Merge "Zygote: Add Arm pointer authentication keychange support." (285dfb31) · Commits · e / os / android_frameworks_base

core/jni/com_android_internal_os_Zygote.cpp

+33 −0

Original line number	Diff line number	Diff line
		@@ -95,6 +95,19 @@

		#include "nativebridge/native_bridge.h"

		/* Functions in the callchain during the fork shall not be protected with
		Armv8.3-A Pointer Authentication, otherwise child will not be able to return. */
		#ifdef __ARM_FEATURE_PAC_DEFAULT
		#ifdef __ARM_FEATURE_BTI_DEFAULT
		#define NO_PAC_FUNC __attribute__((target("branch-protection=bti")))
		#else
		#define NO_PAC_FUNC __attribute__((target("branch-protection=none")))
		#endif /* __ARM_FEATURE_BTI_DEFAULT */
		#else /* !__ARM_FEATURE_PAC_DEFAULT */
		#define NO_PAC_FUNC
		#endif /* __ARM_FEATURE_PAC_DEFAULT */


		namespace {

		// TODO (chriswailes): Add a function to initialize native Zygote data.
		@@ -985,7 +998,23 @@ static void ClearUsapTable() {
		gUsapPoolCount = 0;
		}

		NO_PAC_FUNC
		static void PAuthKeyChange(JNIEnv* env) {
		#ifdef __aarch64__
		unsigned long int hwcaps = getauxval(AT_HWCAP);
		if (hwcaps & HWCAP_PACA) {
		const unsigned long key_mask = PR_PAC_APIAKEY \| PR_PAC_APIBKEY \|
		PR_PAC_APDAKEY \| PR_PAC_APDBKEY \| PR_PAC_APGAKEY;
		if (prctl(PR_PAC_RESET_KEYS, key_mask, 0, 0, 0) != 0) {
		ALOGE("Failed to change the PAC keys: %s", strerror(errno));
		RuntimeAbort(env, __LINE__, "PAC key change failed.");
		}
		}
		#endif
		}

		// Utility routine to fork a process from the zygote.
		NO_PAC_FUNC
		static pid_t ForkCommon(JNIEnv* env, bool is_system_server,
		const std::vector<int>& fds_to_close,
		const std::vector<int>& fds_to_ignore,
		@@ -1036,6 +1065,7 @@ static pid_t ForkCommon(JNIEnv* env, bool is_system_server,
		}

		// The child process.
		PAuthKeyChange(env);
		PreApplicationInit();

		// Clean up any descriptors which must be closed immediately
		@@ -1486,6 +1516,7 @@ static void com_android_internal_os_Zygote_nativePreApplicationInit(JNIEnv*, jcl
		PreApplicationInit();
		}

		NO_PAC_FUNC
		static jint com_android_internal_os_Zygote_nativeForkAndSpecialize(
		JNIEnv* env, jclass, jint uid, jint gid, jintArray gids,
		jint runtime_flags, jobjectArray rlimits,
		@@ -1533,6 +1564,7 @@ static jint com_android_internal_os_Zygote_nativeForkAndSpecialize(
		return pid;
		}

		NO_PAC_FUNC
		static jint com_android_internal_os_Zygote_nativeForkSystemServer(
		JNIEnv* env, jclass, uid_t uid, gid_t gid, jintArray gids,
		jint runtime_flags, jobjectArray rlimits, jlong permitted_capabilities,
		@@ -1600,6 +1632,7 @@ static jint com_android_internal_os_Zygote_nativeForkSystemServer(
		* @param is_priority_fork Controls the nice level assigned to the newly created process
		* @return
		*/
		NO_PAC_FUNC
		static jint com_android_internal_os_Zygote_nativeForkUsap(JNIEnv* env,
		jclass,
		jint read_pipe_fd,