From 60eae0def70b8a2e768c6a5bec352da9d648b26c Mon Sep 17 00:00:00 2001 From: Waldemar Brodkorb Date: Wed, 16 Oct 2019 02:24:18 +0200 Subject: riscv64: add shared library support --- ldso/ldso/riscv64/elfinterp.c | 279 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 279 insertions(+) create mode 100644 ldso/ldso/riscv64/elfinterp.c (limited to 'ldso/ldso/riscv64/elfinterp.c') diff --git a/ldso/ldso/riscv64/elfinterp.c b/ldso/ldso/riscv64/elfinterp.c new file mode 100644 index 000000000..ec1678f2a --- /dev/null +++ b/ldso/ldso/riscv64/elfinterp.c @@ -0,0 +1,279 @@ +/* RISCV ELF shared library loader suppport + * + * Copyright (C) 2001-2004 Erik Andersen + * Copyright (C) 2019 Waldemar Brodkorb + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. The name of the above contributors may not be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* Program to load an ELF binary on a linux system, and run it. + References to symbols in sharable libraries can be resolved by either + an ELF sharable library or a linux style of shared library. */ + +#include "ldso.h" + +#if defined(USE_TLS) && USE_TLS +#include "dl-tls.h" +#include "tlsdeschtab.h" +#endif + +extern int _dl_linux_resolve(void); + +unsigned long _dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry) +{ + ELF_RELOC *this_reloc; + char *strtab; + ElfW(Sym) *symtab; + int symtab_index; + char *rel_addr; + char *new_addr; + char **got_addr; + ElfW(Addr) instr_addr; + char *symname; + + rel_addr = (char *)tpnt->dynamic_info[DT_JMPREL]; + this_reloc = (ELF_RELOC *)(rel_addr + reloc_entry); + symtab_index = ELF_R_SYM(this_reloc->r_info); + + symtab = (ElfW(Sym) *)tpnt->dynamic_info[DT_SYMTAB]; + strtab = (char *)tpnt->dynamic_info[DT_STRTAB]; + symname = strtab + symtab[symtab_index].st_name; + + /* Address of jump instruction to fix up */ + instr_addr = (this_reloc->r_offset + tpnt->loadaddr); + got_addr = (char **)instr_addr; + + /* Get the address of the GOT entry */ + new_addr = _dl_find_hash(symname, &_dl_loaded_modules->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT, NULL); + if (unlikely(!new_addr)) { + _dl_dprintf(2, "%s: can't resolve symbol '%s'\n", _dl_progname, symname); + _dl_exit(1); + } +#if defined (__SUPPORT_LD_DEBUG__) + if (_dl_debug_bindings) { + _dl_dprintf(_dl_debug_file, "\nresolve function: %s", symname); + if (_dl_debug_detail) _dl_dprintf(_dl_debug_file, + "\tpatched %x ==> %x @ %x", *got_addr, new_addr, got_addr); + } + if (!_dl_debug_nofixups) { + *got_addr = new_addr; + } +#else + *got_addr = new_addr; +#endif + return (unsigned long)new_addr; +} + +static int +_dl_parse(struct elf_resolve *tpnt, struct r_scope_elem *scope, + unsigned long rel_addr, unsigned long rel_size, + int (*reloc_fnc) (struct elf_resolve *tpnt, struct r_scope_elem *scope, + ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab)) +{ + unsigned int i; + char *strtab; + ElfW(Sym) *symtab; + ELF_RELOC *rpnt; + int symtab_index; + + /* Parse the relocation information */ + rpnt = (ELF_RELOC *)rel_addr; + rel_size = rel_size / sizeof(ELF_RELOC); + + symtab = (ElfW(Sym) *)tpnt->dynamic_info[DT_SYMTAB]; + strtab = (char *)tpnt->dynamic_info[DT_STRTAB]; + + for (i = 0; i < rel_size; i++, rpnt++) { + int res; + + symtab_index = ELF_R_SYM(rpnt->r_info); + + debug_sym(symtab, strtab, symtab_index); + debug_reloc(symtab, strtab, rpnt); + + res = reloc_fnc(tpnt, scope, rpnt, symtab, strtab); + + if (res==0) + continue; + + _dl_dprintf(2, "\n%s: ", _dl_progname); + + if (symtab_index) + _dl_dprintf(2, "symbol '%s': ", + strtab + symtab[symtab_index].st_name); + + if (unlikely(res < 0)) { + int reloc_type = ELF_R_TYPE(rpnt->r_info); + _dl_dprintf(2, "can't handle reloc type %x\n", reloc_type); + _dl_exit(-res); + } else if (unlikely(res > 0)) { + _dl_dprintf(2, "can't resolve symbol\n"); + return res; + } + } + + return 0; +} + +static int +_dl_do_reloc (struct elf_resolve *tpnt, struct r_scope_elem *scope, + ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab) +{ + int reloc_type; + int symtab_index; + char *symname; +#if defined USE_TLS && USE_TLS + struct elf_resolve *tls_tpnt = NULL; +#endif + struct symbol_ref sym_ref; + ElfW(Addr) *reloc_addr; + ElfW(Addr) symbol_addr; +#if defined (__SUPPORT_LD_DEBUG__) + ElfW(Addr) old_val; +#endif + + reloc_addr = (ElfW(Addr)*)(tpnt->loadaddr + (unsigned long)rpnt->r_offset); + reloc_type = ELF_R_TYPE(rpnt->r_info); + symtab_index = ELF_R_SYM(rpnt->r_info); + sym_ref.sym = &symtab[symtab_index]; + sym_ref.tpnt = NULL; + symbol_addr = 0; + symname = strtab + sym_ref.sym->st_name; + + if (symtab_index) { + symbol_addr = (ElfW(Addr))_dl_find_hash(symname, scope, tpnt, + elf_machine_type_class(reloc_type), &sym_ref); + + /* + * We want to allow undefined references to weak symbols - this might + * have been intentional. We should not be linking local symbols + * here, so all bases should be covered. + */ + if (unlikely (!symbol_addr && + (ELF_ST_TYPE(symtab[symtab_index].st_info) != STT_TLS) && + (ELF_ST_BIND(symtab[symtab_index].st_info) != STB_WEAK))) { + return 1; + } + if (_dl_trace_prelink) { + _dl_debug_lookup (symname, tpnt, &symtab[symtab_index], + &sym_ref, elf_machine_type_class(reloc_type)); + } +#if defined USE_TLS && USE_TLS + tls_tpnt = sym_ref.tpnt; +#endif + } else { + /* + * Relocs against STN_UNDEF are usually treated as using a + * symbol value of zero, and using the module containing the + * reloc itself. + */ + symbol_addr = sym_ref.sym->st_value; +#if defined USE_TLS && USE_TLS + tls_tpnt = tpnt; +#endif + } + +#if defined (__SUPPORT_LD_DEBUG__) + old_val = *reloc_addr; +#endif + + switch (reloc_type) { + case R_RISCV_NONE: + break; + case R_RISCV_64: /* REL_SYMBOLIC */ + case R_RISCV_JUMP_SLOT: /* REL_PLT */ + *reloc_addr = symbol_addr + rpnt->r_addend; + break; + case R_RISCV_RELATIVE: + *reloc_addr += tpnt->loadaddr + rpnt->r_addend; + break; + case R_RISCV_COPY: + _dl_memcpy((void *) reloc_addr, + (void *) symbol_addr, sym_ref.sym->st_size); + break; + default: + return -1; /*call _dl_exit(1) */ + } + +#if defined (__SUPPORT_LD_DEBUG__) + if (_dl_debug_reloc && _dl_debug_detail) { + _dl_dprintf(_dl_debug_file, "\tpatched: %x ==> %x @ %x\n", + old_val, *reloc_addr, reloc_addr); + } +#endif + + return 0; +} + +static int +_dl_do_lazy_reloc (struct elf_resolve *tpnt, struct r_scope_elem *scope, + ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab) +{ + int reloc_type; + ElfW(Addr) *reloc_addr; +#if defined (__SUPPORT_LD_DEBUG__) + ElfW(Addr) old_val; +#endif + + (void)scope; + (void)strtab; + + reloc_addr = (ElfW(Addr)*)(tpnt->loadaddr + rpnt->r_offset); + reloc_type = ELF_R_TYPE(rpnt->r_info); + +#if defined (__SUPPORT_LD_DEBUG__) + old_val = *reloc_addr; +#endif + + switch (reloc_type) { + case R_RISCV_NONE: + break; + case R_RISCV_JUMP_SLOT: + *reloc_addr += tpnt->loadaddr; + break; + default: + return -1; /*call _dl_exit(1) */ + } + +#if defined (__SUPPORT_LD_DEBUG__) + if (_dl_debug_reloc && _dl_debug_detail) { + _dl_dprintf(_dl_debug_file, "\tpatched_lazy: %x ==> %x @ %x\n", + old_val, *reloc_addr, reloc_addr); + } +#endif + + return 0; +} + +void _dl_parse_lazy_relocation_information(struct dyn_elf *rpnt, + unsigned long rel_addr, unsigned long rel_size) +{ + (void)_dl_parse(rpnt->dyn, NULL, rel_addr, rel_size, _dl_do_lazy_reloc); +} + +int _dl_parse_relocation_information(struct dyn_elf *rpnt, + struct r_scope_elem *scope, unsigned long rel_addr, unsigned long rel_size) +{ + return _dl_parse(rpnt->dyn, scope, rel_addr, rel_size, _dl_do_reloc); +} -- cgit v1.2.3