17c478bd9Sstevel@tonic-gate /* 27c478bd9Sstevel@tonic-gate * CDDL HEADER START 37c478bd9Sstevel@tonic-gate * 47c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the 57c478bd9Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 67c478bd9Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 77c478bd9Sstevel@tonic-gate * with the License. 87c478bd9Sstevel@tonic-gate * 97c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 107c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 117c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions 127c478bd9Sstevel@tonic-gate * and limitations under the License. 137c478bd9Sstevel@tonic-gate * 147c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 157c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 167c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 177c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 187c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 197c478bd9Sstevel@tonic-gate * 207c478bd9Sstevel@tonic-gate * CDDL HEADER END 217c478bd9Sstevel@tonic-gate */ 227c478bd9Sstevel@tonic-gate /* 237c478bd9Sstevel@tonic-gate * Copyright (c) 1996, by Sun Microsystems, Inc. 247c478bd9Sstevel@tonic-gate * All rights reserved. 257c478bd9Sstevel@tonic-gate */ 267c478bd9Sstevel@tonic-gate 277c478bd9Sstevel@tonic-gate /* 287c478bd9Sstevel@tonic-gate * MKS interface extension. 297c478bd9Sstevel@tonic-gate * Ensure that errno is set if malloc() fails. 307c478bd9Sstevel@tonic-gate * 317c478bd9Sstevel@tonic-gate * Copyright 1992 by Mortice Kern Systems Inc. All rights reserved. 327c478bd9Sstevel@tonic-gate * 337c478bd9Sstevel@tonic-gate */ 347c478bd9Sstevel@tonic-gate #ifdef M_RCSID 357c478bd9Sstevel@tonic-gate #ifndef lint 367c478bd9Sstevel@tonic-gate static char rcsID[] = "$Header: /rd/src/libc/mks/rcs/m_malloc.c 1.4 1993/12/17 15:22:04 rog Exp $"; 377c478bd9Sstevel@tonic-gate #endif /*lint*/ 387c478bd9Sstevel@tonic-gate #endif /*M_RCSID*/ 397c478bd9Sstevel@tonic-gate 407c478bd9Sstevel@tonic-gate #include <mks.h> 417c478bd9Sstevel@tonic-gate #include <errno.h> 427c478bd9Sstevel@tonic-gate #include <stdlib.h> 437c478bd9Sstevel@tonic-gate 447c478bd9Sstevel@tonic-gate #ifdef __STDC__ 457c478bd9Sstevel@tonic-gate #define _VOID void 467c478bd9Sstevel@tonic-gate #else 477c478bd9Sstevel@tonic-gate #define _VOID char 487c478bd9Sstevel@tonic-gate #endif 497c478bd9Sstevel@tonic-gate 507c478bd9Sstevel@tonic-gate #undef m_malloc /* in case <mks.h> included in <errno.h> or <stdlib.h> */ 517c478bd9Sstevel@tonic-gate 527c478bd9Sstevel@tonic-gate /*f 53*1da57d55SToomas Soome * m_malloc: 547c478bd9Sstevel@tonic-gate * Portable replacement for malloc(). 557c478bd9Sstevel@tonic-gate * If malloc() fails (e.g returns NULL) 567c478bd9Sstevel@tonic-gate * then return ENOMEM unless malloc() sets errno for us on this system 577c478bd9Sstevel@tonic-gate * and ensure malloc(0) returns a non-NULL pointer. 587c478bd9Sstevel@tonic-gate * 597c478bd9Sstevel@tonic-gate */ 607c478bd9Sstevel@tonic-gate _VOID* m_malloc(amount)617c478bd9Sstevel@tonic-gatem_malloc(amount) 627c478bd9Sstevel@tonic-gate size_t amount; 637c478bd9Sstevel@tonic-gate { 647c478bd9Sstevel@tonic-gate _VOID* ptr; 657c478bd9Sstevel@tonic-gate 667c478bd9Sstevel@tonic-gate /*l 677c478bd9Sstevel@tonic-gate * Prob 1: 687c478bd9Sstevel@tonic-gate * ANSI does not insist setting errno when malloc() fails. 697c478bd9Sstevel@tonic-gate * But UNIX existing practice (which MKS relies on) always returns 707c478bd9Sstevel@tonic-gate * an errno when malloc() fails. 717c478bd9Sstevel@tonic-gate * Thus, on systems that implement malloc() where an errno is not 727c478bd9Sstevel@tonic-gate * returned, we set ENOMEM. 737c478bd9Sstevel@tonic-gate * 747c478bd9Sstevel@tonic-gate * Note: we don't care about previous value of errno since 757c478bd9Sstevel@tonic-gate * POSIX.1 (Section 2.4) says you can only look at errno 767c478bd9Sstevel@tonic-gate * after a function returns a status indicating an error. 777c478bd9Sstevel@tonic-gate * (and the function explicitly states an errno value can be 787c478bd9Sstevel@tonic-gate * returned - Well, m_malloc() is so stated.) 797c478bd9Sstevel@tonic-gate * 807c478bd9Sstevel@tonic-gate * Prob 2: 817c478bd9Sstevel@tonic-gate * MKS code seems to rely on malloc(0) returning a valid pointer. 827c478bd9Sstevel@tonic-gate * This allows it to realloc() later when actual size is determined. 837c478bd9Sstevel@tonic-gate * 847c478bd9Sstevel@tonic-gate * According to ANSI (4.10.3 line 18-19) the result of malloc(0) is 857c478bd9Sstevel@tonic-gate * implementation-defined. 867c478bd9Sstevel@tonic-gate */ 877c478bd9Sstevel@tonic-gate 887c478bd9Sstevel@tonic-gate errno = 0; 897c478bd9Sstevel@tonic-gate if ((ptr = malloc(amount)) == NULL) { 907c478bd9Sstevel@tonic-gate if (amount == 0) { 917c478bd9Sstevel@tonic-gate /* 927c478bd9Sstevel@tonic-gate * confirm we are really out of memory 937c478bd9Sstevel@tonic-gate */ 947c478bd9Sstevel@tonic-gate return (m_malloc(1)); 957c478bd9Sstevel@tonic-gate } 967c478bd9Sstevel@tonic-gate if (errno==0) { 977c478bd9Sstevel@tonic-gate /* 987c478bd9Sstevel@tonic-gate * ensure errno is always set 997c478bd9Sstevel@tonic-gate */ 1007c478bd9Sstevel@tonic-gate errno = ENOMEM; 1017c478bd9Sstevel@tonic-gate } 1027c478bd9Sstevel@tonic-gate } 1037c478bd9Sstevel@tonic-gate return (ptr); 1047c478bd9Sstevel@tonic-gate } 105