commit 12bbb9164578b6512b8b07a3fb093858244b7c7b
author Torne (Richard Coles) <torne@google.com> Thu Feb 06 14:34:21 2014 +0000
committer Torne (Richard Coles) <torne@google.com> Thu Apr 17 14:22:17 2014 +0100
tree 2a32dc3fe2902444aed43647f0ab1d2612507296
parent 012cb4583a5f8564059142bb1900ea3a31e7cfa9

Support loading libraries to a reserved address.

Add flags and parameters to android_dlopen_ext() to allow loading a
library at an already-reserved fixed address. If the library to be
loaded will not fit within the space reserved, then the linker will
either fail, or allocate its own address space as usual, according to
which flag has been specified. This behaviour only applies to the
specific library requested; any other libraries loaded as dependencies
will be loaded in the normal fashion.

There is a new gtest included to cover the functionality added.

Bug: 13005501
Change-Id: I5d1810375b20fc51ba6a9b3191a25f9792c687f1

linker/linker.cpp

diff --git a/linker/linker.cpp b/linker/linker.cpp
index ba50d5c..85ef63b 100755
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -690,7 +690,7 @@
   return fd;
 }
 
-static soinfo* load_library(const char* name) {
+static soinfo* load_library(const char* name, const android_dlextinfo* extinfo) {
     // Open the file.
     int fd = open_library(name);
     if (fd == -1) {
@@ -700,7 +700,7 @@
 
     // Read the ELF header and load the segments.
     ElfReader elf_reader(name, fd);
-    if (!elf_reader.Load()) {
+    if (!elf_reader.Load(extinfo)) {
         return NULL;
     }
 
@@ -735,7 +735,7 @@
     return NULL;
 }
 
-static soinfo* find_library_internal(const char* name) {
+static soinfo* find_library_internal(const char* name, const android_dlextinfo* extinfo) {
   if (name == NULL) {
     return somain;
   }
@@ -750,7 +750,7 @@
   }
 
   TRACE("[ '%s' has not been loaded yet.  Locating...]", name);
-  si = load_library(name);
+  si = load_library(name, extinfo);
   if (si == NULL) {
     return NULL;
   }
@@ -769,8 +769,8 @@
   return si;
 }
 
-static soinfo* find_library(const char* name) {
-  soinfo* si = find_library_internal(name);
+static soinfo* find_library(const char* name, const android_dlextinfo* extinfo) {
+  soinfo* si = find_library_internal(name, extinfo);
   if (si != NULL) {
     si->ref_count++;
   }
@@ -821,7 +821,7 @@
     return NULL;
   }
   set_soinfo_pool_protection(PROT_READ | PROT_WRITE);
-  soinfo* si = find_library(name);
+  soinfo* si = find_library(name, extinfo);
   if (si != NULL) {
     si->CallConstructors();
   }
@@ -1803,7 +1803,7 @@
         memset(gLdPreloads, 0, sizeof(gLdPreloads));
         size_t preload_count = 0;
         for (size_t i = 0; gLdPreloadNames[i] != NULL; i++) {
-            soinfo* lsi = find_library(gLdPreloadNames[i]);
+            soinfo* lsi = find_library(gLdPreloadNames[i], NULL);
             if (lsi != NULL) {
                 gLdPreloads[preload_count++] = lsi;
             } else {
@@ -1821,7 +1821,7 @@
         if (d->d_tag == DT_NEEDED) {
             const char* library_name = si->strtab + d->d_un.d_val;
             DEBUG("%s needs %s", si->name, library_name);
-            soinfo* lsi = find_library(library_name);
+            soinfo* lsi = find_library(library_name, NULL);
             if (lsi == NULL) {
                 strlcpy(tmp_err_buf, linker_get_error_buffer(), sizeof(tmp_err_buf));
                 DL_ERR("could not load library \"%s\" needed by \"%s\"; caused by %s",