123 lines
3.4 KiB
C
123 lines
3.4 KiB
C
/* Sort array of link maps according to dependencies.
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Copyright (C) 2017-2019 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <ldsodefs.h>
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/* Sort array MAPS according to dependencies of the contained objects.
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Array USED, if non-NULL, is permutated along MAPS. If FOR_FINI this is
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called for finishing an object. */
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void
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_dl_sort_maps (struct link_map **maps, unsigned int nmaps, char *used,
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bool for_fini)
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{
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/* A list of one element need not be sorted. */
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if (nmaps <= 1)
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return;
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unsigned int i = 0;
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uint16_t seen[nmaps];
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memset (seen, 0, nmaps * sizeof (seen[0]));
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while (1)
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{
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/* Keep track of which object we looked at this round. */
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++seen[i];
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struct link_map *thisp = maps[i];
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if (__glibc_unlikely (for_fini))
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{
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/* Do not handle ld.so in secondary namespaces and objects which
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are not removed. */
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if (thisp != thisp->l_real || thisp->l_idx == -1)
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goto skip;
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}
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/* Find the last object in the list for which the current one is
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a dependency and move the current object behind the object
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with the dependency. */
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unsigned int k = nmaps - 1;
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while (k > i)
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{
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struct link_map **runp = maps[k]->l_initfini;
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if (runp != NULL)
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/* Look through the dependencies of the object. */
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while (*runp != NULL)
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if (__glibc_unlikely (*runp++ == thisp))
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{
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move:
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/* Move the current object to the back past the last
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object with it as the dependency. */
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memmove (&maps[i], &maps[i + 1],
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(k - i) * sizeof (maps[0]));
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maps[k] = thisp;
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if (used != NULL)
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{
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char here_used = used[i];
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memmove (&used[i], &used[i + 1],
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(k - i) * sizeof (used[0]));
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used[k] = here_used;
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}
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if (seen[i + 1] > nmaps - i)
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{
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++i;
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goto next_clear;
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}
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uint16_t this_seen = seen[i];
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memmove (&seen[i], &seen[i + 1], (k - i) * sizeof (seen[0]));
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seen[k] = this_seen;
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goto next;
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}
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if (__glibc_unlikely (for_fini && maps[k]->l_reldeps != NULL))
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{
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unsigned int m = maps[k]->l_reldeps->act;
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struct link_map **relmaps = &maps[k]->l_reldeps->list[0];
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/* Look through the relocation dependencies of the object. */
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while (m-- > 0)
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if (__glibc_unlikely (relmaps[m] == thisp))
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{
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/* If a cycle exists with a link time dependency,
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preserve the latter. */
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struct link_map **runp = thisp->l_initfini;
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if (runp != NULL)
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while (*runp != NULL)
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if (__glibc_unlikely (*runp++ == maps[k]))
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goto ignore;
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goto move;
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}
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ignore:;
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}
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--k;
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}
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skip:
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if (++i == nmaps)
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break;
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next_clear:
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memset (&seen[i], 0, (nmaps - i) * sizeof (seen[0]));
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next:;
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}
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}
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