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elf: avoid stack allocation in dl_open_worker

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As the sort was removed, there's no need to keep a separate map of
links. Instead, when relocating objects iterate over l_initfini
directly.

This allows us to remove the loop copying l_initfini elements into
map. We still need a loop to identify the first and last elements that
need relocation.

Tested by running the testsuite on x86_64.
This commit is contained in:
David Kilroy 2020-02-12 14:31:17 -03:00 committed by Adhemerval Zanella
parent 71bcfa6245
commit 0a8ce6a096
1 changed files with 12 additions and 16 deletions
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28
elf/dl-open.c
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@ -621,25 +621,18 @@ dl_open_worker (void *a)
This allows IFUNC relocations to work and it also means copy
relocation of dependencies are if necessary overwritten.
__dl_map_object_deps has already sorted l_initfini for us. */
unsigned int nmaps = 0;
unsigned int first = UINT_MAX;
unsigned int last = 0;
unsigned int j = 0;
struct link_map *l = new->l_initfini[0];
do
{
if (! l->l_real->l_relocated)
++nmaps;
l = new->l_initfini[++j];
}
while (l != NULL);
/* Stack allocation is limited by the number of loaded objects. */
struct link_map *maps[nmaps];
nmaps = 0;
j = 0;
l = new->l_initfini[0];
do
{
if (! l->l_real->l_relocated)
maps[nmaps++] = l;
{
if (first == UINT_MAX)
first = j;
last = j + 1;
}
l = new->l_initfini[++j];
}
while (l != NULL);
@ -654,9 +647,12 @@ dl_open_worker (void *a)
them. However, such relocation dependencies in IFUNC resolvers
are undefined anyway, so this is not a problem. */
for (unsigned int i = nmaps; i-- > 0; )
for (unsigned int i = last; i-- > first; )
{
l = maps[i];
l = new->l_initfini[i];
if (l->l_real->l_relocated)
continue;
if (! relocation_in_progress)
{