diff options
| -rw-r--r-- | ChangeLog | 9 | ||||
| -rw-r--r-- | sysdeps/aarch64/dl-dtprocnum.h | 21 | ||||
| -rw-r--r-- | sysdeps/aarch64/dl-machine.h | 42 | ||||
| -rw-r--r-- | sysdeps/aarch64/linkmap.h | 1 |
4 files changed, 69 insertions, 4 deletions
@@ -1,5 +1,14 @@ 2019-06-13 Szabolcs Nagy <szabolcs.nagy@arm.com> + * sysdeps/aarch64/dl-dtprocnum.h: New file. + * sysdeps/aarch64/dl-machine.h (DT_AARCH64): Define. + (elf_machine_runtime_setup): Handle DT_AARCH64_VARIANT_PCS. + (elf_machine_lazy_rel): Check STO_AARCH64_VARIANT_PCS and bind such + symbols at load time. + * sysdeps/aarch64/linkmap.h (struct link_map_machine): Add variant_pcs. + +2019-06-13 Szabolcs Nagy <szabolcs.nagy@arm.com> + * elf/elf.h (STO_AARCH64_VARIANT_PCS): Define. (DT_AARCH64_VARIANT_PCS): Define. diff --git a/sysdeps/aarch64/dl-dtprocnum.h b/sysdeps/aarch64/dl-dtprocnum.h new file mode 100644 index 0000000000..4ac2adf234 --- /dev/null +++ b/sysdeps/aarch64/dl-dtprocnum.h @@ -0,0 +1,21 @@ +/* Configuration of lookup functions. AArch64 version. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + <http://www.gnu.org/licenses/>. */ + +/* Number of extra dynamic section entries for this architecture. By + default there are none. */ +#define DT_THISPROCNUM DT_AARCH64_NUM diff --git a/sysdeps/aarch64/dl-machine.h b/sysdeps/aarch64/dl-machine.h index 823eefba46..4f27637b20 100644 --- a/sysdeps/aarch64/dl-machine.h +++ b/sysdeps/aarch64/dl-machine.h @@ -27,6 +27,9 @@ #include <dl-irel.h> #include <cpu-features.c> +/* Translate a processor specific dynamic tag to the index in l_info array. */ +#define DT_AARCH64(x) (DT_AARCH64_##x - DT_LOPROC + DT_NUM) + /* Return nonzero iff ELF header is compatible with the running host. */ static inline int __attribute__ ((unused)) elf_machine_matches_host (const ElfW(Ehdr) *ehdr) @@ -102,6 +105,10 @@ elf_machine_runtime_setup (struct link_map *l, int lazy, int profile) } } + /* Check if STO_AARCH64_VARIANT_PCS needs to be handled. */ + if (l->l_info[DT_AARCH64 (VARIANT_PCS)]) + l->l_mach.variant_pcs = 1; + return lazy; } @@ -388,10 +395,37 @@ elf_machine_lazy_rel (struct link_map *map, /* Check for unexpected PLT reloc type. */ if (__builtin_expect (r_type == AARCH64_R(JUMP_SLOT), 1)) { - if (__builtin_expect (map->l_mach.plt, 0) == 0) - *reloc_addr += l_addr; - else - *reloc_addr = map->l_mach.plt; + if (map->l_mach.plt == 0) + { + /* Prelinking. */ + *reloc_addr += l_addr; + return; + } + + if (__glibc_unlikely (map->l_mach.variant_pcs)) + { + /* Check the symbol table for variant PCS symbols. */ + const Elf_Symndx symndx = ELFW (R_SYM) (reloc->r_info); + const ElfW (Sym) *symtab = + (const void *)D_PTR (map, l_info[DT_SYMTAB]); + const ElfW (Sym) *sym = &symtab[symndx]; + if (__glibc_unlikely (sym->st_other & STO_AARCH64_VARIANT_PCS)) + { + /* Avoid lazy resolution of variant PCS symbols. */ + const struct r_found_version *version = NULL; + if (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL) + { + const ElfW (Half) *vernum = + (const void *)D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]); + version = &map->l_versions[vernum[symndx] & 0x7fff]; + } + elf_machine_rela (map, reloc, sym, version, reloc_addr, + skip_ifunc); + return; + } + } + + *reloc_addr = map->l_mach.plt; } else if (__builtin_expect (r_type == AARCH64_R(TLSDESC), 1)) { diff --git a/sysdeps/aarch64/linkmap.h b/sysdeps/aarch64/linkmap.h index ba74fe10e1..7f801b14db 100644 --- a/sysdeps/aarch64/linkmap.h +++ b/sysdeps/aarch64/linkmap.h @@ -20,4 +20,5 @@ struct link_map_machine { ElfW(Addr) plt; /* Address of .plt */ void *tlsdesc_table; /* Address of TLS descriptor hash table. */ + int variant_pcs; /* If set, PLT calls may follow a variant PCS. */ }; |