musl-gcc: undefined reference to __memcpy_chk

Question

I need to compile a C program against musl-libc to make it run on an embedded device. However, I'm failing to compile the program. The source depends on a couple libraries which I pass to the linker like so:

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

This is the output I get:

/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

The same command with gcc works fine. Are these functions not implemented in musl?

Answer 1

The include paths in your question are all glibc files, so it looks like the library you're trying to link to was built with glibc. This can sometimes be made to work, but there are limitations. In your case, it was built with the glibc version of _FORTIFY_SOURCE, which uses symbols from glibc that are not presently available in musl (the _FORTIFY_SOURCE implementation typically used on musl works differently). Making this work has been on the long-term agenda for a long time, but not a priority; if you can, it's much better to rebuild the library against musl.

Answer 2

Maybe it is irrelevant to your case but I had same __memcpy_chk issue when cross-compiling using MinGW under linux.

And this undefined reference was fixed by adding -lssp flag to linker. If you have configure then you can do LDFLAGS="-lssp" ./configure ...