From 94d2f0af157d8c02e688a315039f8044aedbcc89 Mon Sep 17 00:00:00 2001 From: Szabolcs Nagy Date: Fri, 20 Oct 2017 17:53:44 +0100 Subject: arm: Remove lazy tlsdesc initialization related code Lazy tlsdesc initialization is no longer used in the dynamic linker so all related code can be removed. * sysdeps/arm/dl-machine.h (elf_machine_runtime_setup): Remove DT_TLSDESC_GOT initialization. * sysdeps/arm/dl-tlsdesc.S (_dl_tlsdesc_lazy_resolver): Remove. (_dl_tlsdesc_resolve_hold): Likewise. * sysdeps/aarch64/dl-tlsdesc.h (_dl_tlsdesc_lazy_resolver): Remove. (_dl_tlsdesc_resolve_hold): Likewise. * sysdeps/aarch64/tlsdesc.c (_dl_tlsdesc_lazy_resolver_fixup): Remove. (_dl_tlsdesc_resolve_hold_fixup): Likewise. --- sysdeps/arm/dl-machine.h | 4 -- sysdeps/arm/dl-tlsdesc.S | 84 --------------------------------- sysdeps/arm/dl-tlsdesc.h | 4 +- sysdeps/arm/tlsdesc.c | 119 +---------------------------------------------- 4 files changed, 2 insertions(+), 209 deletions(-) (limited to 'sysdeps/arm') diff --git a/sysdeps/arm/dl-machine.h b/sysdeps/arm/dl-machine.h index ec3a0274e3..fb5468a93b 100644 --- a/sysdeps/arm/dl-machine.h +++ b/sysdeps/arm/dl-machine.h @@ -127,10 +127,6 @@ elf_machine_runtime_setup (struct link_map *l, int lazy, int profile) got[2] = (Elf32_Addr) &_dl_runtime_resolve; } - if (l->l_info[ADDRIDX (DT_TLSDESC_GOT)] && lazy) - *(Elf32_Addr*)(D_PTR (l, l_info[ADDRIDX (DT_TLSDESC_GOT)]) + l->l_addr) - = (Elf32_Addr) &_dl_tlsdesc_lazy_resolver; - return lazy; } diff --git a/sysdeps/arm/dl-tlsdesc.S b/sysdeps/arm/dl-tlsdesc.S index e7bed02188..99d4b8327f 100644 --- a/sysdeps/arm/dl-tlsdesc.S +++ b/sysdeps/arm/dl-tlsdesc.S @@ -132,87 +132,3 @@ _dl_tlsdesc_dynamic: cfi_endproc .size _dl_tlsdesc_dynamic, .-_dl_tlsdesc_dynamic #endif /* SHARED */ - -/* lazy resolved for tls descriptors. */ - .hidden _dl_tlsdesc_lazy_resolver - .global _dl_tlsdesc_lazy_resolver - .type _dl_tlsdesc_lazy_resolver,#function - cfi_startproc - eabi_fnstart - .align 2 -_dl_tlsdesc_lazy_resolver: - /* r0 points at the tlsdesc, - r1 points at the GOT - r2 was pushed by the trampoline and used as a temp, - we need to pop it here. - We push the remaining call-clobbered registers here, and also - R1 -- to keep the stack correctly aligned. */ - /* Tell the unwinder that r2 has already been pushed. */ - eabi_save ({r2}) - cfi_adjust_cfa_offset (4) - cfi_rel_offset (r2, 0) - eabi_save ({r0,r1,r3,ip,lr}) - push {r0, r1, r3, ip, lr} - cfi_adjust_cfa_offset (20) - cfi_rel_offset (r0, 0) - cfi_rel_offset (r1, 4) - cfi_rel_offset (r3, 8) - cfi_rel_offset (ip, 12) - cfi_rel_offset (lr, 16) - bl _dl_tlsdesc_lazy_resolver_fixup - pop {r0, r1, r3, ip, lr} - cfi_adjust_cfa_offset (-20) - cfi_restore (lr) - cfi_restore (ip) - cfi_restore (r3) - cfi_restore (r1) - cfi_restore (r0) - pop {r2} - cfi_adjust_cfa_offset (-4) - cfi_restore (r2) - ldr r1, [r0, #4] - BX (r1) - eabi_fnend - cfi_endproc - .size _dl_tlsdesc_lazy_resolver, .-_dl_tlsdesc_lazy_resolver - -/* Holder for lazy tls descriptors being resolve in another thread. - - Our calling convention is to clobber r0, r1 and the processor - flags. All others that are modified must be saved */ - .hidden _dl_tlsdesc_resolve_hold - .global _dl_tlsdesc_resolve_hold - .type _dl_tlsdesc_resolve_hold,#function - cfi_startproc - eabi_fnstart - .align 2 -_dl_tlsdesc_resolve_hold: - /* r0 is saved so its original value can be used after the call and - r1 is saved only to keep the stack aligned. (r0 points to the tls - descriptor, it is passed to _dl_tlsdesc_resolve_hold_fixup which - is a void function that may clobber r0, later r0 is used to load - the new resolver.) */ - eabi_save ({r0,r1,r2,r3,ip,lr}) - push {r0, r1, r2, r3, ip, lr} - cfi_adjust_cfa_offset (24) - cfi_rel_offset (r0, 0) - cfi_rel_offset (r1, 4) - cfi_rel_offset (r2, 8) - cfi_rel_offset (r3, 12) - cfi_rel_offset (ip, 16) - cfi_rel_offset (lr, 20) - adr r1, _dl_tlsdesc_resolve_hold - bl _dl_tlsdesc_resolve_hold_fixup - pop {r0, r1, r2, r3, ip, lr} - cfi_adjust_cfa_offset (-24) - cfi_restore (lr) - cfi_restore (ip) - cfi_restore (r3) - cfi_restore (r2) - cfi_restore (r1) - cfi_restore (r0) - ldr r1, [r0, #4] - BX (r1) - eabi_fnend - cfi_endproc - .size _dl_tlsdesc_resolve_hold, .-_dl_tlsdesc_resolve_hold diff --git a/sysdeps/arm/dl-tlsdesc.h b/sysdeps/arm/dl-tlsdesc.h index 2770af0260..bb2c731e74 100644 --- a/sysdeps/arm/dl-tlsdesc.h +++ b/sysdeps/arm/dl-tlsdesc.h @@ -48,9 +48,7 @@ struct tlsdesc_dynamic_arg extern ptrdiff_t attribute_hidden _dl_tlsdesc_return(struct tlsdesc *), - _dl_tlsdesc_undefweak(struct tlsdesc *), - _dl_tlsdesc_resolve_hold(struct tlsdesc *), - _dl_tlsdesc_lazy_resolver(struct tlsdesc *); + _dl_tlsdesc_undefweak(struct tlsdesc *); # ifdef SHARED extern void *_dl_make_tlsdesc_dynamic (struct link_map *map, size_t ti_offset); diff --git a/sysdeps/arm/tlsdesc.c b/sysdeps/arm/tlsdesc.c index ad79506178..329f26e308 100644 --- a/sysdeps/arm/tlsdesc.c +++ b/sysdeps/arm/tlsdesc.c @@ -16,130 +16,13 @@ License along with the GNU C Library. If not, see . */ -#include #include -#include #include #include #include +#define _dl_tlsdesc_resolve_hold 0 #include -/* This function is used to lazily resolve TLS_DESC REL relocations - Besides the TLS descriptor itself, we get the module's got address - as the second parameter. */ - -void -attribute_hidden -_dl_tlsdesc_lazy_resolver_fixup (struct tlsdesc volatile *td, - Elf32_Addr *got) -{ - struct link_map *l = (struct link_map *)got[1]; - lookup_t result; - unsigned long value; - - if (_dl_tlsdesc_resolve_early_return_p - (td, (void*)(D_PTR (l, l_info[ADDRIDX (DT_TLSDESC_PLT)]) + l->l_addr))) - return; - - if (td->argument.value & 0x80000000) - { - /* A global symbol, this is the symbol index. */ - /* The code below was borrowed from _dl_fixup(). */ - const Elf_Symndx symndx = td->argument.value ^ 0x80000000; - 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[symndx]; - - /* 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[symndx] & 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); - if (sym) - value = sym->st_value; - else - { - td->entry = _dl_tlsdesc_undefweak; - goto done; - } - } - else - { - /* We already found the symbol. The module (and therefore its load - address) is also known. */ - result = l; - value = sym->st_value; - } - } - else - { - /* A local symbol, this is the offset within our tls section. - */ - value = td->argument.value; - result = l; - } - -#ifndef SHARED - CHECK_STATIC_TLS (l, result); -#else - if (!TRY_STATIC_TLS (l, result)) - { - td->argument.pointer = _dl_make_tlsdesc_dynamic (result, value); - td->entry = _dl_tlsdesc_dynamic; - } - else -#endif - { - td->argument.value = value + result->l_tls_offset; - td->entry = _dl_tlsdesc_return; - } - - done: - _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. */ -- cgit v1.2.3