From b8fcdddcbb192fc367ff04bbd753b9deb69b09f3 Mon Sep 17 00:00:00 2001 From: Waldemar Brodkorb Date: Sat, 28 May 2016 18:12:58 +0200 Subject: nios2: sync support with glibc Only static linking is supported for now. More debugging and analyzing for ld.so, TLS and NPTL is required. But at least you can bootup a static root fileystem in Qemu. --- ldso/ldso/nios2/dl-debug.h | 18 +++ ldso/ldso/nios2/dl-inlines.h | 12 ++ ldso/ldso/nios2/dl-startup.h | 34 +++++ ldso/ldso/nios2/dl-syscalls.h | 1 + ldso/ldso/nios2/dl-sysdep.h | 74 +++++++++++ ldso/ldso/nios2/elfinterp.c | 297 ++++++++++++++++++++++++++++++++++++++++++ ldso/ldso/nios2/resolve.S | 73 +++++++++++ 7 files changed, 509 insertions(+) create mode 100644 ldso/ldso/nios2/dl-debug.h create mode 100644 ldso/ldso/nios2/dl-inlines.h create mode 100644 ldso/ldso/nios2/dl-startup.h create mode 100644 ldso/ldso/nios2/dl-syscalls.h create mode 100644 ldso/ldso/nios2/dl-sysdep.h create mode 100644 ldso/ldso/nios2/elfinterp.c create mode 100644 ldso/ldso/nios2/resolve.S (limited to 'ldso') diff --git a/ldso/ldso/nios2/dl-debug.h b/ldso/ldso/nios2/dl-debug.h new file mode 100644 index 000000000..1fb596ae3 --- /dev/null +++ b/ldso/ldso/nios2/dl-debug.h @@ -0,0 +1,18 @@ +/* nios2 shared library loader suppport */ + +static const char * const _dl_reltypes_tab[] = + { + "R_NIOS2_NONE", + "R_NIOS2_BFD_RELOC_32", + "R_NIOS2_BFD_RELOC_16", + "R_NIOS2_BFD_RELOC_8", + "R_NIOS2_GNU_VTINHERIT", + "R_NIOS2_GNU_VTENTRY", + "R_NIOS2_GOT16", + "R_NIOS2_CALL16", + "R_NIOS2_JUMP_SLOT", + "R_NIOS2_GLOB_DAT", + "R_NIOS2_RELATIVE", + "R_NIOS2_GOTOFF", + "R_NIOS2_COPY", + }; diff --git a/ldso/ldso/nios2/dl-inlines.h b/ldso/ldso/nios2/dl-inlines.h new file mode 100644 index 000000000..7cf7e4afd --- /dev/null +++ b/ldso/ldso/nios2/dl-inlines.h @@ -0,0 +1,12 @@ + +unsigned int +internal_function +_dl_nios2_get_gp_value (struct link_map *main_map) +{ + ElfW(Dyn) *dyn = main_map->l_ld; + for (dyn = main_map->l_ld; dyn->d_tag != DT_NULL; ++dyn) + if (dyn->d_tag == DT_NIOS2_GP) + return (unsigned int)(dyn->d_un.d_ptr); + return 0; +} + diff --git a/ldso/ldso/nios2/dl-startup.h b/ldso/ldso/nios2/dl-startup.h new file mode 100644 index 000000000..982e55532 --- /dev/null +++ b/ldso/ldso/nios2/dl-startup.h @@ -0,0 +1,34 @@ +__asm__ ("\ + .text\n\ + .globl _start\n\ + .type _start, %function\n\ +_start:\n\ + mov r4, sp\n\ + br _dl_start\n\ + mov r16, r4\n\ + jmp r16\n\ +"); + +/* + * Get a pointer to the argv array. On many platforms this can be just + * the address of the first argument, on other platforms we need to + * do something a little more subtle here. + */ +#define GET_ARGV(ARGVP, ARGS) ARGVP = (((unsigned long*) ARGS)+1) + +/* The ld.so library requires relocations */ +#define ARCH_NEEDS_BOOTSTRAP_RELOCS + +static __always_inline +void PERFORM_BOOTSTRAP_RELOC(ELF_RELOC *rpnt, unsigned long *reloc_addr, + unsigned long symbol_addr, unsigned long load_addr, attribute_unused Elf32_Sym *symtab) +{ + switch (ELF_R_TYPE(rpnt->r_info)) { + case R_NIOS2_RELATIVE: + *reloc_addr = load_addr + rpnt->r_addend; + break; + default: + _dl_exit(1); + break; + } +} diff --git a/ldso/ldso/nios2/dl-syscalls.h b/ldso/ldso/nios2/dl-syscalls.h new file mode 100644 index 000000000..f40c4fd31 --- /dev/null +++ b/ldso/ldso/nios2/dl-syscalls.h @@ -0,0 +1 @@ +/* stub for arch-specific syscall issues */ diff --git a/ldso/ldso/nios2/dl-sysdep.h b/ldso/ldso/nios2/dl-sysdep.h new file mode 100644 index 000000000..5ae3ce311 --- /dev/null +++ b/ldso/ldso/nios2/dl-sysdep.h @@ -0,0 +1,74 @@ +/* Use reloca */ +#define ELF_USES_RELOCA + +#include + +/* Initialise the GOT */ +#define INIT_GOT(GOT_BASE,MODULE) \ +do { \ + GOT_BASE[2] = (unsigned long) _dl_linux_resolve; \ + GOT_BASE[1] = (unsigned long) MODULE; \ +} while(0) + +/* Here we define the magic numbers that this dynamic loader should accept */ + +#define MAGIC1 EM_ALTERA_NIOS2 +#undef MAGIC2 +/* Used for error messages */ +#define ELF_TARGET "nios2" + +struct elf_resolve; +unsigned long _dl_linux_resolver(struct elf_resolve * tpnt, int reloc_entry); + +/* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so + PLT entries should not be allowed to define the value. + ELF_RTYPE_CLASS_COPY iff TYPE should not be allowed to resolve to one + of the main executable's symbols, as for a COPY reloc. */ +#define elf_machine_type_class(type) \ + ((((type) == R_NIOS2_JUMP_SLOT \ + || (type) == R_NIOS2_TLS_DTPMOD \ + || (type) == R_NIOS2_TLS_DTPREL \ + || (type) == R_NIOS2_TLS_TPREL) * ELF_RTYPE_CLASS_PLT) \ + | (((type) == R_NIOS2_COPY) * ELF_RTYPE_CLASS_COPY)) + +/* Return the link-time address of _DYNAMIC. Conveniently, this is the + first element of the GOT. */ +static inline Elf32_Addr +elf_machine_dynamic (void) +{ + Elf32_Addr *dynamic; + int tmp; + __asm__ ("nextpc\t%0\n\t" + "1: movhi\t%1, %%hiadj(_GLOBAL_OFFSET_TABLE_ - 1b)\n\t" + "addi\t%1, %1, %%lo(_GLOBAL_OFFSET_TABLE_ - 1b)\n\t" + "add\t%0, %0, %1\n" + : "=r" (dynamic), "=r" (tmp)); + return *dynamic; +} + +/* Return the run-time load address of the shared object. */ +static inline Elf32_Addr +elf_machine_load_address (void) +{ + Elf32_Addr result; + int tmp; + __asm__ ("nextpc\t%0\n\t" + "1: movhi\t%1, %%hiadj(1b)\n\t" + "addi\t%1, %1, %%lo(1b)\n\t" + "sub\t%0, %0, %1\n" + : "=r" (result), "=r" (tmp)); + return result; +} + +static __always_inline void +elf_machine_relative (Elf32_Addr load_off, const Elf32_Addr rel_addr, + Elf32_Word relative_count) +{ + Elf32_Rel * rpnt = (void *) rel_addr; + do { + Elf32_Addr *const reloc_addr = (void *) (load_off + (rpnt)->r_offset); + + *reloc_addr += load_off; + } while (--relative_count); +} + diff --git a/ldso/ldso/nios2/elfinterp.c b/ldso/ldso/nios2/elfinterp.c new file mode 100644 index 000000000..bdbaa3383 --- /dev/null +++ b/ldso/ldso/nios2/elfinterp.c @@ -0,0 +1,297 @@ +/* nios2 ELF shared library loader suppport + * + * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald, + * David Engel, Hongjiu Lu and Mitch D'Souza + * Copyright (C) 2001-2004 Erik Andersen + * + * 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. + */ + +#include "ldso.h" + +/* 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. */ + +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 the 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\n", + *got_addr, new_addr, got_addr); + } + if (!_dl_debug_nofixups) +#endif + *got_addr = new_addr; + + 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 /= 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 " +#if defined (__SUPPORT_LD_DEBUG__) + "%s\n", _dl_reltypes(reloc_type)); +#else + "%x\n", reloc_type); +#endif + _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(sym_ref.sym->st_info) != STT_TLS) + && (ELF_ST_BIND(sym_ref.sym->st_info) != STB_WEAK))) { + /* This may be non-fatal if called from dlopen. */ + return 1; + } +#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__) + if (reloc_addr) { + old_val = *reloc_addr; + } else { + old_val = 0; + } +#endif + + switch (reloc_type) { + case R_NIOS2_NONE: + break; + + case R_NIOS2_BFD_RELOC_32: + case R_NIOS2_GLOB_DAT: + case R_NIOS2_JUMP_SLOT: + *reloc_addr = symbol_addr + rpnt->r_addend; + break; + + case R_NIOS2_RELATIVE: + *reloc_addr = (unsigned long)tpnt->loadaddr + rpnt->r_addend; + break; + + case R_NIOS2_COPY: + if (symbol_addr) { +#if defined (__SUPPORT_LD_DEBUG__) + if (_dl_debug_move) + _dl_dprintf(_dl_debug_file, + "\t%s move %d bytes from %x to %x\n", + symname, sym_ref.sym->st_size, + symbol_addr, reloc_addr); +#endif + + _dl_memcpy((char *)reloc_addr, + (char *)symbol_addr, + sym_ref.sym->st_size); + } + break; + + default: + return -1; /* Calls _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_NIOS2_NONE: + break; + case R_NIOS2_JUMP_SLOT: + *reloc_addr += (unsigned long)tpnt->loadaddr; + break; + default: + _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); +} diff --git a/ldso/ldso/nios2/resolve.S b/ldso/ldso/nios2/resolve.S new file mode 100644 index 000000000..a71839e17 --- /dev/null +++ b/ldso/ldso/nios2/resolve.S @@ -0,0 +1,73 @@ +/* PLT trampolines. Nios II version. + Copyright (C) 2005-2016 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + . */ + +/* This code is used in dl-runtime.c to call the `fixup' function + and then redirect to the address it returns. */ + + .text + .align 4 + .globl _dl_linux_resolver + .globl _dl_linux_resolve + .type _dl_linux_resolve,@function + +_dl_linux_resolve: +/* The runtime resolver receives the original function arguments in r4 + through r7, the shared library identifier from GOT[1]? in r14, and the + relocation index times four in r15. It updates the corresponding PLT GOT + entry so that the PLT entry will transfer control directly to the target + in the future, and then transfers control to the target. */ + /* Save arguments and return address. */ + subi sp, sp, 28 + stw r22, 24(sp) + stw r8, 20(sp) /* save r8, because this might be a call to mcount */ + stw r7, 16(sp) + stw r6, 12(sp) + stw r5, 8(sp) + stw r4, 4(sp) + stw ra, 0(sp) + + /* Get pointer to linker struct. */ + mov r4, r14 + + /* Get the relocation offset. We're given a multiple of 4 and + need a multiple of 12, so multiply by 3. */ + slli r5, r15, 1 + add r5, r5, r15 + + /* Call the fixup routine. */ + nextpc r22 +1: movhi r2, %hiadj(_gp_got - 1b) + addi r2, r2, %lo(_gp_got - 1b) + add r22, r22, r2 + ldw r2, %call(_dl_linux_resolver)(r22) + callr r2 + + /* Restore the arguments and return address. */ + ldw ra, 0(sp) + ldw r4, 4(sp) + ldw r5, 8(sp) + ldw r6, 12(sp) + ldw r7, 16(sp) + ldw r8, 20(sp) + ldw r22, 24(sp) + addi sp, sp, 28 + + /* Jump to the newly found address. */ + jmp r2 + + .size _dl_linux_resolve, . - _dl_linux_resolve -- cgit v1.2.3