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Don't allow text relocations on 64-bit.

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I've also updated our <sys/exec_elf.h> to match upstream.

Change-Id: I52f9fce3167541811208d273ff23ceaa112f7135
This commit is contained in:
Elliott Hughes
2013-10-28 14:19:05 -07:00
parent 3ec5d8954b
commit e4d792adb8
4 changed files with 65 additions and 27 deletions
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27
linker/linker.cpp
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@@ -1548,25 +1548,32 @@ static bool soinfo_link_image(soinfo* si) {
si->preinit_array_count = ((unsigned)d->d_un.d_val) / sizeof(Elf_Addr);
break;
case DT_TEXTREL:
#if defined(__LP64__)
DL_ERR("text relocations (DT_TEXTREL) found in 64-bit ELF file \"%s\"", si->name);
return false;
#else
si->has_text_relocations = true;
break;
#endif
case DT_SYMBOLIC:
si->has_DT_SYMBOLIC = true;
break;
case DT_NEEDED:
++needed_count;
break;
#if defined DT_FLAGS
// TODO: why is DT_FLAGS not defined?
case DT_FLAGS:
if (d->d_un.d_val & DF_TEXTREL) {
#if defined(__LP64__)
DL_ERR("text relocations (DF_TEXTREL) found in 64-bit ELF file \"%s\"", si->name);
return false;
#else
si->has_text_relocations = true;
#endif
}
if (d->d_un.d_val & DF_SYMBOLIC) {
si->has_DT_SYMBOLIC = true;
}
break;
#endif
#if defined(__mips__)
case DT_STRSZ:
case DT_SYMENT:
@@ -1661,12 +1668,10 @@ static bool soinfo_link_image(soinfo* si) {
}
*pneeded = NULL;
#if !defined(__LP64__)
if (si->has_text_relocations) {
/* Unprotect the segments, i.e. make them writable, to allow
* text relocations to work properly. We will later call
* phdr_table_protect_segments() after all of them are applied
* and all constructors are run.
*/
// Make segments writable to allow text relocations to work properly. We will later call
// phdr_table_protect_segments() after all of them are applied and all constructors are run.
DL_WARN("%s has text relocations. This is wasting memory and prevents "
"security hardening. Please fix.", si->name);
if (phdr_table_unprotect_segments(si->phdr, si->phnum, si->load_bias) < 0) {
@@ -1675,6 +1680,7 @@ static bool soinfo_link_image(soinfo* si) {
return false;
}
}
#endif
#if defined(USE_RELA)
if (si->plt_rela != NULL) {
@@ -1713,15 +1719,16 @@ static bool soinfo_link_image(soinfo* si) {
si->flags |= FLAG_LINKED;
DEBUG("[ finished linking %s ]", si->name);
#if !defined(__LP64__)
if (si->has_text_relocations) {
/* All relocations are done, we can protect our segments back to
* read-only. */
// All relocations are done, we can protect our segments back to read-only.
if (phdr_table_protect_segments(si->phdr, si->phnum, si->load_bias) < 0) {
DL_ERR("can't protect segments for \"%s\": %s",
si->name, strerror(errno));
return false;
}
}
#endif
/* We can also turn on GNU RELRO protection */
if (phdr_table_protect_gnu_relro(si->phdr, si->phnum, si->load_bias) < 0) {