platform_system_core/libvndksupport/linker.c
Jayant Chowdhary a229d3e23e Special case init for android_is_in_vendor_process.
Init is executed without ld.config.<ver>.txt loaded (since sysprop
service isn't up in order for it to read ro.vndk.version and know <ver>). It uses the hard-coded
namespaces in the linker and therefore, does not know about the vndk namespace. That does not mean
it is not a system process.

Bug: 124128212

Test: Boot up device with selinux enforced, use camera to take pictures/ record videos (sanity)
Test: Watch movies on youtube (sanity)

Change-Id: If8701af2ee5dfa3bb36d0ce0a17a23808d184d9f
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>
2019-03-11 11:18:06 -07:00

88 lines
3 KiB
C

/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "linker.h"
#include <android/dlext.h>
#include <dlfcn.h>
#define LOG_TAG "vndksupport"
#include <log/log.h>
#include <sys/types.h>
#include <unistd.h>
__attribute__((weak)) extern struct android_namespace_t* android_get_exported_namespace(const char*);
__attribute__((weak)) extern void* android_dlopen_ext(const char*, int, const android_dlextinfo*);
static const char* namespace_name = NULL;
static struct android_namespace_t* get_vendor_namespace() {
const char* namespace_names[] = {"sphal", "default", NULL};
static struct android_namespace_t* vendor_namespace = NULL;
if (vendor_namespace == NULL) {
int name_idx = 0;
while (namespace_names[name_idx] != NULL) {
if (android_get_exported_namespace != NULL) {
vendor_namespace = android_get_exported_namespace(namespace_names[name_idx]);
}
if (vendor_namespace != NULL) {
namespace_name = namespace_names[name_idx];
break;
}
name_idx++;
}
}
return vendor_namespace;
}
int android_is_in_vendor_process() {
// Special case init, since when init runs, ld.config.<ver>.txt hasn't been
// loaded (sysprop service isn't up for init to know <ver>).
if (getpid() == 1) {
return 0;
}
if (android_get_exported_namespace == NULL) {
ALOGD("android_get_exported_namespace() not available. Assuming system process.");
return 0;
}
// In vendor process, 'vndk' namespace is not visible, whereas in system
// process, it is.
return android_get_exported_namespace("vndk") == NULL;
}
void* android_load_sphal_library(const char* name, int flag) {
struct android_namespace_t* vendor_namespace = get_vendor_namespace();
if (vendor_namespace != NULL) {
const android_dlextinfo dlextinfo = {
.flags = ANDROID_DLEXT_USE_NAMESPACE, .library_namespace = vendor_namespace,
};
void* handle = NULL;
if (android_dlopen_ext != NULL) {
handle = android_dlopen_ext(name, flag, &dlextinfo);
}
if (!handle) {
ALOGE("Could not load %s from %s namespace: %s.", name, namespace_name, dlerror());
}
return handle;
} else {
ALOGD("Loading %s from current namespace instead of sphal namespace.", name);
return dlopen(name, flag);
}
}
int android_unload_sphal_library(void* handle) {
return dlclose(handle);
}