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authorSzabolcs Nagy <szabolcs.nagy@arm.com>2021-02-11 11:52:24 +0000
committerSzabolcs Nagy <szabolcs.nagy@arm.com>2021-04-15 09:47:47 +0100
commit55c9f3238080e9aba733bc0902779c46cfa16446 (patch)
tree2ceef5a7b37819f6c7bae1ef1685abf884ec7395 /sysdeps/x86_64/tlsdesc.c
parentddcacd91cc10ff92d6201eda87047d029c14158d (diff)
downloadglibc-55c9f3238080e9aba733bc0902779c46cfa16446.tar.gz
x86_64: Remove lazy tlsdesc relocation related code
_dl_tlsdesc_resolve_rela and _dl_tlsdesc_resolve_hold are only used for lazy tlsdesc relocation processing which is no longer supported.
Diffstat (limited to 'sysdeps/x86_64/tlsdesc.c')
-rw-r--r--sysdeps/x86_64/tlsdesc.c109
1 files changed, 1 insertions, 108 deletions
diff --git a/sysdeps/x86_64/tlsdesc.c b/sysdeps/x86_64/tlsdesc.c
index 4083849f22..ecf864d6ee 100644
--- a/sysdeps/x86_64/tlsdesc.c
+++ b/sysdeps/x86_64/tlsdesc.c
@@ -16,120 +16,13 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
-#include <link.h>
#include <ldsodefs.h>
-#include <elf/dynamic-link.h>
#include <tls.h>
#include <dl-tlsdesc.h>
#include <dl-unmap-segments.h>
+#define _dl_tlsdesc_resolve_hold 0
#include <tlsdeschtab.h>
-/* The following 2 functions take a caller argument, that contains the
- address expected to be in the TLS descriptor. If it's changed, we
- want to return immediately. */
-
-/* This function is used to lazily resolve TLS_DESC RELA relocations.
- The argument location is used to hold a pointer to the relocation. */
-
-void
-attribute_hidden
-_dl_tlsdesc_resolve_rela_fixup (struct tlsdesc volatile *td,
- struct link_map *l)
-{
- const ElfW(Rela) *reloc = td->arg;
-
- if (_dl_tlsdesc_resolve_early_return_p
- (td, (void*)(D_PTR (l, l_info[ADDRIDX (DT_TLSDESC_PLT)]) + l->l_addr)))
- return;
-
- /* The code below was borrowed from _dl_fixup(). */
- const ElfW(Sym) *const symtab
- = (const void *) D_PTR (l, l_info[DT_SYMTAB]);
- const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]);
- const ElfW(Sym) *sym = &symtab[ELFW(R_SYM) (reloc->r_info)];
- lookup_t result;
-
- /* Look up the target symbol. If the normal lookup rules are not
- used don't look in the global scope. */
- if (ELFW(ST_BIND) (sym->st_info) != STB_LOCAL
- && __builtin_expect (ELFW(ST_VISIBILITY) (sym->st_other), 0) == 0)
- {
- const struct r_found_version *version = NULL;
-
- if (l->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
- {
- const ElfW(Half) *vernum =
- (const void *) D_PTR (l, l_info[VERSYMIDX (DT_VERSYM)]);
- ElfW(Half) ndx = vernum[ELFW(R_SYM) (reloc->r_info)] & 0x7fff;
- version = &l->l_versions[ndx];
- if (version->hash == 0)
- version = NULL;
- }
-
- result = _dl_lookup_symbol_x (strtab + sym->st_name, l, &sym,
- l->l_scope, version, ELF_RTYPE_CLASS_PLT,
- DL_LOOKUP_ADD_DEPENDENCY, NULL);
- }
- else
- {
- /* We already found the symbol. The module (and therefore its load
- address) is also known. */
- result = l;
- }
-
- if (! sym)
- {
- td->arg = (void*)reloc->r_addend;
- td->entry = _dl_tlsdesc_undefweak;
- }
- else
- {
-# ifndef SHARED
- CHECK_STATIC_TLS (l, result);
-# else
- if (!TRY_STATIC_TLS (l, result))
- {
- td->arg = _dl_make_tlsdesc_dynamic (result, sym->st_value
- + reloc->r_addend);
- td->entry = _dl_tlsdesc_dynamic;
- }
- else
-# endif
- {
- td->arg = (void*)(sym->st_value - result->l_tls_offset
- + reloc->r_addend);
- td->entry = _dl_tlsdesc_return;
- }
- }
-
- _dl_tlsdesc_wake_up_held_fixups ();
-}
-
-/* This function is used to avoid busy waiting for other threads to
- complete the lazy relocation. Once another thread wins the race to
- relocate a TLS descriptor, it sets the descriptor up such that this
- function is called to wait until the resolver releases the
- lock. */
-
-void
-attribute_hidden
-_dl_tlsdesc_resolve_hold_fixup (struct tlsdesc volatile *td,
- void *caller)
-{
- /* Maybe we're lucky and can return early. */
- if (caller != td->entry)
- return;
-
- /* Locking here will stop execution until the running resolver runs
- _dl_tlsdesc_wake_up_held_fixups(), releasing the lock.
-
- FIXME: We'd be better off waiting on a condition variable, such
- that we didn't have to hold the lock throughout the relocation
- processing. */
- __rtld_lock_lock_recursive (GL(dl_load_lock));
- __rtld_lock_unlock_recursive (GL(dl_load_lock));
-}
-
/* Unmap the dynamic object, but also release its TLS descriptor table
if there is one. */