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Merge "Reenable support for non-PIE executables"

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Nick Kralevich 2014-06-19 17:04:12 +00:00 committed by Gerrit Code Review
commit 8a7cffc85d
1 changed files with 91 additions and 22 deletions
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113
linker/linker.cpp
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@ -59,6 +59,7 @@
*
* open issues / todo:
*
* - are we doing everything we should for ARM_COPY relocations?
* - cleaner error reporting
* - after linking, set as much stuff as possible to READONLY
* and NOEXEC
@ -1037,17 +1038,52 @@ static int soinfo_relocate(soinfo* si, ElfW(Rela)* rela, unsigned count, soinfo*
break;
case R_AARCH64_COPY:
/*
* ET_EXEC is not supported so this should not happen.
*
* http://infocenter.arm.com/help/topic/com.arm.doc.ihi0044d/IHI0044D_aaelf.pdf
*
* Section 4.7.1.10 "Dynamic relocations"
* R_AARCH64_COPY may only appear in executable objects where e_type is
* set to ET_EXEC.
*/
DL_ERR("%s R_AARCH64_COPY relocations are not supported", si->name);
return -1;
if ((si->flags & FLAG_EXE) == 0) {
/*
* http://infocenter.arm.com/help/topic/com.arm.doc.ihi0044d/IHI0044D_aaelf.pdf
*
* Section 4.7.1.10 "Dynamic relocations"
* R_AARCH64_COPY may only appear in executable objects where e_type is
* set to ET_EXEC.
*
* FLAG_EXE is set for both ET_DYN and ET_EXEC executables.
* We should explicitly disallow ET_DYN executables from having
* R_AARCH64_COPY relocations.
*/
DL_ERR("%s R_AARCH64_COPY relocations only supported for ET_EXEC", si->name);
return -1;
}
count_relocation(kRelocCopy);
MARK(rela->r_offset);
TRACE_TYPE(RELO, "RELO COPY %16llx <- %lld @ %16llx %s\n",
reloc,
s->st_size,
(sym_addr + rela->r_addend),
sym_name);
if (reloc == (sym_addr + rela->r_addend)) {
ElfW(Sym)* src = soinfo_do_lookup(NULL, sym_name, &lsi, needed);
if (src == NULL) {
DL_ERR("%s R_AARCH64_COPY relocation source cannot be resolved", si->name);
return -1;
}
if (lsi->has_DT_SYMBOLIC) {
DL_ERR("%s invalid R_AARCH64_COPY relocation against DT_SYMBOLIC shared "
"library %s (built with -Bsymbolic?)", si->name, lsi->name);
return -1;
}
if (s->st_size < src->st_size) {
DL_ERR("%s R_AARCH64_COPY relocation size mismatch (%lld < %lld)",
si->name, s->st_size, src->st_size);
return -1;
}
memcpy(reinterpret_cast<void*>(reloc),
reinterpret_cast<void*>(src->st_value + lsi->load_bias), src->st_size);
} else {
DL_ERR("%s R_AARCH64_COPY relocation target cannot be resolved", si->name);
return -1;
}
break;
case R_AARCH64_TLS_TPREL64:
TRACE_TYPE(RELO, "RELO TLS_TPREL64 *** %16llx <- %16llx - %16llx\n",
reloc, (sym_addr + rela->r_addend), rela->r_offset);
@ -1225,17 +1261,48 @@ static int soinfo_relocate(soinfo* si, ElfW(Rel)* rel, unsigned count, soinfo* n
*reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr - rel->r_offset;
break;
case R_ARM_COPY:
/*
* ET_EXEC is not supported so this should not happen.
*
* http://infocenter.arm.com/help/topic/com.arm.doc.ihi0044d/IHI0044D_aaelf.pdf
*
* Section 4.7.1.10 "Dynamic relocations"
* R_ARM_COPY may only appear in executable objects where e_type is
* set to ET_EXEC.
*/
DL_ERR("%s R_ARM_COPY relocations are not supported", si->name);
return -1;
if ((si->flags & FLAG_EXE) == 0) {
/*
* http://infocenter.arm.com/help/topic/com.arm.doc.ihi0044d/IHI0044D_aaelf.pdf
*
* Section 4.7.1.10 "Dynamic relocations"
* R_ARM_COPY may only appear in executable objects where e_type is
* set to ET_EXEC.
*
* TODO: FLAG_EXE is set for both ET_DYN and ET_EXEC executables.
* We should explicitly disallow ET_DYN executables from having
* R_ARM_COPY relocations.
*/
DL_ERR("%s R_ARM_COPY relocations only supported for ET_EXEC", si->name);
return -1;
}
count_relocation(kRelocCopy);
MARK(rel->r_offset);
TRACE_TYPE(RELO, "RELO %08x <- %d @ %08x %s", reloc, s->st_size, sym_addr, sym_name);
if (reloc == sym_addr) {
ElfW(Sym)* src = soinfo_do_lookup(NULL, sym_name, &lsi, needed);
if (src == NULL) {
DL_ERR("%s R_ARM_COPY relocation source cannot be resolved", si->name);
return -1;
}
if (lsi->has_DT_SYMBOLIC) {
DL_ERR("%s invalid R_ARM_COPY relocation against DT_SYMBOLIC shared "
"library %s (built with -Bsymbolic?)", si->name, lsi->name);
return -1;
}
if (s->st_size < src->st_size) {
DL_ERR("%s R_ARM_COPY relocation size mismatch (%d < %d)",
si->name, s->st_size, src->st_size);
return -1;
}
memcpy(reinterpret_cast<void*>(reloc),
reinterpret_cast<void*>(src->st_value + lsi->load_bias), src->st_size);
} else {
DL_ERR("%s R_ARM_COPY relocation target cannot be resolved", si->name);
return -1;
}
break;
#elif defined(__i386__)
case R_386_JMP_SLOT:
count_relocation(kRelocAbsolute);
@ -2105,11 +2172,13 @@ static ElfW(Addr) __linker_init_post_relocation(KernelArgumentBlock& args, ElfW(
si->dynamic = NULL;
si->ref_count = 1;
#if defined(__LP64__)
ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(si->base);
if (elf_hdr->e_type != ET_DYN) {
__libc_format_fd(2, "error: only position independent executables (PIE) are supported.\n");
exit(EXIT_FAILURE);
}
#endif
// Use LD_LIBRARY_PATH and LD_PRELOAD (but only if we aren't setuid/setgid).
parse_LD_LIBRARY_PATH(ldpath_env);