xnu-1699.32.7.tar.gz

[apple/xnu.git] / osfmk / i386 / pcb_native.c

/*
 * Copyright (c) 2000-2010 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@
 */
/*
 * @OSF_COPYRIGHT@
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */

#include <mach_rt.h>
#include <mach_debug.h>
#include <mach_ldebug.h>

#include <sys/kdebug.h>

#include <mach/kern_return.h>
#include <mach/thread_status.h>
#include <mach/vm_param.h>

#include <kern/counters.h>
#include <kern/kalloc.h>
#include <kern/mach_param.h>
#include <kern/processor.h>
#include <kern/cpu_data.h>
#include <kern/cpu_number.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/spl.h>
#include <kern/machine.h>
#include <ipc/ipc_port.h>
#include <vm/vm_kern.h>
#include <vm/vm_map.h>
#include <vm/pmap.h>
#include <vm/vm_protos.h>

#include <i386/commpage/commpage.h>
#include <i386/cpu_data.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/mp_desc.h>
#include <i386/misc_protos.h>
#include <i386/thread.h>
#if defined(__i386__)
#include <i386/fpu.h>
#endif
#include <i386/seg.h>
#include <i386/machine_routines.h>

#define ASSERT_IS_16BYTE_MULTIPLE_SIZEOF(_type_)        \
extern char assert_is_16byte_multiple_sizeof_ ## _type_ \
                [(sizeof(_type_) % 16) == 0 ? 1 : -1]

/* Compile-time checks for vital save area sizing: */
ASSERT_IS_16BYTE_MULTIPLE_SIZEOF(x86_64_intr_stack_frame_t);
ASSERT_IS_16BYTE_MULTIPLE_SIZEOF(x86_sframe64_t);
ASSERT_IS_16BYTE_MULTIPLE_SIZEOF(x86_saved_state_compat32_t);
ASSERT_IS_16BYTE_MULTIPLE_SIZEOF(x86_saved_state_t);

#define DIRECTION_FLAG_DEBUG (DEBUG | DEVELOPMENT)

extern zone_t           iss_zone;               /* zone for saved_state area */
extern zone_t           ids_zone;               /* zone for debug_state area */

extern void *get_bsduthreadarg(thread_t);
void
act_machine_switch_pcb(__unused thread_t old, thread_t new)
{
        pcb_t                   pcb = THREAD_TO_PCB(new);
        cpu_data_t              *cdp = current_cpu_datap();
        struct real_descriptor  *ldtp;
        mach_vm_offset_t        pcb_stack_top;

        assert(new->kernel_stack != 0);
        assert(ml_get_interrupts_enabled() == FALSE);
#ifdef  DIRECTION_FLAG_DEBUG
        if (x86_get_flags() & EFL_DF) {
                panic("Direction flag detected: 0x%lx", x86_get_flags());
        }
#endif

#if defined(__x86_64__)
        /*
         * Clear segment state
         * unconditionally for DS/ES/FS but more carefully for GS whose
         * cached state we track.
         */
        set_ds(NULL_SEG);
        set_es(NULL_SEG);
        set_fs(NULL_SEG);
        if (get_gs() != NULL_SEG) {
                swapgs();               /* switch to user's GS context */
                set_gs(NULL_SEG);
                swapgs();               /* and back to kernel */

                /* record the active machine state lost */
                cdp->cpu_uber.cu_user_gs_base = 0;
        } 

        if (is_saved_state64(pcb->iss)) {
                /*
                 * The test above is performed against the thread save state
                 * flavor and not task's 64-bit feature flag because of the
                 * thread/task 64-bit state divergence that can arise in
                 * task_set_64bit() x86: the task state is changed before
                 * the individual thread(s).
                 */
                x86_saved_state64_tagged_t      *iss64;
                vm_offset_t                     isf;

                assert(is_saved_state64(pcb->iss));
                                                   
                iss64 = (x86_saved_state64_tagged_t *) pcb->iss;
        
                /*
                 * Set pointer to PCB's interrupt stack frame in cpu data.
                 * Used by syscall and double-fault trap handlers.
                 */
                isf = (vm_offset_t) &iss64->state.isf;
                cdp->cpu_uber.cu_isf = isf;
                pcb_stack_top = (vm_offset_t) (iss64 + 1);
                /* require 16-byte alignment */
                assert((pcb_stack_top & 0xF) == 0);

                /* Interrupt stack is pcb */
                current_ktss64()->rsp0 = pcb_stack_top;

                /*
                 * Top of temporary sysenter stack points to pcb stack.
                 * Although this is not normally used by 64-bit users,
                 * it needs to be set in case a sysenter is attempted.
                 */
                *current_sstk64() = pcb_stack_top;

                cdp->cpu_task_map = new->map->pmap->pm_task_map; 

                /*
                 * Enable the 64-bit user code segment, USER64_CS.
                 * Disable the 32-bit user code segment, USER_CS.
                 */
                ldt_desc_p(USER64_CS)->access |= ACC_PL_U;
                ldt_desc_p(USER_CS)->access &= ~ACC_PL_U;

                /*
                 * Switch user's GS base if necessary
                 * by setting the Kernel's GS base MSR
                 * - this will become the user's on the swapgs when
                 * returning to user-space.  Avoid this for
                 * kernel threads (no user TLS support required)
                 * and verify the memory shadow of the segment base
                 * in the event it was altered in user space.
                 */
                if ((pcb->cthread_self != 0) || (new->task != kernel_task)) {
                        if ((cdp->cpu_uber.cu_user_gs_base != pcb->cthread_self) || (pcb->cthread_self != rdmsr64(MSR_IA32_KERNEL_GS_BASE))) {
                                cdp->cpu_uber.cu_user_gs_base = pcb->cthread_self;
                                wrmsr64(MSR_IA32_KERNEL_GS_BASE, pcb->cthread_self);
                        }
                }
        } else {
                x86_saved_state_compat32_t      *iss32compat;
                vm_offset_t                     isf;

                assert(is_saved_state32(pcb->iss));
                iss32compat = (x86_saved_state_compat32_t *) pcb->iss;

                pcb_stack_top = (uintptr_t) (iss32compat + 1);
                /* require 16-byte alignment */
                assert((pcb_stack_top & 0xF) == 0);

                /*
                 * Set pointer to PCB's interrupt stack frame in cpu data.
                 * Used by debug trap handler.
                 */
                isf = (vm_offset_t) &iss32compat->isf64;
                cdp->cpu_uber.cu_isf = isf;

                /* Top of temporary sysenter stack points to pcb stack */
                *current_sstk64() = pcb_stack_top;

                /* Interrupt stack is pcb */
                current_ktss64()->rsp0 = pcb_stack_top;

                cdp->cpu_task_map = TASK_MAP_32BIT;
                /* Precalculate pointers to syscall argument store, for use
                 * in the trampolines.
                 */
                cdp->cpu_uber_arg_store = (vm_offset_t)get_bsduthreadarg(new);
                cdp->cpu_uber_arg_store_valid = (vm_offset_t)&pcb->arg_store_valid;
                pcb->arg_store_valid = 0;

                /*
                 * Disable USER64_CS
                 * Enable USER_CS
                 */
                ldt_desc_p(USER64_CS)->access &= ~ACC_PL_U;
                ldt_desc_p(USER_CS)->access |= ACC_PL_U;

                /*
                 * Set the thread`s cthread (a.k.a pthread)
                 * For 32-bit user this involves setting the USER_CTHREAD
                 * descriptor in the LDT to point to the cthread data.
                 * The involves copying in the pre-initialized descriptor.
                 */ 
                ldtp = (struct real_descriptor *)current_ldt();
                ldtp[sel_idx(USER_CTHREAD)] = pcb->cthread_desc;
                if (pcb->uldt_selector != 0)
                        ldtp[sel_idx(pcb->uldt_selector)] = pcb->uldt_desc;
                cdp->cpu_uber.cu_user_gs_base = pcb->cthread_self;

                /*
                 * Set the thread`s LDT or LDT entry.
                 */
                if (new->task == TASK_NULL || new->task->i386_ldt == 0) {
                        /*
                         * Use system LDT.
                         */
                        ml_cpu_set_ldt(KERNEL_LDT);
                } else {
                        /*
                         * Task has its own LDT.
                         */
                        user_ldt_set(new);
                }
        }

#else /* !__x86_64__ */

        vm_offset_t             hi_pcb_stack_top;
        vm_offset_t             hi_iss;

        if (!cpu_mode_is64bit()) {
                x86_saved_state32_tagged_t      *hi_iss32;
                /*
                 *      Save a pointer to the top of the "kernel" stack -
                 *      actually the place in the PCB where a trap into
                 *      kernel mode will push the registers.
                 */
                hi_iss = (vm_offset_t)((unsigned long)
                        pmap_cpu_high_map_vaddr(cpu_number(), HIGH_CPU_ISS0) |
                        ((unsigned long)pcb->iss & PAGE_MASK));

                cdp->cpu_hi_iss = (void *)hi_iss;

                pmap_high_map(pcb->iss_pte0, HIGH_CPU_ISS0);
                pmap_high_map(pcb->iss_pte1, HIGH_CPU_ISS1);

                hi_iss32 = (x86_saved_state32_tagged_t *) hi_iss;
                assert(hi_iss32->tag == x86_SAVED_STATE32);

                hi_pcb_stack_top = (int) (hi_iss32 + 1);

                /*
                 * For fast syscall, top of interrupt stack points to pcb stack
                 */
                *(vm_offset_t *) current_sstk() = hi_pcb_stack_top;

                current_ktss()->esp0 = hi_pcb_stack_top;

        } else if (is_saved_state64(pcb->iss)) {
                /*
                 * The test above is performed against the thread save state
                 * flavor and not task's 64-bit feature flag because of the
                 * thread/task 64-bit state divergence that can arise in
                 * task_set_64bit() x86: the task state is changed before
                 * the individual thread(s).
                 */
                x86_saved_state64_tagged_t      *iss64;
                vm_offset_t                     isf;

                assert(is_saved_state64(pcb->iss));
                                                   
                iss64 = (x86_saved_state64_tagged_t *) pcb->iss;
        
                /*
                 * Set pointer to PCB's interrupt stack frame in cpu data.
                 * Used by syscall and double-fault trap handlers.
                 */
                isf = (vm_offset_t) &iss64->state.isf;
                cdp->cpu_uber.cu_isf = UBER64(isf);
                pcb_stack_top = (vm_offset_t) (iss64 + 1);
                /* require 16-byte alignment */
                assert((pcb_stack_top & 0xF) == 0);
                /* Interrupt stack is pcb */
                current_ktss64()->rsp0 = UBER64(pcb_stack_top);

                /*
                 * Top of temporary sysenter stack points to pcb stack.
                 * Although this is not normally used by 64-bit users,
                 * it needs to be set in case a sysenter is attempted.
                 */
                *current_sstk64() = UBER64(pcb_stack_top);

                cdp->cpu_task_map = new->map->pmap->pm_task_map; 

                /*
                 * Enable the 64-bit user code segment, USER64_CS.
                 * Disable the 32-bit user code segment, USER_CS.
                 */
                ldt_desc_p(USER64_CS)->access |= ACC_PL_U;
                ldt_desc_p(USER_CS)->access &= ~ACC_PL_U;

        } else {
                x86_saved_state_compat32_t      *iss32compat;
                vm_offset_t                     isf;

                assert(is_saved_state32(pcb->iss));
                iss32compat = (x86_saved_state_compat32_t *) pcb->iss;

                pcb_stack_top = (int) (iss32compat + 1);
                /* require 16-byte alignment */
                assert((pcb_stack_top & 0xF) == 0);

                /*
                 * Set pointer to PCB's interrupt stack frame in cpu data.
                 * Used by debug trap handler.
                 */
                isf = (vm_offset_t) &iss32compat->isf64;
                cdp->cpu_uber.cu_isf = UBER64(isf);

                /* Top of temporary sysenter stack points to pcb stack */
                *current_sstk64() = UBER64(pcb_stack_top);

                /* Interrupt stack is pcb */
                current_ktss64()->rsp0 = UBER64(pcb_stack_top);

                cdp->cpu_task_map = TASK_MAP_32BIT;
                /* Precalculate pointers to syscall argument store, for use
                 * in the trampolines.
                 */
                cdp->cpu_uber_arg_store = UBER64((vm_offset_t)get_bsduthreadarg(new));
                cdp->cpu_uber_arg_store_valid = UBER64((vm_offset_t)&pcb->arg_store_valid);
                pcb->arg_store_valid = 0;

                /*
                 * Disable USER64_CS
                 * Enable USER_CS
                 */
                ldt_desc_p(USER64_CS)->access &= ~ACC_PL_U;
                ldt_desc_p(USER_CS)->access |= ACC_PL_U;
        }

        /*
         * Set the thread`s cthread (a.k.a pthread)
         * For 32-bit user this involves setting the USER_CTHREAD
         * descriptor in the LDT to point to the cthread data.
         * The involves copying in the pre-initialized descriptor.
         */ 
        ldtp = (struct real_descriptor *)current_ldt();
        ldtp[sel_idx(USER_CTHREAD)] = pcb->cthread_desc;
        if (pcb->uldt_selector != 0)
                ldtp[sel_idx(pcb->uldt_selector)] = pcb->uldt_desc;

        /*
         * For 64-bit, we additionally set the 64-bit User GS base
         * address. On return to 64-bit user, the GS.Base MSR will be written.
         */
        cdp->cpu_uber.cu_user_gs_base = pcb->cthread_self;

        /*
         * Set the thread`s LDT or LDT entry.
         */
        if (new->task == TASK_NULL || new->task->i386_ldt == 0) {
                /*
                 * Use system LDT.
                 */
                ml_cpu_set_ldt(KERNEL_LDT);
        } else {
                /*
                 * Task has its own LDT.
                 */
                user_ldt_set(new);
        }
#endif

        /*
         * Bump the scheduler generation count in the commpage.
         * This can be read by user code to detect its preemption.
         */
        commpage_sched_gen_inc();
}
void
thread_set_wq_state32(thread_t thread, thread_state_t tstate)
{
        x86_thread_state32_t    *state;
        x86_saved_state32_t     *saved_state;
        thread_t curth = current_thread();
        spl_t                   s=0;

        pal_register_cache_state(thread, DIRTY);

        saved_state = USER_REGS32(thread);

        state = (x86_thread_state32_t *)tstate;
        
        if (curth != thread) {
                s = splsched();
                thread_lock(thread);
        }

        saved_state->ebp = 0;
        saved_state->eip = state->eip;
        saved_state->eax = state->eax;
        saved_state->ebx = state->ebx;
        saved_state->ecx = state->ecx;
        saved_state->edx = state->edx;
        saved_state->edi = state->edi;
        saved_state->esi = state->esi;
        saved_state->uesp = state->esp;
        saved_state->efl = EFL_USER_SET;

        saved_state->cs = USER_CS;
        saved_state->ss = USER_DS;
        saved_state->ds = USER_DS;
        saved_state->es = USER_DS;

        if (curth != thread) {
                thread_unlock(thread);
                splx(s);
        }
}


void
thread_set_wq_state64(thread_t thread, thread_state_t tstate)
{
        x86_thread_state64_t    *state;
        x86_saved_state64_t     *saved_state;
        thread_t curth = current_thread();
        spl_t                   s=0;

        pal_register_cache_state(thread, DIRTY);

        saved_state = USER_REGS64(thread);
        state = (x86_thread_state64_t *)tstate;
        
        if (curth != thread) {
                s = splsched();
                thread_lock(thread);
        }

        saved_state->rbp = 0;
        saved_state->rdi = state->rdi;
        saved_state->rsi = state->rsi;
        saved_state->rdx = state->rdx;
        saved_state->rcx = state->rcx;
        saved_state->r8  = state->r8;
        saved_state->r9  = state->r9;

        saved_state->isf.rip = state->rip;
        saved_state->isf.rsp = state->rsp;
        saved_state->isf.cs = USER64_CS;
        saved_state->isf.rflags = EFL_USER_SET;

        if (curth != thread) {
                thread_unlock(thread);
                splx(s);
        }
}

/*
 * Initialize the machine-dependent state for a new thread.
 */
kern_return_t
machine_thread_create(
        thread_t                thread,
        task_t                  task)
{
        pcb_t                   pcb = THREAD_TO_PCB(thread);
        x86_saved_state_t       *iss;

#if NCOPY_WINDOWS > 0
        inval_copy_windows(thread);

        thread->machine.physwindow_pte = 0;
        thread->machine.physwindow_busy = 0;
#endif

        /*
         * Allocate save frame only if required.
         */
        if (pcb->sf == NULL) {
                assert((get_preemption_level() == 0));
                pcb->sf = zalloc(iss_zone);
                if (pcb->sf == NULL)
                        panic("iss_zone");
        }

        if (task_has_64BitAddr(task)) {
                x86_sframe64_t          *sf64;

                sf64 = (x86_sframe64_t *) pcb->sf;

                bzero((char *)sf64, sizeof(x86_sframe64_t));

                iss = (x86_saved_state_t *) &sf64->ssf;
                iss->flavor = x86_SAVED_STATE64;
                /*
                 *      Guarantee that the bootstrapped thread will be in user
                 *      mode.
                 */
                iss->ss_64.isf.rflags = EFL_USER_SET;
                iss->ss_64.isf.cs = USER64_CS;
                iss->ss_64.isf.ss = USER_DS;
                iss->ss_64.fs = USER_DS;
                iss->ss_64.gs = USER_DS;
        } else {
                if (cpu_mode_is64bit()) {
                        x86_sframe_compat32_t      *sfc32;

                        sfc32 = (x86_sframe_compat32_t *)pcb->sf;

                        bzero((char *)sfc32, sizeof(x86_sframe_compat32_t));

                        iss = (x86_saved_state_t *) &sfc32->ssf.iss32;
                        iss->flavor = x86_SAVED_STATE32;
#if defined(__i386__)
#if DEBUG
                        {
                                sfc32->pad_for_16byte_alignment[0] = 0x64326432;
                                sfc32->pad_for_16byte_alignment[1] = 0x64326432;
                        }
#endif /* DEBUG */
                } else {
                        x86_sframe32_t          *sf32;
                        struct real_descriptor  *ldtp;
                        pmap_paddr_t            paddr;

                        sf32 = (x86_sframe32_t *) pcb->sf;

                        bzero((char *)sf32, sizeof(x86_sframe32_t));

                        iss = (x86_saved_state_t *) &sf32->ssf;
                        iss->flavor = x86_SAVED_STATE32;

                        pcb->iss_pte0 = pte_kernel_rw(kvtophys((vm_offset_t)iss));
                        if (0 == (paddr = pa_to_pte(kvtophys((vm_offset_t)iss + PAGE_SIZE))))
                                pcb->iss_pte1 = INTEL_PTE_INVALID;
                        else
                                pcb->iss_pte1 = pte_kernel_rw(paddr);

                        ldtp = (struct real_descriptor *)
                                    pmap_index_to_virt(HIGH_FIXED_LDT_BEGIN);
                        pcb->cthread_desc = ldtp[sel_idx(USER_DS)];
                        pcb->uldt_desc = ldtp[sel_idx(USER_DS)];
#endif /* __i386__ */
                }
                /*
                 *      Guarantee that the bootstrapped thread will be in user
                 *      mode.
                 */
                iss->ss_32.cs = USER_CS;
                iss->ss_32.ss = USER_DS;
                iss->ss_32.ds = USER_DS;
                iss->ss_32.es = USER_DS;
                iss->ss_32.fs = USER_DS;
                iss->ss_32.gs = USER_DS;
                iss->ss_32.efl = EFL_USER_SET;

        }
        pcb->iss = iss;

        simple_lock_init(&pcb->lock, 0);

        pcb->arg_store_valid = 0;
        pcb->cthread_self = 0;
        pcb->uldt_selector = 0;

        /* Ensure that the "cthread" descriptor describes a valid
         * segment.
         */
        if ((pcb->cthread_desc.access & ACC_P) == 0) {
                struct real_descriptor  *ldtp;
                ldtp = (struct real_descriptor *)current_ldt();
                pcb->cthread_desc = ldtp[sel_idx(USER_DS)];
        }

        return(KERN_SUCCESS);
}

/*
 * Machine-dependent cleanup prior to destroying a thread
 */
void
machine_thread_destroy(
        thread_t                thread)
{
        register pcb_t  pcb = THREAD_TO_PCB(thread);

        if (pcb->ifps != 0)
                fpu_free(pcb->ifps);
        if (pcb->sf != 0) {
                zfree(iss_zone, pcb->sf);
                pcb->sf = 0;
        }
        if (pcb->ids) {
                zfree(ids_zone, pcb->ids);
                pcb->ids = NULL;
        }
}