1 /* 2 * Copyright (C) 2012 ARM Ltd. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program. If not, see <http://www.gnu.org/licenses/>. 15 */ 16 #ifndef __ASM_MODULE_H 17 #define __ASM_MODULE_H 18 19 #include <asm-generic/module.h> 20 21 #define MODULE_ARCH_VERMAGIC "aarch64" 22 23 #ifdef CONFIG_ARM64_MODULE_PLTS 24 struct mod_plt_sec { 25 int plt_shndx; 26 int plt_num_entries; 27 int plt_max_entries; 28 }; 29 30 struct mod_arch_specific { 31 struct mod_plt_sec core; 32 struct mod_plt_sec init; 33 34 /* for CONFIG_DYNAMIC_FTRACE */ 35 struct plt_entry *ftrace_trampoline; 36 }; 37 #endif 38 39 u64 module_emit_plt_entry(struct module *mod, Elf64_Shdr *sechdrs, 40 void *loc, const Elf64_Rela *rela, 41 Elf64_Sym *sym); 42 43 u64 module_emit_veneer_for_adrp(struct module *mod, Elf64_Shdr *sechdrs, 44 void *loc, u64 val); 45 46 #ifdef CONFIG_RANDOMIZE_BASE 47 extern u64 module_alloc_base; 48 #else 49 #define module_alloc_base ((u64)_etext - MODULES_VSIZE) 50 #endif 51 52 struct plt_entry { 53 /* 54 * A program that conforms to the AArch64 Procedure Call Standard 55 * (AAPCS64) must assume that a veneer that alters IP0 (x16) and/or 56 * IP1 (x17) may be inserted at any branch instruction that is 57 * exposed to a relocation that supports long branches. Since that 58 * is exactly what we are dealing with here, we are free to use x16 59 * as a scratch register in the PLT veneers. 60 */ 61 __le32 adrp; /* adrp x16, .... */ 62 __le32 add; /* add x16, x16, #0x.... */ 63 __le32 br; /* br x16 */ 64 }; 65 66 static inline bool is_forbidden_offset_for_adrp(void *place) 67 { 68 return IS_ENABLED(CONFIG_ARM64_ERRATUM_843419) && 69 cpus_have_const_cap(ARM64_WORKAROUND_843419) && 70 ((u64)place & 0xfff) >= 0xff8; 71 } 72 73 struct plt_entry get_plt_entry(u64 dst, void *pc); 74 bool plt_entries_equal(const struct plt_entry *a, const struct plt_entry *b); 75 76 static inline bool plt_entry_is_initialized(const struct plt_entry *e) 77 { 78 return e->adrp || e->add || e->br; 79 } 80 81 #endif /* __ASM_MODULE_H */ 82