source: src/libcfa/interpose.c @ d43cd01

//                              -*- Mode: CFA -*-
//
// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// interpose.c --
//
// Author           : Thierry Delisle
// Created On       : Wed Mar 29 16:10:31 2017
// Last Modified By : 
// Last Modified On : 
// Update Count     : 0
//

#include <stdarg.h>
#include <stddef.h>

extern "C" {
#include <stdio.h>
#include <string.h>
#include <dlfcn.h>
#include <unistd.h>
}

#include "libhdr/libdebug.h"
#include "libhdr/libtools.h"
#include "startup.h"

void interpose_startup(void)  __attribute__(( constructor( STARTUP_PRIORITY_CORE ) ));

typedef void (*generic_fptr_t)(void);
generic_fptr_t interpose_symbol( const char* symbol, const char *version ) {
        const char * error;

        static void * library;
        if ( ! library ) {
                #if defined( RTLD_NEXT )
                        library = RTLD_NEXT;
                #else
                        // missing RTLD_NEXT => must hard-code library name, assuming libstdc++
                        library = dlopen( "libc.so.6", RTLD_LAZY );
                        error = dlerror();
                        if ( error ) {
                                abortf( "interpose_symbol : failed to open libc, %s\n", error );
                        }
                #endif
        } // if

        union { generic_fptr_t fptr; void* ptr; } originalFunc;
        
        #if defined( _GNU_SOURCE )
                if ( version ) {
                        originalFunc.ptr = dlvsym( library, symbol, version );
                } else {
                        originalFunc.ptr = dlsym( library, symbol );
                }
        #else
                originalFunc.ptr = dlsym( library, symbol );
        #endif // _GNU_SOURCE
        
        error = dlerror();
        if ( error ) abortf( "interpose_symbol : internal error, %s\n", error ); 

        return originalFunc.fptr;
}


__typeof__( exit ) libc_exit __attribute__(( noreturn ));
__typeof__( abort ) libc_abort __attribute__(( noreturn ));

// #define INIT_REALRTN( x, ver ) libc_##x = (__typeof__(libc_##x))interpose_symbol( #x, ver )

forall(dtype T)
static inline void assign_ptr( T** symbol_ptr, const char * symbol_name, const char * version) {
        union { 
                generic_fptr_t gp;
                T* tp; 
        } u;

        u.gp = interpose_symbol( symbol_name, version );

        *symbol_ptr = u.tp;
}

#define INIT_REALRTN( x, ver ) assign_ptr( (void**)&libc_##x, #x, ver)

void interpose_startup() {
        const char *version = NULL;

        INIT_REALRTN( abort, version );
        INIT_REALRTN( exit, version );
}

extern "C" {
        void abort (void) __attribute__ ((__nothrow__, __leaf__, __noreturn__)) {
                abortf( NULL );
        }

        void exit (int __status) __attribute__ ((__nothrow__, __leaf__, __noreturn__)) {
                libc_exit(__status);
        }
}

void abort( const char *fmt, va_list argp ) __attribute__ ((__nothrow__, __leaf__, __noreturn__)) {
        abortf( fmt, argp );
}

void * kernel_abort    (void) __attribute__ ((__nothrow__, __leaf__, __weak__)) { return NULL; }
void   kernel_abort_msg(void * data, char * buffer, int size) __attribute__ ((__nothrow__, __leaf__, __weak__)) {}

enum { abort_text_size = 1024 };
static char abort_text[ abort_text_size ];

extern "C" {
        void abortf( const char fmt[], ... ) __attribute__ ((__nothrow__, __leaf__, __noreturn__)) {
                void * kernel_data = kernel_abort();

                int len;

                if( fmt ) {
                        va_list args;
                        va_start( args, fmt );

                        len = vsnprintf( abort_text, abort_text_size, fmt, args );

                        va_end( args );

                        __lib_debug_write( STDERR_FILENO, abort_text, len );
                        __lib_debug_write( STDERR_FILENO, "\n", 1 );
                }

                len = snprintf( abort_text, abort_text_size, "Cforall Runtime error (UNIX pid:%ld)\n", (long int)getpid() ); // use UNIX pid (versus getPid)
                __lib_debug_write( STDERR_FILENO, abort_text, len );


                kernel_abort_msg( kernel_data, abort_text, abort_text_size );

                libc_abort();
        }
}