/*
* Copyright (c) 2010-2012 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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*/
#include <mach_ldebug.h>
#include <mach/kern_return.h>
#include <mach/mach_traps.h>
#include <mach/thread_status.h>
#include <mach/vm_param.h>
#include <kern/cpu_data.h>
#include <kern/mach_param.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <kern/sched_prim.h>
#include <kern/misc_protos.h>
#include <kern/assert.h>
#include <kern/debug.h>
#include <kern/spl.h>
#include <kern/syscall_sw.h>
#include <ipc/ipc_port.h>
#include <vm/vm_kern.h>
#include <vm/pmap.h>
#include <i386/cpu_number.h>
#include <i386/eflags.h>
#include <i386/proc_reg.h>
#include <i386/tss.h>
#include <i386/user_ldt.h>
#include <i386/fpu.h>
#include <i386/machdep_call.h>
#include <i386/vmparam.h>
#include <i386/mp_desc.h>
#include <i386/misc_protos.h>
#include <i386/thread.h>
#include <i386/trap_internal.h>
#include <i386/seg.h>
#include <mach/i386/syscall_sw.h>
#include <sys/syscall.h>
#include <sys/kdebug.h>
#include <sys/errno.h>
#include <../bsd/sys/sysent.h>
/*
* Duplicate parent state in child
* for U**X fork.
*/
kern_return_t
machine_thread_dup(
thread_t parent,
thread_t child,
__unused boolean_t is_corpse
)
{
pcb_t parent_pcb = THREAD_TO_PCB(parent);
pcb_t child_pcb = THREAD_TO_PCB(child);
/*
* Copy over the x86_saved_state registers
*/
if (thread_is_64bit_addr(parent)) {
bcopy(USER_REGS64(parent), USER_REGS64(child), sizeof(x86_saved_state64_t));
} else {
bcopy(USER_REGS32(parent), USER_REGS32(child), sizeof(x86_saved_state32_t));
}
/*
* Check to see if parent is using floating point
* and if so, copy the registers to the child
*/
fpu_dup_fxstate(parent, child);
#ifdef MACH_BSD
/*
* Copy the parent's cthread id and USER_CTHREAD descriptor, if 32-bit.
*/
child_pcb->cthread_self = parent_pcb->cthread_self;
if (!thread_is_64bit_addr(parent)) {
child_pcb->cthread_desc = parent_pcb->cthread_desc;
}
/*
* FIXME - should a user specified LDT, TSS and V86 info
* be duplicated as well?? - probably not.
*/
// duplicate any use LDT entry that was set I think this is appropriate.
if (parent_pcb->uldt_selector != 0) {
child_pcb->uldt_selector = parent_pcb->uldt_selector;
child_pcb->uldt_desc = parent_pcb->uldt_desc;
}
#endif
return KERN_SUCCESS;
}
/*
* thread_fast_set_cthread_self: Sets the machine kernel thread ID of the
* current thread to the given thread ID; fast version for 32-bit processes
*
* Parameters: self Thread ID to set
*
* Returns: 0 Success
* !0 Not success
*/
kern_return_t
thread_fast_set_cthread_self(uint32_t self)
{
machine_thread_set_tsd_base(current_thread(), self);
return USER_CTHREAD; /* N.B.: not a kern_return_t! */
}
/*
* thread_fast_set_cthread_self64: Sets the machine kernel thread ID of the
* current thread to the given thread ID; fast version for 64-bit processes
*
* Parameters: self Thread ID
*
* Returns: 0 Success
* !0 Not success
*/
kern_return_t
thread_fast_set_cthread_self64(uint64_t self)
{
machine_thread_set_tsd_base(current_thread(), self);
return USER_CTHREAD; /* N.B.: not a kern_return_t! */
}
/*
* thread_set_user_ldt routine is the interface for the user level
* settable ldt entry feature. allowing a user to create arbitrary
* ldt entries seems to be too large of a security hole, so instead
* this mechanism is in place to allow user level processes to have
* an ldt entry that can be used in conjunction with the FS register.
*
* Swapping occurs inside the pcb.c file along with initialization
* when a thread is created. The basic functioning theory is that the
* pcb->uldt_selector variable will contain either 0 meaning the
* process has not set up any entry, or the selector to be used in
* the FS register. pcb->uldt_desc contains the actual descriptor the
* user has set up stored in machine usable ldt format.
*
* Currently one entry is shared by all threads (USER_SETTABLE), but
* this could be changed in the future by changing how this routine
* allocates the selector. There seems to be no real reason at this
* time to have this added feature, but in the future it might be
* needed.
*
* address is the linear address of the start of the data area size
* is the size in bytes of the area flags should always be set to 0
* for now. in the future it could be used to set R/W permisions or
* other functions. Currently the segment is created as a data segment
* up to 1 megabyte in size with full read/write permisions only.
*
* this call returns the segment selector or -1 if any error occurs
*/
kern_return_t
thread_set_user_ldt(uint32_t address, uint32_t size, uint32_t flags)
{
pcb_t pcb;
struct fake_descriptor temp;
if (flags != 0) {
return -1; // flags not supported
}
if (size > 0xFFFFF) {
return -1; // size too big, 1 meg is the limit
}
mp_disable_preemption();
// create a "fake" descriptor so we can use fix_desc()
// to build a real one...
// 32 bit default operation size
// standard read/write perms for a data segment
pcb = THREAD_TO_PCB(current_thread());
temp.offset = address;
temp.lim_or_seg = size;
temp.size_or_wdct = SZ_32;
temp.access = ACC_P | ACC_PL_U | ACC_DATA_W;
// turn this into a real descriptor
fix_desc(&temp, 1);
// set up our data in the pcb
pcb->uldt_desc = *(struct real_descriptor*)&temp;
pcb->uldt_selector = USER_SETTABLE; // set the selector value
// now set it up in the current table...
*ldt_desc_p(USER_SETTABLE) = *(struct real_descriptor*)&temp;
mp_enable_preemption();
return USER_SETTABLE;
}