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Commit 6c7ddcc4 authored by Elliott Hughes's avatar Elliott Hughes Committed by Automerger Merge Worker
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Merge "Zygote: Add Arm pointer authentication keychange support." am:... 

Merge "Zygote: Add Arm pointer authentication keychange support." am: 285dfb31 am: 9b63f4e9 am: 54cb1fce am: 6844bdf2 am: 9fcc15c6

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1215821

Change-Id: I1b2bc517c93809a673c4fc197e7118d3f470c9dd
parents 7be38456 9fcc15c6

core/jni/com_android_internal_os_Zygote.cpp

+33 −0
Original line number Diff line number Diff line
@@ -101,6 +101,19 @@ 


#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.
@@ -1066,7 +1079,23 @@ 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,
@@ -1117,6 +1146,7 @@ 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
@@ -2052,6 +2082,7 @@ 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,
@@ -2104,6 +2135,7 @@ 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,
@@ -2175,6 +2207,7 @@ 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,