab[i].st_info)) {
case STB_LOCAL: VG_(printf)("LOC "); break;
case STB_GLOBAL: VG_(printf)("GLO "); break;
case STB_WEAK: VG_(printf)("WEA "); break;
case STB_LOPROC: VG_(printf)("lop "); break;
case STB_HIPROC: VG_(printf)("hip "); break;
default: VG_(printf)("??? "); break;
}
switch (ELF32_ST_TYPE(o_symtab[i].st_info)) {
case STT_NOTYPE: VG_(printf)("NOT "); break;
case STT_OBJECT: VG_(printf)("OBJ "); break;
case STT_FUNC: VG_(printf)("FUN "); break;
case STT_SECTION: VG_(printf)("SEC "); break;
case STT_FILE: VG_(printf)("FIL "); break;
case STT_LOPROC: VG_(printf)("lop "); break;
case STT_HIPROC: VG_(printf)("hip "); break;
default: VG_(printf)("??? "); break;
}
VG_(printf)(
": value %p, size %d, name %s\n",
si->offset+(UChar*)o_symtab[i].st_value,
o_symtab[i].st_size,
o_symtab[i].st_name
? ((Char*)o_strtab+o_symtab[i].st_name)
: (Char*)"NONAME");
# endif
/* Figure out if we're interested in the symbol.
Firstly, is it of the right flavour?
*/
snaffle_it
= ( (ELF32_ST_BIND(o_symtab[i].st_info) == STB_GLOBAL ||
ELF32_ST_BIND(o_symtab[i].st_info) == STB_LOCAL /* ||
ELF32_ST_BIND(o_symtab[i].st_info) == STB_WEAK */)
&&
(ELF32_ST_TYPE(o_symtab[i].st_info) == STT_FUNC /*||
ELF32_ST_TYPE(o_symtab[i].st_info) == STT_OBJECT*/)
);
/* Secondly, if it's apparently in a GOT or PLT, it's really
a reference to a symbol defined elsewhere, so ignore it.
*/
sym_addr = si->offset
+ (UInt)o_symtab[i].st_value;
if (o_got != NULL
&& sym_addr >= (Addr)o_got
&& sym_addr < (Addr)(o_got+o_got_sz)) {
snaffle_it = False;
if (VG_(clo_trace_symtab)) {
VG_(printf)( "in GOT: %s\n",
o_strtab+o_symtab[i].st_name);
}
}
if (o_plt != NULL
&& sym_addr >= (Addr)o_plt
&& sym_addr < (Addr)(o_plt+o_plt_sz)) {
snaffle_it = False;
if (VG_(clo_trace_symtab)) {
VG_(printf)( "in PLT: %s\n",
o_strtab+o_symtab[i].st_name);
}
}
/* Don't bother if nameless, or zero-sized. */
if (snaffle_it
&& (o_symtab[i].st_name == (Elf32_Word)NULL
|| /* VG_(strlen)(o_strtab+o_symtab[i].st_name) == 0 */
/* equivalent but cheaper ... */
* ((UChar*)(o_strtab+o_symtab[i].st_name)) == 0
|| o_symtab[i].st_size == 0)) {
snaffle_it = False;
if (VG_(clo_trace_symtab)) {
VG_(printf)( "size=0: %s\n",
o_strtab+o_symtab[i].st_name);
}
}
# if 0
/* Avoid _dl_ junk. (Why?) */
/* 01-02-24: disabled until I find out if it really helps. */
if (snaffle_it
&& (VG_(strncmp)("_dl_", o_strtab+o_symtab[i].st_name, 4) == 0
|| VG_(strncmp)("_r_debug",
o_strtab+o_symtab[i].st_name, 8) == 0)) {
snaffle_it = False;
if (VG_(clo_trace_symtab)) {
VG_(printf)( "_dl_ junk: %s\n",
o_strtab+o_symtab[i].st_name);
}
}
# endif
/* This seems to significantly reduce the number of junk
symbols, and particularly reduces the number of
overlapping address ranges. Don't ask me why ... */
if (snaffle_it && (Int)o_symtab[i].st_value == 0) {
snaffle_it = False;
if (VG_(clo_trace_symtab)) {
VG_(printf)( "valu=0: %s\n",
o_strtab+o_symtab[i].st_name);
}
}
/* If no part of the symbol falls within the mapped range,
ignore it. */
if (sym_addr+o_symtab[i].st_size <= si->start
|| sym_addr >= si->start+si->size) {
snaffle_it = False;
}
if (snaffle_it) {
/* it's an interesting symbol; record ("snaffle") it. */
RiSym sym;
Char* t0 = o_symtab[i].st_name
? (Char*)(o_strtab+o_symtab[i].st_name)
: (Char*)"NONAME";
Int nmoff = addStr ( si, t0 );
vg_assert(nmoff >= 0
/* && 0==VG_(strcmp)(t0,&vg_strtab[nmoff]) */ );
vg_assert( (Int)o_symtab[i].st_value >= 0);
/* VG_(printf)("%p + %d: %s\n", si->addr,
(Int)o_symtab[i].st_value, t0 ); */
sym.addr = sym_addr;
sym.size = o_symtab[i].st_size;
sym.nmoff = nmoff;
addSym ( si, &sym );
}
}
}
}
/* Reading of the "stabs" debug format information, if any. */
stabstr = NULL;
stab = NULL;
stabstr_sz = 0;
stab_sz = 0;
/* find the .stabstr and .stab sections */
for (i = 0; i < ehdr->e_shnum; i++) {
if (0 == VG_(strcmp)(".stab",sh_strtab + shdr[i].sh_name)) {
stab = (struct nlist *)(oimage + shdr[i].sh_offset);
stab_sz = shdr[i].sh_size;
}
if (0 == VG_(strcmp)(".stabstr",sh_strtab + shdr[i].sh_name)) {
stabstr = (UChar*)(oimage + shdr[i].sh_offset);
stabstr_sz = shdr[i].sh_size;
}
}
if (stab == NULL || stabstr == NULL) {
vg_symerr(" object doesn't have any debug info");
VG_(munmap) ( (void*)oimage, n_oimage );
return;
}
if ( stab_sz + (UChar*)stab > n_oimage + (UChar*)oimage
|| stabstr_sz + (UChar*)stabstr
> n_oimage + (UChar*)oimage ) {
vg_symerr(" ELF debug data is beyond image end?!");
VG_(munmap) ( (void*)oimage, n_oimage );
return;
}
/* Ok. It all looks plausible. Go on and read debug data.
stab kinds: 100 N_SO a source file name
68 N_SLINE a source line number
36 N_FUN ? start of a function
In this loop, we maintain a current file name, updated
as N_SOs appear, and a current function base address,
updated as N_FUNs appear. Based on that, address ranges
for N_SLINEs are calculated, and stuffed into the
line info table.
N_SLINE indicates the start of a source line. Functions are
delimited by N_FUNS, at the start with a non-empty string and at
the end with an empty string. The latter facilitates detecting
where to close the last N_SLINE for a function.
*/
curr_filenmoff = addStr(si,"???");
curr_fnbaseaddr = (Addr)NULL;
range_startAddr = 0;
range_lineno = 0;
for (i = 0; i < stab_sz/(int)sizeof(struct nlist); i++) {
# if 0
VG_(printf) ( " %2d ", i );
VG_(printf) ( "type=0x%x othr=%d desc=%d value=0x%x strx=%d %s",
stab[i].n_type, stab[i].n_other, stab[i].n_desc,
(int)stab[i].n_value,
(int)stab[i].n_un.n_strx,
stabstr + stab[i].n_un.n_strx );
VG_(printf)("\n");
# endif
switch (stab[i].n_type) {
case 68: { /* N_SLINE */
/* flush the current line, if any, and start a new one */
Addr range_endAddr
= curr_fnbaseaddr
+ (UInt)stab[i].n_value - 1;
if (range_startAddr != 0) {
addLineInfo ( si,
curr_filenmoff,
range_startAddr,
range_endAddr,
range_lineno );
}
range_startAddr = range_endAddr + 1;
range_lineno = stab[i].n_desc;
break;
}
case 36: { /* N_FUN */
if ('\0' == * (stabstr + stab[i].n_un.n_strx) ) {
/* N_FUN with no name -- indicates the end of a fn.
Flush the current line, if any, but don't start a
new one. */
Addr range_endAddr
= curr_fnbaseaddr
+ (UInt)stab[i].n_value - 1;
if (range_startAddr != 0) {
addLineInfo ( si,
curr_filenmoff,
range_startAddr,
range_endAddr,
range_lineno );
}
range_startAddr = 0;
} else {
/* N_FUN with a name -- indicates the start of a fn. */
curr_fnbaseaddr = si->offset
+ (Addr)stab[i].n_value;
range_startAddr = curr_fnbaseaddr;
}
break;
}
case 100: /* N_SO */
case 132: /* N_SOL */
/* seems to give lots of locations in header files */
/* case 130: */ /* BINCL */
{
UChar* nm = stabstr + stab[i].n_un.n_strx;
UInt len = VG_(strlen)(nm);
if (len > 0 && nm[len-1] != '/')
curr_filenmoff = addStr ( si, nm );
else
if (len == 0)
curr_filenmoff = addStr ( si, "?1\0" );
break;
}
# if 0
case 162: /* EINCL */
curr_filenmoff = addStr ( si, "?2\0" );
break;
# endif
default:
break;
}
} /* for (i = 0; i < stab_sz/(int)sizeof(struct nlist); i++) */
/* Last, but not least, heave the oimage back overboard. */
VG_(munmap) ( (void*)oimage, n_oimage );
}
/*------------------------------------------------------------*/
/*--- Main entry point for symbols table reading. ---*/
/*------------------------------------------------------------*/
/* The root structure for the entire symbol table system. It is a
linked list of SegInfos. Note that this entire mechanism assumes
that what we read from /proc/self/maps doesn't contain overlapping
address ranges, and as a result the SegInfos in this list describe
disjoint address ranges.
*/
static SegInfo* segInfo = NULL;
static
void read_symtab_callback (
Addr start, UInt size,
Char rr, Char ww, Char xx,
UInt foffset, UChar* filename )
{
SegInfo* si;
/* Stay sane ... */
if (size == 0)
return;
/* We're only interested in collecting symbols in executable
segments which are associated with a real file. Hence: */
if (filename == NULL || xx != 'x')
return;
if (0 == VG_(strcmp)(filename, "/dev/zero"))
return;
/* Perhaps we already have this one? If so, skip. */
for (si = segInfo; si != NULL; si = si->next) {
/*
if (0==VG_(strcmp)(si->filename, filename))
VG_(printf)("same fnames: %c%c%c (%p, %d) (%p, %d) %s\n",
rr,ww,xx,si->start,si->size,start,size,filename);
*/
/* For some reason the observed size of a mapping can change, so
we don't use that to determine uniqueness. */
if (si->start == start
/* && si->size == size */
&& 0==VG_(strcmp)(si->filename, filename)) {
return;
}
}
/* Get the record initialised right. */
si = VG_(malloc)(VG_AR_SYMTAB, sizeof(SegInfo));
si->next = segInfo;
segInfo = si;
si->start = start;
si->size = size;
si->foffset = foffset;
si->filename = VG_(malloc)(VG_AR_SYMTAB, 1 + VG_(strlen)(filename));
VG_(strcpy)(si->filename, filename);
si->symtab = NULL;
si->symtab_size = si->symtab_used = 0;
si->loctab = NULL;
si->loctab_size = si->loctab_used = 0;
si->strtab = NULL;
si->strtab_size = si->strtab_used = 0;
/* Kludge ... */
si->offset
= si->start==VG_ASSUMED_EXE_BASE ? 0 : si->start;
/* And actually fill it up. */
vg_read_lib_symbols ( si );
canonicaliseSymtab ( si );
canonicaliseLoctab ( si );
}
/* This one really is the Head Honcho. Update the symbol tables to
reflect the current state of /proc/self/maps. Rather than re-read
everything, just read the entries which are not already in segInfo.
So we can call here repeatedly, after every mmap of a non-anonymous
segment with execute permissions, for example, to pick up new
libraries as they are dlopen'd. Conversely, when the client does
munmap(), vg_symtab_notify_munmap() throws away any symbol tables
which happen to correspond to the munmap()d area. */
void VG_(read_symbols) ( void )
{
if (! VG_(clo_instrument))
return;
VG_(read_procselfmaps) ( read_symtab_callback );
/* Do a sanity check on the symbol tables: ensure that the address
space pieces they cover do not overlap (otherwise we are severely
hosed). This is a quadratic algorithm, but there shouldn't be
many of them.
*/
{ SegInfo *si, *si2;
for (si = segInfo; si != NULL; si = si->next) {
/* Check no overlap between *si and those in the rest of the
list. */
for (si2 = si->next; si2 != NULL; si2 = si2->next) {
Addr lo = si->start;
Addr hi = si->start + si->size - 1;
Addr lo2 = si2->start;
Addr hi2 = si2->start + si2->size - 1;
Bool overlap;
vg_assert(lo < hi);
vg_assert(lo2 < hi2);
/* the main assertion */
overlap = (lo <= lo2 && lo2 <= hi)
|| (lo <= hi2 && hi2 <= hi);
//vg_assert(!overlap);
if (overlap) {
VG_(printf)("\n\nOVERLAPPING SEGMENTS\n" );
ppSegInfo ( si );
ppSegInfo ( si2 );
VG_(printf)("\n\n");
vg_assert(! overlap);
}
}
}
}
}
/* When an munmap() call happens, check to see whether it corresponds
to a segment for a .so, and if so discard the relevant SegInfo.
This might not be a very clever idea from the point of view of
accuracy of error messages, but we need to do it in order to
maintain the no-overlapping invariant.
*/
void VG_(symtab_notify_munmap) ( Addr start, UInt length )
{
SegInfo *prev, *curr;
if (! VG_(clo_instrument))
return;
prev = NULL;
curr = segInfo;
while (True) {
if (curr == NULL) break;
if (start == curr->start) break;
prev = curr;
curr = curr->next;
}
if (curr == NULL) return;
VG_(message)(Vg_UserMsg,
"discard syms in %s due to munmap()",
curr->filename ? curr->filename : (UChar*)"???");
vg_assert(prev == NULL || prev->next == curr);
if (prev == NULL) {
segInfo = curr->next;
} else {
prev->next = curr->next;
}
freeSegInfo(curr);
}
/*------------------------------------------------------------*/
/*--- Use of symbol table & location info to create ---*/
/*--- plausible-looking stack dumps. ---*/
/*------------------------------------------------------------*/
/* Find a symbol-table index containing the specified pointer, or -1
if not found. Binary search. */
static Int search_one_symtab ( SegInfo* si, Addr ptr )
{
Addr a_mid_lo, a_mid_hi;
Int mid,
lo = 0,
hi = si->symtab_used-1;
while (True) {
/* current unsearched space is from lo to hi, inclusive. */
if (lo > hi) return -1; /* not found */
mid = (lo + hi) / 2;
a_mid_lo = si->symtab[mid].addr;
a_mid_hi = ((Addr)si->symtab[mid].addr) + si->symtab[mid].size - 1;
if (ptr < a_mid_lo) { hi = mid-1; continue; }
if (ptr > a_mid_hi) { lo = mid+1; continue; }
vg_assert(ptr >= a_mid_lo && ptr <= a_mid_hi);
return mid;
}
}
/* Search all symtabs that we know about to locate ptr. If found, set
*psi to the relevant SegInfo, and *symno to the symtab entry number
within that. If not found, *psi is set to NULL. */
static void search_all_symtabs ( Addr ptr, SegInfo** psi, Int* symno )
{
Int sno;
SegInfo* si;
for (si = segInfo; si != NULL; si = si->next) {
if (si->start <= ptr && ptr < si->start+si->size) {
sno = search_one_symtab ( si, ptr );
if (sno == -1) goto not_found;
*symno = sno;
*psi = si;
return;
}
}
not_found:
*psi = NULL;
}
/* Find a location-table index containing the specified pointer, or -1
if not found. Binary search. */
static Int search_one_loctab ( SegInfo* si, Addr ptr )
{
Addr a_mid_lo, a_mid_hi;
Int mid,
lo = 0,
hi = si->loctab_used-1;
while (True) {
/* current unsearched space is from lo to hi, inclusive. */
if (lo > hi) return -1; /* not found */
mid = (lo + hi) / 2;
a_mid_lo = si->loctab[mid].addr;
a_mid_hi = ((Addr)si->loctab[mid].addr) + si->loctab[mid].size - 1;
if (ptr < a_mid_lo) { hi = mid-1; continue; }
if (ptr > a_mid_hi) { lo = mid+1; continue; }
vg_assert(ptr >= a_mid_lo && ptr <= a_mid_hi);
return mid;
}
}
/* Search all loctabs that we know about to locate ptr. If found, set
*psi to the relevant SegInfo, and *locno to the loctab entry number
within that. If not found, *psi is set to NULL.
*/
static void search_all_loctabs ( Addr ptr, SegInfo** psi, Int* locno )
{
Int lno;
SegInfo* si;
for (si = segInfo; si != NULL; si = si->next) {
if (si->start <= ptr && ptr < si->start+si->size) {
lno = search_one_loctab ( si, ptr );
if (lno == -1) goto not_found;
*locno = lno;
*psi = si;
return;
}
}
not_found:
*psi = NULL;
}
/* The whole point of this whole big deal: map a code address to a
plausible symbol name. Returns False if no idea; otherwise True.
Caller supplies buf and nbuf. If no_demangle is True, don't do
demangling, regardless of vg_clo_demangle -- probably because the
call has come from vg_what_fn_or_object_is_this. */
static
Bool vg_what_fn_is_this ( Bool no_demangle, Addr a,
Char* buf, Int nbuf )
{
SegInfo* si;
Int sno;
search_all_symtabs ( a, &si, &sno );
if (si == NULL)
return False;
if (no_demangle) {
VG_(strncpy_safely)
( buf, & si->strtab[si->symtab[sno].nmoff], nbuf );
} else {
VG_(demangle) ( & si->strtab[si->symtab[sno].nmoff], buf, nbuf );
}
return True;
}
/* Map a code address to the name of a shared object file. Returns
False if no idea; otherwise False. Caller supplies buf and
nbuf. */
static
Bool vg_what_object_is_this ( Addr a, Char* buf, Int nbuf )
{
SegInfo* si;
for (si = segInfo; si != NULL; si = si->next) {
if (si->start <= a && a < si->start+si->size) {
VG_(strncpy_safely)(buf, si->filename, nbuf);
return True;
}
}
return False;
}
/* Return the name of an erring fn in a way which is useful
for comparing against the contents of a suppressions file.
Always writes something to buf. Also, doesn't demangle the
name, because we want to refer to mangled names in the
suppressions file.
*/
void VG_(what_obj_and_fun_is_this) ( Addr a,
Char* obj_buf, Int n_obj_buf,
Char* fun_buf, Int n_fun_buf )
{
(void)vg_what_object_is_this ( a, obj_buf, n_obj_buf );
(void)vg_what_fn_is_this ( True, a, fun_buf, n_fun_buf );
}
/* Map a code address to a (filename, line number) pair.
Returns True if successful.
*/
static
Bool vg_what_line_is_this ( Addr a,
UChar* filename, Int n_filename,
UInt* lineno )
{
SegInfo* si;
Int locno;
search_all_loctabs ( a, &si, &locno );
if (si == NULL)
return False;
VG_(strncpy_safely)(filename, & si->strtab[si->loctab[locno].fnmoff],
n_filename);
*lineno = si->loctab[locno].lineno;
return True;
}
/* Print a mini stack dump, showing the current location. */
void VG_(mini_stack_dump) ( ExeContext* ec )
{
#define APPEND(str) \
{ UChar* sss; \
for (sss = str; n < M_VG_ERRTXT-1 && *sss != 0; n++,sss++) \
buf[n] = *sss; \
buf[n] = 0; \
}
Bool know_fnname;
Bool know_objname;
Bool know_srcloc;
UInt lineno;
UChar ibuf[20];
UInt i, n, clueless;
UChar buf[M_VG_ERRTXT];
UChar buf_fn[M_VG_ERRTXT];
UChar buf_obj[M_VG_ERRTXT];
UChar buf_srcloc[M_VG_ERRTXT];
Int stop_at = VG_(clo_backtrace_size);
n = 0;
know_fnname = vg_what_fn_is_this(False,ec->eips[0], buf_fn, M_VG_ERRTXT);
know_objname = vg_what_object_is_this(ec->eips[0], buf_obj, M_VG_ERRTXT);
know_srcloc = vg_what_line_is_this(ec->eips[0],
buf_srcloc, M_VG_ERRTXT,
&lineno);
APPEND(" at ");
VG_(sprintf)(ibuf,"0x%x: ", ec->eips[0]);
APPEND(ibuf);
if (know_fnname) {
APPEND(buf_fn);
if (!know_srcloc && know_objname) {
APPEND(" (in ");
APPEND(buf_obj);
APPEND(")");
}
} else if (know_objname && !know_srcloc) {
APPEND("(within ");
APPEND(buf_obj);
APPEND(")");
} else {
APPEND("???");
}
if (know_srcloc) {
APPEND(" (");
APPEND(buf_srcloc);
APPEND(":");
VG_(sprintf)(ibuf,"%d",lineno);
APPEND(ibuf);
APPEND(")");
}
VG_(message)(Vg_UserMsg, "%s", buf);
clueless = 0;
for (i = 1; i < stop_at; i++) {
know_fnname = vg_what_fn_is_this(False,ec->eips[i], buf_fn, M_VG_ERRTXT);
know_objname = vg_what_object_is_this(ec->eips[i],buf_obj, M_VG_ERRTXT);
know_srcloc = vg_what_line_is_this(ec->eips[i],
buf_srcloc, M_VG_ERRTXT,
&lineno);
n = 0;
APPEND(" by ");
if (ec->eips[i] == 0) {
APPEND("<bogus frame pointer> ");
} else {
VG_(sprintf)(ibuf,"0x%x: ",ec->eips[i]);
APPEND(ibuf);
}
if (know_fnname) {
APPEND(buf_fn)
if (!know_srcloc && know_objname) {
APPEND(" (in ");
APPEND(buf_obj);
APPEND(")");
}
} else {
if (know_objname && !know_srcloc) {
APPEND("(within ");
APPEND(buf_obj);
APPEND(")");
} else {
APPEND("???");
}
if (!know_srcloc) clueless++;
if (clueless == 2)
i = stop_at; /* force exit after this iteration */
};
if (know_srcloc) {
APPEND(" (");
APPEND(buf_srcloc);
APPEND(":");
VG_(sprintf)(ibuf,"%d",lineno);
APPEND(ibuf);
APPEND(")");
}
VG_(message)(Vg_UserMsg, "%s", buf);
}
}
#undef APPEND
/*--------------------------------------------------------------------*/
/*--- end vg_symtab2.c ---*/
/*--------------------------------------------------------------------*/
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