java - Android - 加载库失败

Question

我有一个与 this question 类似的问题，但略有不同。我已经编译了一个 .so 库来与 JNI 一起使用。因为它很大(15 MB)，所以我将它放在 SDCard 上而不是标准应用程序位置。

该文件名为 libSample.so，位于 /data/library/libSample.so

我将它加载到静态初始化 block 中:

try {
        File sdcard = Environment.getExternalStorageDirectory();
        File libraryLoc = new File(sdcard.getAbsolutePath() + "/library/libSample.so");
        Log.i("Library", "Does the library exist?" + libraryLoc.exists());

        System.load(libraryLoc.getAbsolutePath());
    }
    catch (UnsatisfiedLinkError e) {
        Log.e("Translator", e.getMessage());
        Log.e("Translator", e.toString());
    }

这是相关的 logcat 输出:

09-02 16:42:58.882: DEBUG/dalvikvm(4185): Trying to load lib /data/data/com.example.hellojni/lib/libhello-jni.so 0x434fb6f8
09-02 16:42:58.892: DEBUG/dalvikvm(4185): Added shared lib /data/data/com.example.hellojni/lib/libhello-jni.so 0x434fb6f8
09-02 16:42:58.892: DEBUG/dalvikvm(4185): No JNI_OnLoad found in /data/data/com.example.hellojni/lib/libhello-jni.so 0x434fb6f8
09-02 16:42:58.892: INFO/Library(4185): Library exists: true
09-02 16:42:58.902: INFO/Library(4185): Library can be read: true
09-02 16:42:58.902: DEBUG/dalvikvm(4185): Trying to load lib /sdcard/library/libSample.so 0x434fb6f8
09-02 16:42:58.902: INFO/dalvikvm(4185): Unable to dlopen(/sdcard/library/libSample.so): Cannot find library
09-02 16:42:58.912: ERROR/Translator(4185): Library /sdcard/library/libSample.so not found
09-02 16:42:58.912: ERROR/Translator(4185): java.lang.UnsatisfiedLinkError: Library /sdcard/library/libSample.so not found

知道哪里出了问题吗？

我阅读了关于 can android load dll's from sdcard in native mode 的帖子其中说 sdcard 不能用于加载库，所以我将 .so 移动到/data/data/com.example.hellojni/lib/libSample.so (私有(private)应用程序数据存储位置)。没有变化:

09-02 16:53:18.332: DEBUG/dalvikvm(4515): Trying to load lib /data/data/com.example.hellojni/lib/libhello-jni.so 0x434fb6f8
09-02 16:53:18.342: DEBUG/dalvikvm(4515): Added shared lib /data/data/com.example.hellojni/lib/libhello-jni.so 0x434fb6f8
09-02 16:53:18.342: DEBUG/dalvikvm(4515): No JNI_OnLoad found in /data/data/com.example.hellojni/lib/libhello-jni.so 0x434fb6f8
09-02 16:53:18.352: INFO/Library(4515): Library exists: true
09-02 16:53:18.352: INFO/Library(4515): Library can be read: true
09-02 16:53:18.352: DEBUG/dalvikvm(4515): Trying to load lib /data/data/com.example.hellojni/lib/libSample.so 0x434fb6f8
09-02 16:53:18.482: INFO/dalvikvm(4515): Unable to dlopen(/data/data/com.example.hellojni/lib/libSample.so): Cannot find library
09-02 16:53:18.492: ERROR/Translator(4515): Library /data/data/com.example.hellojni/lib/libSample.so not found
09-02 16:53:18.492: ERROR/Translator(4515): java.lang.UnsatisfiedLinkError: Library /data/data/com.example.hellojni/lib/libSample.so not found

我不明白的是，库显然存在，并且操作系统正在尝试加载它……那么什么会导致它失败？

在其中一位评论者的建议下，我尝试通过 strace 附加以获取更详细的错误信息。日志可以作为 github gist 找到。 .

错误出现在第 47-51 行:

mprotect(0x4235d000, 4096, PROT_READ)   = 0
ioctl(1, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbeb58080) = -1 ENOTTY (Not a typewriter)
write(1, "bionic/linker/linker.c:1243| ERROR:    34 unknown reloc type 3 @ 0x811a854c (2441)\n", 83) = 83
write(1, "bionic/linker/linker.c:1641| ERROR: failed to link /data/data/com.example.hellojni/lib/libSample.so\n", 100) = 100
munmap(0x81000000, 8839168)             = 0

这是图书馆的阅读:

arm-eabi-readelf -d libSample.so 

Dynamic section at offset 0x80b648 contains 17 entries:
  Tag        Type                         Name/Value
 0x00000019 (INIT_ARRAY)                 0x7ff234
 0x0000001b (INIT_ARRAYSZ)               76 (bytes)
 0x00000004 (HASH)                       0xd4
 0x00000005 (STRTAB)                     0x7f41c
 0x00000006 (SYMTAB)                     0x2650c
 0x0000000a (STRSZ)                      1197287 (bytes)
 0x0000000b (SYMENT)                     16 (bytes)
 0x00000003 (PLTGOT)                     0x80c6f0
 0x00000002 (PLTRELSZ)                   76480 (bytes)
 0x00000014 (PLTREL)                     REL
 0x00000017 (JMPREL)                     0x1ccb84
 0x00000011 (REL)                        0x1a3904
 0x00000012 (RELSZ)                      168576 (bytes)
 0x00000013 (RELENT)                     8 (bytes)
 0x00000016 (TEXTREL)                    0x0
 0x6ffffffa (RELCOUNT)                   2412
 0x00000000 (NULL)                       0x0

Answer 1

我认为更有可能是找不到您的 .so 所依赖的库。但前提是 .so 文件可以首先从 SDCard 加载。