libhardware: sensors: update multi hal to support 64bit builds

To get multi hal working on both 32 & 64 bit targets,
removing hardcoded paths & checks in multi HAL.

Sensor HAL libs must be installed path that is available through
LD_LIBRARY_PATH.
/system/lib & /system/vendor/lib for 32-bit targets.
/system/lib64 & /system/vendor/lib64 for 64-bit targets.

Change-Id: Ib1c1f25f08855c4584d53cc04fbe82a3a768b180

2 files changed, 15 insertions, 35 deletions

diff --git a/modules/sensors/Android.mk b/modules/sensors/Android.mk
index 445f69e..94d100b 100644
--- a/modules/sensors/Android.mk
+++ b/modules/sensors/Android.mk
@@ -20,9 +20,9 @@ ifeq ($(USE_SENSOR_MULTI_HAL),true)
 
 include $(CLEAR_VARS)
 
-LOCAL_MODULE := sensors.$(TARGET_DEVICE)
+LOCAL_MODULE := sensors.$(TARGET_BOARD_PLATFORM)
 
-LOCAL_MODULE_PATH := $(TARGET_OUT_SHARED_LIBRARIES)/hw
+LOCAL_MODULE_RELATIVE_PATH := hw
 
 LOCAL_CFLAGS := -DLOG_TAG=\"MultiHal\"
 
diff --git a/modules/sensors/multihal.cpp b/modules/sensors/multihal.cpp
index cd67f6d..5fedd4d 100644
--- a/modules/sensors/multihal.cpp
+++ b/modules/sensors/multihal.cpp
@@ -27,6 +27,8 @@
 #include <cutils/log.h>
 
 #include <vector>
+#include <string>
+#include <fstream>
 #include <map>
 #include <string>
 
@@ -36,8 +38,6 @@
 
 
 static const char* CONFIG_FILENAME = "/system/etc/sensors/hals.conf";
-static const char* LEGAL_SUBHAL_PATH_PREFIX = "/system/lib/hw/";
-static const char* LEGAL_SUBHAL_ALTERNATE_PATH_PREFIX = "/system/vendor/lib/";
 static const int MAX_CONF_LINE_LENGTH = 1024;
 
 static pthread_mutex_t init_modules_mutex = PTHREAD_MUTEX_INITIALIZER;
@@ -463,39 +463,19 @@ static bool starts_with(const char* s, const char* prefix) {
  * Adds valid paths from the config file to the vector passed in.
  * The vector must not be null.
  */
-static void get_so_paths(std::vector<char*> *so_paths) {
-    FILE *conf_file = fopen(CONFIG_FILENAME, "r");
-    if (conf_file == NULL) {
+static void get_so_paths(std::vector<std::string> *so_paths) {
+    std::string line;
+    std::ifstream conf_file(CONFIG_FILENAME);
+
+    if(!conf_file) {
         ALOGW("No multihal config file found at %s", CONFIG_FILENAME);
         return;
     }
     ALOGV("Multihal config file found at %s", CONFIG_FILENAME);
-    char *line = NULL;
-    size_t len = 0;
-    int line_count = 0;
-    while (getline(&line, &len, conf_file) != -1) {
-        // overwrite trailing eoln with null char
-        char* pch = strchr(line, '\n');
-        if (pch != NULL) {
-            *pch = '\0';
-        }
-        ALOGV("config file line #%d: '%s'", ++line_count, line);
-        char *real_path = realpath(line, NULL);
-        if (starts_with(real_path, LEGAL_SUBHAL_PATH_PREFIX) ||
-		starts_with(real_path, LEGAL_SUBHAL_ALTERNATE_PATH_PREFIX)) {
-            ALOGV("accepting valid path '%s'", real_path);
-            char* compact_line = new char[strlen(real_path) + 1];
-            strcpy(compact_line, real_path);
-            so_paths->push_back(compact_line);
-        } else {
-            ALOGW("rejecting path '%s' because it does not start with '%s' or '%s'",
-                    real_path, LEGAL_SUBHAL_PATH_PREFIX, LEGAL_SUBHAL_ALTERNATE_PATH_PREFIX);
-        }
-        free(real_path);
+    while (std::getline(conf_file, line)) {
+        ALOGV("config file line: '%s'", line.c_str());
+        so_paths->push_back(line);
     }
-    free(line);
-    fclose(conf_file);
-    ALOGV("hals.conf contained %d lines", line_count);
 }
 
 /*
@@ -508,15 +488,15 @@ static void lazy_init_modules() {
         pthread_mutex_unlock(&init_modules_mutex);
         return;
     }
-    std::vector<char*> *so_paths = new std::vector<char*>();
+    std::vector<std::string> *so_paths = new std::vector<std::string>();
     get_so_paths(so_paths);
 
     // dlopen the module files and cache their module symbols in sub_hw_modules
     sub_hw_modules = new std::vector<hw_module_t *>();
     dlerror(); // clear any old errors
     const char* sym = HAL_MODULE_INFO_SYM_AS_STR;
-    for (std::vector<char*>::iterator it = so_paths->begin(); it != so_paths->end(); it++) {
-        char* path = *it;
+    for (std::vector<std::string>::iterator it = so_paths->begin(); it != so_paths->end(); it++) {
+        const char* path = it->c_str();
         void* lib_handle = dlopen(path, RTLD_LAZY);
         if (lib_handle == NULL) {
             ALOGW("dlerror(): %s", dlerror());