Linking OpenSSL engine with a third party dynamic library

[Shariful Alam]

Hello,
I have a custom OpenSSL engine and it is working fine with pthread. I was
trying to use a third-party thread library
<https://github.com/stonebuddha/uthread> by linking this library with my
engine. However, upon linking and running the engine, I'm getting a
Segmentation fault. I just could not figure out why. I have a hunch that my
linking with the newly built dynamic library is not correct,

Following is what I did
1. Compile the thread library as a dynamic library

CC      = gcc
CFLAGS  = -Wall -fPIC -g -O3 -MD
LDFLAGS = -shared
OBJ     = uthread.o


all: libuthread.so


libuthread.so: $(OBJ)

        $(LD) -shared -o $(@) $(OBJ)


clean:

        rm -f *.o *.d libuthread.so


-include *.d


%.o: %.c

        $(CC) $(CFLAGS) -o $@ -c $<

2. Copy this library to */lib/x86_64-linux-gnu/*
3. My Make file to compile my OpenSSL engine

*gcc -g -fPIC -c -fomit-frame-pointer rsa-engine.c*
*gcc -g -shared -o librsa_engine.so -L./libdune rsa-engine.o rsa/rsa.o
rsa/bignum.o rsa/aes.o -Wl,-Bstatic -ldune -Wl,-Bdynamic -lcrypto -luthread*

*mv librsa_engine.so rsa-engine-new.so*

4. After compilation, $*ldd rsa-engine-new.so*  shows the following,


linux-vdso.so.1 =>  (0x00007ffded367000)

libcrypto.so.1.1 => /opt/openssl/lib/libcrypto.so.1.1 (0x00007f895c5fa000)
libuthread.so => /lib/x86_64-linux-gnu/libuthread.so (0x00007f895c3f4000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f895c02a000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f895be26000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0
(0x00007f895bc09000)
/lib64/ld-linux-x86-64.so.2 (0x00007f895cd56000)

I use gdb to find out what causes the segmentation fault, I find out
that *uthread_join(),
*is failing at some point. Can someone please tell me what I'm, doing
wrong?
N.B: I checked the library with a simple program and the library works
fine.

Thanks,
Shariful
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