diff options
Diffstat (limited to 'sysdeps/aarch64')
| -rw-r--r-- | sysdeps/aarch64/dl-machine.h | 4 | ||||
| -rw-r--r-- | sysdeps/aarch64/dl-tlsdesc.S | 203 | ||||
| -rw-r--r-- | sysdeps/aarch64/dl-tlsdesc.h | 9 | ||||
| -rw-r--r-- | sysdeps/aarch64/tlsdesc.c | 127 |
4 files changed, 1 insertions, 342 deletions
diff --git a/sysdeps/aarch64/dl-machine.h b/sysdeps/aarch64/dl-machine.h index 837e28134b..acbd3e3a0a 100644 --- a/sysdeps/aarch64/dl-machine.h +++ b/sysdeps/aarch64/dl-machine.h @@ -102,10 +102,6 @@ elf_machine_runtime_setup (struct link_map *l, int lazy, int profile) } } - if (l->l_info[ADDRIDX (DT_TLSDESC_GOT)] && lazy) - *(ElfW(Addr)*)(D_PTR (l, l_info[ADDRIDX (DT_TLSDESC_GOT)]) + l->l_addr) - = (ElfW(Addr)) &_dl_tlsdesc_resolve_rela; - return lazy; } diff --git a/sysdeps/aarch64/dl-tlsdesc.S b/sysdeps/aarch64/dl-tlsdesc.S index 3b2da62f39..70550c7ce0 100644 --- a/sysdeps/aarch64/dl-tlsdesc.S +++ b/sysdeps/aarch64/dl-tlsdesc.S @@ -80,30 +80,6 @@ _dl_tlsdesc_return: cfi_endproc .size _dl_tlsdesc_return, .-_dl_tlsdesc_return - /* Same as _dl_tlsdesc_return but with synchronization for - lazy relocation. - Prototype: - _dl_tlsdesc_return_lazy (tlsdesc *) ; - */ - .hidden _dl_tlsdesc_return_lazy - .global _dl_tlsdesc_return_lazy - .type _dl_tlsdesc_return_lazy,%function - cfi_startproc - .align 2 -_dl_tlsdesc_return_lazy: - /* The ldar here happens after the load from [x0] at the call site - (that is generated by the compiler as part of the TLS access ABI), - so it reads the same value (this function is the final value of - td->entry) and thus it synchronizes with the release store to - td->entry in _dl_tlsdesc_resolve_rela_fixup ensuring that the load - from [x0,#PTR_SIZE] here happens after the initialization of td->arg. */ - DELOUSE (0) - ldar PTR_REG (zr), [x0] - ldr PTR_REG (0), [x0, #PTR_SIZE] - RET - cfi_endproc - .size _dl_tlsdesc_return_lazy, .-_dl_tlsdesc_return_lazy - /* Handler for undefined weak TLS symbols. Prototype: _dl_tlsdesc_undefweak (tlsdesc *); @@ -121,14 +97,7 @@ _dl_tlsdesc_return_lazy: _dl_tlsdesc_undefweak: str x1, [sp, #-16]! cfi_adjust_cfa_offset (16) - /* The ldar here happens after the load from [x0] at the call site - (that is generated by the compiler as part of the TLS access ABI), - so it reads the same value (this function is the final value of - td->entry) and thus it synchronizes with the release store to - td->entry in _dl_tlsdesc_resolve_rela_fixup ensuring that the load - from [x0,#8] here happens after the initialization of td->arg. */ DELOUSE (0) - ldar PTR_REG (zr), [x0] ldr PTR_REG (0), [x0, #PTR_SIZE] mrs x1, tpidr_el0 sub PTR_REG (0), PTR_REG (0), PTR_REG (1) @@ -192,13 +161,6 @@ _dl_tlsdesc_dynamic: cfi_rel_offset (x4, 32+24) mrs x4, tpidr_el0 - /* The ldar here happens after the load from [x0] at the call site - (that is generated by the compiler as part of the TLS access ABI), - so it reads the same value (this function is the final value of - td->entry) and thus it synchronizes with the release store to - td->entry in _dl_tlsdesc_resolve_rela_fixup ensuring that the load - from [x0,#PTR_SIZE] here happens after the initialization of td->arg. */ - ldar PTR_REG (zr), [x0] ldr PTR_REG (1), [x0,#TLSDESC_ARG] ldr PTR_REG (0), [x4,#TCBHEAD_DTV] ldr PTR_REG (3), [x1,#TLSDESC_GEN_COUNT] @@ -276,168 +238,3 @@ _dl_tlsdesc_dynamic: .size _dl_tlsdesc_dynamic, .-_dl_tlsdesc_dynamic # undef NSAVEXREGPAIRS #endif - - /* This function is a wrapper for a lazy resolver for TLS_DESC - RELA relocations. - When the actual resolver returns, it will have adjusted the - TLS descriptor such that we can tail-call it for it to return - the TP offset of the symbol. */ - - .hidden _dl_tlsdesc_resolve_rela - .global _dl_tlsdesc_resolve_rela - .type _dl_tlsdesc_resolve_rela,%function - cfi_startproc - .align 2 -_dl_tlsdesc_resolve_rela: -#define NSAVEXREGPAIRS 9 - /* The tlsdesc PLT entry pushes x2 and x3 to the stack. */ - cfi_adjust_cfa_offset (16) - cfi_rel_offset (x2, 0) - cfi_rel_offset (x3, 8) - stp x29, x30, [sp, #-(32+16*NSAVEXREGPAIRS)]! - cfi_adjust_cfa_offset (32+16*NSAVEXREGPAIRS) - cfi_rel_offset (x29, 0) - cfi_rel_offset (x30, 8) - mov x29, sp - stp x1, x4, [sp, #32+16*0] - stp x5, x6, [sp, #32+16*1] - stp x7, x8, [sp, #32+16*2] - stp x9, x10, [sp, #32+16*3] - stp x11, x12, [sp, #32+16*4] - stp x13, x14, [sp, #32+16*5] - stp x15, x16, [sp, #32+16*6] - stp x17, x18, [sp, #32+16*7] - str x0, [sp, #32+16*8] - cfi_rel_offset (x1, 32) - cfi_rel_offset (x4, 32+8) - cfi_rel_offset (x5, 32+16) - cfi_rel_offset (x6, 32+16+8) - cfi_rel_offset (x7, 32+16*2) - cfi_rel_offset (x8, 32+16*2+8) - cfi_rel_offset (x9, 32+16*3) - cfi_rel_offset (x10, 32+16*3+8) - cfi_rel_offset (x11, 32+16*4) - cfi_rel_offset (x12, 32+16*4+8) - cfi_rel_offset (x13, 32+16*5) - cfi_rel_offset (x14, 32+16*5+8) - cfi_rel_offset (x15, 32+16*6) - cfi_rel_offset (x16, 32+16*6+8) - cfi_rel_offset (x17, 32+16*7) - cfi_rel_offset (x18, 32+16*7+8) - cfi_rel_offset (x0, 32+16*8) - - SAVE_Q_REGISTERS - - DELOUSE (3) - ldr PTR_REG (1), [x3, #PTR_SIZE] - bl _dl_tlsdesc_resolve_rela_fixup - - RESTORE_Q_REGISTERS - - ldr x0, [sp, #32+16*8] - DELOUSE (0) - ldr PTR_REG (1), [x0] - blr x1 - - ldp x1, x4, [sp, #32+16*0] - ldp x5, x6, [sp, #32+16*1] - ldp x7, x8, [sp, #32+16*2] - ldp x9, x10, [sp, #32+16*3] - ldp x11, x12, [sp, #32+16*4] - ldp x13, x14, [sp, #32+16*5] - ldp x15, x16, [sp, #32+16*6] - ldp x17, x18, [sp, #32+16*7] - ldp x29, x30, [sp], #(32+16*NSAVEXREGPAIRS) - cfi_adjust_cfa_offset (-32-16*NSAVEXREGPAIRS) - cfi_restore (x29) - cfi_restore (x30) - ldp x2, x3, [sp], #16 - cfi_adjust_cfa_offset (-16) - RET -#undef NSAVEXREGPAIRS - cfi_endproc - .size _dl_tlsdesc_resolve_rela, .-_dl_tlsdesc_resolve_rela - - /* This function is a placeholder for lazy resolving of TLS - relocations. Once some thread starts resolving a TLS - relocation, it sets up the TLS descriptor to use this - resolver, such that other threads that would attempt to - resolve it concurrently may skip the call to the original lazy - resolver and go straight to a condition wait. - - When the actual resolver returns, it will have adjusted the - TLS descriptor such that we can tail-call it for it to return - the TP offset of the symbol. */ - - .hidden _dl_tlsdesc_resolve_hold - .global _dl_tlsdesc_resolve_hold - .type _dl_tlsdesc_resolve_hold,%function - cfi_startproc - .align 2 -_dl_tlsdesc_resolve_hold: -#define NSAVEXREGPAIRS 10 -1: - stp x29, x30, [sp, #-(32+16*NSAVEXREGPAIRS)]! - cfi_adjust_cfa_offset (32+16*NSAVEXREGPAIRS) - cfi_rel_offset (x29, 0) - cfi_rel_offset (x30, 8) - mov x29, sp - stp x1, x2, [sp, #32+16*0] - stp x3, x4, [sp, #32+16*1] - stp x5, x6, [sp, #32+16*2] - stp x7, x8, [sp, #32+16*3] - stp x9, x10, [sp, #32+16*4] - stp x11, x12, [sp, #32+16*5] - stp x13, x14, [sp, #32+16*6] - stp x15, x16, [sp, #32+16*7] - stp x17, x18, [sp, #32+16*8] - str x0, [sp, #32+16*9] - cfi_rel_offset (x1, 32) - cfi_rel_offset (x2, 32+8) - cfi_rel_offset (x3, 32+16) - cfi_rel_offset (x4, 32+16+8) - cfi_rel_offset (x5, 32+16*2) - cfi_rel_offset (x6, 32+16*2+8) - cfi_rel_offset (x7, 32+16*3) - cfi_rel_offset (x8, 32+16*3+8) - cfi_rel_offset (x9, 32+16*4) - cfi_rel_offset (x10, 32+16*4+8) - cfi_rel_offset (x11, 32+16*5) - cfi_rel_offset (x12, 32+16*5+8) - cfi_rel_offset (x13, 32+16*6) - cfi_rel_offset (x14, 32+16*6+8) - cfi_rel_offset (x15, 32+16*7) - cfi_rel_offset (x16, 32+16*7+8) - cfi_rel_offset (x17, 32+16*8) - cfi_rel_offset (x18, 32+16*8+8) - cfi_rel_offset (x0, 32+16*9) - - SAVE_Q_REGISTERS - - adr x1, 1b - bl _dl_tlsdesc_resolve_hold_fixup - - RESTORE_Q_REGISTERS - - ldr x0, [sp, #32+16*9] - DELOUSE (0) - ldr PTR_REG (1), [x0] - blr x1 - - ldp x1, x2, [sp, #32+16*0] - ldp x3, x4, [sp, #32+16*1] - ldp x5, x6, [sp, #32+16*2] - ldp x7, x8, [sp, #32+16*3] - ldp x9, x10, [sp, #32+16*4] - ldp x11, x12, [sp, #32+16*5] - ldp x13, x14, [sp, #32+16*6] - ldp x15, x16, [sp, #32+16*7] - ldp x17, x18, [sp, #32+16*8] - ldp x29, x30, [sp], #(32+16*NSAVEXREGPAIRS) - cfi_adjust_cfa_offset (-32-16*NSAVEXREGPAIRS) - cfi_restore (x29) - cfi_restore (x30) - RET - cfi_endproc - .size _dl_tlsdesc_resolve_hold, .-_dl_tlsdesc_resolve_hold -#undef NSAVEXREGPAIRS diff --git a/sysdeps/aarch64/dl-tlsdesc.h b/sysdeps/aarch64/dl-tlsdesc.h index 66ec0dea7f..25b5b64e6e 100644 --- a/sysdeps/aarch64/dl-tlsdesc.h +++ b/sysdeps/aarch64/dl-tlsdesc.h @@ -46,17 +46,8 @@ extern ptrdiff_t attribute_hidden _dl_tlsdesc_return (struct tlsdesc *); extern ptrdiff_t attribute_hidden -_dl_tlsdesc_return_lazy (struct tlsdesc *); - -extern ptrdiff_t attribute_hidden _dl_tlsdesc_undefweak (struct tlsdesc *); -extern ptrdiff_t attribute_hidden -_dl_tlsdesc_resolve_rela (struct tlsdesc *); - -extern ptrdiff_t attribute_hidden -_dl_tlsdesc_resolve_hold (struct tlsdesc *); - # ifdef SHARED extern void *_dl_make_tlsdesc_dynamic (struct link_map *, size_t); diff --git a/sysdeps/aarch64/tlsdesc.c b/sysdeps/aarch64/tlsdesc.c index 4c8a5a81d1..bd1356fa8e 100644 --- a/sysdeps/aarch64/tlsdesc.c +++ b/sysdeps/aarch64/tlsdesc.c @@ -18,137 +18,12 @@ License along with the GNU C Library; if not, see <http://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> -#include <atomic.h> - -/* The following functions take an entry_check_offset argument. It's - computed by the caller as an offset between its entry point and the - call site, such that by adding the built-in return address that is - implicitly passed to the function with this offset, we can easily - obtain the caller's entry point to compare with the entry point - given 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 *td, struct link_map *l) -{ - const ElfW(Rela) *reloc = atomic_load_relaxed (&td->arg); - - /* After GL(dl_load_lock) is grabbed only one caller can see td->entry in - initial state in _dl_tlsdesc_resolve_early_return_p, other concurrent - callers will return and retry calling td->entry. The updated td->entry - synchronizes with the single writer so all read accesses here can use - relaxed order. */ - 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(), - except for checking for STB_LOCAL. */ - 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) - { - atomic_store_relaxed (&td->arg, (void *) reloc->r_addend); - /* This release store synchronizes with the ldar acquire load - instruction in _dl_tlsdesc_undefweak. */ - atomic_store_release (&td->entry, _dl_tlsdesc_undefweak); - } - else - { -# ifndef SHARED - CHECK_STATIC_TLS (l, result); -# else - if (!TRY_STATIC_TLS (l, result)) - { - void *p = _dl_make_tlsdesc_dynamic (result, sym->st_value - + reloc->r_addend); - atomic_store_relaxed (&td->arg, p); - /* This release store synchronizes with the ldar acquire load - instruction in _dl_tlsdesc_dynamic. */ - atomic_store_release (&td->entry, _dl_tlsdesc_dynamic); - } - else -# endif - { - void *p = (void*) (sym->st_value + result->l_tls_offset - + reloc->r_addend); - atomic_store_relaxed (&td->arg, p); - /* This release store synchronizes with the ldar acquire load - instruction in _dl_tlsdesc_return_lazy. */ - atomic_store_release (&td->entry, _dl_tlsdesc_return_lazy); - } - } - - _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 *td, void *caller) -{ - /* Maybe we're lucky and can return early. */ - if (caller != atomic_load_relaxed (&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. */ |