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am 673c092e: am 54830578: am f34ecbff: Merge "MIPS support to the linker"

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* commit '673c092e0fc40afa291086d06ab39a6d22e7f894':
  MIPS support to the linker
This commit is contained in:
Elliott Hughes 2012-08-02 15:43:44 -07:00 committed by Android Git Automerger
commit 0b8dda0e42
7 changed files with 311 additions and 56 deletions
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15
linker/Android.mk
View File

@ -16,7 +16,8 @@ LOCAL_LDFLAGS := -shared
LOCAL_CFLAGS += -fno-stack-protector \
-Wstrict-overflow=5 \
-fvisibility=hidden \
-std=gnu99
-std=gnu99 \
-Wall -Wextra
# Set LINKER_DEBUG to either 1 or 0
#
@ -33,11 +34,15 @@ LOCAL_CFLAGS += \
-I$(LOCAL_PATH)/../libc/arch-$(TARGET_ARCH)/bionic
ifeq ($(TARGET_ARCH),arm)
LOCAL_CFLAGS += -DANDROID_ARM_LINKER
else
ifeq ($(TARGET_ARCH),x86)
LOCAL_CFLAGS += -DANDROID_ARM_LINKER
endif
ifeq ($(TARGET_ARCH),x86)
LOCAL_CFLAGS += -DANDROID_X86_LINKER
endif
endif
ifeq ($(TARGET_ARCH),mips)
LOCAL_CFLAGS += -DANDROID_MIPS_LINKER
endif
LOCAL_MODULE:= linker

107
linker/arch/mips/begin.S Normal file
View File

@ -0,0 +1,107 @@
/*
* Copyright (C) 2012 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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
* COPYRIGHT OWNER OR 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.
*/
.text
.align 4
.type __start,@function
.ent __start
.globl __start
__start:
.set noreorder
bal 1f
nop
1: .cpload $31
.set reorder
/* Discover the load address */
la $t0, 1f
bal 1f
1: subu $t0, $ra, $t0
#define DT_PLTGOT 3
#define DT_MIPS_LOCAL_GOTNO 0x7000000a
/* Search dynamic table for DT_MIPS_LOCAL_GOTNO and DT_PLTGOT values */
la $t1, _DYNAMIC
addu $t1, $t0
li $t3, DT_PLTGOT
li $t4, DT_MIPS_LOCAL_GOTNO
0:
lw $t2, 0($t1)
beqz $t2, .Lrelocate_local_got
bne $t2, $t3, 1f /* DT_PLTGOT? */
lw $s0, 4($t1)
addu $s0, $t0
b 2f
1: bne $t2, $t4, 1f /* DT_MIPS_LOCAL_GOTNO? */
lw $s1, 4($t1)
b 2f
1:
2: addu $t1, 8
b 0b
.Lrelocate_local_got:
/*
* Relocate the local GOT entries
* got[0] is address of lazy resolver function
* got[1] may be used for a GNU extension
*/
addu $s0, 4
subu $s1, 1
lw $t1, ($s0)
bgez $t1, 9f
addu $s0, 4
subu $s1, 1
b 9f
1: lw $t1, ($s0)
addu $t1, $t0
sw $t1, ($s0)
addu $s0, 4
9: subu $s1, 1
bgez $s1, 1b
/* call linker_init */
move $a0, $sp
addiu $sp, -4*4 /* space for arg saves in linker_init */
la $t9, __linker_init
jalr $t9
move $t9, $v0
addu $sp, 4*4 /* restore sp */
j $t9
.end __start
.section .ctors, "wa"
.globl __CTOR_LIST__
__CTOR_LIST__:
.long -1

6
linker/debugger.c
View File

@ -131,7 +131,9 @@ static void logSignalSummary(int signum, const siginfo_t* info)
case SIGBUS: signame = "SIGBUS"; break;
case SIGFPE: signame = "SIGFPE"; break;
case SIGSEGV: signame = "SIGSEGV"; break;
#if defined(SIGSTKFLT)
case SIGSTKFLT: signame = "SIGSTKFLT"; break;
#endif
case SIGPIPE: signame = "SIGPIPE"; break;
default: signame = "???"; break;
}
@ -214,7 +216,9 @@ void debugger_signal_handler(int n, siginfo_t* info, void* unused)
case SIGABRT:
case SIGFPE:
case SIGPIPE:
#ifdef SIGSTKFLT
case SIGSTKFLT:
#endif
(void) tgkill(getpid(), gettid(), n);
break;
default: // SIGILL, SIGBUS, SIGSEGV
@ -235,6 +239,8 @@ void debugger_init()
sigaction(SIGBUS, &act, NULL);
sigaction(SIGFPE, &act, NULL);
sigaction(SIGSEGV, &act, NULL);
#if defined(SIGSTKFLT)
sigaction(SIGSTKFLT, &act, NULL);
#endif
sigaction(SIGPIPE, &act, NULL);
}

6
linker/dlfcn.c
View File

@ -170,13 +170,13 @@ int dlclose(void *handle)
#define ANDROID_LIBDL_STRTAB \
"dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0dl_unwind_find_exidx\0"
#elif defined(ANDROID_X86_LINKER)
#elif defined(ANDROID_X86_LINKER) || defined(ANDROID_MIPS_LINKER)
// 0000000 00011111 111112 22222222 2333333 3333444444444455
// 0123456 78901234 567890 12345678 9012345 6789012345678901
#define ANDROID_LIBDL_STRTAB \
"dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0dl_iterate_phdr\0"
#else
#error Unsupported architecture. Only ARM and x86 are presently supported.
#error Unsupported architecture. Only ARM, MIPS, and x86 are presently supported.
#endif
@ -218,7 +218,7 @@ static Elf32_Sym libdl_symtab[] = {
st_info: STB_GLOBAL << 4,
st_shndx: 1,
},
#elif defined(ANDROID_X86_LINKER)
#elif defined(ANDROID_X86_LINKER) || defined(ANDROID_MIPS_LINKER)
{ st_name: 36,
st_value: (Elf32_Addr) &dl_iterate_phdr,
st_info: STB_GLOBAL << 4,

159
linker/linker.c
View File

@ -350,7 +350,7 @@ _Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc, int *pcount)
*pcount = 0;
return NULL;
}
#elif defined(ANDROID_X86_LINKER)
#elif defined(ANDROID_X86_LINKER) || defined(ANDROID_MIPS_LINKER)
/* Here, we only have to provide a callback to iterate across all the
* loaded libraries. gcc_eh does the rest. */
int
@ -455,7 +455,7 @@ soinfo_do_lookup(soinfo *si, const char *name, Elf32_Addr *offset)
lsi = (soinfo *)d[1];
if (!validate_soinfo(lsi)) {
DL_ERR("%5d bad DT_NEEDED pointer in %s",
pid, si->name);
pid, lsi->name);
return NULL;
}
@ -691,6 +691,8 @@ verify_elf_header(const Elf32_Ehdr* hdr)
if (hdr->e_machine != EM_ARM) return -1;
#elif defined(ANDROID_X86_LINKER)
if (hdr->e_machine != EM_386) return -1;
#elif defined(ANDROID_MIPS_LINKER)
if (hdr->e_machine != EM_MIPS) return -1;
#endif
return 0;
}
@ -975,7 +977,7 @@ static int soinfo_relocate(soinfo *si, Elf32_Rel *rel, unsigned count)
Elf32_Rel *start = rel;
unsigned idx;
for (idx = 0; idx < count; ++idx) {
for (idx = 0; idx < count; ++idx, ++rel) {
unsigned type = ELF32_R_TYPE(rel->r_info);
unsigned sym = ELF32_R_SYM(rel->r_info);
unsigned reloc = (unsigned)(rel->r_offset + si->load_bias);
@ -984,6 +986,9 @@ static int soinfo_relocate(soinfo *si, Elf32_Rel *rel, unsigned count)
DEBUG("%5d Processing '%s' relocation at index %d\n", pid,
si->name, idx);
if (type == 0) { // R_*_NONE
continue;
}
if(sym != 0) {
sym_name = (char *)(strtab + symtab[sym].st_name);
s = soinfo_do_lookup(si, sym_name, &offset);
@ -1015,9 +1020,8 @@ static int soinfo_relocate(soinfo *si, Elf32_Rel *rel, unsigned count)
case R_ARM_GLOB_DAT:
case R_ARM_ABS32:
case R_ARM_RELATIVE: /* Don't care. */
case R_ARM_NONE: /* Don't care. */
#elif defined(ANDROID_X86_LINKER)
case R_386_JUMP_SLOT:
case R_386_JMP_SLOT:
case R_386_GLOB_DAT:
case R_386_32:
case R_386_RELATIVE: /* Dont' care. */
@ -1094,7 +1098,7 @@ static int soinfo_relocate(soinfo *si, Elf32_Rel *rel, unsigned count)
*((unsigned*)reloc) += sym_addr - rel->r_offset;
break;
#elif defined(ANDROID_X86_LINKER)
case R_386_JUMP_SLOT:
case R_386_JMP_SLOT:
COUNT_RELOC(RELOC_ABSOLUTE);
MARK(rel->r_offset);
TRACE_TYPE(RELO, "%5d RELO JMP_SLOT %08x <- %08x %s\n", pid,
@ -1108,6 +1112,25 @@ static int soinfo_relocate(soinfo *si, Elf32_Rel *rel, unsigned count)
reloc, sym_addr, sym_name);
*((unsigned*)reloc) = sym_addr;
break;
#elif defined(ANDROID_MIPS_LINKER)
case R_MIPS_JUMP_SLOT:
COUNT_RELOC(RELOC_ABSOLUTE);
MARK(rel->r_offset);
TRACE_TYPE(RELO, "%5d RELO JMP_SLOT %08x <- %08x %s\n", pid,
reloc, sym_addr, sym_name);
*((unsigned*)reloc) = sym_addr;
break;
case R_MIPS_REL32:
COUNT_RELOC(RELOC_ABSOLUTE);
MARK(rel->r_offset);
TRACE_TYPE(RELO, "%5d RELO REL32 %08x <- %08x %s\n", pid,
reloc, sym_addr, (sym_name) ? sym_name : "*SECTIONHDR*");
if (s) {
*((unsigned*)reloc) += sym_addr;
} else {
*((unsigned*)reloc) += si->base;
}
break;
#endif /* ANDROID_*_LINKER */
#if defined(ANDROID_ARM_LINKER)
@ -1154,8 +1177,6 @@ static int soinfo_relocate(soinfo *si, Elf32_Rel *rel, unsigned count)
reloc, s->st_size, sym_addr, sym_name);
memcpy((void*)reloc, (void*)sym_addr, s->st_size);
break;
case R_ARM_NONE:
break;
#endif /* ANDROID_ARM_LINKER */
default:
@ -1163,11 +1184,79 @@ static int soinfo_relocate(soinfo *si, Elf32_Rel *rel, unsigned count)
pid, type, rel, (int) (rel - start));
return -1;
}
rel++;
}
return 0;
}
#ifdef ANDROID_MIPS_LINKER
int mips_relocate_got(struct soinfo *si)
{
unsigned *got;
unsigned local_gotno, gotsym, symtabno;
Elf32_Sym *symtab, *sym;
unsigned g;
got = si->plt_got;
local_gotno = si->mips_local_gotno;
gotsym = si->mips_gotsym;
symtabno = si->mips_symtabno;
symtab = si->symtab;
/*
* got[0] is address of lazy resolver function
* got[1] may be used for a GNU extension
* set it to a recognisable address in case someone calls it
* (should be _rtld_bind_start)
* FIXME: maybe this should be in a separate routine
*/
if ((si->flags & FLAG_LINKER) == 0) {
g = 0;
got[g++] = 0xdeadbeef;
if (got[g] & 0x80000000) {
got[g++] = 0xdeadfeed;
}
/*
* Relocate the local GOT entries need to be relocated
*/
for (; g < local_gotno; g++) {
got[g] += si->load_bias;
}
}
/* Now for the global GOT entries */
sym = symtab + gotsym;
got = si->plt_got + local_gotno;
for (g = gotsym; g < symtabno; g++, sym++, got++) {
const char *sym_name;
unsigned base;
Elf32_Sym *s;
/* This is an undefined reference... try to locate it */
sym_name = si->strtab + sym->st_name;
s = soinfo_do_lookup(si, sym_name, &base);
if (s == NULL) {
/* We only allow an undefined symbol if this is a weak
reference.. */
s = &symtab[g];
if (ELF32_ST_BIND(s->st_info) != STB_WEAK) {
DL_ERR("%5d cannot locate '%s'...\n", pid, sym_name);
return -1;
}
*got = 0;
}
else {
/* FIXME: is this sufficient?
* For reference see NetBSD link loader
* http://cvsweb.netbsd.org/bsdweb.cgi/src/libexec/ld.elf_so/arch/mips/mips_reloc.c?rev=1.53&content-type=text/x-cvsweb-markup
*/
*got = base + s->st_value;
}
}
return 0;
}
#endif
/* Please read the "Initialization and Termination functions" functions.
* of the linker design note in bionic/linker/README.TXT to understand
* what the following code is doing.
@ -1442,8 +1531,10 @@ static int soinfo_link_image(soinfo *si, unsigned wr_offset)
si->plt_got = (unsigned *)(base + *d);
break;
case DT_DEBUG:
#if !defined(ANDROID_MIPS_LINKER)
// Set the DT_DEBUG entry to the addres of _r_debug for GDB
*d = (int) &_r_debug;
#endif
break;
case DT_RELA:
DL_ERR("%5d DT_RELA not supported", pid);
@ -1491,6 +1582,50 @@ static int soinfo_link_image(soinfo *si, unsigned wr_offset)
DEBUG("%5d Text segment should be writable during relocation.\n",
pid);
break;
#if defined(ANDROID_MIPS_LINKER)
case DT_NEEDED:
case DT_STRSZ:
case DT_SYMENT:
case DT_RELENT:
break;
case DT_MIPS_RLD_MAP:
/* Set the DT_MIPS_RLD_MAP entry to the addres of _r_debug for GDB */
{
struct r_debug **dp = (struct r_debug **)*d;
*dp = &_r_debug;
}
break;
case DT_MIPS_RLD_VERSION:
case DT_MIPS_FLAGS:
case DT_MIPS_BASE_ADDRESS:
case DT_MIPS_UNREFEXTNO:
case DT_MIPS_RWPLT:
break;
case DT_MIPS_PLTGOT:
#if 0
/* not yet... */
si->mips_pltgot = (unsigned *)(si->base + *d);
#endif
break;
case DT_MIPS_SYMTABNO:
si->mips_symtabno = *d;
break;
case DT_MIPS_LOCAL_GOTNO:
si->mips_local_gotno = *d;
break;
case DT_MIPS_GOTSYM:
si->mips_gotsym = *d;
break;
default:
DEBUG("%5d Unused DT entry: type 0x%08x arg 0x%08x\n",
pid, d[-1], d[0]);
break;
#endif
}
}
@ -1552,6 +1687,12 @@ static int soinfo_link_image(soinfo *si, unsigned wr_offset)
goto fail;
}
#ifdef ANDROID_MIPS_LINKER
if(mips_relocate_got(si)) {
goto fail;
}
#endif
si->flags |= FLAG_LINKED;
DEBUG("[ %5d finished linking %s ]\n", pid, si->name);

42
linker/linker.h
View File

@ -150,11 +150,19 @@ struct soinfo
void (*init_func)(void);
void (*fini_func)(void);
#ifdef ANDROID_ARM_LINKER
#if defined(ANDROID_ARM_LINKER)
/* ARM EABI section used for stack unwinding. */
unsigned *ARM_exidx;
unsigned ARM_exidx_count;
#elif defined(ANDROID_MIPS_LINKER)
#if 0
/* not yet */
unsigned *mips_pltgot
#endif
unsigned mips_symtabno;
unsigned mips_local_gotno;
unsigned mips_gotsym;
#endif /* ANDROID_*_LINKER */
unsigned refcount;
struct link_map linkmap;
@ -169,29 +177,31 @@ struct soinfo
extern soinfo libdl_info;
#ifdef ANDROID_ARM_LINKER
#include <asm/elf.h>
#if defined(ANDROID_ARM_LINKER)
// These aren't defined in <arch-arm/asm/elf.h>.
#define R_ARM_REL32 3
#define R_ARM_COPY 20
#define R_ARM_GLOB_DAT 21
#define R_ARM_JUMP_SLOT 22
#define R_ARM_RELATIVE 23
/* According to the AAPCS specification, we only
* need the above relocations. However, in practice,
* the following ones turn up from time to time.
*/
#define R_ARM_ABS32 2
#define R_ARM_REL32 3
#elif defined(ANDROID_MIPS_LINKER)
// These aren't defined in <arch-arm/mips/elf.h>.
#define R_MIPS_JUMP_SLOT 127
#define DT_MIPS_PLTGOT 0x70000032
#define DT_MIPS_RWPLT 0x70000034
#elif defined(ANDROID_X86_LINKER)
#define R_386_32 1
#define R_386_PC32 2
#define R_386_GLOB_DAT 6
#define R_386_JUMP_SLOT 7
#define R_386_RELATIVE 8
// x86 has everything it needs in <arch-arm/x86/elf.h>.
#endif
#endif /* ANDROID_*_LINKER */
#ifndef DT_INIT_ARRAY
#define DT_INIT_ARRAY 25
@ -227,10 +237,10 @@ Elf32_Sym *soinfo_find_symbol(soinfo* si, const void *addr);
Elf32_Sym *soinfo_lookup(soinfo *si, const char *name);
void soinfo_call_constructors(soinfo *si);
#ifdef ANDROID_ARM_LINKER
#if defined(ANDROID_ARM_LINKER)
typedef long unsigned int *_Unwind_Ptr;
_Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc, int *pcount);
#elif defined(ANDROID_X86_LINKER)
#elif defined(ANDROID_X86_LINKER) || defined(ANDROID_MIPS_LINKER)
int dl_iterate_phdr(int (*cb)(struct dl_phdr_info *, size_t, void *), void *);
#endif

14
linker/linker_format.c
View File

@ -413,20 +413,6 @@ format_integer(char *buffer, size_t buffsize, uint64_t value, int base, int isSi
format_number(buffer, buffsize, value, base, "0123456789");
}
/* Write an octal into a buffer, assumes buffsize > 2 */
static void
format_octal(char *buffer, size_t buffsize, uint64_t value, int isSigned)
{
format_integer(buffer, buffsize, value, 8, isSigned);
}
/* Write a decimal into a buffer, assumes buffsize > 2 */
static void
format_decimal(char *buffer, size_t buffsize, uint64_t value, int isSigned)
{
format_integer(buffer, buffsize, value, 10, isSigned);
}
/* Write an hexadecimal into a buffer, isCap is true for capital alphas.
* Assumes bufsize > 2 */
static void