How to make Linux shared library executable

Examples for Linux x86_64 platform:Library

/* test.c * Heiher  */?#include #include ?int main (int argc, char *argv[]);?#if defined(__x86_64__)const char lib_interp[] __attribute__((section(".interp"))) = "/lib64/ld-linux-x86-64.so.2";#define init_args(argc, argv) __asm__ volatile ( \"mov 0x8(%%rbp), %%edx \n\tmov %%edx, %0 \n\tlea 0x10(%%rbp), %1 \n\t" \:"=m"(argc), "=r"(argv)::"memory")#endif /* __x86_64__ */?void_entry (void){int ret = 0;int argc = 0;char **argv = NULL;?init_args (argc, argv);ret = main (argc, argv);exit (ret);}?intmain (int argc, char *argv[]){int i = 0;void *p = malloc (4096);?printf ("argc: %d, argv: %p, p: %p\n", argc, argv, p);for (i=0; i<argc; i++)  printf ("argv[%d]: %s\n", i, argv[i]);?free (p);?return 0;}?inttest (int a, int b){return a + b;}

Build

gcc -fPIC -shared -o libtest.so test.c -Wl,-e_entry

Run

./libtest.so a b c

argc: 4, argv: 0x7ffff3c165b8, p: 0x7fea935c4010argv[0]: ./libtest.soargv[1]: aargv[2]: bargv[3]: c

App

/* call.c * Heiher  */?#include ?int test(int a, int b);?intmain (int argc, char *argv[]){printf ("%d\n", test (1, 2));?return 0;}

Build

gcc -o call call.c -L. -ltest

Run

LD_LIBRARY_PATH=. ./call

3

Over!