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* elf/dl-fini.c (_dl_fini): Split sorting of the maps in separate
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	function _dl_sort_fini.
	(_dl_sort_fini): New function.
	* sysdeps/generic/ldsodefs.h: Declare _dl_sort_fini.
	* elf/dl-close.c (_dl_close): Call _dl_sort_fini before running
	destructors to call them in the right order.
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Ulrich Drepper committed Mar 19, 2005
1 parent bb4bb82 commit c3381f3
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Showing 4 changed files with 152 additions and 103 deletions.
9 changes: 9 additions & 0 deletions ChangeLog
Original file line number Diff line number Diff line change
@@ -1,3 +1,12 @@
2005-03-18 Ulrich Drepper <drepper@redhat.com>

* elf/dl-fini.c (_dl_fini): Split sorting of the maps in separate
function _dl_sort_fini.
(_dl_sort_fini): New function.
* sysdeps/generic/ldsodefs.h: Declare _dl_sort_fini.
* elf/dl-close.c (_dl_close): Call _dl_sort_fini before running
destructors to call them in the right order.

2005-02-07 Steven Munroe <sjmunroe@us.ibm.com>

* sysdeps/powerpc/bits/link.h (La_ppc64_regs): Add lr_vrsave.
Expand Down
64 changes: 35 additions & 29 deletions elf/dl-close.c
Original file line number Diff line number Diff line change
Expand Up @@ -136,15 +136,9 @@ _dl_close (void *_map)
return;
}

#define NWORDS(n) (((n) + 8 * sizeof (unsigned long int) - 1) \
/ (sizeof (unsigned long int)))
#define SETBIT(a, n) a[(n) / sizeof (unsigned long int)] \
|= 1 << ((n) % (sizeof (unsigned long int)))
#define ISSET(a, n) (a[(n) / sizeof (unsigned long int)] \
& 1 << ((n) % (sizeof (unsigned long int))))
const unsigned int nloaded = GL(dl_ns)[ns]._ns_nloaded;
unsigned long int used[NWORDS (nloaded)];
unsigned long int done[NWORDS (nloaded)];
char used[nloaded];
char done[nloaded];
struct link_map *maps[nloaded];

/* Run over the list and assign indeces to the link maps and enter
Expand All @@ -168,34 +162,39 @@ _dl_close (void *_map)
{
struct link_map *l = maps[done_index];

if (ISSET (done, done_index))
if (done[done_index])
/* Already handled. */
continue;

/* Check whether this object is still used. */
if (l->l_type == lt_loaded
&& l->l_direct_opencount == 0
&& (l->l_flags_1 & DF_1_NODELETE) == 0
&& !ISSET (used, done_index))
&& !used[done_index])
continue;

/* We need this object and we handle it now. */
SETBIT (done, done_index);
SETBIT (used, done_index);
done[done_index] = 1;
used[done_index] = 1;
/* Signal the object is still needed. */
l->l_idx = -1;

/* Mark all dependencies as used. */
if (l->l_initfini != NULL)
{
struct link_map **lp = &l->l_initfini[1];
while (*lp != NULL)
{
assert ((*lp)->l_idx >= 0 && (*lp)->l_idx < nloaded);

if (!ISSET (used, (*lp)->l_idx))
if ((*lp)->l_idx != -1)
{
SETBIT (used, (*lp)->l_idx);
if ((*lp)->l_idx - 1 < done_index)
done_index = (*lp)->l_idx - 1;
assert ((*lp)->l_idx >= 0 && (*lp)->l_idx < nloaded);

if (!used[(*lp)->l_idx])
{
used[(*lp)->l_idx] = 1;
if ((*lp)->l_idx - 1 < done_index)
done_index = (*lp)->l_idx - 1;
}
}

++lp;
Expand All @@ -207,17 +206,23 @@ _dl_close (void *_map)
{
struct link_map *jmap = l->l_reldeps[j];

assert (jmap->l_idx >= 0 && jmap->l_idx < nloaded);

if (!ISSET (used, jmap->l_idx))
if (jmap->l_idx != -1)
{
SETBIT (used, jmap->l_idx);
if (jmap->l_idx - 1 < done_index)
done_index = jmap->l_idx - 1;
assert (jmap->l_idx >= 0 && jmap->l_idx < nloaded);

if (!used[jmap->l_idx])
{
used[jmap->l_idx] = 1;
if (jmap->l_idx - 1 < done_index)
done_index = jmap->l_idx - 1;
}
}
}
}

/* Sort the entries. */
_dl_sort_fini (GL(dl_ns)[ns]._ns_loaded, maps, nloaded, used, ns);

/* Call all termination functions at once. */
#ifdef SHARED
bool do_audit = GLRO(dl_naudit) > 0 && !GL(dl_ns)[ns]._ns_loaded->l_auditing;
Expand All @@ -231,7 +236,7 @@ _dl_close (void *_map)
/* All elements must be in the same namespace. */
assert (imap->l_ns == ns);

if (!ISSET (used, i))
if (!used[i])
{
assert (imap->l_type == lt_loaded
&& (imap->l_flags_1 & DF_1_NODELETE) == 0);
Expand Down Expand Up @@ -291,7 +296,7 @@ _dl_close (void *_map)
if (i < first_loaded)
first_loaded = i;
}
/* Else ISSET (used, i). */
/* Else used[i]. */
else if (imap->l_type == lt_loaded)
{
if (imap->l_searchlist.r_list == NULL
Expand Down Expand Up @@ -320,8 +325,9 @@ _dl_close (void *_map)
}
}

/* The loader is gone, so mark the object as not having one. */
if (imap->l_loader != NULL && !ISSET (used, imap->l_loader->l_idx))
/* The loader is gone, so mark the object as not having one.
Note: l_idx == -1 -> object will be removed. */
if (imap->l_loader != NULL && imap->l_loader->l_idx != -1)
imap->l_loader = NULL;

/* Remember where the first dynamically loaded object is. */
Expand Down Expand Up @@ -370,7 +376,7 @@ _dl_close (void *_map)
for (i = first_loaded; i < nloaded; ++i)
{
struct link_map *imap = maps[i];
if (!ISSET (used, i))
if (!used[i])
{
assert (imap->l_type == lt_loaded);

Expand Down
177 changes: 103 additions & 74 deletions elf/dl-fini.c
Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,94 @@
typedef void (*fini_t) (void);


void
internal_function
_dl_sort_fini (struct link_map *l, struct link_map **maps, size_t nmaps,
char *used, Lmid_t ns)
{
if (ns == LM_ID_BASE)
/* The main executable always comes first. */
l = l->l_next;

for (; l != NULL; l = l->l_next)
/* Do not handle ld.so in secondary namespaces and object which
are not removed. */
if (l == l->l_real && l->l_idx != -1)
{
/* Find the place in the 'maps' array. */
unsigned int j;
for (j = ns == LM_ID_BASE ? 1 : 0; maps[j] != l; ++j)
assert (j < nmaps);

/* Find all object for which the current one is a dependency
and move the found object (if necessary) in front. */
for (unsigned int k = j + 1; k < nmaps; ++k)
{
struct link_map **runp = maps[k]->l_initfini;
if (runp != NULL)
{
while (*runp != NULL)
if (*runp == l)
{
struct link_map *here = maps[k];

/* Move it now. */
memmove (&maps[j] + 1,
&maps[j], (k - j) * sizeof (struct link_map *));
maps[j] = here;

if (used != NULL)
{
char here_used = used[k];

memmove (&used[j] + 1,
&used[j], (k - j) * sizeof (char));
used[j] = here_used;
}

++j;

break;
}
else
++runp;
}

if (__builtin_expect (maps[k]->l_reldeps != NULL, 0))
{
unsigned int m = maps[k]->l_reldepsact;
struct link_map **relmaps = maps[k]->l_reldeps;

while (m-- > 0)
{
if (relmaps[m] == l)
{
struct link_map *here = maps[k];

/* Move it now. */
memmove (&maps[j] + 1,
&maps[j],
(k - j) * sizeof (struct link_map *));
maps[j] = here;

if (used != NULL)
{
char here_used = used[k];

memmove (&used[j] + 1,
&used[j], (k - j) * sizeof (char));
used[j] = here_used;
}

break;
}
}
}
}
}
}


void
internal_function
_dl_fini (void)
Expand All @@ -52,25 +140,25 @@ _dl_fini (void)
int do_audit = 0;
again:
#endif
for (Lmid_t cnt = DL_NNS - 1; cnt >= 0; --cnt)
for (Lmid_t ns = DL_NNS - 1; ns >= 0; --ns)
{
/* Protect against concurrent loads and unloads. */
__rtld_lock_lock_recursive (GL(dl_load_lock));

unsigned int nmaps = 0;
unsigned int nloaded = GL(dl_ns)[cnt]._ns_nloaded;
unsigned int nloaded = GL(dl_ns)[ns]._ns_nloaded;
/* No need to do anything for empty namespaces or those used for
auditing DSOs. */
if (nloaded == 0
#ifdef SHARED
|| GL(dl_ns)[cnt]._ns_loaded->l_auditing != do_audit
|| GL(dl_ns)[ns]._ns_loaded->l_auditing != do_audit
#endif
)
goto out;

/* XXX Could it be (in static binaries) that there is no object
loaded? */
assert (cnt != LM_ID_BASE || nloaded > 0);
assert (ns != LM_ID_BASE || nloaded > 0);

/* Now we can allocate an array to hold all the pointers and copy
the pointers in. */
Expand All @@ -89,87 +177,28 @@ _dl_fini (void)

unsigned int i;
struct link_map *l;
assert (nloaded != 0 || GL(dl_ns)[cnt]._ns_loaded == NULL);
for (l = GL(dl_ns)[cnt]._ns_loaded, i = 0; l != NULL; l = l->l_next)
assert (nloaded != 0 || GL(dl_ns)[ns]._ns_loaded == NULL);
for (l = GL(dl_ns)[ns]._ns_loaded, i = 0; l != NULL; l = l->l_next)
/* Do not handle ld.so in secondary namespaces. */
if (l == l->l_real)
{
assert (i < nloaded);

maps[i++] = l;
maps[i] = l;
l->l_idx = i;
++i;

/* Bump l_direct_opencount of all objects so that they are
not dlclose()ed from underneath us. */
++l->l_direct_opencount;
}
assert (cnt != LM_ID_BASE || i == nloaded);
assert (cnt == LM_ID_BASE || i == nloaded || i == nloaded - 1);
assert (ns != LM_ID_BASE || i == nloaded);
assert (ns == LM_ID_BASE || i == nloaded || i == nloaded - 1);
nmaps = i;

if (nmaps != 0)
{
/* Now we have to do the sorting. */
l = GL(dl_ns)[cnt]._ns_loaded;
if (cnt == LM_ID_BASE)
/* The main executable always comes first. */
l = l->l_next;
for (; l != NULL; l = l->l_next)
/* Do not handle ld.so in secondary namespaces. */
if (l == l->l_real)
{
/* Find the place in the 'maps' array. */
unsigned int j;
for (j = cnt == LM_ID_BASE ? 1 : 0; maps[j] != l; ++j)
assert (j < nmaps);

/* Find all object for which the current one is a dependency
and move the found object (if necessary) in front. */
for (unsigned int k = j + 1; k < nmaps; ++k)
{
struct link_map **runp = maps[k]->l_initfini;
if (runp != NULL)
{
while (*runp != NULL)
if (*runp == l)
{
struct link_map *here = maps[k];

/* Move it now. */
memmove (&maps[j] + 1,
&maps[j],
(k - j) * sizeof (struct link_map *));
maps[j++] = here;

break;
}
else
++runp;
}

if (__builtin_expect (maps[k]->l_reldeps != NULL, 0))
{
unsigned int m = maps[k]->l_reldepsact;
struct link_map **relmaps = maps[k]->l_reldeps;

while (m-- > 0)
{
if (relmaps[m] == l)
{
struct link_map *here = maps[k];

/* Move it now. */
memmove (&maps[j] + 1,
&maps[j],
(k - j) * sizeof (struct link_map *));
maps[j] = here;

break;
}
}
}
}
}
}
/* Now we have to do the sorting. */
_dl_sort_fini (GL(dl_ns)[ns]._ns_loaded, maps, nmaps, NULL, ns);

/* We do not rely on the linked list of loaded object anymore from
this point on. We have our own list here (maps). The various
Expand Down Expand Up @@ -200,7 +229,7 @@ _dl_fini (void)
& DL_DEBUG_IMPCALLS, 0))
_dl_debug_printf ("\ncalling fini: %s [%lu]\n\n",
l->l_name[0] ? l->l_name : rtld_progname,
cnt);
ns);

/* First see whether an array is given. */
if (l->l_info[DT_FINI_ARRAY] != NULL)
Expand Down Expand Up @@ -247,12 +276,12 @@ _dl_fini (void)
do_audit = 1;
goto again;
}
#endif

if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS, 0))
_dl_debug_printf ("\nruntime linker statistics:\n"
" final number of relocations: %lu\n"
"final number of relocations from cache: %lu\n",
GL(dl_num_relocations),
GL(dl_num_cache_relocations));
#endif
}
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