1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2012 ARM Ltd. 4 */ 5 #ifndef __ASM_MODULE_H 6 #define __ASM_MODULE_H 7 8 #include <asm-generic/module.h> 9 10 #ifdef CONFIG_ARM64_MODULE_PLTS 11 struct mod_plt_sec { 12 int plt_shndx; 13 int plt_num_entries; 14 int plt_max_entries; 15 }; 16 17 struct mod_arch_specific { 18 struct mod_plt_sec core; 19 struct mod_plt_sec init; 20 21 /* for CONFIG_DYNAMIC_FTRACE */ 22 struct plt_entry *ftrace_trampolines; 23 }; 24 #endif 25 26 u64 module_emit_plt_entry(struct module *mod, Elf64_Shdr *sechdrs, 27 void *loc, const Elf64_Rela *rela, 28 Elf64_Sym *sym); 29 30 u64 module_emit_veneer_for_adrp(struct module *mod, Elf64_Shdr *sechdrs, 31 void *loc, u64 val); 32 33 struct plt_entry { 34 /* 35 * A program that conforms to the AArch64 Procedure Call Standard 36 * (AAPCS64) must assume that a veneer that alters IP0 (x16) and/or 37 * IP1 (x17) may be inserted at any branch instruction that is 38 * exposed to a relocation that supports long branches. Since that 39 * is exactly what we are dealing with here, we are free to use x16 40 * as a scratch register in the PLT veneers. 41 */ 42 __le32 adrp; /* adrp x16, .... */ 43 __le32 add; /* add x16, x16, #0x.... */ 44 __le32 br; /* br x16 */ 45 }; 46 47 static inline bool is_forbidden_offset_for_adrp(void *place) 48 { 49 return IS_ENABLED(CONFIG_ARM64_ERRATUM_843419) && 50 cpus_have_const_cap(ARM64_WORKAROUND_843419) && 51 ((u64)place & 0xfff) >= 0xff8; 52 } 53 54 struct plt_entry get_plt_entry(u64 dst, void *pc); 55 56 static inline const Elf_Shdr *find_section(const Elf_Ehdr *hdr, 57 const Elf_Shdr *sechdrs, 58 const char *name) 59 { 60 const Elf_Shdr *s, *se; 61 const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; 62 63 for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) { 64 if (strcmp(name, secstrs + s->sh_name) == 0) 65 return s; 66 } 67 68 return NULL; 69 } 70 71 #endif /* __ASM_MODULE_H */ 72