glibc/SOURCES/glibc-RHEL-48820-1.patch

121 lines
4.6 KiB
Diff

commit 8f8dd904c4a2207699bb666f30acceb5209c8d3f
Author: Florian Weimer <fweimer@redhat.com>
Date: Wed Nov 6 10:33:44 2024 +0100
elf: rtld_multiple_ref is always true
For a long time, libc.so.6 has dependend on ld.so, which
means that there is a reference to ld.so in all processes,
and rtld_multiple_ref is always true. In fact, if
rtld_multiple_ref were false, some of the ld.so setup code
would not run.
Reviewed-by: DJ Delorie <dj@redhat.com>
Conflicts:
elf/rtld.c (
- prelink support not removed downstream
- "elf: Add _dl_find_object function" not ported
downstream
)
diff --git a/elf/rtld.c b/elf/rtld.c
index d02ecc834c9a4d43..711bb77d70da6563 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -2002,43 +2002,37 @@ dl_main (const ElfW(Phdr) *phdr,
if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map))
break;
- bool rtld_multiple_ref = false;
- if (__glibc_likely (i < main_map->l_searchlist.r_nlist))
- {
- /* Some DT_NEEDED entry referred to the interpreter object itself, so
- put it back in the list of visible objects. We insert it into the
- chain in symbol search order because gdb uses the chain's order as
- its symbol search order. */
- rtld_multiple_ref = true;
+ /* Insert the link map for the dynamic loader into the chain in
+ symbol search order because gdb uses the chain's order as its
+ symbol search order. */
- GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1];
- if (__glibc_likely (state.mode == rtld_mode_normal))
- {
- GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist
- ? main_map->l_searchlist.r_list[i + 1]
- : NULL);
+ GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1];
+ if (__glibc_likely (state.mode == rtld_mode_normal))
+ {
+ GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist
+ ? main_map->l_searchlist.r_list[i + 1]
+ : NULL);
#ifdef NEED_DL_SYSINFO_DSO
- if (GLRO(dl_sysinfo_map) != NULL
- && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
- && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
- GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
+ if (GLRO(dl_sysinfo_map) != NULL
+ && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
+ && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
+ GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
#endif
- }
- else
- /* In trace mode there might be an invisible object (which we
- could not find) after the previous one in the search list.
- In this case it doesn't matter much where we put the
- interpreter object, so we just initialize the list pointer so
- that the assertion below holds. */
- GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
-
- assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
- GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
- if (GL(dl_rtld_map).l_next != NULL)
- {
- assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
- GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
- }
+ }
+ else
+ /* In trace mode there might be an invisible object (which we
+ could not find) after the previous one in the search list.
+ In this case it doesn't matter much where we put the
+ interpreter object, so we just initialize the list pointer so
+ that the assertion below holds. */
+ GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
+
+ assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
+ GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
+ if (GL(dl_rtld_map).l_next != NULL)
+ {
+ assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
+ GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
}
/* Now let us see whether all libraries are available in the
@@ -2212,8 +2206,7 @@ dl_main (const ElfW(Phdr) *phdr,
}
}
- if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
- && rtld_multiple_ref)
+ if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
{
/* Mark the link map as not yet relocated again. */
GL(dl_rtld_map).l_relocated = 0;
@@ -2500,10 +2493,9 @@ dl_main (const ElfW(Phdr) *phdr,
/* Make sure no new search directories have been added. */
assert (GLRO(dl_init_all_dirs) == GL(dl_all_dirs));
- if (! prelinked && rtld_multiple_ref)
+ if (! prelinked)
{
- /* There was an explicit ref to the dynamic linker as a shared lib.
- Re-relocate ourselves with user-controlled symbol definitions.
+ /* Re-relocate ourselves with user-controlled symbol definitions.
We must do this after TLS initialization in case after this
re-relocation, we might call a user-supplied function