Don't allow text relocations on 64-bit.
I've also updated our <sys/exec_elf.h> to match upstream.
Change-Id: I52f9fce3167541811208d273ff23ceaa112f7135
diff --git a/libc/include/sys/exec_elf.h b/libc/include/sys/exec_elf.h
index 6d445bf..ec54a60 100644
--- a/libc/include/sys/exec_elf.h
+++ b/libc/include/sys/exec_elf.h
@@ -1,4 +1,4 @@
-/* $NetBSD: exec_elf.h,v 1.126 2012/08/05 01:43:59 matt Exp $ */
+/* $NetBSD: exec_elf.h,v 1.129 2013/09/10 16:24:02 matt Exp $ */
/*-
* Copyright (c) 1994 The NetBSD Foundation, Inc.
@@ -429,6 +429,13 @@
#define SHT_HIOS 0x6fffffff
#define SHT_LOPROC 0x70000000 /* Processor-specific range */
#define SHT_AMD64_UNWIND 0x70000001 /* unwind information */
+#define SHT_ARM_EXIDX 0x70000001 /* exception index table */
+#define SHT_ARM_PREEMPTMAP 0x70000002 /* BPABI DLL dynamic linking
+ * pre-emption map */
+#define SHT_ARM_ATTRIBUTES 0x70000003 /* Object file compatibility
+ * attributes */
+#define SHT_ARM_DEBUGOVERLAY 0x70000004 /* See DBGOVL for details */
+#define SHT_ARM_OVERLAYSECTION 0x70000005
#define SHT_HIPROC 0x7fffffff
#define SHT_LOUSER 0x80000000 /* Application-specific range */
#define SHT_HIUSER 0xffffffff
@@ -668,7 +675,12 @@
#define DT_FINI_ARRAY 26 /* Size, in bytes, of DT_INIT_ARRAY array */
#define DT_INIT_ARRAYSZ 27 /* Address of termination function array */
#define DT_FINI_ARRAYSZ 28 /* Size, in bytes, of DT_FINI_ARRAY array*/
-#define DT_NUM 29
+#define DT_RUNPATH 29 /* overrides DT_RPATH */
+#define DT_FLAGS 30 /* Encodes ORIGIN, SYMBOLIC, TEXTREL, BIND_NOW, STATIC_TLS */
+#define DT_ENCODING 31 /* ??? */
+#define DT_PREINIT_ARRAY 32 /* Address of pre-init function array */
+#define DT_PREINIT_ARRAYSZ 33 /* Size, in bytes, of DT_PREINIT_ARRAY array */
+#define DT_NUM 34
#define DT_LOOS 0x60000000 /* Operating system specific range */
#define DT_VERSYM 0x6ffffff0 /* Symbol versions */
@@ -802,7 +814,7 @@
* GNU-specific note type: Build ID generated by ld
* name: GNU\0
* desc:
- * word[0..4] SHA1 [default]
+ * word[0..4] SHA1 [default]
* or
* word[0..3] md5 or uuid
* descsz: 16 or 20
@@ -829,7 +841,7 @@
/* SuSE-specific note type: version
* name: SuSE\0\0\0\0
* namesz: 8
- * desc:
+ * desc:
* word[0] = VVTTMMmm
*
* V = version of following data
@@ -848,7 +860,7 @@
/* NetBSD-specific note type: Emulation name.
* name: NetBSD\0\0
* namesz: 8
- * desc:
+ * desc:
* word[0]: MMmmrrpp00
*
* M = major version
@@ -864,7 +876,7 @@
/* NetBSD-specific note name */
#define ELF_NOTE_NETBSD_NAME "NetBSD\0\0"
-/* NetBSD-specific note type: Checksum.
+/* NetBSD-specific note type: Checksum.
* There should be 1 NOTE per PT_LOAD section.
* name: ???
* namesz: ???
@@ -953,6 +965,20 @@
int32_t cpi_siglwp; /* LWP target of killing signal */
};
+/*
+ * NetBSD-specific note type: MACHINE_ARCH.
+ * There should be 1 NOTE per executable.
+ * name: NetBSD\0
+ * namesz: 7
+ * desc: string
+ * descsz: variable
+ */
+#define ELF_NOTE_TYPE_MARCH_TAG 5
+/* NetBSD-specific note name and description sizes */
+#define ELF_NOTE_MARCH_NAMESZ ELF_NOTE_NETBSD_NAMESZ
+/* NetBSD-specific note name */
+#define ELF_NOTE_MARCH_NAME ELF_NOTE_NETBSD_NAME
+
#if !defined(ELFSIZE) && defined(ARCH_ELFSIZE)
#define ELFSIZE ARCH_ELFSIZE
#endif
@@ -1067,7 +1093,7 @@
#define SYMINFO_NUM 2
/*
- * These constants are used for Elf32_Verdef struct's version number.
+ * These constants are used for Elf32_Verdef struct's version number.
*/
#define VER_DEF_NONE 0
#define VER_DEF_CURRENT 1
@@ -1078,7 +1104,7 @@
#define VER_DEF_IDX(x) VER_NDX(x)
/*
- * These constants are used for Elf32_Verdef struct's vd_flags.
+ * These constants are used for Elf32_Verdef struct's vd_flags.
*/
#define VER_FLG_BASE 0x1
#define VER_FLG_WEAK 0x2
@@ -1091,7 +1117,7 @@
#define VER_NDX_GIVEN 2
/*
- * These constants are used for Elf32_Verneed struct's version number.
+ * These constants are used for Elf32_Verneed struct's version number.
*/
#define VER_NEED_NONE 0
#define VER_NEED_CURRENT 1
diff --git a/linker/dlfcn.cpp b/linker/dlfcn.cpp
index 166efac..09f3ddf 100644
--- a/linker/dlfcn.cpp
+++ b/linker/dlfcn.cpp
@@ -295,6 +295,8 @@
{ .l_addr = 0, .l_name = 0, .l_ld = 0, .l_next = 0, .l_prev = 0, },
.constructors_called = false,
.load_bias = 0,
+#if !defined(__LP64__)
.has_text_relocations = false,
+#endif
.has_DT_SYMBOLIC = true,
};
diff --git a/linker/linker.cpp b/linker/linker.cpp
index 5a4f20f..6bf18ac 100755
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -1548,25 +1548,32 @@
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 @@
}
*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 @@
return false;
}
}
+#endif
#if defined(USE_RELA)
if (si->plt_rela != NULL) {
@@ -1713,15 +1719,16 @@
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) {
diff --git a/linker/linker.h b/linker/linker.h
index 4ba354d..b9e1237 100644
--- a/linker/linker.h
+++ b/linker/linker.h
@@ -183,7 +183,9 @@
// value to get the corresponding address in the process' address space.
Elf_Addr load_bias;
+#if !defined(__LP64__)
bool has_text_relocations;
+#endif
bool has_DT_SYMBOLIC;
void CallConstructors();
@@ -195,15 +197,16 @@
void CallFunction(const char* function_name, linker_function_t function);
};
-extern soinfo libdl_info;
+// The possible DT_FLAGS bits are in
+// http://www.sco.com/developers/gabi/latest/ch5.dynamic.html#dynamic_section
+// but not in the upstream NetBSD <sys/exec_elf.h> header file ours is based on.
+#define DF_ORIGIN 0x1
+#define DF_SYMBOLIC 0x2
+#define DF_TEXTREL 0x4
+#define DF_BIND_NOW 0x8
+#define DF_STATIC_TLS 0x10
-// These aren't defined in <sys/exec_elf.h>.
-#ifndef DT_PREINIT_ARRAY
-#define DT_PREINIT_ARRAY 32
-#endif
-#ifndef DT_PREINIT_ARRAYSZ
-#define DT_PREINIT_ARRAYSZ 33
-#endif
+extern soinfo libdl_info;
void do_android_update_LD_LIBRARY_PATH(const char* ld_library_path);
soinfo* do_dlopen(const char* name, int flags);
