Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4007a561 authored by Hans Boehm's avatar Hans Boehm
Browse files

Properly handle wrap system property in zygote 

This was broken with the change to the native fork loop.
If the relevant property is specified, fall back to the Java fork loop.

Test: Build and boot AOSP.
Bug: 216572944
Change-Id: Ib63dcc3020e3406960ad12d296e741c80c7bc001
parent 6b8b9efa

core/jni/com_android_internal_os_ZygoteCommandBuffer.cpp

+20 −4
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
#include <sys/mman.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <sys/system_properties.h>

#include <vector>



namespace android {
@@ -43,10 +44,10 @@ using android::base::StringPrintf; 
using android::zygote::ZygoteFailure;



// WARNING: Knows a little about the wire protocol used to communicate with Zygote.

// TODO: Fix error handling.



// Commands and nice names have large arbitrary size limits to avoid dynamic memory allocation.

constexpr size_t MAX_COMMAND_BYTES = 32768;

constexpr size_t NICE_NAME_BYTES = 50;

constexpr size_t NICE_NAME_BYTES = 128;



// A buffer optionally bundled with a file descriptor from which we can fill it.

// Does not own the file descriptor; destroying a NativeCommandBuffer does not
@@ -190,6 +191,9 @@ class NativeCommandBuffer { 
        size_t copy_len = std::min(name_len, NICE_NAME_BYTES - 1);

        memcpy(mNiceName, arg_start + NN_LENGTH, copy_len);

        mNiceName[copy_len] = '\0';

        if (haveWrapProperty()) {

          return false;

        }

        continue;

      }

      if (arg_end - arg_start == IW_LENGTH
@@ -222,6 +226,8 @@ class NativeCommandBuffer { 
        }

        saw_setgid = true;

      }

      // ro.debuggable can be handled entirely in the child unless --invoke-with is also specified.

      // Thus we do not need to check it here.

    }

    return saw_runtime_args && saw_setuid && saw_setgid;

  }
@@ -249,6 +255,14 @@ class NativeCommandBuffer { 
  }



 private:

  bool haveWrapProperty() {

    static const char* WRAP = "wrap.";

    static const size_t WRAP_LENGTH = strlen(WRAP);

    char propNameBuf[WRAP_LENGTH + NICE_NAME_BYTES];

    strcpy(propNameBuf, WRAP);

    strlcpy(propNameBuf + WRAP_LENGTH, mNiceName, NICE_NAME_BYTES);

    return __system_property_find(propNameBuf) != nullptr;

  }

  // Picky version of atoi(). No sign or unexpected characters allowed. Return -1 on failure.

  static int digitsVal(char* start, char* end) {

    int result = 0;
@@ -269,7 +283,7 @@ class NativeCommandBuffer { 
  uint32_t mNext;  // Index of first character past last line returned by readLine.

  int32_t mLinesLeft;  // Lines in current command that haven't yet been read.

  int mFd;  // Open file descriptor from which we can read more. -1 if none.

  char mNiceName[NICE_NAME_BYTES];

  char mNiceName[NICE_NAME_BYTES];  // Always null terminated.

  char mBuffer[MAX_COMMAND_BYTES];

};
@@ -372,6 +386,7 @@ jboolean com_android_internal_os_ZygoteCommandBuffer_nativeForkRepeatedly( 
            jint minUid,

            jstring managed_nice_name) {



  ALOGI("Entering forkRepeatedly native zygote loop");

  NativeCommandBuffer* n_buffer = reinterpret_cast<NativeCommandBuffer*>(j_buffer);

  int session_socket = n_buffer->getFd();

  std::vector<int> session_socket_fds {session_socket};
@@ -400,7 +415,8 @@ jboolean com_android_internal_os_ZygoteCommandBuffer_nativeForkRepeatedly( 
  socklen_t cred_size = sizeof credentials;

  if (getsockopt(n_buffer->getFd(), SOL_SOCKET, SO_PEERCRED, &credentials, &cred_size) == -1

      || cred_size != sizeof credentials) {

    fail_fn_1(CREATE_ERROR("ForkMany failed to get initial credentials, %s", strerror(errno)));

    fail_fn_1(CREATE_ERROR("ForkRepeatedly failed to get initial credentials, %s",

                           strerror(errno)));

  }



  bool first_time = true;