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MIPS support to the linker

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Change-Id: I37ec2d6c51d82bb9e9dbfef4b38c85366bead255
Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Raghu Gandham <raghu@mips.com>
Signed-off-by: Bhanu Chetlapalli <bhanu@mips.com>
This commit is contained in:
Raghu Gandham
2012-07-31 12:07:22 -07:00
committed by Elliott Hughes
parent 0ca9d0748e
commit d7daacb463
7 changed files with 311 additions and 56 deletions
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177
linker/linker.c
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@@ -142,9 +142,9 @@ static char tmp_err_buf[768];
static char __linker_dl_err_buf[768];
#define DL_ERR(fmt, x...) \
do { \
format_buffer(__linker_dl_err_buf, sizeof(__linker_dl_err_buf), \
format_buffer(__linker_dl_err_buf, sizeof(__linker_dl_err_buf), \
"%s[%d]: " fmt, __func__, __LINE__, ##x); \
ERROR(fmt "\n", ##x); \
ERROR(fmt "\n", ##x); \
} while(0)
const char *linker_get_error(void)
@@ -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. */
@@ -1046,15 +1050,15 @@ static int soinfo_relocate(soinfo *si, Elf32_Rel *rel, unsigned count)
} else {
/* We got a definition. */
#if 0
if((base == 0) && (si->base != 0)){
/* linking from libraries to main image is bad */
DL_ERR("%5d cannot locate '%s'...",
pid, strtab + symtab[sym].st_name);
return -1;
}
if((base == 0) && (si->base != 0)){
/* linking from libraries to main image is bad */
DL_ERR("%5d cannot locate '%s'...",
pid, strtab + symtab[sym].st_name);
return -1;
}
#endif
sym_addr = (unsigned)(s->st_value + offset);
}
}
COUNT_RELOC(RELOC_SYMBOL);
} else {
s = NULL;
@@ -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);