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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548// SPDX-License-Identifier: GPL-2.0+/* * Kernel module help for s390. * * S390 version * Copyright IBM Corp. 2002, 2003 * Author(s): Arnd Bergmann (arndb@de.ibm.com) * Martin Schwidefsky (schwidefsky@de.ibm.com) * * based on i386 version * Copyright (C) 2001 Rusty Russell. */#include <linux/module.h>#include <linux/elf.h>#include <linux/vmalloc.h>#include <linux/fs.h>#include <linux/ftrace.h>#include <linux/string.h>#include <linux/kernel.h>#include <linux/kasan.h>#include <linux/moduleloader.h>#include <linux/bug.h>#include <linux/memory.h>#include <linux/execmem.h>#include <asm/arch-stackprotector.h>#include <asm/alternative.h>#include <asm/nospec-branch.h>#include <asm/facility.h>#include <asm/ftrace.lds.h>#include <asm/set_memory.h>#include <asm/setup.h>#include <asm/asm-offsets.h>
#if 0#define DEBUGP printk#else#define DEBUGP(fmt , ...)#endif
#define PLT_ENTRY_SIZE 22
#ifdef CONFIG_FUNCTION_TRACERvoid module_arch_cleanup(struct module *mod){ execmem_free(mod->arch.trampolines_start);}#endif
void module_arch_freeing_init(struct module *mod){ if (is_livepatch_module(mod) && mod->state == MODULE_STATE_LIVE) return;
vfree(mod->arch.syminfo); mod->arch.syminfo = NULL;}
static void check_rela(Elf_Rela *rela, struct module *me){ struct mod_arch_syminfo *info;
info = me->arch.syminfo + ELF_R_SYM (rela->r_info); switch (ELF_R_TYPE (rela->r_info)) { case R_390_GOT12: /* 12 bit GOT offset. */ case R_390_GOT16: /* 16 bit GOT offset. */ case R_390_GOT20: /* 20 bit GOT offset. */ case R_390_GOT32: /* 32 bit GOT offset. */ case R_390_GOT64: /* 64 bit GOT offset. */ case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */ case R_390_GOTPLT12: /* 12 bit offset to jump slot. */ case R_390_GOTPLT16: /* 16 bit offset to jump slot. */ case R_390_GOTPLT20: /* 20 bit offset to jump slot. */ case R_390_GOTPLT32: /* 32 bit offset to jump slot. */ case R_390_GOTPLT64: /* 64 bit offset to jump slot. */ case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */ if (info->got_offset == -1UL) { info->got_offset = me->arch.got_size; me->arch.got_size += sizeof(void*); } break; case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */ case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */ case R_390_PLT32: /* 32 bit PC relative PLT address. */ case R_390_PLT64: /* 64 bit PC relative PLT address. */ case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */ case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */ case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */ if (info->plt_offset == -1UL) { info->plt_offset = me->arch.plt_size; me->arch.plt_size += PLT_ENTRY_SIZE; } break; case R_390_COPY: case R_390_GLOB_DAT: case R_390_JMP_SLOT: case R_390_RELATIVE: /* Only needed if we want to support loading of modules linked with -shared. */ break; }}
/* * Account for GOT and PLT relocations. We can't add sections for * got and plt but we can increase the core module size. */int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, char *secstrings, struct module *me){ Elf_Shdr *symtab; Elf_Sym *symbols; Elf_Rela *rela; char *strings; int nrela, i, j; struct module_memory *mod_mem;
/* Find symbol table and string table. */ symtab = NULL; for (i = 0; i < hdr->e_shnum; i++) switch (sechdrs[i].sh_type) { case SHT_SYMTAB: symtab = sechdrs + i; break; } if (!symtab) { printk(KERN_ERR "module %s: no symbol table\n", me->name); return -ENOEXEC; }
/* Allocate one syminfo structure per symbol. */ me->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym); me->arch.syminfo = vmalloc(array_size(sizeof(struct mod_arch_syminfo), me->arch.nsyms)); if (!me->arch.syminfo) return -ENOMEM; symbols = (void *) hdr + symtab->sh_offset; strings = (void *) hdr + sechdrs[symtab->sh_link].sh_offset; for (i = 0; i < me->arch.nsyms; i++) { if (symbols[i].st_shndx == SHN_UNDEF && strcmp(strings + symbols[i].st_name, "_GLOBAL_OFFSET_TABLE_") == 0) /* "Define" it as absolute. */ symbols[i].st_shndx = SHN_ABS; me->arch.syminfo[i].got_offset = -1UL; me->arch.syminfo[i].plt_offset = -1UL; me->arch.syminfo[i].got_initialized = 0; me->arch.syminfo[i].plt_initialized = 0; }
/* Search for got/plt relocations. */ me->arch.got_size = me->arch.plt_size = 0; for (i = 0; i < hdr->e_shnum; i++) { if (sechdrs[i].sh_type != SHT_RELA) continue; nrela = sechdrs[i].sh_size / sizeof(Elf_Rela); rela = (void *) hdr + sechdrs[i].sh_offset; for (j = 0; j < nrela; j++) check_rela(rela + j, me); }
/* Increase core size by size of got & plt and set start offsets for got and plt. */ mod_mem = &me->mem[MOD_TEXT]; mod_mem->size = ALIGN(mod_mem->size, 4); me->arch.got_offset = mod_mem->size; mod_mem->size += me->arch.got_size; me->arch.plt_offset = mod_mem->size; if (me->arch.plt_size) { if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_disable) me->arch.plt_size += PLT_ENTRY_SIZE; mod_mem->size += me->arch.plt_size; } return 0;}
static int apply_rela_bits(Elf_Addr loc, Elf_Addr val, int sign, int bits, int shift, void *(*write)(void *dest, const void *src, size_t len)){ unsigned long umax; long min, max; void *dest = (void *)loc;
if (val & ((1UL << shift) - 1)) return -ENOEXEC; if (sign) { val = (Elf_Addr)(((long) val) >> shift); min = -(1L << (bits - 1)); max = (1L << (bits - 1)) - 1; if ((long) val < min || (long) val > max) return -ENOEXEC; } else { val >>= shift; umax = ((1UL << (bits - 1)) << 1) - 1; if ((unsigned long) val > umax) return -ENOEXEC; }
if (bits == 8) { unsigned char tmp = val; write(dest, &tmp, 1); } else if (bits == 12) { unsigned short tmp = (val & 0xfff) | (*(unsigned short *) loc & 0xf000); write(dest, &tmp, 2); } else if (bits == 16) { unsigned short tmp = val; write(dest, &tmp, 2); } else if (bits == 20) { unsigned int tmp = (val & 0xfff) << 16 | (val & 0xff000) >> 4 | (*(unsigned int *) loc & 0xf00000ff); write(dest, &tmp, 4); } else if (bits == 32) { unsigned int tmp = val; write(dest, &tmp, 4); } else if (bits == 64) { unsigned long tmp = val; write(dest, &tmp, 8); } return 0;}
static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab, const char *strtab, struct module *me, void *(*write)(void *dest, const void *src, size_t len)){ struct mod_arch_syminfo *info; Elf_Addr loc, val; int r_type, r_sym; int rc = -ENOEXEC;
/* This is where to make the change */ loc = base + rela->r_offset; /* This is the symbol it is referring to. Note that all undefined symbols have been resolved. */ r_sym = ELF_R_SYM(rela->r_info); r_type = ELF_R_TYPE(rela->r_info); info = me->arch.syminfo + r_sym; val = symtab[r_sym].st_value;
switch (r_type) { case R_390_NONE: /* No relocation. */ rc = 0; break; case R_390_8: /* Direct 8 bit. */ case R_390_12: /* Direct 12 bit. */ case R_390_16: /* Direct 16 bit. */ case R_390_20: /* Direct 20 bit. */ case R_390_32: /* Direct 32 bit. */ case R_390_64: /* Direct 64 bit. */ val += rela->r_addend; if (r_type == R_390_8) rc = apply_rela_bits(loc, val, 0, 8, 0, write); else if (r_type == R_390_12) rc = apply_rela_bits(loc, val, 0, 12, 0, write); else if (r_type == R_390_16) rc = apply_rela_bits(loc, val, 0, 16, 0, write); else if (r_type == R_390_20) rc = apply_rela_bits(loc, val, 1, 20, 0, write); else if (r_type == R_390_32) rc = apply_rela_bits(loc, val, 0, 32, 0, write); else if (r_type == R_390_64) rc = apply_rela_bits(loc, val, 0, 64, 0, write); break; case R_390_PC16: /* PC relative 16 bit. */ case R_390_PC16DBL: /* PC relative 16 bit shifted by 1. */ case R_390_PC32DBL: /* PC relative 32 bit shifted by 1. */ case R_390_PC32: /* PC relative 32 bit. */ case R_390_PC64: /* PC relative 64 bit. */ val += rela->r_addend - loc; if (r_type == R_390_PC16) rc = apply_rela_bits(loc, val, 1, 16, 0, write); else if (r_type == R_390_PC16DBL) rc = apply_rela_bits(loc, val, 1, 16, 1, write); else if (r_type == R_390_PC32DBL) rc = apply_rela_bits(loc, val, 1, 32, 1, write); else if (r_type == R_390_PC32) rc = apply_rela_bits(loc, val, 1, 32, 0, write); else if (r_type == R_390_PC64) rc = apply_rela_bits(loc, val, 1, 64, 0, write); break; case R_390_GOT12: /* 12 bit GOT offset. */ case R_390_GOT16: /* 16 bit GOT offset. */ case R_390_GOT20: /* 20 bit GOT offset. */ case R_390_GOT32: /* 32 bit GOT offset. */ case R_390_GOT64: /* 64 bit GOT offset. */ case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */ case R_390_GOTPLT12: /* 12 bit offset to jump slot. */ case R_390_GOTPLT20: /* 20 bit offset to jump slot. */ case R_390_GOTPLT16: /* 16 bit offset to jump slot. */ case R_390_GOTPLT32: /* 32 bit offset to jump slot. */ case R_390_GOTPLT64: /* 64 bit offset to jump slot. */ case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */ if (info->got_initialized == 0) { Elf_Addr *gotent = me->mem[MOD_TEXT].base + me->arch.got_offset + info->got_offset;
write(gotent, &val, sizeof(*gotent)); info->got_initialized = 1; } val = info->got_offset + rela->r_addend; if (r_type == R_390_GOT12 || r_type == R_390_GOTPLT12) rc = apply_rela_bits(loc, val, 0, 12, 0, write); else if (r_type == R_390_GOT16 || r_type == R_390_GOTPLT16) rc = apply_rela_bits(loc, val, 0, 16, 0, write); else if (r_type == R_390_GOT20 || r_type == R_390_GOTPLT20) rc = apply_rela_bits(loc, val, 1, 20, 0, write); else if (r_type == R_390_GOT32 || r_type == R_390_GOTPLT32) rc = apply_rela_bits(loc, val, 0, 32, 0, write); else if (r_type == R_390_GOT64 || r_type == R_390_GOTPLT64) rc = apply_rela_bits(loc, val, 0, 64, 0, write); else if (r_type == R_390_GOTENT || r_type == R_390_GOTPLTENT) { val += (Elf_Addr)me->mem[MOD_TEXT].base + me->arch.got_offset - loc; rc = apply_rela_bits(loc, val, 1, 32, 1, write); } break; case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */ case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */ case R_390_PLT32: /* 32 bit PC relative PLT address. */ case R_390_PLT64: /* 64 bit PC relative PLT address. */ case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */ case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */ case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */ if (info->plt_initialized == 0) { unsigned char insn[PLT_ENTRY_SIZE]; char *plt_base; char *ip;
plt_base = me->mem[MOD_TEXT].base + me->arch.plt_offset; ip = plt_base + info->plt_offset; *(int *)insn = 0x0d10e310; /* basr 1,0 */ *(int *)&insn[4] = 0x100c0004; /* lg 1,12(1) */ if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_disable) { char *jump_r1;
jump_r1 = plt_base + me->arch.plt_size - PLT_ENTRY_SIZE; /* brcl 0xf,__jump_r1 */ *(short *)&insn[8] = 0xc0f4; *(int *)&insn[10] = (jump_r1 - (ip + 8)) / 2; } else { *(int *)&insn[8] = 0x07f10000; /* br %r1 */ } *(long *)&insn[14] = val;
write(ip, insn, sizeof(insn)); info->plt_initialized = 1; } if (r_type == R_390_PLTOFF16 || r_type == R_390_PLTOFF32 || r_type == R_390_PLTOFF64) val = me->arch.plt_offset - me->arch.got_offset + info->plt_offset + rela->r_addend; else { if (!((r_type == R_390_PLT16DBL && val - loc + 0xffffUL < 0x1ffffeUL) || (r_type == R_390_PLT32DBL && val - loc + 0xffffffffULL < 0x1fffffffeULL))) val = (Elf_Addr) me->mem[MOD_TEXT].base + me->arch.plt_offset + info->plt_offset; val += rela->r_addend - loc; } if (r_type == R_390_PLT16DBL) rc = apply_rela_bits(loc, val, 1, 16, 1, write); else if (r_type == R_390_PLTOFF16) rc = apply_rela_bits(loc, val, 0, 16, 0, write); else if (r_type == R_390_PLT32DBL) rc = apply_rela_bits(loc, val, 1, 32, 1, write); else if (r_type == R_390_PLT32 || r_type == R_390_PLTOFF32) rc = apply_rela_bits(loc, val, 0, 32, 0, write); else if (r_type == R_390_PLT64 || r_type == R_390_PLTOFF64) rc = apply_rela_bits(loc, val, 0, 64, 0, write); break; case R_390_GOTOFF16: /* 16 bit offset to GOT. */ case R_390_GOTOFF32: /* 32 bit offset to GOT. */ case R_390_GOTOFF64: /* 64 bit offset to GOT. */ val = val + rela->r_addend - ((Elf_Addr) me->mem[MOD_TEXT].base + me->arch.got_offset); if (r_type == R_390_GOTOFF16) rc = apply_rela_bits(loc, val, 0, 16, 0, write); else if (r_type == R_390_GOTOFF32) rc = apply_rela_bits(loc, val, 0, 32, 0, write); else if (r_type == R_390_GOTOFF64) rc = apply_rela_bits(loc, val, 0, 64, 0, write); break; case R_390_GOTPC: /* 32 bit PC relative offset to GOT. */ case R_390_GOTPCDBL: /* 32 bit PC rel. off. to GOT shifted by 1. */ val = (Elf_Addr) me->mem[MOD_TEXT].base + me->arch.got_offset + rela->r_addend - loc; if (r_type == R_390_GOTPC) rc = apply_rela_bits(loc, val, 1, 32, 0, write); else if (r_type == R_390_GOTPCDBL) rc = apply_rela_bits(loc, val, 1, 32, 1, write); break; case R_390_COPY: case R_390_GLOB_DAT: /* Create GOT entry. */ case R_390_JMP_SLOT: /* Create PLT entry. */ case R_390_RELATIVE: /* Adjust by program base. */ /* Only needed if we want to support loading of modules linked with -shared. */ return -ENOEXEC; default: printk(KERN_ERR "module %s: unknown relocation: %u\n", me->name, r_type); return -ENOEXEC; } if (rc) { printk(KERN_ERR "module %s: relocation error for symbol %s " "(r_type %i, value 0x%lx)\n", me->name, strtab + symtab[r_sym].st_name, r_type, (unsigned long) val); return rc; } return 0;}
static int __apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *me, void *(*write)(void *dest, const void *src, size_t len)){ Elf_Addr base; Elf_Sym *symtab; Elf_Rela *rela; unsigned long i, n; int rc;
DEBUGP("Applying relocate section %u to %u\n", relsec, sechdrs[relsec].sh_info); base = sechdrs[sechdrs[relsec].sh_info].sh_addr; symtab = (Elf_Sym *) sechdrs[symindex].sh_addr; rela = (Elf_Rela *) sechdrs[relsec].sh_addr; n = sechdrs[relsec].sh_size / sizeof(Elf_Rela);
for (i = 0; i < n; i++, rela++) { rc = apply_rela(rela, base, symtab, strtab, me, write); if (rc) return rc; } return 0;}
int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *me){ bool early = me->state == MODULE_STATE_UNFORMED; void *(*write)(void *, const void *, size_t) = memcpy;
if (!early) write = s390_kernel_write;
return __apply_relocate_add(sechdrs, strtab, symindex, relsec, me, write);}
#ifdef CONFIG_FUNCTION_TRACERstatic int module_alloc_ftrace_hotpatch_trampolines(struct module *me, const Elf_Shdr *s){ char *start, *end; int numpages; size_t size;
size = FTRACE_HOTPATCH_TRAMPOLINES_SIZE(s->sh_size); numpages = DIV_ROUND_UP(size, PAGE_SIZE); start = execmem_alloc(EXECMEM_FTRACE, numpages * PAGE_SIZE); if (!start) return -ENOMEM; set_memory_rox((unsigned long)start, numpages); end = start + size;
me->arch.trampolines_start = (struct ftrace_hotpatch_trampoline *)start; me->arch.trampolines_end = (struct ftrace_hotpatch_trampoline *)end; me->arch.next_trampoline = me->arch.trampolines_start;
return 0;}#endif /* CONFIG_FUNCTION_TRACER */
int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *me){ const Elf_Shdr *s; char *secstrings, *secname; void *aseg; int rc = 0;
if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_disable && me->arch.plt_size) { unsigned int *ij;
ij = me->mem[MOD_TEXT].base + me->arch.plt_offset + me->arch.plt_size - PLT_ENTRY_SIZE; ij[0] = 0xc6000000; /* exrl %r0,.+10 */ ij[1] = 0x0005a7f4; /* j . */ ij[2] = 0x000007f1; /* br %r1 */ }
secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { aseg = (void *) s->sh_addr; secname = secstrings + s->sh_name;
if (!strcmp(".altinstructions", secname)) /* patch .altinstructions */ apply_alternatives(aseg, aseg + s->sh_size);
if (IS_ENABLED(CONFIG_EXPOLINE) && (str_has_prefix(secname, ".s390_indirect"))) nospec_revert(aseg, aseg + s->sh_size);
if (IS_ENABLED(CONFIG_EXPOLINE) && (str_has_prefix(secname, ".s390_return"))) nospec_revert(aseg, aseg + s->sh_size);
if (IS_ENABLED(CONFIG_STACKPROTECTOR) && (str_has_prefix(secname, "__stack_protector_loc"))) { rc = stack_protector_apply(aseg, aseg + s->sh_size); if (rc) break; }
#ifdef CONFIG_FUNCTION_TRACER if (!strcmp(FTRACE_CALLSITE_SECTION, secname)) { rc = module_alloc_ftrace_hotpatch_trampolines(me, s); if (rc) break; }#endif /* CONFIG_FUNCTION_TRACER */ }
return rc;}