14e6a05feSThiemo Seufer /* 24e6a05feSThiemo Seufer * This program is free software; you can redistribute it and/or modify 34e6a05feSThiemo Seufer * it under the terms of the GNU General Public License as published by 44e6a05feSThiemo Seufer * the Free Software Foundation; either version 2 of the License, or 54e6a05feSThiemo Seufer * (at your option) any later version. 64e6a05feSThiemo Seufer * 74e6a05feSThiemo Seufer * This program is distributed in the hope that it will be useful, 84e6a05feSThiemo Seufer * but WITHOUT ANY WARRANTY; without even the implied warranty of 94e6a05feSThiemo Seufer * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 104e6a05feSThiemo Seufer * GNU General Public License for more details. 114e6a05feSThiemo Seufer * 124e6a05feSThiemo Seufer * You should have received a copy of the GNU General Public License 134e6a05feSThiemo Seufer * along with this program; if not, write to the Free Software 144e6a05feSThiemo Seufer * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 154e6a05feSThiemo Seufer * 164e6a05feSThiemo Seufer * Copyright (C) 2001 Rusty Russell. 174e6a05feSThiemo Seufer * Copyright (C) 2003, 2004 Ralf Baechle (ralf@linux-mips.org) 184e6a05feSThiemo Seufer * Copyright (C) 2005 Thiemo Seufer 194e6a05feSThiemo Seufer */ 204e6a05feSThiemo Seufer 214e6a05feSThiemo Seufer #undef DEBUG 224e6a05feSThiemo Seufer 234e6a05feSThiemo Seufer #include <linux/moduleloader.h> 244e6a05feSThiemo Seufer #include <linux/elf.h> 2527ac792cSAndrea Righi #include <linux/mm.h> 26761845f0SRalf Baechle #include <linux/numa.h> 274e6a05feSThiemo Seufer #include <linux/vmalloc.h> 284e6a05feSThiemo Seufer #include <linux/slab.h> 294e6a05feSThiemo Seufer #include <linux/fs.h> 304e6a05feSThiemo Seufer #include <linux/string.h> 314e6a05feSThiemo Seufer #include <linux/kernel.h> 321da177e4SLinus Torvalds #include <linux/spinlock.h> 3394bb0c1aSDavid Daney #include <linux/jump_label.h> 3494bb0c1aSDavid Daney 35656be92fSAtsushi Nemoto #include <asm/pgtable.h> /* MODULE_START */ 361da177e4SLinus Torvalds 374e6a05feSThiemo Seufer struct mips_hi16 { 384e6a05feSThiemo Seufer struct mips_hi16 *next; 394e6a05feSThiemo Seufer Elf_Addr *addr; 404e6a05feSThiemo Seufer Elf_Addr value; 414e6a05feSThiemo Seufer }; 424e6a05feSThiemo Seufer 431da177e4SLinus Torvalds static LIST_HEAD(dbe_list); 441da177e4SLinus Torvalds static DEFINE_SPINLOCK(dbe_lock); 451da177e4SLinus Torvalds 4666574cc0SJonas Bonn #ifdef MODULE_START 474e6a05feSThiemo Seufer void *module_alloc(unsigned long size) 484e6a05feSThiemo Seufer { 49d0a21265SDavid Rientjes return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END, 50cb9e3c29SAndrey Ryabinin GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE, 51d0a21265SDavid Rientjes __builtin_return_address(0)); 5266574cc0SJonas Bonn } 53656be92fSAtsushi Nemoto #endif 544e6a05feSThiemo Seufer 556ede8123SRalf Baechle int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v) 564e6a05feSThiemo Seufer { 574e6a05feSThiemo Seufer return 0; 584e6a05feSThiemo Seufer } 594e6a05feSThiemo Seufer 604e6a05feSThiemo Seufer static int apply_r_mips_32_rel(struct module *me, u32 *location, Elf_Addr v) 614e6a05feSThiemo Seufer { 624e6a05feSThiemo Seufer *location += v; 634e6a05feSThiemo Seufer 644e6a05feSThiemo Seufer return 0; 654e6a05feSThiemo Seufer } 664e6a05feSThiemo Seufer 674e6a05feSThiemo Seufer static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v) 684e6a05feSThiemo Seufer { 694e6a05feSThiemo Seufer if (v % 4) { 706f9fdeb6SRalf Baechle pr_err("module %s: dangerous R_MIPS_26 REL relocation\n", 716f9fdeb6SRalf Baechle me->name); 724e6a05feSThiemo Seufer return -ENOEXEC; 734e6a05feSThiemo Seufer } 744e6a05feSThiemo Seufer 754e6a05feSThiemo Seufer if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { 7655d791f3SSteven J. Hill pr_err("module %s: relocation overflow\n", 774e6a05feSThiemo Seufer me->name); 784e6a05feSThiemo Seufer return -ENOEXEC; 794e6a05feSThiemo Seufer } 804e6a05feSThiemo Seufer 814e6a05feSThiemo Seufer *location = (*location & ~0x03ffffff) | 824e6a05feSThiemo Seufer ((*location + (v >> 2)) & 0x03ffffff); 834e6a05feSThiemo Seufer 844e6a05feSThiemo Seufer return 0; 854e6a05feSThiemo Seufer } 864e6a05feSThiemo Seufer 874e6a05feSThiemo Seufer static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v) 884e6a05feSThiemo Seufer { 894e6a05feSThiemo Seufer struct mips_hi16 *n; 904e6a05feSThiemo Seufer 914e6a05feSThiemo Seufer /* 924e6a05feSThiemo Seufer * We cannot relocate this one now because we don't know the value of 934e6a05feSThiemo Seufer * the carry we need to add. Save the information, and let LO16 do the 944e6a05feSThiemo Seufer * actual relocation. 954e6a05feSThiemo Seufer */ 964e6a05feSThiemo Seufer n = kmalloc(sizeof *n, GFP_KERNEL); 974e6a05feSThiemo Seufer if (!n) 984e6a05feSThiemo Seufer return -ENOMEM; 994e6a05feSThiemo Seufer 1004e6a05feSThiemo Seufer n->addr = (Elf_Addr *)location; 1014e6a05feSThiemo Seufer n->value = v; 102861667dcSRalf Baechle n->next = me->arch.r_mips_hi16_list; 103861667dcSRalf Baechle me->arch.r_mips_hi16_list = n; 1044e6a05feSThiemo Seufer 1054e6a05feSThiemo Seufer return 0; 1064e6a05feSThiemo Seufer } 1074e6a05feSThiemo Seufer 108c54de490SRalf Baechle static void free_relocation_chain(struct mips_hi16 *l) 109c54de490SRalf Baechle { 110c54de490SRalf Baechle struct mips_hi16 *next; 111c54de490SRalf Baechle 112c54de490SRalf Baechle while (l) { 113c54de490SRalf Baechle next = l->next; 114c54de490SRalf Baechle kfree(l); 115c54de490SRalf Baechle l = next; 116c54de490SRalf Baechle } 117c54de490SRalf Baechle } 118c54de490SRalf Baechle 1194e6a05feSThiemo Seufer static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v) 1204e6a05feSThiemo Seufer { 1214e6a05feSThiemo Seufer unsigned long insnlo = *location; 122c54de490SRalf Baechle struct mips_hi16 *l; 1234e6a05feSThiemo Seufer Elf_Addr val, vallo; 1244e6a05feSThiemo Seufer 1254e6a05feSThiemo Seufer /* Sign extend the addend we extract from the lo insn. */ 1264e6a05feSThiemo Seufer vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000; 1274e6a05feSThiemo Seufer 128861667dcSRalf Baechle if (me->arch.r_mips_hi16_list != NULL) { 129861667dcSRalf Baechle l = me->arch.r_mips_hi16_list; 1304e6a05feSThiemo Seufer while (l != NULL) { 131c54de490SRalf Baechle struct mips_hi16 *next; 1324e6a05feSThiemo Seufer unsigned long insn; 1334e6a05feSThiemo Seufer 1344e6a05feSThiemo Seufer /* 1354e6a05feSThiemo Seufer * The value for the HI16 had best be the same. 1364e6a05feSThiemo Seufer */ 1374e6a05feSThiemo Seufer if (v != l->value) 1384e6a05feSThiemo Seufer goto out_danger; 1394e6a05feSThiemo Seufer 1404e6a05feSThiemo Seufer /* 1414e6a05feSThiemo Seufer * Do the HI16 relocation. Note that we actually don't 1424e6a05feSThiemo Seufer * need to know anything about the LO16 itself, except 1434e6a05feSThiemo Seufer * where to find the low 16 bits of the addend needed 1444e6a05feSThiemo Seufer * by the LO16. 1454e6a05feSThiemo Seufer */ 1464e6a05feSThiemo Seufer insn = *l->addr; 1474e6a05feSThiemo Seufer val = ((insn & 0xffff) << 16) + vallo; 1484e6a05feSThiemo Seufer val += v; 1494e6a05feSThiemo Seufer 1504e6a05feSThiemo Seufer /* 1514e6a05feSThiemo Seufer * Account for the sign extension that will happen in 1524e6a05feSThiemo Seufer * the low bits. 1534e6a05feSThiemo Seufer */ 1544e6a05feSThiemo Seufer val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff; 1554e6a05feSThiemo Seufer 1564e6a05feSThiemo Seufer insn = (insn & ~0xffff) | val; 1574e6a05feSThiemo Seufer *l->addr = insn; 1584e6a05feSThiemo Seufer 1594e6a05feSThiemo Seufer next = l->next; 1604e6a05feSThiemo Seufer kfree(l); 1614e6a05feSThiemo Seufer l = next; 1624e6a05feSThiemo Seufer } 1634e6a05feSThiemo Seufer 164861667dcSRalf Baechle me->arch.r_mips_hi16_list = NULL; 1654e6a05feSThiemo Seufer } 1664e6a05feSThiemo Seufer 1674e6a05feSThiemo Seufer /* 1684e6a05feSThiemo Seufer * Ok, we're done with the HI16 relocs. Now deal with the LO16. 1694e6a05feSThiemo Seufer */ 1704e6a05feSThiemo Seufer val = v + vallo; 1714e6a05feSThiemo Seufer insnlo = (insnlo & ~0xffff) | (val & 0xffff); 1724e6a05feSThiemo Seufer *location = insnlo; 1734e6a05feSThiemo Seufer 1744e6a05feSThiemo Seufer return 0; 1754e6a05feSThiemo Seufer 1764e6a05feSThiemo Seufer out_danger: 177c54de490SRalf Baechle free_relocation_chain(l); 178c54de490SRalf Baechle me->arch.r_mips_hi16_list = NULL; 179d3cac35cSRalf Baechle 1806f9fdeb6SRalf Baechle pr_err("module %s: dangerous R_MIPS_LO16 REL relocation\n", me->name); 1814e6a05feSThiemo Seufer 1824e6a05feSThiemo Seufer return -ENOEXEC; 1834e6a05feSThiemo Seufer } 1844e6a05feSThiemo Seufer 1855d3c7925SPaul Burton static int apply_r_mips_pc_rel(struct module *me, u32 *location, Elf_Addr v, 1865d3c7925SPaul Burton unsigned bits) 1875d3c7925SPaul Burton { 1885d3c7925SPaul Burton unsigned long mask = GENMASK(bits - 1, 0); 1895d3c7925SPaul Burton unsigned long se_bits; 1905d3c7925SPaul Burton long offset; 1915d3c7925SPaul Burton 1925d3c7925SPaul Burton if (v % 4) { 1935d3c7925SPaul Burton pr_err("module %s: dangerous R_MIPS_PC%u REL relocation\n", 1945d3c7925SPaul Burton me->name, bits); 1955d3c7925SPaul Burton return -ENOEXEC; 1965d3c7925SPaul Burton } 1975d3c7925SPaul Burton 1985d3c7925SPaul Burton /* retrieve & sign extend implicit addend */ 1995d3c7925SPaul Burton offset = *location & mask; 2005d3c7925SPaul Burton offset |= (offset & BIT(bits - 1)) ? ~mask : 0; 2015d3c7925SPaul Burton 2025d3c7925SPaul Burton offset += ((long)v - (long)location) >> 2; 2035d3c7925SPaul Burton 2045d3c7925SPaul Burton /* check the sign bit onwards are identical - ie. we didn't overflow */ 2055d3c7925SPaul Burton se_bits = (offset & BIT(bits - 1)) ? ~0ul : 0; 2065d3c7925SPaul Burton if ((offset & ~mask) != (se_bits & ~mask)) { 2075d3c7925SPaul Burton pr_err("module %s: relocation overflow\n", me->name); 2085d3c7925SPaul Burton return -ENOEXEC; 2095d3c7925SPaul Burton } 2105d3c7925SPaul Burton 2115d3c7925SPaul Burton *location = (*location & ~mask) | (offset & mask); 2125d3c7925SPaul Burton 2135d3c7925SPaul Burton return 0; 2145d3c7925SPaul Burton } 2155d3c7925SPaul Burton 2165d3c7925SPaul Burton static int apply_r_mips_pc16_rel(struct module *me, u32 *location, Elf_Addr v) 2175d3c7925SPaul Burton { 2185d3c7925SPaul Burton return apply_r_mips_pc_rel(me, location, v, 16); 2195d3c7925SPaul Burton } 2205d3c7925SPaul Burton 2215d3c7925SPaul Burton static int apply_r_mips_pc21_rel(struct module *me, u32 *location, Elf_Addr v) 2225d3c7925SPaul Burton { 2235d3c7925SPaul Burton return apply_r_mips_pc_rel(me, location, v, 21); 2245d3c7925SPaul Burton } 2255d3c7925SPaul Burton 2265d3c7925SPaul Burton static int apply_r_mips_pc26_rel(struct module *me, u32 *location, Elf_Addr v) 2275d3c7925SPaul Burton { 2285d3c7925SPaul Burton return apply_r_mips_pc_rel(me, location, v, 26); 2295d3c7925SPaul Burton } 2305d3c7925SPaul Burton 2314e6a05feSThiemo Seufer static int (*reloc_handlers_rel[]) (struct module *me, u32 *location, 2324e6a05feSThiemo Seufer Elf_Addr v) = { 2334e6a05feSThiemo Seufer [R_MIPS_NONE] = apply_r_mips_none, 2344e6a05feSThiemo Seufer [R_MIPS_32] = apply_r_mips_32_rel, 2354e6a05feSThiemo Seufer [R_MIPS_26] = apply_r_mips_26_rel, 2364e6a05feSThiemo Seufer [R_MIPS_HI16] = apply_r_mips_hi16_rel, 2375d3c7925SPaul Burton [R_MIPS_LO16] = apply_r_mips_lo16_rel, 2385d3c7925SPaul Burton [R_MIPS_PC16] = apply_r_mips_pc16_rel, 2395d3c7925SPaul Burton [R_MIPS_PC21_S2] = apply_r_mips_pc21_rel, 2405d3c7925SPaul Burton [R_MIPS_PC26_S2] = apply_r_mips_pc26_rel, 2414e6a05feSThiemo Seufer }; 2424e6a05feSThiemo Seufer 2434e6a05feSThiemo Seufer int apply_relocate(Elf_Shdr *sechdrs, const char *strtab, 2444e6a05feSThiemo Seufer unsigned int symindex, unsigned int relsec, 2454e6a05feSThiemo Seufer struct module *me) 2464e6a05feSThiemo Seufer { 2474e6a05feSThiemo Seufer Elf_Mips_Rel *rel = (void *) sechdrs[relsec].sh_addr; 24804211a57SPaul Burton int (*handler)(struct module *me, u32 *location, Elf_Addr v); 2494e6a05feSThiemo Seufer Elf_Sym *sym; 2504e6a05feSThiemo Seufer u32 *location; 25104211a57SPaul Burton unsigned int i, type; 2524e6a05feSThiemo Seufer Elf_Addr v; 2534e6a05feSThiemo Seufer int res; 2544e6a05feSThiemo Seufer 2554e6a05feSThiemo Seufer pr_debug("Applying relocate section %u to %u\n", relsec, 2564e6a05feSThiemo Seufer sechdrs[relsec].sh_info); 2574e6a05feSThiemo Seufer 258861667dcSRalf Baechle me->arch.r_mips_hi16_list = NULL; 2594e6a05feSThiemo Seufer for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { 2604e6a05feSThiemo Seufer /* This is where to make the change */ 2614e6a05feSThiemo Seufer location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr 2624e6a05feSThiemo Seufer + rel[i].r_offset; 2634e6a05feSThiemo Seufer /* This is the symbol it is referring to */ 2644e6a05feSThiemo Seufer sym = (Elf_Sym *)sechdrs[symindex].sh_addr 2654e6a05feSThiemo Seufer + ELF_MIPS_R_SYM(rel[i]); 266ba837d38SAndrzej Hajda if (sym->st_value >= -MAX_ERRNO) { 267f3bf07b9SAtsushi Nemoto /* Ignore unresolved weak symbol */ 268f3bf07b9SAtsushi Nemoto if (ELF_ST_BIND(sym->st_info) == STB_WEAK) 269f3bf07b9SAtsushi Nemoto continue; 27055d791f3SSteven J. Hill pr_warn("%s: Unknown symbol %s\n", 2714e6a05feSThiemo Seufer me->name, strtab + sym->st_name); 2724e6a05feSThiemo Seufer return -ENOENT; 2734e6a05feSThiemo Seufer } 2744e6a05feSThiemo Seufer 27504211a57SPaul Burton type = ELF_MIPS_R_TYPE(rel[i]); 2764e6a05feSThiemo Seufer 27704211a57SPaul Burton if (type < ARRAY_SIZE(reloc_handlers_rel)) 27804211a57SPaul Burton handler = reloc_handlers_rel[type]; 27904211a57SPaul Burton else 28004211a57SPaul Burton handler = NULL; 28104211a57SPaul Burton 28204211a57SPaul Burton if (!handler) { 28304211a57SPaul Burton pr_err("%s: Unknown relocation type %u\n", 28404211a57SPaul Burton me->name, type); 28504211a57SPaul Burton return -EINVAL; 28604211a57SPaul Burton } 28704211a57SPaul Burton 28804211a57SPaul Burton v = sym->st_value; 28904211a57SPaul Burton res = handler(me, location, v); 2904e6a05feSThiemo Seufer if (res) 2914e6a05feSThiemo Seufer return res; 2924e6a05feSThiemo Seufer } 2934e6a05feSThiemo Seufer 294c54de490SRalf Baechle /* 295c54de490SRalf Baechle * Normally the hi16 list should be deallocated at this point. A 296c54de490SRalf Baechle * malformed binary however could contain a series of R_MIPS_HI16 297c54de490SRalf Baechle * relocations not followed by a R_MIPS_LO16 relocation. In that 298c54de490SRalf Baechle * case, free up the list and return an error. 299c54de490SRalf Baechle */ 300c54de490SRalf Baechle if (me->arch.r_mips_hi16_list) { 301c54de490SRalf Baechle free_relocation_chain(me->arch.r_mips_hi16_list); 302c54de490SRalf Baechle me->arch.r_mips_hi16_list = NULL; 303c54de490SRalf Baechle 304c54de490SRalf Baechle return -ENOEXEC; 305c54de490SRalf Baechle } 306c54de490SRalf Baechle 3074e6a05feSThiemo Seufer return 0; 3084e6a05feSThiemo Seufer } 3094e6a05feSThiemo Seufer 3101da177e4SLinus Torvalds /* Given an address, look for it in the module exception tables. */ 3111da177e4SLinus Torvalds const struct exception_table_entry *search_module_dbetables(unsigned long addr) 3121da177e4SLinus Torvalds { 3131da177e4SLinus Torvalds unsigned long flags; 3141da177e4SLinus Torvalds const struct exception_table_entry *e = NULL; 3151da177e4SLinus Torvalds struct mod_arch_specific *dbe; 3161da177e4SLinus Torvalds 3171da177e4SLinus Torvalds spin_lock_irqsave(&dbe_lock, flags); 3181da177e4SLinus Torvalds list_for_each_entry(dbe, &dbe_list, dbe_list) { 3191da177e4SLinus Torvalds e = search_extable(dbe->dbe_start, dbe->dbe_end - 1, addr); 3201da177e4SLinus Torvalds if (e) 3211da177e4SLinus Torvalds break; 3221da177e4SLinus Torvalds } 3231da177e4SLinus Torvalds spin_unlock_irqrestore(&dbe_lock, flags); 3241da177e4SLinus Torvalds 3251da177e4SLinus Torvalds /* Now, if we found one, we are running inside it now, hence 3261da177e4SLinus Torvalds we cannot unload the module, hence no refcnt needed. */ 3271da177e4SLinus Torvalds return e; 3281da177e4SLinus Torvalds } 3291da177e4SLinus Torvalds 3303a4fa0a2SRobert P. J. Day /* Put in dbe list if necessary. */ 3311da177e4SLinus Torvalds int module_finalize(const Elf_Ehdr *hdr, 3321da177e4SLinus Torvalds const Elf_Shdr *sechdrs, 3331da177e4SLinus Torvalds struct module *me) 3341da177e4SLinus Torvalds { 3351da177e4SLinus Torvalds const Elf_Shdr *s; 3361da177e4SLinus Torvalds char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; 3371da177e4SLinus Torvalds 33894bb0c1aSDavid Daney /* Make jump label nops. */ 33994bb0c1aSDavid Daney jump_label_apply_nops(me); 34094bb0c1aSDavid Daney 3411da177e4SLinus Torvalds INIT_LIST_HEAD(&me->arch.dbe_list); 3421da177e4SLinus Torvalds for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { 3431da177e4SLinus Torvalds if (strcmp("__dbe_table", secstrings + s->sh_name) != 0) 3441da177e4SLinus Torvalds continue; 3451da177e4SLinus Torvalds me->arch.dbe_start = (void *)s->sh_addr; 3461da177e4SLinus Torvalds me->arch.dbe_end = (void *)s->sh_addr + s->sh_size; 3471da177e4SLinus Torvalds spin_lock_irq(&dbe_lock); 3481da177e4SLinus Torvalds list_add(&me->arch.dbe_list, &dbe_list); 3491da177e4SLinus Torvalds spin_unlock_irq(&dbe_lock); 3501da177e4SLinus Torvalds } 3511da177e4SLinus Torvalds return 0; 3521da177e4SLinus Torvalds } 3531da177e4SLinus Torvalds 3541da177e4SLinus Torvalds void module_arch_cleanup(struct module *mod) 3551da177e4SLinus Torvalds { 3561da177e4SLinus Torvalds spin_lock_irq(&dbe_lock); 3571da177e4SLinus Torvalds list_del(&mod->arch.dbe_list); 3581da177e4SLinus Torvalds spin_unlock_irq(&dbe_lock); 3591da177e4SLinus Torvalds } 360