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merge from eclair

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This commit is contained in:
Jean-Baptiste Queru
2009-11-15 12:05:31 -08:00
parent 71c0aeb44f 194d3fa048
commit 95604529ec
47 changed files with 5014 additions and 3135 deletions
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182
linker/linker.c
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@@ -51,6 +51,7 @@
#include "ba.h"
#define ALLOW_SYMBOLS_FROM_MAIN 1
#define SO_MAX 96
/* Assume average path length of 64 and max 8 paths */
@@ -86,6 +87,27 @@ static soinfo sopool[SO_MAX];
static soinfo *freelist = NULL;
static soinfo *solist = &libdl_info;
static soinfo *sonext = &libdl_info;
#if ALLOW_SYMBOLS_FROM_MAIN
static soinfo *somain; /* main process, always the one after libdl_info */
#endif
/* Set up for the buddy allocator managing the prelinked libraries. */
static struct ba_bits ba_prelink_bitmap[(LIBLAST - LIBBASE) / LIBINC];
static struct ba ba_prelink = {
.base = LIBBASE,
.size = LIBLAST - LIBBASE,
.min_alloc = LIBINC,
/* max_order will be determined automatically */
.bitmap = ba_prelink_bitmap,
.num_entries = sizeof(ba_prelink_bitmap)/sizeof(ba_prelink_bitmap[0]),
};
static inline int validate_soinfo(soinfo *si)
{
return (si >= sopool && si < sopool + SO_MAX) ||
si == &libdl_info;
}
static char ldpaths_buf[LDPATH_BUFSIZE];
static const char *ldpaths[LDPATH_MAX + 1];
@@ -422,53 +444,98 @@ _do_lookup_in_so(soinfo *si, const char *name, unsigned *elf_hash)
return _elf_lookup (si, *elf_hash, name);
}
/* This is used by dl_sym() */
Elf32_Sym *lookup_in_library(soinfo *si, const char *name)
{
unsigned unused = 0;
return _do_lookup_in_so(si, name, &unused);
}
static Elf32_Sym *
_do_lookup(soinfo *user_si, const char *name, unsigned *base)
_do_lookup(soinfo *si, const char *name, unsigned *base)
{
unsigned elf_hash = 0;
Elf32_Sym *s = NULL;
soinfo *si;
Elf32_Sym *s;
unsigned *d;
soinfo *lsi = si;
/* Look for symbols in the local scope first (the object who is
* searching). This happens with C++ templates on i386 for some
* reason. */
if (user_si) {
s = _do_lookup_in_so(user_si, name, &elf_hash);
if (s != NULL)
*base = user_si->base;
}
s = _do_lookup_in_so(si, name, &elf_hash);
if(s != NULL)
goto done;
for(si = solist; (s == NULL) && (si != NULL); si = si->next)
{
if((si->flags & FLAG_ERROR) || (si == user_si))
continue;
s = _do_lookup_in_so(si, name, &elf_hash);
if (s != NULL) {
*base = si->base;
break;
for(d = si->dynamic; *d; d += 2) {
if(d[0] == DT_NEEDED){
lsi = (soinfo *)d[1];
if (!validate_soinfo(lsi)) {
DL_ERR("%5d bad DT_NEEDED pointer in %s",
pid, si->name);
return 0;
}
DEBUG("%5d %s: looking up %s in %s\n",
pid, si->name, name, lsi->name);
s = _do_lookup_in_so(lsi, name, &elf_hash);
if(s != NULL)
goto done;
}
}
if (s != NULL) {
TRACE_TYPE(LOOKUP, "%5d %s s->st_value = 0x%08x, "
"si->base = 0x%08x\n", pid, name, s->st_value, si->base);
#if ALLOW_SYMBOLS_FROM_MAIN
/* If we are resolving relocations while dlopen()ing a library, it's OK for
* the library to resolve a symbol that's defined in the executable itself,
* although this is rare and is generally a bad idea.
*/
if (somain) {
lsi = somain;
DEBUG("%5d %s: looking up %s in executable %s\n",
pid, si->name, name, lsi->name);
s = _do_lookup_in_so(lsi, name, &elf_hash);
}
#endif
done:
if(s != NULL) {
TRACE_TYPE(LOOKUP, "%5d si %s sym %s s->st_value = 0x%08x, "
"found in %s, base = 0x%08x\n",
pid, si->name, name, s->st_value, lsi->name, lsi->base);
*base = lsi->base;
return s;
}
return 0;
}
/* This is used by dl_sym() */
Elf32_Sym *lookup(const char *name, unsigned *base)
/* This is used by dl_sym(). It performs symbol lookup only within the
specified soinfo object and not in any of its dependencies.
*/
Elf32_Sym *lookup_in_library(soinfo *si, const char *name)
{
return _do_lookup(NULL, name, base);
unsigned unused = 0;
return _do_lookup_in_so(si, name, &unused);
}
/* This is used by dl_sym(). It performs a global symbol lookup.
*/
Elf32_Sym *lookup(const char *name, soinfo **found)
{
unsigned elf_hash = 0;
Elf32_Sym *s = NULL;
soinfo *si;
for(si = solist; (s == NULL) && (si != NULL); si = si->next)
{
if(si->flags & FLAG_ERROR)
continue;
s = _do_lookup_in_so(si, name, &elf_hash);
if (s != NULL) {
*found = si;
break;
}
}
if(s != NULL) {
TRACE_TYPE(LOOKUP, "%5d %s s->st_value = 0x%08x, "
"si->base = 0x%08x\n", pid, name, s->st_value, si->base);
return s;
}
return 0;
}
#if 0
@@ -729,14 +796,14 @@ alloc_mem_region(soinfo *si)
for it from the buddy allocator, which manages the area between
LIBBASE and LIBLAST.
*/
si->ba_index = ba_allocate(si->size);
si->ba_index = ba_allocate(&ba_prelink, si->size);
if(si->ba_index >= 0) {
si->base = ba_start_addr(si->ba_index);
si->base = ba_start_addr(&ba_prelink, si->ba_index);
PRINT("%5d mapping library '%s' at %08x (index %d) " \
"through buddy allocator.\n",
pid, si->name, si->base, si->ba_index);
if (reserve_mem_region(si) < 0) {
ba_free(si->ba_index);
ba_free(&ba_prelink, si->ba_index);
si->ba_index = -1;
si->base = 0;
goto err;
@@ -1032,7 +1099,7 @@ load_library(const char *name)
/* Now actually load the library's segments into right places in memory */
if (load_segments(fd, &__header[0], si) < 0) {
if (si->ba_index >= 0) {
ba_free(si->ba_index);
ba_free(&ba_prelink, si->ba_index);
si->ba_index = -1;
}
goto fail;
@@ -1086,7 +1153,10 @@ soinfo *find_library(const char *name)
for(si = solist; si != 0; si = si->next){
if(!strcmp(bname, si->name)) {
if(si->flags & FLAG_ERROR) return 0;
if(si->flags & FLAG_ERROR) {
DL_ERR("%5d '%s' failed to load previously", pid, bname);
return NULL;
}
if(si->flags & FLAG_LINKED) return si;
DL_ERR("OOPS: %5d recursive link to '%s'", pid, si->name);
return NULL;
@@ -1114,14 +1184,16 @@ unsigned unload_library(soinfo *si)
for(d = si->dynamic; *d; d += 2) {
if(d[0] == DT_NEEDED){
TRACE("%5d %s needs to unload %s\n", pid,
si->name, si->strtab + d[1]);
soinfo *lsi = find_library(si->strtab + d[1]);
if(lsi)
soinfo *lsi = (soinfo *)d[1];
d[1] = 0;
if (validate_soinfo(lsi)) {
TRACE("%5d %s needs to unload %s\n", pid,
si->name, lsi->name);
unload_library(lsi);
}
else
DL_ERR("%5d could not unload '%s'",
pid, si->strtab + d[1]);
DL_ERR("%5d %s: could not unload dependent library",
pid, si->name);
}
}
@@ -1130,7 +1202,7 @@ unsigned unload_library(soinfo *si)
PRINT("%5d releasing library '%s' address space at %08x "\
"through buddy allocator.\n",
pid, si->name, si->base);
ba_free(si->ba_index);
ba_free(&ba_prelink, si->ba_index);
}
notify_gdb_of_unload(si);
free_info(si);
@@ -1181,9 +1253,13 @@ static int reloc_library(soinfo *si, Elf32_Rel *rel, unsigned count)
return -1;
}
#endif
if ((s->st_shndx == SHN_UNDEF) && (s->st_value != 0)) {
DL_ERR("%5d In '%s', shndx=%d && value=0x%08x. We do not "
"handle this yet", pid, si->name, s->st_shndx,
// st_shndx==SHN_UNDEF means an undefined symbol.
// st_value should be 0 then, except that the low bit of st_value is
// used to indicate whether the symbol points to an ARM or thumb function,
// and should be ignored in the following check.
if ((s->st_shndx == SHN_UNDEF) && ((s->st_value & ~1) != 0)) {
DL_ERR("%5d In '%s', symbol=%s shndx=%d && value=0x%08x. We do not "
"handle this yet", pid, si->name, sym_name, s->st_shndx,
s->st_value);
return -1;
}
@@ -1755,6 +1831,14 @@ static int link_image(soinfo *si, unsigned wr_offset)
pid, si->strtab + d[1], si->name, tmp_err_buf);
goto fail;
}
/* Save the soinfo of the loaded DT_NEEDED library in the payload
of the DT_NEEDED entry itself, so that we can retrieve the
soinfo directly later from the dynamic segment. This is a hack,
but it allows us to map from DT_NEEDED to soinfo efficiently
later on when we resolve relocations, trying to look up a symgol
with dlsym().
*/
d[1] = (unsigned)lsi;
lsi->refcount++;
}
}
@@ -1955,7 +2039,7 @@ unsigned __linker_init(unsigned **elfdata)
vecs += 2;
}
ba_init();
ba_init(&ba_prelink);
si->base = 0;
si->dynamic = (unsigned *)-1;
@@ -1973,6 +2057,14 @@ unsigned __linker_init(unsigned **elfdata)
exit(-1);
}
#if ALLOW_SYMBOLS_FROM_MAIN
/* Set somain after we've loaded all the libraries in order to prevent
* linking of symbols back to the main image, which is not set up at that
* point yet.
*/
somain = si;
#endif
#if TIMING
gettimeofday(&t1,NULL);
PRINT("LINKER TIME: %s: %d microseconds\n", argv[0], (int) (