@@ -, +, @@ 17645) --- elf/Makefile | 1 + elf/dl-deps.c | 143 +++++++++++++++++++++++++++++------------------ elf/dl-fini.c | 176 +++++++++++++++++++++++++++++++--------------------------- elf/dl-open.c | 74 ++++++++++++++++++++++++ 4 files changed, 256 insertions(+), 138 deletions(-) --- a/elf/Makefile +++ a/elf/Makefile @@ -513,6 +513,7 @@ $(objpfx)unload8mod1.so: $(objpfx)unload8mod2.so $(objpfx)unload8mod2.so: $(objpfx)unload8mod3.so $(objpfx)unload8mod3.so: $(libdl) $(objpfx)tst-initordera2.so: $(objpfx)tst-initordera1.so +$(objpfx)tst-initorderb1.so: $(objpfx)tst-initordera2.so $(objpfx)tst-initorderb2.so: $(objpfx)tst-initorderb1.so $(objpfx)tst-initordera2.so $(objpfx)tst-initordera3.so: $(objpfx)tst-initorderb2.so $(objpfx)tst-initorderb1.so $(objpfx)tst-initordera4.so: $(objpfx)tst-initordera3.so --- a/elf/dl-deps.c +++ a/elf/dl-deps.c @@ -139,6 +139,93 @@ cannot load auxiliary `%s' because of empty dynamic string token " \ __result; }) static void +weight (struct link_map **maps, size_t nmaps, char *seen, unsigned int *w) +{ + int i, c; + struct link_map *m, **r; + + /* Start at 1 because the first entry is the binary itself. */ + for (i = 1; i < nmaps; ++i) + { + m = maps[i]; + if ((r = m->l_initfini)) + { + c = 0; + while (*r) + { + + /* If not a self reference, not being unloaded, and not + already removed from the list, increment the reference + counter. */ + if (*r != m && (*r)->l_idx >= 0 && !seen[(*r)->l_idx]) + ++c; + ++r; + } + + /* Update the {w}eight vector with {c}ount map(s) dependency */ + w[i] = c; + } + else + w[i] = 0; + } +} + +static void +sort (struct link_map **maps, size_t nmaps) +{ + int c, i, k; + unsigned int w[nmaps]; + char seen[nmaps]; + struct link_map *t; + memset(seen, 0, nmaps); + + /* Use the l_idx field as an unique identifier. */ + for (i = 0; i < nmaps; ++i) + { + /* Ensure to not touch a link_map with l_idx < 0 as it is + used to flag a dso is being unloaded. */ + if (maps[i]->l_idx >= 0) + maps[i]->l_idx = i; + } + + /* We can skip looking for the binary itself which is at the front + of the search list. */ + w[0] = 0; + seen[0] = 1; + + /* The list is sorted in place, with entries added from end to start. */ + weight(maps, k = nmaps, seen, w); + c = 0; + while (c < k) + { + for (i = k - 1; i >= 1; --i) + { + if (w[i] == c && maps[i]->l_idx >= 0) + { + seen[maps[i]->l_idx] = 1; + + /* Reducing the number of entries or swaping entries + require remaking the {w}eight map. */ + if (--k != i) + { + t = maps[k]; + maps[k] = maps[i]; + maps[i] = t; + } + weight(maps, k, seen, w); + c = -1; + break; + } + } + + /* If c != 0, there are cycles, and the first entry in the map, + with the lowest reference {c}ount is removed attempting to + to break the cycle. */ + ++c; + } +} + +static void preload (struct list *known, unsigned int *nlist, struct link_map *map) { known[*nlist].done = 0; @@ -611,61 +698,7 @@ Filters not supported with LD_TRACE_PRELINKING")); memcpy (l_initfini, map->l_searchlist.r_list, nlist * sizeof (struct link_map *)); if (__glibc_likely (nlist > 1)) - { - /* We can skip looking for the binary itself which is at the front - of the search list. */ - i = 1; - uint16_t seen[nlist]; - memset (seen, 0, nlist * sizeof (seen[0])); - while (1) - { - /* Keep track of which object we looked at this round. */ - ++seen[i]; - struct link_map *thisp = l_initfini[i]; - - /* Find the last object in the list for which the current one is - a dependency and move the current object behind the object - with the dependency. */ - unsigned int k = nlist - 1; - while (k > i) - { - struct link_map **runp = l_initfini[k]->l_initfini; - if (runp != NULL) - /* Look through the dependencies of the object. */ - while (*runp != NULL) - if (__glibc_unlikely (*runp++ == thisp)) - { - /* Move the current object to the back past the last - object with it as the dependency. */ - memmove (&l_initfini[i], &l_initfini[i + 1], - (k - i) * sizeof (l_initfini[0])); - l_initfini[k] = thisp; - - if (seen[i + 1] > nlist - i) - { - ++i; - goto next_clear; - } - - uint16_t this_seen = seen[i]; - memmove (&seen[i], &seen[i + 1], - (k - i) * sizeof (seen[0])); - seen[k] = this_seen; - - goto next; - } - - --k; - } - - if (++i == nlist) - break; - next_clear: - memset (&seen[i], 0, (nlist - i) * sizeof (seen[0])); - - next:; - } - } + sort (l_initfini, nlist); /* Terminate the list of dependencies. */ l_initfini[nlist] = NULL; --- a/elf/dl-fini.c +++ a/elf/dl-fini.c @@ -26,102 +26,112 @@ typedef void (*fini_t) (void); -void -internal_function -_dl_sort_fini (struct link_map **maps, size_t nmaps, char *used, Lmid_t ns) +static void +weight (struct link_map **maps, size_t nmaps, char *seen, unsigned int *w, int from) { - /* A list of one element need not be sorted. */ - if (nmaps == 1) - return; + int i, c; + struct link_map *m, **r; + for (i = from; i < nmaps; ++i) + { + m = maps[i]; + if ((r = m->l_initfini)) + { + c = 0; + while (*r) + { + /* If not a self reference, not being unloaded, and not + already removed from the list, increment the reference + counter. */ + if (*r != m && (*r)->l_idx >= 0 && !seen[(*r)->l_idx]) + ++c; + ++r; + } + /* Update the {w}eight vector with {c}ount map(s) dependency */ + w[i] = c; + } + else + w[i] = 0; + } +} + + +static void +sort (struct link_map **maps, size_t nmaps, char *used, Lmid_t ns) +{ + int from; + int c, i, k; + unsigned int w[nmaps]; + char seen[nmaps]; + struct link_map *t; + + memset(seen, 0, nmaps); + + /* Use the l_idx field as an unique identifier. */ + for (i = 0; i < nmaps; ++i) + { + /* Ensure to not touch a link_map with l_idx < 0 as it is + used to flag a dso is being unloaded. */ + if (maps[i]->l_idx >= 0) + maps[i]->l_idx = i; + } /* We can skip looking for the binary itself which is at the front of the search list for the main namespace. */ - unsigned int i = ns == LM_ID_BASE; - uint16_t seen[nmaps]; - memset (seen, 0, nmaps * sizeof (seen[0])); - while (1) + from = ns == LM_ID_BASE; + if (from) { - /* Keep track of which object we looked at this round. */ - ++seen[i]; - struct link_map *thisp = maps[i]; - - /* Do not handle ld.so in secondary namespaces and object which - are not removed. */ - if (thisp != thisp->l_real || thisp->l_idx == -1) - goto skip; - - /* Find the last object in the list for which the current one is - a dependency and move the current object behind the object - with the dependency. */ - unsigned int k = nmaps - 1; - while (k > i) - { - struct link_map **runp = maps[k]->l_initfini; - if (runp != NULL) - /* Look through the dependencies of the object. */ - while (*runp != NULL) - if (__glibc_unlikely (*runp++ == thisp)) - { - move: - /* Move the current object to the back past the last - object with it as the dependency. */ - memmove (&maps[i], &maps[i + 1], - (k - i) * sizeof (maps[0])); - maps[k] = thisp; - - if (used != NULL) - { - char here_used = used[i]; - memmove (&used[i], &used[i + 1], - (k - i) * sizeof (used[0])); - used[k] = here_used; - } + w[0] = 0; + seen[0] = 1; + } - if (seen[i + 1] > nmaps - i) + /* The list is sorted in place, with entries added from end to start. */ + weight(maps, k = nmaps, seen, w, from); + c = 0; + while (c < k) + { + for (i = k - 1; i >= from; --i) + { + t = maps[i]; + /* Do not handle ld.so in secondary namespaces and object which + are not removed. */ + if (w[i] == c && maps[i]->l_idx >= 0 && t->l_real == t) + { + seen[maps[i]->l_idx] = 1; + /* Reducing the number of entries or swaping entries + require remaking the {w}eight map. */ + if (--k != i) + { + maps[i] = maps[k]; + maps[k] = t; + if (used) { - ++i; - goto next_clear; + char c = used[i]; + used[i] = used[k]; + used[k] = c; } - - uint16_t this_seen = seen[i]; - memmove (&seen[i], &seen[i + 1], (k - i) * sizeof (seen[0])); - seen[k] = this_seen; - - goto next; } - - if (__glibc_unlikely (maps[k]->l_reldeps != NULL)) - { - unsigned int m = maps[k]->l_reldeps->act; - struct link_map **relmaps = &maps[k]->l_reldeps->list[0]; - - /* Look through the relocation dependencies of the object. */ - while (m-- > 0) - if (__glibc_unlikely (relmaps[m] == thisp)) - { - /* If a cycle exists with a link time dependency, - preserve the latter. */ - struct link_map **runp = thisp->l_initfini; - if (runp != NULL) - while (*runp != NULL) - if (__glibc_unlikely (*runp++ == maps[k])) - goto ignore; - goto move; - } - ignore:; + weight(maps, k, seen, w, from); + c = -1; + break; } - - --k; } + /* If c != 0, there are cycles, and the first entry in the map, + with the lowest reference {c}ount is removed attempting to + to break the cycle. */ + ++c; + } +} - skip: - if (++i == nmaps) - break; - next_clear: - memset (&seen[i], 0, (nmaps - i) * sizeof (seen[0])); - next:; - } +void +internal_function +_dl_sort_fini (struct link_map **maps, size_t nmaps, char *used, Lmid_t ns) +{ + /* A list of one element need not be sorted. */ + if (nmaps == 1) + return; + + sort (maps, nmaps, used, ns); } --- a/elf/dl-open.c +++ a/elf/dl-open.c @@ -182,6 +182,80 @@ _dl_find_dso_for_object (const ElfW(Addr) addr) rtld_hidden_def (_dl_find_dso_for_object); static void +weight (struct link_map **maps, size_t nmaps, char *seen, unsigned int *w) +{ + int i, c; + struct link_map *m, **r; + for (i = 0; i < nmaps; ++i) + { + m = maps[i]; + if ((r = m->l_initfini)) + { + c = 0; + while (*r) + { + /* If not a self reference, not being unloaded, and not + already removed from the list, increment the reference + counter. */ + if (*r != m && (*r)->l_idx >= 0 && !seen[(*r)->l_idx]) + ++c; + ++r; + } + /* Update the {w}eight vector with {c}ount map(s) dependency */ + w[i] = c; + } + else + w[i] = 0; + } +} + +static void +sort (struct link_map **maps, size_t nmaps) +{ + int c, i, k; + unsigned int w[nmaps]; + char seen[nmaps]; + struct link_map *t; + memset(seen, 0, nmaps); + /* Use the l_idx field as an unique identifier. */ + for (i = 0; i < nmaps; ++i) + { + /* Ensure to not touch a link_map with l_idx < 0 as it is + used to flag a dso is being unloaded. */ + if (maps[i]->l_idx >= 0) + maps[i]->l_idx = i; + } + /* The list is sorted in place, with entries added from end to start. */ + weight(maps, k = nmaps, seen, w); + c = 0; + while (c < k) + { + for (i = k - 1; i >= 0; --i) + { + if (w[i] == c && maps[i]->l_idx >= 0) + { + seen[maps[i]->l_idx] = 1; + /* Reducing the number of entries or swaping entries + require remaking the {w}eight map. */ + if (--k != i) + { + t = maps[k]; + maps[k] = maps[i]; + maps[i] = t; + } + weight(maps, k, seen, w); + c = -1; + break; + } + } + /* If c != 0, there are cycles, and the first entry in the map, + with the lowest reference {c}ount is removed attempting to + to break the cycle. */ + ++c; + } +} + +static void dl_open_worker (void *a) { struct dl_open_args *args = a; --