Python on alpine ctypes loadlibrary() failed with OSError: Error relocating ./cc.so: : initial-exec TLS resolves to dynamic definition in ./cc.so


(Chao) #1

I working on using golang builded shared library in python script(ctypes loadlibrary) on alpine based container.

/usr/src/app # go build -o cc.so -buildmode=c-shared main.go

/usr/src/app # readelf -d cc.so

Dynamic section at offset 0x10cd10 contains 22 entries:

Tag Type Name/Value

0x0000000000000001 (NEEDED) Shared library: [libc.musl-x86_64.so.1]

0x0000000000000010 (SYMBOLIC) 0x0

0x000000000000000c (INIT) 0x42000

0x000000000000000d (FINI) 0x92ed9

0x0000000000000019 (INIT_ARRAY) 0xa2078

0x000000000000001b (INIT_ARRAYSZ) 8 (bytes)

0x000000006ffffef5 (GNU_HASH) 0x270

0x0000000000000005 (STRTAB) 0xa50

0x0000000000000006 (SYMTAB) 0x378

0x000000000000000a (STRSZ) 1026 (bytes)

0x000000000000000b (SYMENT) 24 (bytes)

0x0000000000000003 (PLTGOT) 0x10deb0

0x0000000000000002 (PLTRELSZ) 720 (bytes)

0x0000000000000014 (PLTREL) RELA

0x0000000000000017 (JMPREL) 0x41a00

0x0000000000000007 (RELA) 0xe58

0x0000000000000008 (RELASZ) 265128 (bytes)

0x0000000000000009 (RELAENT) 24 (bytes)

0x000000000000001e (FLAGS) SYMBOLIC BIND_NOW STATIC_TLS

0x000000006ffffffb (FLAGS_1) Flags: NOW NODELETE

0x000000006ffffff9 (RELACOUNT) 11040

0x0000000000000000 (NULL) 0x0

/usr/src/app # python test.py

Traceback (most recent call last):

File “test.py”, line 2, in

lib = ctypes.cdll.LoadLibrary(’./cc.so’)

File “/usr/lib/python2.7/ctypes/init.py”, line 444, in LoadLibrary

return self._dlltype(name)

File “/usr/lib/python2.7/ctypes/init.py”, line 366, in init

self._handle = _dlopen(self._name, mode)

OSError: Error relocating ./cc.so: : initial-exec TLS resolves to dynamic definition in ./cc.so

But if I use ubuntu16.04 image and install go and python to do the same test, it works.

The main.go and test.py are as follows,

//main.go
package main

import "C"

//export add
func add(left, right int) int {
return left + right
}

//export minus
func minus(left, right int) int {
return left - right
}

//export multiply
func multiply(left, right int) int {
return left * right
}

//export divide
func divide(left, right int) int {
return left / right
}

//export testPrint
func testPrint(){
print("test")
}

func main() {
}

// test.py
import ctypes
lib = ctypes.cdll.LoadLibrary('./cc.so')
if lib is not None:
print ("can load so")

Has anyone the suggestion that how to specify the go build command line to solve the problem?

Thanks’
Chao