1*0Sstevel@tonic-gate /* 2*0Sstevel@tonic-gate * CDDL HEADER START 3*0Sstevel@tonic-gate * 4*0Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*0Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 6*0Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 7*0Sstevel@tonic-gate * with the License. 8*0Sstevel@tonic-gate * 9*0Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*0Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 11*0Sstevel@tonic-gate * See the License for the specific language governing permissions 12*0Sstevel@tonic-gate * and limitations under the License. 13*0Sstevel@tonic-gate * 14*0Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 15*0Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*0Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 17*0Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 18*0Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 19*0Sstevel@tonic-gate * 20*0Sstevel@tonic-gate * CDDL HEADER END 21*0Sstevel@tonic-gate */ 22*0Sstevel@tonic-gate /* 23*0Sstevel@tonic-gate * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 24*0Sstevel@tonic-gate * Use is subject to license terms. 25*0Sstevel@tonic-gate */ 26*0Sstevel@tonic-gate 27*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 28*0Sstevel@tonic-gate 29*0Sstevel@tonic-gate /* Copyright (c) 1988 AT&T */ 30*0Sstevel@tonic-gate /* All Rights Reserved */ 31*0Sstevel@tonic-gate 32*0Sstevel@tonic-gate 33*0Sstevel@tonic-gate #pragma weak makecontext = _makecontext 34*0Sstevel@tonic-gate #pragma weak __makecontext_v2 = ___makecontext_v2 35*0Sstevel@tonic-gate 36*0Sstevel@tonic-gate #include "synonyms.h" 37*0Sstevel@tonic-gate #include <stdarg.h> 38*0Sstevel@tonic-gate #include <strings.h> 39*0Sstevel@tonic-gate #include <sys/ucontext.h> 40*0Sstevel@tonic-gate #include <sys/stack.h> 41*0Sstevel@tonic-gate #include <sys/frame.h> 42*0Sstevel@tonic-gate 43*0Sstevel@tonic-gate /* 44*0Sstevel@tonic-gate * The ucontext_t that the user passes in must have been primed with a 45*0Sstevel@tonic-gate * call to getcontext(2), have the uc_stack member set to reflect the 46*0Sstevel@tonic-gate * stack which this context will use, and have the uc_link member set 47*0Sstevel@tonic-gate * to the context which should be resumed when this context returns. 48*0Sstevel@tonic-gate * When makecontext() returns, the ucontext_t will be set to run the 49*0Sstevel@tonic-gate * given function with the given parameters on the stack specified by 50*0Sstevel@tonic-gate * uc_stack, and which will return to the ucontext_t specified by uc_link. 51*0Sstevel@tonic-gate */ 52*0Sstevel@tonic-gate 53*0Sstevel@tonic-gate static void resumecontext(void); 54*0Sstevel@tonic-gate 55*0Sstevel@tonic-gate void 56*0Sstevel@tonic-gate _makecontext(ucontext_t *ucp, void (*func)(), int argc, ...) 57*0Sstevel@tonic-gate { 58*0Sstevel@tonic-gate greg_t *reg; 59*0Sstevel@tonic-gate long *tsp; 60*0Sstevel@tonic-gate char *sp; 61*0Sstevel@tonic-gate int argno; 62*0Sstevel@tonic-gate va_list ap; 63*0Sstevel@tonic-gate size_t size; 64*0Sstevel@tonic-gate 65*0Sstevel@tonic-gate reg = ucp->uc_mcontext.gregs; 66*0Sstevel@tonic-gate reg[REG_PC] = (greg_t)func; 67*0Sstevel@tonic-gate reg[REG_nPC] = reg[REG_PC] + 0x4; 68*0Sstevel@tonic-gate 69*0Sstevel@tonic-gate /* 70*0Sstevel@tonic-gate * Reserve enough space for a frame and the arguments beyond the 71*0Sstevel@tonic-gate * sixth; round to stack alignment. 72*0Sstevel@tonic-gate */ 73*0Sstevel@tonic-gate size = sizeof (struct frame); 74*0Sstevel@tonic-gate size += (argc > 6 ? argc - 6 : 0) * sizeof (long); 75*0Sstevel@tonic-gate 76*0Sstevel@tonic-gate /* 77*0Sstevel@tonic-gate * The legacy implemenation of makecontext() on sparc has been to 78*0Sstevel@tonic-gate * interpret the uc_stack.ss_sp member incorrectly as the top of the 79*0Sstevel@tonic-gate * stack rather than the base. We preserve this behavior here, but 80*0Sstevel@tonic-gate * provide the correct semantics in __makecontext_v2(). 81*0Sstevel@tonic-gate */ 82*0Sstevel@tonic-gate sp = (char *)(((uintptr_t)ucp->uc_stack.ss_sp - size) & 83*0Sstevel@tonic-gate ~(STACK_ALIGN - 1)); 84*0Sstevel@tonic-gate 85*0Sstevel@tonic-gate /* 86*0Sstevel@tonic-gate * Copy all args to the stack, and put the first 6 args into the 87*0Sstevel@tonic-gate * ucontext_t. Zero the other fields of the frame. 88*0Sstevel@tonic-gate */ 89*0Sstevel@tonic-gate /* LINTED pointer cast may result in improper alignment */ 90*0Sstevel@tonic-gate tsp = &((struct frame *)sp)->fr_argd[0]; 91*0Sstevel@tonic-gate bzero(sp, sizeof (struct frame)); 92*0Sstevel@tonic-gate 93*0Sstevel@tonic-gate va_start(ap, argc); 94*0Sstevel@tonic-gate 95*0Sstevel@tonic-gate for (argno = 0; argno < argc; argno++) { 96*0Sstevel@tonic-gate if (argno < 6) 97*0Sstevel@tonic-gate *tsp++ = reg[REG_O0 + argno] = va_arg(ap, long); 98*0Sstevel@tonic-gate else 99*0Sstevel@tonic-gate *tsp++ = va_arg(ap, long); 100*0Sstevel@tonic-gate } 101*0Sstevel@tonic-gate 102*0Sstevel@tonic-gate va_end(ap); 103*0Sstevel@tonic-gate 104*0Sstevel@tonic-gate reg[REG_SP] = (greg_t)sp - STACK_BIAS; /* sp (when done) */ 105*0Sstevel@tonic-gate reg[REG_O7] = (greg_t)resumecontext - 8; /* return pc */ 106*0Sstevel@tonic-gate } 107*0Sstevel@tonic-gate 108*0Sstevel@tonic-gate void 109*0Sstevel@tonic-gate __makecontext_v2(ucontext_t *ucp, void (*func)(), int argc, ...) 110*0Sstevel@tonic-gate { 111*0Sstevel@tonic-gate greg_t *reg; 112*0Sstevel@tonic-gate long *tsp; 113*0Sstevel@tonic-gate char *sp; 114*0Sstevel@tonic-gate int argno; 115*0Sstevel@tonic-gate va_list ap; 116*0Sstevel@tonic-gate size_t size; 117*0Sstevel@tonic-gate 118*0Sstevel@tonic-gate reg = ucp->uc_mcontext.gregs; 119*0Sstevel@tonic-gate reg[REG_PC] = (greg_t)func; 120*0Sstevel@tonic-gate reg[REG_nPC] = reg[REG_PC] + 0x4; 121*0Sstevel@tonic-gate 122*0Sstevel@tonic-gate /* 123*0Sstevel@tonic-gate * Reserve enough space for a frame and the arguments beyond the 124*0Sstevel@tonic-gate * sixth; round to stack alignment. 125*0Sstevel@tonic-gate */ 126*0Sstevel@tonic-gate size = sizeof (struct frame); 127*0Sstevel@tonic-gate size += (argc > 6 ? argc - 6 : 0) * sizeof (long); 128*0Sstevel@tonic-gate 129*0Sstevel@tonic-gate sp = (char *)(((uintptr_t)ucp->uc_stack.ss_sp + 130*0Sstevel@tonic-gate ucp->uc_stack.ss_size - size) & ~(STACK_ALIGN - 1)); 131*0Sstevel@tonic-gate 132*0Sstevel@tonic-gate /* 133*0Sstevel@tonic-gate * Copy all args to the stack, and put the first 6 args into the 134*0Sstevel@tonic-gate * ucontext_t. Zero the other fields of the frame. 135*0Sstevel@tonic-gate */ 136*0Sstevel@tonic-gate /* LINTED pointer cast may result in improper alignment */ 137*0Sstevel@tonic-gate tsp = &((struct frame *)sp)->fr_argd[0]; 138*0Sstevel@tonic-gate bzero(sp, sizeof (struct frame)); 139*0Sstevel@tonic-gate 140*0Sstevel@tonic-gate va_start(ap, argc); 141*0Sstevel@tonic-gate 142*0Sstevel@tonic-gate for (argno = 0; argno < argc; argno++) { 143*0Sstevel@tonic-gate if (argno < 6) 144*0Sstevel@tonic-gate *tsp++ = reg[REG_O0 + argno] = va_arg(ap, long); 145*0Sstevel@tonic-gate else 146*0Sstevel@tonic-gate *tsp++ = va_arg(ap, long); 147*0Sstevel@tonic-gate } 148*0Sstevel@tonic-gate 149*0Sstevel@tonic-gate va_end(ap); 150*0Sstevel@tonic-gate 151*0Sstevel@tonic-gate reg[REG_SP] = (greg_t)sp - STACK_BIAS; /* sp (when done) */ 152*0Sstevel@tonic-gate reg[REG_O7] = (greg_t)resumecontext - 8; /* return pc */ 153*0Sstevel@tonic-gate } 154*0Sstevel@tonic-gate 155*0Sstevel@tonic-gate static void 156*0Sstevel@tonic-gate resumecontext(void) 157*0Sstevel@tonic-gate { 158*0Sstevel@tonic-gate /* 159*0Sstevel@tonic-gate * We can't include ucontext.h (where these functions are defined) 160*0Sstevel@tonic-gate * because it remaps the symbol makecontext. 161*0Sstevel@tonic-gate */ 162*0Sstevel@tonic-gate extern int getcontext(ucontext_t *); 163*0Sstevel@tonic-gate extern int setcontext(const ucontext_t *); 164*0Sstevel@tonic-gate ucontext_t uc; 165*0Sstevel@tonic-gate 166*0Sstevel@tonic-gate (void) getcontext(&uc); 167*0Sstevel@tonic-gate (void) setcontext(uc.uc_link); 168*0Sstevel@tonic-gate } 169