musl-gcc：对 __memcpy_chk 的未定义引用

Question

我需要针对 musl-libc 编译一个 C 程序以使其在嵌入式设备上运行。但是，我无法编译该程序。源取决于我传递给链接器的几个库，如下所示：

/usr/local/musl/bin/musl-gcc app.c -o app -I../lib -lzlog -lfilter

这是我得到的输出：

/usr/local/musl/lib/libzlog.a(category.o): In function `strcpy':
/usr/include/x86_64-linux-gnu/bits/string3.h:110: undefined reference to `__memcpy_chk'
/usr/local/musl/lib/libzlog.a(conf.o): In function `strcpy':
/usr/include/x86_64-linux-gnu/bits/string3.h:110: undefined reference to `__strcpy_chk'
/usr/include/x86_64-linux-gnu/bits/string3.h:110: undefined reference to `__strcpy_chk'
/usr/include/x86_64-linux-gnu/bits/string3.h:110: undefined reference to `__strcpy_chk'
/usr/include/x86_64-linux-gnu/bits/string3.h:110: undefined reference to `__strcpy_chk'
/usr/local/musl/lib/libzlog.a(event.o): In function `sprintf':
/usr/include/x86_64-linux-gnu/bits/stdio2.h:33: undefined reference to `__sprintf_chk'
/usr/include/x86_64-linux-gnu/bits/stdio2.h:33: undefined reference to `__sprintf_chk'
/usr/local/musl/lib/libzlog.a(format.o): In function `memcpy':
/usr/include/x86_64-linux-gnu/bits/string3.h:53: undefined reference to `__memcpy_chk'
/usr/local/musl/lib/libzlog.a(record.o): In function `strcpy':
/usr/include/x86_64-linux-gnu/bits/string3.h:110: undefined reference to `__memcpy_chk'
/usr/local/musl/lib/libzlog.a(rotater.o): In function `snprintf':
/usr/include/x86_64-linux-gnu/bits/stdio2.h:64: undefined reference to `__snprintf_chk'
/usr/include/x86_64-linux-gnu/bits/stdio2.h:64: undefined reference to `__snprintf_chk'
/usr/include/x86_64-linux-gnu/bits/stdio2.h:64: undefined reference to `__snprintf_chk'
/usr/include/x86_64-linux-gnu/bits/stdio2.h:64: undefined reference to `__snprintf_chk'
/usr/include/x86_64-linux-gnu/bits/stdio2.h:64: undefined reference to `__snprintf_chk'
/usr/local/musl/lib/libzlog.a(rule.o): In function `syslog':
/usr/include/x86_64-linux-gnu/bits/syslog.h:31: undefined reference to `__syslog_chk'
/usr/local/musl/lib/libzlog.a(rule.o): In function `strcpy':
/usr/include/x86_64-linux-gnu/bits/string3.h:110: undefined reference to `__strcpy_chk'
/usr/local/musl/lib/libzlog.a(rule.o): In function `memcpy':
/usr/include/x86_64-linux-gnu/bits/string3.h:53: undefined reference to `__memcpy_chk'
/usr/local/musl/lib/libzlog.a(spec.o): In function `sprintf':
/usr/include/x86_64-linux-gnu/bits/stdio2.h:33: undefined reference to `__sprintf_chk'
/usr/local/musl/lib/libzlog.a(zc_profile.o): In function `vfprintf':
/usr/include/x86_64-linux-gnu/bits/stdio2.h:127: undefined reference to `__vfprintf_chk'
/usr/local/musl/lib/libzlog.a(zc_profile.o): In function `fprintf':
/usr/include/x86_64-linux-gnu/bits/stdio2.h:97: undefined reference to `__fprintf_chk'
/usr/include/x86_64-linux-gnu/bits/stdio2.h:97: undefined reference to `__fprintf_chk'
/usr/local/musl/lib/libzlog.a(zc_util.o): In function `snprintf':
/usr/include/x86_64-linux-gnu/bits/stdio2.h:64: undefined reference to `__snprintf_chk'
/usr/local/musl/lib/libzlog.a(buf.o): In function `strcpy':
/usr/include/x86_64-linux-gnu/bits/string3.h:110: undefined reference to `__memcpy_chk'
/usr/local/musl/lib/libzlog.a(buf.o): In function `vsnprintf':
/usr/include/x86_64-linux-gnu/bits/stdio2.h:77: undefined reference to `__vsnprintf_chk'
/usr/include/x86_64-linux-gnu/bits/stdio2.h:77: undefined reference to `__vsnprintf_chk'
/usr/include/x86_64-linux-gnu/bits/stdio2.h:77: undefined reference to `__vsnprintf_chk'
collect2: error: ld returned 1 exit status

与 gcc 相同的命令工作正常。 musl中没有实现这些功能吗？

Answer 1

您问题中的包含路径都是 glibc 文件，因此看起来您尝试 link 的库是用 glibc 构建的。这有时可以工作，但有局限性。在您的情况下，它是使用 _FORTIFY_SOURCE 的 glibc 版本构建的，它使用 glibc 中目前在 musl 中不可用的符号（通常在 musl 上使用的 _FORTIFY_SOURCE 实现的工作方式不同）。长期以来，这项工作一直在长期议程上，但不是优先事项；如果可以的话，最好针对 musl 重建库。

Answer 2

也许这与您的情况无关，但我在 linux.

下使用 MinGW 进行交叉编译时遇到了同样的 __memcpy_chk 问题

并且通过向链接器添加 -lssp 标志修复了这个未定义的引用。如果你有 configure 那么你可以 LDFLAGS="-lssp" ./configure ...

musl-gcc：对 __memcpy_chk 的未定义引用

musl-gcc: undefined reference to __memcpy_chk

c

gcc

musl