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author | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2021-02-11 11:52:24 +0000 |
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committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2021-04-15 09:47:47 +0100 |
commit | 55c9f3238080e9aba733bc0902779c46cfa16446 (patch) | |
tree | 2ceef5a7b37819f6c7bae1ef1685abf884ec7395 /sysdeps/x86_64/tlsdesc.c | |
parent | ddcacd91cc10ff92d6201eda87047d029c14158d (diff) | |
download | glibc-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.c | 109 |
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. */ |