libvndksupport: Add android_is_in_vendor_process()
In preparation for cleaning up conditionally compiled VNDK libraries,
we need a function that determines if the current process is running in
the system process or the vendor process.
Bug: 119423884
Test: Add a dummy VNDK library that prints different string in system
vs vendor process. Use the library in different processs and
check the output.
Change-Id: Ic00927d8eadd2a21fcba9cb64cc93eaadd5bdd2d
diff --git a/libvndksupport/include/vndksupport/linker.h b/libvndksupport/include/vndksupport/linker.h
index f509564..5f48c39 100644
--- a/libvndksupport/include/vndksupport/linker.h
+++ b/libvndksupport/include/vndksupport/linker.h
@@ -20,6 +20,16 @@
extern "C" {
#endif
+/*
+ * Returns whether the current process is a vendor process.
+ *
+ * Note that this is only checking what process is running and has nothing to
+ * do with what namespace the caller is loaded at. For example, a VNDK-SP
+ * library loaded by SP-HAL calling this function may still get a 'false',
+ * because it is running in a system process.
+ */
+int android_is_in_vendor_process();
+
void* android_load_sphal_library(const char* name, int flag);
int android_unload_sphal_library(void* handle);
diff --git a/libvndksupport/libvndksupport.map.txt b/libvndksupport/libvndksupport.map.txt
index d3db10f..ac9a99c 100644
--- a/libvndksupport/libvndksupport.map.txt
+++ b/libvndksupport/libvndksupport.map.txt
@@ -1,5 +1,6 @@
LIBVNDKSUPPORT {
global:
+ android_is_in_vendor_process; # vndk apex
android_load_sphal_library; # vndk apex
android_unload_sphal_library; # vndk apex
local:
diff --git a/libvndksupport/linker.c b/libvndksupport/linker.c
index bc5620b..821940a 100644
--- a/libvndksupport/linker.c
+++ b/libvndksupport/linker.c
@@ -45,6 +45,17 @@
return vendor_namespace;
}
+int android_is_in_vendor_process() {
+ 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) {