linker: New sources to manage the ELF program header table.
This patch introduces two new source files containing a set of functions
to manage the program header table in an ELF binary, including the ability
to load PT_LOAD segments, and apply PT_GNU_RELRO protection.
Note: the files are not used currently, this will appear in a series
of future patches that will gradually modify linker.c to use
the phdr_table_xxx functions properly.
Change-Id: Ia3d4c1ff5fc3e265d8258b64b492f4e643f51bdc
diff --git a/linker/linker_phdr.h b/linker/linker_phdr.h
new file mode 100644
index 0000000..d542e46
--- /dev/null
+++ b/linker/linker_phdr.h
@@ -0,0 +1,112 @@
+/*
+ * 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.
+ */
+#ifndef LINKER_PHDR_H
+#define LINKER_PHDR_H
+
+/* Declarations related to the ELF program header table and segments.
+ *
+ * The design goal is to provide an API that is as close as possible
+ * to the ELF spec, and does not depend on linker-specific data
+ * structures (e.g. the exact layout of struct soinfo).
+ */
+
+#include "linker.h"
+
+/* See linker_phdr.c for all usage documentation */
+
+int
+phdr_table_load(int fd,
+ Elf32_Addr phdr_offset,
+ Elf32_Half phdr_num,
+ void** phdr_mmap,
+ Elf32_Addr* phdr_size,
+ const Elf32_Phdr** phdr_table);
+
+void
+phdr_table_unload(void* phdr_mmap, Elf32_Addr phdr_memsize);
+
+Elf32_Addr
+phdr_table_get_load_size(const Elf32_Phdr* phdr_table,
+ int phdr_count);
+
+int
+phdr_table_reserve_memory(const Elf32_Phdr* phdr_table,
+ int phdr_count,
+ Elf32_Addr required_base,
+ void** load_start,
+ Elf32_Addr* load_size,
+ Elf32_Addr* load_bias);
+
+int
+phdr_table_load_segments(const Elf32_Phdr* phdr_table,
+ int phdr_count,
+ void* load_start,
+ Elf32_Addr load_size,
+ Elf32_Addr load_bias,
+ int fd);
+
+int
+phdr_table_protect_segments(const Elf32_Phdr* phdr_table,
+ int phdr_count,
+ Elf32_Addr load_bias);
+
+int
+phdr_table_unprotect_segments(const Elf32_Phdr* phdr_table,
+ int phdr_count,
+ Elf32_Addr load_bias);
+
+int
+phdr_table_protect_gnu_relro(const Elf32_Phdr* phdr_table,
+ int phdr_count,
+ Elf32_Addr load_bias);
+
+int
+phdr_table_unprotect_gnu_relro(const Elf32_Phdr* phdr_table,
+ int phdr_count,
+ Elf32_Addr load_bias);
+
+const Elf32_Phdr*
+phdr_table_get_loaded_phdr(const Elf32_Phdr* phdr_table,
+ int phdr_count,
+ Elf32_Addr load_bias);
+
+#ifdef ANDROID_ARM_LINKER
+int
+phdr_table_get_arm_exidx(const Elf32_Phdr* phdr_table,
+ int phdr_count,
+ Elf32_Addr load_bias,
+ Elf32_Addr** arm_exidx,
+ unsigned* arm_exidix_count);
+#endif
+
+Elf32_Addr*
+phdr_table_get_dynamic_section(const Elf32_Phdr* phdr_table,
+ int phdr_count,
+ Elf32_Addr load_bias);
+
+#endif /* LINKER_PHDR_H */