diff options
Diffstat (limited to 'libc/elf/dl-open.c')
| -rw-r--r-- | libc/elf/dl-open.c | 124 |
1 files changed, 94 insertions, 30 deletions
diff --git a/libc/elf/dl-open.c b/libc/elf/dl-open.c index 5e780f6ef..9006446ed 100644 --- a/libc/elf/dl-open.c +++ b/libc/elf/dl-open.c @@ -1,5 +1,5 @@ /* Load a shared object at runtime, relocate it, and run its initializer. - Copyright (C) 1996-2007, 2009, 2010, 2011 Free Software Foundation, Inc. + Copyright (C) 1996-2007, 2009, 2010, 2011, 2012 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -302,45 +302,109 @@ dl_open_worker (void *a) if (GLRO(dl_lazy)) reloc_mode |= mode & RTLD_LAZY; - /* Relocate the objects loaded. We do this in reverse order so that copy - relocs of earlier objects overwrite the data written by later objects. */ - + /* Sort the objects by dependency for the relocation process. This + allows IFUNC relocations to work and it also means copy + relocation of dependencies are if necessary overwritten. */ + size_t nmaps = 0; struct link_map *l = new; - while (l->l_next) - l = l->l_next; - while (1) + do + { + if (! l->l_real->l_relocated) + ++nmaps; + l = l->l_next; + } + while (l != NULL); + struct link_map *maps[nmaps]; + nmaps = 0; + l = new; + do { if (! l->l_real->l_relocated) + maps[nmaps++] = l; + l = l->l_next; + } + while (l != NULL); + if (nmaps > 1) + { + char seen[nmaps]; + memset (seen, '\0', nmaps); + size_t i = 0; + while (1) { -#ifdef SHARED - if (__builtin_expect (GLRO(dl_profile) != NULL, 0)) + ++seen[i]; + struct link_map *thisp = maps[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. */ + size_t k = nmaps - 1; + while (k > i) { - /* If this here is the shared object which we want to profile - make sure the profile is started. We can find out whether - this is necessary or not by observing the `_dl_profile_map' - variable. If was NULL but is not NULL afterwars we must - start the profiling. */ - struct link_map *old_profile_map = GL(dl_profile_map); + struct link_map **runp = maps[k]->l_initfini; + if (runp != NULL) + /* Look through the dependencies of the object. */ + while (*runp != NULL) + if (__builtin_expect (*runp++ == thisp, 0)) + { + /* 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 (seen[i + 1] > 1) + { + ++i; + goto next_clear; + } + + char this_seen = seen[i]; + memmove (&seen[i], &seen[i + 1], + (k - i) * sizeof (seen[0])); + seen[k] = this_seen; + + goto next; + } + + --k; + } - _dl_relocate_object (l, l->l_scope, reloc_mode | RTLD_LAZY, 1); + if (++i == nmaps) + break; + next_clear: + memset (&seen[i], 0, (nmaps - i) * sizeof (seen[0])); + next:; + } + } - if (old_profile_map == NULL && GL(dl_profile_map) != NULL) - { - /* We must prepare the profiling. */ - _dl_start_profile (); + for (size_t i = nmaps; i-- > 0; ) + { + l = maps[i]; - /* Prevent unloading the object. */ - GL(dl_profile_map)->l_flags_1 |= DF_1_NODELETE; - } +#ifdef SHARED + if (__builtin_expect (GLRO(dl_profile) != NULL, 0)) + { + /* If this here is the shared object which we want to profile + make sure the profile is started. We can find out whether + this is necessary or not by observing the `_dl_profile_map' + variable. If it was NULL but is not NULL afterwars we must + start the profiling. */ + struct link_map *old_profile_map = GL(dl_profile_map); + + _dl_relocate_object (l, l->l_scope, reloc_mode | RTLD_LAZY, 1); + + if (old_profile_map == NULL && GL(dl_profile_map) != NULL) + { + /* We must prepare the profiling. */ + _dl_start_profile (); + + /* Prevent unloading the object. */ + GL(dl_profile_map)->l_flags_1 |= DF_1_NODELETE; } - else -#endif - _dl_relocate_object (l, l->l_scope, reloc_mode, 0); } - - if (l == new) - break; - l = l->l_prev; + else +#endif + _dl_relocate_object (l, l->l_scope, reloc_mode, 0); } /* If the file is not loaded now as a dependency, add the search |