1/* 2 * Copyright (c) 2010-2012 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28#include <mach_rt.h> 29#include <mach_debug.h> 30#include <mach_ldebug.h> 31 32#include <mach/kern_return.h> 33#include <mach/mach_traps.h> 34#include <mach/thread_status.h> 35#include <mach/vm_param.h> 36 37#include <kern/counters.h> 38#include <kern/cpu_data.h> 39#include <kern/mach_param.h> 40#include <kern/task.h> 41#include <kern/thread.h> 42#include <kern/sched_prim.h> 43#include <kern/misc_protos.h> 44#include <kern/assert.h> 45#include <kern/debug.h> 46#include <kern/spl.h> 47#include <kern/syscall_sw.h> 48#include <ipc/ipc_port.h> 49#include <vm/vm_kern.h> 50#include <vm/pmap.h> 51 52#include <i386/cpu_number.h> 53#include <i386/eflags.h> 54#include <i386/proc_reg.h> 55#include <i386/tss.h> 56#include <i386/user_ldt.h> 57#include <i386/fpu.h> 58#include <i386/machdep_call.h> 59#include <i386/vmparam.h> 60#include <i386/mp_desc.h> 61#include <i386/misc_protos.h> 62#include <i386/thread.h> 63#include <i386/trap.h> 64#include <i386/seg.h> 65#include <mach/i386/syscall_sw.h> 66#include <sys/syscall.h> 67#include <sys/kdebug.h> 68#include <sys/errno.h> 69#include <../bsd/sys/sysent.h> 70 71 72/* 73 * Duplicate parent state in child 74 * for U**X fork. 75 */ 76kern_return_t 77machine_thread_dup( 78 thread_t parent, 79 thread_t child 80) 81{ 82 83 pcb_t parent_pcb = THREAD_TO_PCB(parent); 84 pcb_t child_pcb = THREAD_TO_PCB(child); 85 86 /* 87 * Copy over the x86_saved_state registers 88 */ 89 if (thread_is_64bit(parent)) 90 bcopy(USER_REGS64(parent), USER_REGS64(child), sizeof(x86_saved_state64_t)); 91 else 92 bcopy(USER_REGS32(parent), USER_REGS32(child), sizeof(x86_saved_state32_t)); 93 94 /* 95 * Check to see if parent is using floating point 96 * and if so, copy the registers to the child 97 */ 98 fpu_dup_fxstate(parent, child); 99 100#ifdef MACH_BSD 101 /* 102 * Copy the parent's cthread id and USER_CTHREAD descriptor, if 32-bit. 103 */ 104 child_pcb->cthread_self = parent_pcb->cthread_self; 105 if (!thread_is_64bit(parent)) 106 child_pcb->cthread_desc = parent_pcb->cthread_desc; 107 108 /* 109 * FIXME - should a user specified LDT, TSS and V86 info 110 * be duplicated as well?? - probably not. 111 */ 112 // duplicate any use LDT entry that was set I think this is appropriate. 113 if (parent_pcb->uldt_selector!= 0) { 114 child_pcb->uldt_selector = parent_pcb->uldt_selector; 115 child_pcb->uldt_desc = parent_pcb->uldt_desc; 116 } 117#endif 118 119 return (KERN_SUCCESS); 120} 121 122void thread_set_parent(thread_t parent, int pid); 123 124void 125thread_set_parent(thread_t parent, int pid) 126{ 127 pal_register_cache_state(parent, DIRTY); 128 129 if (thread_is_64bit(parent)) { 130 x86_saved_state64_t *iss64; 131 132 iss64 = USER_REGS64(parent); 133 134 iss64->rax = pid; 135 iss64->rdx = 0; 136 iss64->isf.rflags &= ~EFL_CF; 137 } else { 138 x86_saved_state32_t *iss32; 139 140 iss32 = USER_REGS32(parent); 141 142 iss32->eax = pid; 143 iss32->edx = 0; 144 iss32->efl &= ~EFL_CF; 145 } 146} 147 148/* 149 * thread_fast_set_cthread_self: Sets the machine kernel thread ID of the 150 * current thread to the given thread ID; fast version for 32-bit processes 151 * 152 * Parameters: self Thread ID to set 153 * 154 * Returns: 0 Success 155 * !0 Not success 156 */ 157kern_return_t 158thread_fast_set_cthread_self(uint32_t self) 159{ 160 machine_thread_set_tsd_base(current_thread(), self); 161 return (USER_CTHREAD); /* N.B.: not a kern_return_t! */ 162} 163 164/* 165 * thread_fast_set_cthread_self64: Sets the machine kernel thread ID of the 166 * current thread to the given thread ID; fast version for 64-bit processes 167 * 168 * Parameters: self Thread ID 169 * 170 * Returns: 0 Success 171 * !0 Not success 172 */ 173kern_return_t 174thread_fast_set_cthread_self64(uint64_t self) 175{ 176 machine_thread_set_tsd_base(current_thread(), self); 177 return (USER_CTHREAD); /* N.B.: not a kern_return_t! */ 178} 179 180/* 181 * thread_set_user_ldt routine is the interface for the user level 182 * settable ldt entry feature. allowing a user to create arbitrary 183 * ldt entries seems to be too large of a security hole, so instead 184 * this mechanism is in place to allow user level processes to have 185 * an ldt entry that can be used in conjunction with the FS register. 186 * 187 * Swapping occurs inside the pcb.c file along with initialization 188 * when a thread is created. The basic functioning theory is that the 189 * pcb->uldt_selector variable will contain either 0 meaning the 190 * process has not set up any entry, or the selector to be used in 191 * the FS register. pcb->uldt_desc contains the actual descriptor the 192 * user has set up stored in machine usable ldt format. 193 * 194 * Currently one entry is shared by all threads (USER_SETTABLE), but 195 * this could be changed in the future by changing how this routine 196 * allocates the selector. There seems to be no real reason at this 197 * time to have this added feature, but in the future it might be 198 * needed. 199 * 200 * address is the linear address of the start of the data area size 201 * is the size in bytes of the area flags should always be set to 0 202 * for now. in the future it could be used to set R/W permisions or 203 * other functions. Currently the segment is created as a data segment 204 * up to 1 megabyte in size with full read/write permisions only. 205 * 206 * this call returns the segment selector or -1 if any error occurs 207 */ 208kern_return_t 209thread_set_user_ldt(uint32_t address, uint32_t size, uint32_t flags) 210{ 211 pcb_t pcb; 212 struct fake_descriptor temp; 213 214 if (flags != 0) 215 return -1; // flags not supported 216 if (size > 0xFFFFF) 217 return -1; // size too big, 1 meg is the limit 218 219 mp_disable_preemption(); 220 221 // create a "fake" descriptor so we can use fix_desc() 222 // to build a real one... 223 // 32 bit default operation size 224 // standard read/write perms for a data segment 225 pcb = THREAD_TO_PCB(current_thread()); 226 temp.offset = address; 227 temp.lim_or_seg = size; 228 temp.size_or_wdct = SZ_32; 229 temp.access = ACC_P|ACC_PL_U|ACC_DATA_W; 230 231 // turn this into a real descriptor 232 fix_desc(&temp,1); 233 234 // set up our data in the pcb 235 pcb->uldt_desc = *(struct real_descriptor*)&temp; 236 pcb->uldt_selector = USER_SETTABLE; // set the selector value 237 238 // now set it up in the current table... 239 *ldt_desc_p(USER_SETTABLE) = *(struct real_descriptor*)&temp; 240 241 mp_enable_preemption(); 242 243 return USER_SETTABLE; 244} 245