552 lines
15 KiB
C
552 lines
15 KiB
C
/* $NetBSD: ppc_reloc.c,v 1.60 2019/12/08 23:49:16 uwe Exp $ */
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/*-
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* Copyright (C) 1998 Tsubai Masanari
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* Portions copyright 2002 Charles M. Hannum <root@ihack.net>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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#ifndef lint
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__RCSID("$NetBSD: ppc_reloc.c,v 1.60 2019/12/08 23:49:16 uwe Exp $");
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#endif /* not lint */
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#include <stdarg.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/types.h>
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#include <machine/cpu.h>
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#include "debug.h"
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#include "rtld.h"
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void _rtld_powerpc_pltcall(Elf_Word);
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void _rtld_powerpc_pltresolve(Elf_Word, Elf_Word);
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#define __u64(x) ((uint64_t)(x))
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#define __u32(x) ((uint32_t)(x))
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#define __ha48 __u64(0xffffffff8000)
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#define __ha32 __u64(0xffff8000)
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#define __ha16 __u32(0x8000)
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#define __ha(x,n) ((((x) >> (n)) + (((x) & __ha##n) == __ha##n)) & 0xffff)
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#define __hi(x,n) (((x) >> (n)) & 0xffff)
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#ifdef __LP64
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#define highesta(x) __ha(__u64(x), 48)
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#define highest(x) __hi(__u64(x), 48)
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#define higher(x) __ha(__u64(x), 32)
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#define higher(x) __hi(__u64(x), 32)
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#endif
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#define ha(x) __ha(__u32(x), 16)
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#define hi(x) __hi(__u32(x), 16)
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#define lo(x) (__u32(x) & 0xffff)
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#ifdef _LP64
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/* function descriptor for _rtld_bind_start */
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extern const uint64_t _rtld_bind_start[3];
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#else
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void _rtld_bind_bssplt_start(void);
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void _rtld_bind_secureplt_start(void);
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#endif
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Elf_Addr _rtld_bind(const Obj_Entry *, Elf_Word);
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void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
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static int _rtld_relocate_plt_object(const Obj_Entry *,
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const Elf_Rela *, int, Elf_Addr *);
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/*
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* The PPC32 PLT format consists of three sections:
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* (1) The "pltcall" and "pltresolve" glue code. This is always 18 words.
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* (2) The code part of the PLT entries. There are 2 words per entry for
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* up to 8192 entries, then 4 words per entry for any additional entries.
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* (3) The data part of the PLT entries, comprising a jump table.
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* This section is half the size of the second section (ie. 1 or 2 words
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* per entry).
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*/
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void
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_rtld_setup_pltgot(const Obj_Entry *obj)
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{
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#ifdef _LP64
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/*
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* For powerpc64, just copy the function descriptor to pltgot[0].
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*/
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if (obj->pltgot != NULL) {
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obj->pltgot[0] = (Elf_Addr) _rtld_bind_start[0];
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obj->pltgot[1] = (Elf_Addr) _rtld_bind_start[1];
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obj->pltgot[2] = (Elf_Addr) obj;
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}
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#else
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/*
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* Secure-PLT is much more sane.
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*/
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if (obj->gotptr != NULL) {
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obj->gotptr[1] = (Elf_Addr) _rtld_bind_secureplt_start;
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obj->gotptr[2] = (Elf_Addr) obj;
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dbg(("obj %s secure-plt gotptr=%p start=%p obj=%p",
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obj->path, obj->gotptr,
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(void *) obj->gotptr[1], (void *) obj->gotptr[2]));
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} else {
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/*
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* Setup the plt glue routines (for bss-plt).
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*/
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#define BSSPLTCALL_SIZE 20
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#define BSSPLTRESOLVE_SIZE 24
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Elf_Word *pltcall, *pltresolve;
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Elf_Word *jmptab;
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int N = obj->pltrelalim - obj->pltrela;
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/* Entries beyond 8192 take twice as much space. */
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if (N > 8192)
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N += N-8192;
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dbg(("obj %s bss-plt pltgot=%p jmptab=%u start=%p obj=%p",
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obj->path, obj->pltgot, 18 + N * 2,
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_rtld_bind_bssplt_start, obj));
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pltcall = obj->pltgot;
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jmptab = pltcall + 18 + N * 2;
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memcpy(pltcall, _rtld_powerpc_pltcall, BSSPLTCALL_SIZE);
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pltcall[1] |= ha(jmptab);
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pltcall[2] |= lo(jmptab);
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pltresolve = obj->pltgot + 8;
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memcpy(pltresolve, _rtld_powerpc_pltresolve, BSSPLTRESOLVE_SIZE);
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pltresolve[0] |= ha(_rtld_bind_bssplt_start);
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pltresolve[1] |= lo(_rtld_bind_bssplt_start);
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pltresolve[3] |= ha(obj);
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pltresolve[4] |= lo(obj);
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/*
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* Invalidate the icache for only the code part of the PLT
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* (and not the jump table at the end).
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*/
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__syncicache(pltcall, (char *)jmptab - (char *)pltcall);
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}
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#endif
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}
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void
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_rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
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{
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const Elf_Rela *rela = 0, *relalim;
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Elf_Addr relasz = 0;
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Elf_Addr *where;
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for (; dynp->d_tag != DT_NULL; dynp++) {
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switch (dynp->d_tag) {
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case DT_RELA:
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rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr);
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break;
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case DT_RELASZ:
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relasz = dynp->d_un.d_val;
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break;
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}
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}
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relalim = (const Elf_Rela *)((const uint8_t *)rela + relasz);
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for (; rela < relalim; rela++) {
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where = (Elf_Addr *)(relocbase + rela->r_offset);
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*where = (Elf_Addr)(relocbase + rela->r_addend);
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}
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}
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int
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_rtld_relocate_nonplt_objects(Obj_Entry *obj)
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{
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const Elf_Rela *rela;
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const Elf_Sym *def = NULL;
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const Obj_Entry *defobj = NULL;
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unsigned long last_symnum = ULONG_MAX;
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for (rela = obj->rela; rela < obj->relalim; rela++) {
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Elf_Addr *where;
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Elf_Addr tmp;
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unsigned long symnum;
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where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
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symnum = ELF_R_SYM(rela->r_info);
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switch (ELF_R_TYPE(rela->r_info)) {
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#ifdef _LP64
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case R_TYPE(ADDR64): /* <address> S + A */
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#else
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case R_TYPE(ADDR32): /* <address> S + A */
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#endif
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case R_TYPE(GLOB_DAT): /* <address> S + A */
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case R_TYPE(ADDR16_LO):
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case R_TYPE(ADDR16_HI):
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case R_TYPE(ADDR16_HA):
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case R_TYPE(DTPMOD):
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case R_TYPE(DTPREL):
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case R_TYPE(TPREL):
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if (last_symnum != symnum) {
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last_symnum = symnum;
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def = _rtld_find_symdef(symnum, obj, &defobj,
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false);
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if (def == NULL)
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return -1;
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}
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break;
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default:
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break;
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}
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switch (ELF_R_TYPE(rela->r_info)) {
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#if 1 /* XXX Should not be necessary. */
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case R_TYPE(JMP_SLOT):
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#endif
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case R_TYPE(NONE):
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break;
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#ifdef _LP64
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case R_TYPE(ADDR64): /* <address> S + A */
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#else
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case R_TYPE(ADDR32): /* <address> S + A */
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#endif
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case R_TYPE(GLOB_DAT): /* <address> S + A */
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tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
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rela->r_addend);
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if (*where != tmp)
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*where = tmp;
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rdbg(("32/GLOB_DAT %s in %s --> %p in %s",
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obj->strtab + obj->symtab[symnum].st_name,
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obj->path, (void *)*where, defobj->path));
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break;
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/*
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* Recent GNU ld does not resolve ADDR16_{LO,HI,HA} if
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* the reloc is in a writable section and the symbol
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* is not already referenced from text.
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*/
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case R_TYPE(ADDR16_LO): {
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tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
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rela->r_addend);
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uint16_t tmp16 = lo(tmp);
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uint16_t *where16 = (uint16_t *)where;
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if (*where16 != tmp16)
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*where16 = tmp16;
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rdbg(("ADDR16_LO %s in %s --> #lo(%p) = 0x%x in %s",
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obj->strtab + obj->symtab[symnum].st_name,
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obj->path, (void *)tmp, tmp16, defobj->path));
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break;
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}
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case R_TYPE(ADDR16_HI):
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case R_TYPE(ADDR16_HA): {
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tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
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rela->r_addend);
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uint16_t tmp16 = hi(tmp);
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if (ELF_R_TYPE(rela->r_info) == R_TYPE(ADDR16_HA)
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&& (tmp & __ha16))
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++tmp16; /* adjust to ha(tmp) */
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uint16_t *where16 = (uint16_t *)where;
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if (*where16 != tmp16)
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*where16 = tmp16;
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rdbg(("ADDR16_H%c %s in %s --> #h%c(%p) = 0x%x in %s",
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(ELF_R_TYPE(rela->r_info) == R_TYPE(ADDR16_HI)
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? 'I' : 'A'),
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obj->strtab + obj->symtab[symnum].st_name,
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obj->path,
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(ELF_R_TYPE(rela->r_info) == R_TYPE(ADDR16_HI)
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? 'i' : 'a'),
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(void *)tmp, tmp16, defobj->path));
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break;
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}
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case R_TYPE(RELATIVE): /* <address> B + A */
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*where = (Elf_Addr)(obj->relocbase + rela->r_addend);
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rdbg(("RELATIVE in %s --> %p", obj->path,
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(void *)*where));
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break;
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case R_TYPE(COPY):
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/*
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* These are deferred until all other relocations have
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* been done. All we do here is make sure that the
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* COPY relocation is not in a shared library. They
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* are allowed only in executable files.
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*/
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if (obj->isdynamic) {
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_rtld_error(
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"%s: Unexpected R_COPY relocation in shared library",
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obj->path);
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return -1;
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}
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rdbg(("COPY (avoid in main)"));
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break;
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case R_TYPE(DTPMOD):
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*where = (Elf_Addr)defobj->tlsindex;
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rdbg(("DTPMOD32 %s in %s --> %p in %s",
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obj->strtab + obj->symtab[symnum].st_name,
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obj->path, (void *)*where, defobj->path));
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break;
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case R_TYPE(DTPREL):
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if (!defobj->tls_done && _rtld_tls_offset_allocate(obj))
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return -1;
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*where = (Elf_Addr)(def->st_value + rela->r_addend
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- TLS_DTV_OFFSET);
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rdbg(("DTPREL32 %s in %s --> %p in %s",
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obj->strtab + obj->symtab[symnum].st_name,
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obj->path, (void *)*where, defobj->path));
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break;
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case R_TYPE(TPREL):
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if (!defobj->tls_done && _rtld_tls_offset_allocate(obj))
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return -1;
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*where = (Elf_Addr)(def->st_value + rela->r_addend
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+ defobj->tlsoffset - TLS_TP_OFFSET);
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rdbg(("TPREL32 %s in %s --> %p in %s",
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obj->strtab + obj->symtab[symnum].st_name,
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obj->path, (void *)*where, defobj->path));
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break;
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case R_TYPE(IRELATIVE):
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/* IFUNC relocations are handled in _rtld_call_ifunc */
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if (obj->ifunc_remaining_nonplt == 0) {
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obj->ifunc_remaining_nonplt =
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obj->relalim - rela;
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}
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break;
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default:
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rdbg(("sym = %lu, type = %lu, offset = %p, "
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"addend = %p, contents = %p, symbol = %s",
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(u_long)ELF_R_SYM(rela->r_info),
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(u_long)ELF_R_TYPE(rela->r_info),
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(void *)rela->r_offset, (void *)rela->r_addend,
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(void *)*where,
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obj->strtab + obj->symtab[symnum].st_name));
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_rtld_error("%s: Unsupported relocation type %ld "
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"in non-PLT relocations",
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obj->path, (u_long) ELF_R_TYPE(rela->r_info));
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return -1;
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}
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}
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return 0;
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}
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int
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_rtld_relocate_plt_lazy(Obj_Entry *obj)
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{
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#ifdef _LP64
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/*
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* For PowerPC64, the plt stubs handle an empty function descriptor
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* so there's nothing to do.
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*/
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/* XXX ifunc support */
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#else
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Elf_Addr * const pltresolve = obj->pltgot + 8;
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const Elf_Rela *rela;
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for (rela = obj->pltrelalim; rela-- > obj->pltrela;) {
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size_t reloff = rela - obj->pltrela;
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Elf_Word *where = (Elf_Word *)(obj->relocbase + rela->r_offset);
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assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT) ||
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ELF_R_TYPE(rela->r_info) == R_TYPE(IRELATIVE));
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if (ELF_R_TYPE(rela->r_info) == R_TYPE(IRELATIVE)) {
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/* No ifunc support for old-style insecure PLT. */
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assert(obj->gotptr != NULL);
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obj->ifunc_remaining = obj->pltrelalim - rela;
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}
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if (obj->gotptr != NULL) {
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/*
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* For now, simply treat then as relative.
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*/
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*where += (Elf_Addr)obj->relocbase;
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} else {
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int distance;
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if (reloff < 32768) {
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/* li r11,reloff */
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*where++ = 0x39600000 | reloff;
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} else {
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/* lis r11,ha(reloff) */
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/* addi r11,lo(reloff) */
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*where++ = 0x3d600000 | ha(reloff);
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*where++ = 0x396b0000 | lo(reloff);
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}
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/* b pltresolve */
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distance = (Elf_Addr)pltresolve - (Elf_Addr)where;
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*where++ = 0x48000000 | (distance & 0x03fffffc);
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/*
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* Icache invalidation is not done for each entry here
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* because we sync the entire code part of the PLT once
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* in _rtld_setup_pltgot() after all the entries have been
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* initialized.
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*/
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/* __syncicache(where - 3, 12); */
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}
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}
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#endif /* !_LP64 */
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return 0;
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}
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static int
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_rtld_relocate_plt_object(const Obj_Entry *obj, const Elf_Rela *rela, int reloff, Elf_Addr *tp)
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{
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Elf_Word *where = (Elf_Word *)(obj->relocbase + rela->r_offset);
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Elf_Addr value;
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const Elf_Sym *def;
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const Obj_Entry *defobj;
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unsigned long info = rela->r_info;
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assert(ELF_R_TYPE(info) == R_TYPE(JMP_SLOT));
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def = _rtld_find_plt_symdef(ELF_R_SYM(info), obj, &defobj, tp != NULL);
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if (__predict_false(def == NULL))
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return -1;
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if (__predict_false(def == &_rtld_sym_zero))
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return 0;
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if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
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if (tp == NULL)
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return 0;
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value = _rtld_resolve_ifunc(defobj, def);
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} else {
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value = (Elf_Addr)(defobj->relocbase + def->st_value);
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}
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rdbg(("bind now/fixup in %s --> new=%p",
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defobj->strtab + def->st_name, (void *)value));
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#ifdef _LP64
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/*
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* For PowerPC64 we simply replace the function descriptor in the
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* PLTGOT with the one from source object.
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*/
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assert(where >= (Elf_Word *)obj->pltgot);
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assert(where < (Elf_Word *)obj->pltgot + (obj->pltrelalim - obj->pltrela));
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const Elf_Addr * const fdesc = (Elf_Addr *) value;
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where[0] = fdesc[0];
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where[1] = fdesc[1];
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where[2] = fdesc[2];
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#else
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ptrdiff_t distance = value - (Elf_Addr)where;
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if (obj->gotptr != NULL) {
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/*
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* For Secure-PLT we simply replace the entry in GOT with the
|
|
* address of the routine.
|
|
*/
|
|
assert(where >= (Elf_Word *)obj->pltgot);
|
|
assert(where < (Elf_Word *)obj->pltgot + (obj->pltrelalim - obj->pltrela));
|
|
*where = value;
|
|
} else if (labs(distance) < 32*1024*1024) { /* inside 32MB? */
|
|
/* b value # branch directly */
|
|
*where = 0x48000000 | (distance & 0x03fffffc);
|
|
__syncicache(where, 4);
|
|
} else {
|
|
Elf_Addr *pltcall, *jmptab;
|
|
int N = obj->pltrelalim - obj->pltrela;
|
|
|
|
/* Entries beyond 8192 take twice as much space. */
|
|
if (N > 8192)
|
|
N += N-8192;
|
|
|
|
pltcall = obj->pltgot;
|
|
jmptab = pltcall + 18 + N * 2;
|
|
|
|
jmptab[reloff] = value;
|
|
|
|
if (reloff < 32768) {
|
|
/* li r11,reloff */
|
|
*where++ = 0x39600000 | reloff;
|
|
} else {
|
|
#ifdef notyet
|
|
/* lis r11,ha(value) */
|
|
/* addi r11,lo(value) */
|
|
/* mtctr r11 */
|
|
/* bctr */
|
|
*where++ = 0x3d600000 | ha(value);
|
|
*where++ = 0x396b0000 | lo(value);
|
|
*where++ = 0x7d6903a6;
|
|
*where++ = 0x4e800420;
|
|
#else
|
|
/* lis r11,ha(reloff) */
|
|
/* addi r11,lo(reloff) */
|
|
*where++ = 0x3d600000 | ha(reloff);
|
|
*where++ = 0x396b0000 | lo(reloff);
|
|
#endif
|
|
}
|
|
/* b pltcall */
|
|
distance = (Elf_Addr)pltcall - (Elf_Addr)where;
|
|
*where++ = 0x48000000 | (distance & 0x03fffffc);
|
|
__syncicache(where - 3, 12);
|
|
}
|
|
#endif /* _LP64 */
|
|
|
|
if (tp)
|
|
*tp = value;
|
|
return 0;
|
|
}
|
|
|
|
Elf_Addr
|
|
_rtld_bind(const Obj_Entry *obj, Elf_Word reloff)
|
|
{
|
|
const Elf_Rela *rela = obj->pltrela + reloff;
|
|
Elf_Addr new_value;
|
|
int err;
|
|
|
|
new_value = 0; /* XXX gcc */
|
|
|
|
_rtld_shared_enter();
|
|
err = _rtld_relocate_plt_object(obj, rela, reloff, &new_value);
|
|
if (err)
|
|
_rtld_die();
|
|
_rtld_shared_exit();
|
|
|
|
#ifdef _LP64
|
|
return obj->glink;
|
|
#else
|
|
return new_value;
|
|
#endif
|
|
}
|
|
|
|
int
|
|
_rtld_relocate_plt_objects(const Obj_Entry *obj)
|
|
{
|
|
const Elf_Rela *rela;
|
|
int reloff;
|
|
|
|
for (rela = obj->pltrela, reloff = 0; rela < obj->pltrelalim; rela++, reloff++) {
|
|
if (_rtld_relocate_plt_object(obj, rela, reloff, NULL) < 0)
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|