addrinfo.c

T-kernel 的extension源代码

/*
 *----------------------------------------------------------------------
 *    T-Kernel / Standard Extension
 *
 *    Copyright (C) 2006 by Ken Sakamura. All rights reserved.
 *    T-Kernel / Standard Extension is distributed 
 *      under the T-License for T-Kernel / Standard Extension.
 *----------------------------------------------------------------------
 *
 *    Version:   1.00.00
 *    Released by T-Engine Forum(http://www.t-engine.org) at 2006/8/11.
 *
 *----------------------------------------------------------------------
 */

/*
 *	@(#)addrinfo.c (libdl) 
 *
 *	DLL support library 
 *	Address information
 */

#include "libdl.h"
#include "symtab.h"

#define ERR_DLADDR	0	/* error code (dladdr) */

#include <tm/tmonitor.h>

/*
 * Specified address library information acquisition
 *	Return the information on the library that owns the address specified in "addr" to the "info".
 *	Additionaly,return the access handle of the shared object to the return value.
 *	Return E_NOEXS if there is no shared object at "addr" location.
 *
 *	typedef struct {
 *		ATR		atr;		object attribute
 *		VP	 	path;		filename
 *		VP	 	fbase;		base address
 *		const B 	*sname;		symbol name
 *		VP		saddr;		symbol address
 *	} T_DLINFO;
 *
 *	atr;	object attribute
 *	path	filename
 *	fbase	Load address of the shared object 
 *	sname	Symbol name  of the nearest location in "addr" location or
 *		the address smaller than "addr" 
 *	saddr	Symbol value of sname (Address) 
 */
EXPORT WER tkse_dladdr( VP addr, T_DLINFO *info )
{
	DLInfo	*dlp;
	Elf32_Sym	*symtab, *end, *match;
	UW		saddr;
	ER		err;

	err = LockDL();
	if ( err < E_OK ) {
		goto err_ret1;
	}

	/* Target object search */
	dlp = __addrdlinfo(addr);
	if ( dlp == NULL ) {
		err = E_NOEXS;
		goto err_ret2;
	}

	symtab = dlp->symtab;
	end = GET_SYMTAB_END(symtab, dlp);

	saddr = (UW)addr - (UW)dlp->ldofs;
	match = symtab;
	while ( ++symtab < end ) {
		if (( (UW)symtab->st_value <= saddr )
		  &&( (UW)symtab->st_value > (UW)match->st_value )) {
			switch ( ELF32_ST_BIND(symtab->st_info) ) {
			  case STB_GLOBAL:
			  case STB_WEAK:
				match = symtab;
			  default:
				/* nothing to do */
				break;
			}
		}
	}

	/* Storage of the shared object information */
	info->path = (VP)(dlp->soHdr.src.path);
	info->fbase = (VP)(dlp->ldofs);
	info->sname = (const B *)(( match->st_name == 0U ) ? NULL:
						(dlp->strtab + match->st_name));
	info->saddr = (VP)(( dlp->symtab == match ) ? NULL:
						((B*)match->st_value + dlp->ldofs));

	UnlockDL();

	return (WER)DLInfoID(dlp);

err_ret2:
	UnlockDL();
err_ret1:
	DEBUG_PRINT(("tkse_dladdr err = %d\n", err));
	return err;
}


/*
 * Specified address library information acquisition
 *
 */
EXPORT int dladdr( void *addr, Dl_info *info )
{
	WER err;
	T_DLINFO dlInfo;

	err = tkse_dladdr( addr, &dlInfo );
	if (err < E_OK) {
		err = ERR_DLADDR;
	}

	info->dli_fname = (char *)(dlInfo.path);
	info->dli_fbase = dlInfo.fbase;
	info->dli_sname = dlInfo.sname;
	info->dli_saddr = dlInfo.saddr;

	return (int)err;
}