--- /dev/null
+/*
+ * Copyright (c) 2010 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,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ */
+#include <mach_rt.h>
+#include <mach_debug.h>
+#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/counters.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.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
+)
+{
+
+ pcb_t parent_pcb = THREAD_TO_PCB(parent);
+ pcb_t child_pcb = THREAD_TO_PCB(child);
+
+ /*
+ * Copy over the x86_saved_state registers
+ */
+ if (cpu_mode_is64bit()) {
+ if (thread_is_64bit(parent))
+ bcopy(USER_REGS64(parent), USER_REGS64(child), sizeof(x86_saved_state64_t));
+ else
+ bcopy(USER_REGS32(parent), USER_REGS32(child), sizeof(x86_saved_state_compat32_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(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);
+}
+
+void thread_set_parent(thread_t parent, int pid);
+
+void
+thread_set_parent(thread_t parent, int pid)
+{
+ pal_register_cache_state(parent, DIRTY);
+
+ if (thread_is_64bit(parent)) {
+ x86_saved_state64_t *iss64;
+
+ iss64 = USER_REGS64(parent);
+
+ iss64->rax = pid;
+ iss64->rdx = 0;
+ iss64->isf.rflags &= ~EFL_CF;
+ } else {
+ x86_saved_state32_t *iss32;
+
+ iss32 = USER_REGS32(parent);
+
+ iss32->eax = pid;
+ iss32->edx = 0;
+ iss32->efl &= ~EFL_CF;
+ }
+}
+
+/*
+ * 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)
+{
+ thread_t thread = current_thread();
+ pcb_t pcb = THREAD_TO_PCB(thread);
+ struct real_descriptor desc = {
+ .limit_low = 1,
+ .limit_high = 0,
+ .base_low = self & 0xffff,
+ .base_med = (self >> 16) & 0xff,
+ .base_high = (self >> 24) & 0xff,
+ .access = ACC_P|ACC_PL_U|ACC_DATA_W,
+ .granularity = SZ_32|SZ_G,
+ };
+
+ current_thread()->machine.cthread_self = (uint64_t) self; /* preserve old func too */
+
+ /* assign descriptor */
+ mp_disable_preemption();
+ pcb->cthread_desc = desc;
+ *ldt_desc_p(USER_CTHREAD) = desc;
+ saved_state32(pcb->iss)->gs = USER_CTHREAD;
+ mp_enable_preemption();
+
+ return (USER_CTHREAD);
+}
+
+/*
+ * 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)
+{
+ pcb_t pcb = THREAD_TO_PCB(current_thread());
+ cpu_data_t *cdp;
+
+ /* check for canonical address, set 0 otherwise */
+ if (!IS_USERADDR64_CANONICAL(self))
+ self = 0ULL;
+
+ pcb->cthread_self = self;
+ mp_disable_preemption();
+ cdp = current_cpu_datap();
+#if defined(__x86_64__)
+ if ((cdp->cpu_uber.cu_user_gs_base != pcb->cthread_self) ||
+ (pcb->cthread_self != rdmsr64(MSR_IA32_KERNEL_GS_BASE)))
+ wrmsr64(MSR_IA32_KERNEL_GS_BASE, self);
+#endif
+ cdp->cpu_uber.cu_user_gs_base = self;
+ mp_enable_preemption();
+ 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;
+}
projects / apple / xnu.git / blobdiff