1 // SPDX-License-Identifier: GPL-2.0-only
3  * Copyright (C) 2014-2017 Linaro Ltd. <ard.biesheuvel@linaro.org>
8 #include <linux/module.h>
21 							(PLT_ENT_STRIDE - 4))
24 						    (PLT_ENT_STRIDE - 8))
32 static bool in_init(const struct module *mod, unsigned long loc)  in in_init()
34 	return loc - (u32)mod->init_layout.base < mod->init_layout.size;  in in_init()
37 u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val)  in get_module_plt()
39 	struct mod_plt_sec *pltsec = !in_init(mod, loc) ? &mod->arch.core :  in get_module_plt()
40 							  &mod->arch.init;  in get_module_plt()
42 	struct plt_entries *plt = (struct plt_entries *)pltsec->plt->sh_addr;  in get_module_plt()
50 	if (pltsec->plt_count > 0) {  in get_module_plt()
51 		plt += (pltsec->plt_count - 1) / PLT_ENT_COUNT;  in get_module_plt()
52 		idx = (pltsec->plt_count - 1) % PLT_ENT_COUNT;  in get_module_plt()
54 		if (plt->lit[idx] == val)  in get_module_plt()
55 			return (u32)&plt->ldr[idx];  in get_module_plt()
62 	pltsec->plt_count++;  in get_module_plt()
63 	BUG_ON(pltsec->plt_count * PLT_ENT_SIZE > pltsec->plt->sh_size);  in get_module_plt()
68 			{ [0 ... PLT_ENT_COUNT - 1] = PLT_ENT_LDR, },  in get_module_plt()
72 		plt->lit[idx] = val;  in get_module_plt()
74 	return (u32)&plt->ldr[idx];  in get_module_plt()
77 #define cmp_3way(a,b)	((a) < (b) ? -1 : (a) > (b))
85 	i = cmp_3way(ELF32_R_TYPE(x->r_info), ELF32_R_TYPE(y->r_info));  in cmp_rel()
87 		i = cmp_3way(ELF32_R_SYM(x->r_info), ELF32_R_SYM(y->r_info));  in cmp_rel()
93 	u32 *tval = (u32 *)(base + rel->r_offset);  in is_zero_addend_relocation()
98 	 * Note that a zero-addend jump/call relocation is encoded taking the  in is_zero_addend_relocation()
99 	 * PC bias into account, i.e., -8 for ARM and -4 for Thumb2.  in is_zero_addend_relocation()
101 	switch (ELF32_R_TYPE(rel->r_info)) {  in is_zero_addend_relocation()
131 	prev = rel + num - 1;  in duplicate_rel()
163 			if (s->st_shndx == dstidx)  in count_plts()
167 			 * Jump relocations with non-zero addends against  in count_plts()
174 			 * the addend is zero. (Note that calls into the core  in count_plts()
175 			 * module via init PLT entries could involve section  in count_plts()
176 			 * relative symbol references with non-zero addends, for  in count_plts()
179 			 * region as soon as module loading completes.)  in count_plts()
190 			      char *secstrings, struct module *mod)  in module_frob_arch_sections()
194 	Elf32_Shdr *s, *sechdrs_end = sechdrs + ehdr->e_shnum;  in module_frob_arch_sections()
198 	 * To store the PLTs, we expand the .text section for core module code  in module_frob_arch_sections()
202 		if (strcmp(".plt", secstrings + s->sh_name) == 0)  in module_frob_arch_sections()
203 			mod->arch.core.plt = s;  in module_frob_arch_sections()
204 		else if (strcmp(".init.plt", secstrings + s->sh_name) == 0)  in module_frob_arch_sections()
205 			mod->arch.init.plt = s;  in module_frob_arch_sections()
206 		else if (s->sh_type == SHT_SYMTAB)  in module_frob_arch_sections()
207 			syms = (Elf32_Sym *)s->sh_addr;  in module_frob_arch_sections()
210 	if (!mod->arch.core.plt || !mod->arch.init.plt) {  in module_frob_arch_sections()
211 		pr_err("%s: module PLT section(s) missing\n", mod->name);  in module_frob_arch_sections()
212 		return -ENOEXEC;  in module_frob_arch_sections()
215 		pr_err("%s: module symtab section missing\n", mod->name);  in module_frob_arch_sections()
216 		return -ENOEXEC;  in module_frob_arch_sections()
220 		Elf32_Rel *rels = (void *)ehdr + s->sh_offset;  in module_frob_arch_sections()
221 		int numrels = s->sh_size / sizeof(Elf32_Rel);  in module_frob_arch_sections()
222 		Elf32_Shdr *dstsec = sechdrs + s->sh_info;  in module_frob_arch_sections()
224 		if (s->sh_type != SHT_REL)  in module_frob_arch_sections()
227 		/* ignore relocations that operate on non-exec sections */  in module_frob_arch_sections()
228 		if (!(dstsec->sh_flags & SHF_EXECINSTR))  in module_frob_arch_sections()
234 		if (strncmp(secstrings + dstsec->sh_name, ".init", 5) != 0)  in module_frob_arch_sections()
235 			core_plts += count_plts(syms, dstsec->sh_addr, rels,  in module_frob_arch_sections()
236 						numrels, s->sh_info);  in module_frob_arch_sections()
238 			init_plts += count_plts(syms, dstsec->sh_addr, rels,  in module_frob_arch_sections()
239 						numrels, s->sh_info);  in module_frob_arch_sections()
242 	mod->arch.core.plt->sh_type = SHT_NOBITS;  in module_frob_arch_sections()
243 	mod->arch.core.plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC;  in module_frob_arch_sections()
244 	mod->arch.core.plt->sh_addralign = L1_CACHE_BYTES;  in module_frob_arch_sections()
245 	mod->arch.core.plt->sh_size = round_up(core_plts * PLT_ENT_SIZE,  in module_frob_arch_sections()
247 	mod->arch.core.plt_count = 0;  in module_frob_arch_sections()
249 	mod->arch.init.plt->sh_type = SHT_NOBITS;  in module_frob_arch_sections()
250 	mod->arch.init.plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC;  in module_frob_arch_sections()
251 	mod->arch.init.plt->sh_addralign = L1_CACHE_BYTES;  in module_frob_arch_sections()
252 	mod->arch.init.plt->sh_size = round_up(init_plts * PLT_ENT_SIZE,  in module_frob_arch_sections()
254 	mod->arch.init.plt_count = 0;  in module_frob_arch_sections()
257 		 mod->arch.core.plt->sh_size, mod->arch.init.plt->sh_size);  in module_frob_arch_sections()