]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/i386/trap.c
xnu-2422.115.4.tar.gz
[apple/xnu.git] / osfmk / i386 / trap.c
index 55be4fc7585cced87da54cf6238ed6e7fbce11a5..e15f40b059769587ba11c69b239b76900b4d4a72 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2010 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2012 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
@@ -60,8 +60,6 @@
 * Hardware trap/fault handler.
  */
 
-#include <mach_kdb.h>
-#include <mach_kgdb.h>
 #include <mach_kdp.h>
 #include <mach_ldebug.h>
 
 #include <kern/spl.h>
 #include <kern/misc_protos.h>
 #include <kern/debug.h>
-
+#if CONFIG_TELEMETRY
+#include <kern/telemetry.h>
+#endif
 #include <sys/kdebug.h>
 
-#if    MACH_KGDB
-#include <kgdb/kgdb_defs.h>
-#endif /* MACH_KGDB */
-
-#if    MACH_KDB
-#include <debug.h>
-#include <ddb/db_watch.h>
-#include <ddb/db_run.h>
-#include <ddb/db_break.h>
-#include <ddb/db_trap.h>
-#endif /* MACH_KDB */
-
 #include <string.h>
 
 #include <i386/postcode.h>
 #include <mach/i386/syscall_sw.h>
 
 #include <libkern/OSDebug.h>
-
+#include <i386/cpu_threads.h>
 #include <machine/pal_routines.h>
 
 extern void throttle_lowpri_io(int);
@@ -127,14 +115,8 @@ extern void kprint_state(x86_saved_state64_t *saved_state);
  * Forward declarations
  */
 static void user_page_fault_continue(kern_return_t kret);
-#ifdef __i386__
-static void panic_trap(x86_saved_state32_t *saved_state);
-static void set_recovery_ip(x86_saved_state32_t *saved_state, vm_offset_t ip);
-extern void panic_64(x86_saved_state_t *, int, const char *, boolean_t);
-#else
 static void panic_trap(x86_saved_state64_t *saved_state);
 static void set_recovery_ip(x86_saved_state64_t *saved_state, vm_offset_t ip);
-#endif
 
 volatile perfCallback perfTrapHook = NULL; /* Pointer to CHUD trap hook routine */
 
@@ -145,6 +127,8 @@ perfCallback tempDTraceTrapHook = NULL; /* Pointer to DTrace fbt trap hook routi
 extern boolean_t dtrace_tally_fault(user_addr_t);
 #endif
 
+extern boolean_t pmap_smep_enabled;
+
 void
 thread_syscall_return(
         kern_return_t ret)
@@ -165,7 +149,7 @@ thread_syscall_return(
                            == (SYSCALL_CLASS_MACH << SYSCALL_CLASS_SHIFT);
                if (kdebug_enable && is_mach) {
                        /* Mach trap */
-                       KERNEL_DEBUG_CONSTANT(
+                       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, 
                              MACHDBG_CODE(DBG_MACH_EXCP_SC,code)|DBG_FUNC_END,
                              ret, 0, 0, 0, 0);
                }
@@ -189,7 +173,7 @@ thread_syscall_return(
                is_mach = (code < 0);
                if (kdebug_enable && is_mach) {
                        /* Mach trap */
-                       KERNEL_DEBUG_CONSTANT(
+                       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, 
                              MACHDBG_CODE(DBG_MACH_EXCP_SC,-code)|DBG_FUNC_END,
                              ret, 0, 0, 0, 0);
                }
@@ -205,51 +189,13 @@ thread_syscall_return(
                                ret);
 #endif
        }
-       throttle_lowpri_io(TRUE);
+       throttle_lowpri_io(1);
 
        thread_exception_return();
         /*NOTREACHED*/
 }
 
 
-#if    MACH_KDB
-boolean_t      debug_all_traps_with_kdb = FALSE;
-extern struct db_watchpoint *db_watchpoint_list;
-extern boolean_t db_watchpoints_inserted;
-extern boolean_t db_breakpoints_inserted;
-
-void
-thread_kdb_return(void)
-{
-       thread_t                thr_act = current_thread();
-       x86_saved_state_t       *iss = USER_STATE(thr_act);
-
-       pal_register_cache_state(thr_act, DIRTY);
-
-        if (is_saved_state64(iss)) {
-               x86_saved_state64_t     *regs;
-               
-               regs = saved_state64(iss);
-
-               if (kdb_trap(regs->isf.trapno, (int)regs->isf.err, (void *)regs)) {
-                       thread_exception_return();
-                       /*NOTREACHED*/
-               }
-
-       } else {
-               x86_saved_state32_t     *regs;
-               
-               regs = saved_state32(iss);
-
-               if (kdb_trap(regs->trapno, regs->err, (void *)regs)) {
-                       thread_exception_return();
-                       /*NOTREACHED*/
-               }
-       }
-}
-
-#endif /* MACH_KDB */
-
 static inline void
 user_page_fault_continue(
                         kern_return_t  kr)
@@ -257,61 +203,20 @@ user_page_fault_continue(
        thread_t        thread = current_thread();
        user_addr_t     vaddr;
 
-#if    MACH_KDB
-       x86_saved_state_t *regs = USER_STATE(thread);
-       int             err;
-       int             trapno;
-
-       assert((is_saved_state32(regs) && !thread_is_64bit(thread)) ||
-              (is_saved_state64(regs) &&  thread_is_64bit(thread)));
-#endif
-
-        if (thread_is_64bit(thread)) {
-               x86_saved_state64_t     *uregs;
+       if (thread_is_64bit(thread)) {
+               x86_saved_state64_t     *uregs;
 
                uregs = USER_REGS64(thread);
 
-#if    MACH_KDB
-               trapno = uregs->isf.trapno;
-               err = (int)uregs->isf.err;
-#endif
                vaddr = (user_addr_t)uregs->cr2;
        } else {
                x86_saved_state32_t     *uregs;
 
                uregs = USER_REGS32(thread);
 
-#if    MACH_KDB
-               trapno = uregs->trapno;
-               err = uregs->err;
-#endif
                vaddr = uregs->cr2;
        }
 
-       if (__probable((kr == KERN_SUCCESS) || (kr == KERN_ABORTED))) {
-#if    MACH_KDB
-               if (!db_breakpoints_inserted) {
-                       db_set_breakpoints();
-               }
-               if (db_watchpoint_list &&
-                   db_watchpoints_inserted &&
-                   (err & T_PF_WRITE) &&
-                   db_find_watchpoint(thread->map,
-                                      (vm_offset_t)vaddr,
-                                      saved_state32(regs)))
-                       kdb_trap(T_WATCHPOINT, 0, saved_state32(regs));
-#endif /* MACH_KDB */
-               thread_exception_return();
-               /*NOTREACHED*/
-       }
-
-#if    MACH_KDB
-       if (debug_all_traps_with_kdb &&
-           kdb_trap(trapno, err, saved_state32(regs))) {
-               thread_exception_return();
-               /*NOTREACHED*/
-       }
-#endif /* MACH_KDB */
 
        /* PAL debug hook */
        pal_dbg_page_fault( thread, vaddr, kr );
@@ -426,6 +331,9 @@ void interrupt_populate_latency_stats(char *buf, unsigned bufsize) {
                snprintf(buf, bufsize, "0x%x 0x%x 0x%llx", tcpu, cpu_data_ptr[tcpu]->cpu_max_observed_int_latency_vector, cpu_data_ptr[tcpu]->cpu_max_observed_int_latency);
 }
 
+uint32_t interrupt_timer_coalescing_enabled = 1;
+uint64_t interrupt_coalesced_timers;
+
 /*
  * Handle interrupts:
  *  - local APIC interrupts (IPIs, timers, etc) are handled by the kernel,
@@ -440,6 +348,8 @@ interrupt(x86_saved_state_t *state)
        boolean_t       user_mode = FALSE;
        int             ipl;
        int             cnum = cpu_number();
+       cpu_data_t      *cdp = cpu_data_ptr[cnum];
+       int             itype = 0;
 
        if (is_saved_state64(state) == TRUE) {
                x86_saved_state64_t     *state64;
@@ -463,14 +373,37 @@ interrupt(x86_saved_state_t *state)
                interrupt_num = state32->trapno;
        }
 
-       KERNEL_DEBUG_CONSTANT(
+       if (cpu_data_ptr[cnum]->lcpu.package->num_idle == topoParms.nLThreadsPerPackage)
+               cpu_data_ptr[cnum]->cpu_hwIntpexits[interrupt_num]++;
+
+       if (interrupt_num == (LAPIC_DEFAULT_INTERRUPT_BASE + LAPIC_INTERPROCESSOR_INTERRUPT))
+               itype = 1;
+       else if (interrupt_num == (LAPIC_DEFAULT_INTERRUPT_BASE + LAPIC_TIMER_INTERRUPT))
+               itype = 2;
+       else
+               itype = 3;
+
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, 
                MACHDBG_CODE(DBG_MACH_EXCP_INTR, 0) | DBG_FUNC_START,
-               interrupt_num, rip, user_mode, 0, 0);
+               interrupt_num,
+               (user_mode ? rip : VM_KERNEL_UNSLIDE(rip)),
+               user_mode, itype, 0);
 
        SCHED_STATS_INTERRUPT(current_processor());
 
-       ipl = get_preemption_level();
+#if CONFIG_TELEMETRY
+       if (telemetry_needs_record
+               && (current_task() != kernel_task)
+#if CONFIG_SCHED_IDLE_IN_PLACE
+               && ((current_thread()->state & TH_IDLE) == 0) /* idle-in-place should be treated like the idle thread */
+#endif
+               ) {
+               telemetry_mark_curthread(user_mode);
+       }
+#endif
 
+       ipl = get_preemption_level();
+       
        /*
         * Handle local APIC interrupts
         * else call platform expert for devices.
@@ -482,21 +415,41 @@ interrupt(x86_saved_state_t *state)
                panic("Preemption level altered by interrupt vector 0x%x: initial 0x%x, final: 0x%x\n", interrupt_num, ipl, get_preemption_level());
        }
 
-       KERNEL_DEBUG_CONSTANT(
-               MACHDBG_CODE(DBG_MACH_EXCP_INTR, 0) | DBG_FUNC_END,
-               interrupt_num, 0, 0, 0, 0);
 
-       if (cpu_data_ptr[cnum]->cpu_nested_istack) {
-               cpu_data_ptr[cnum]->cpu_nested_istack_events++;
+       if (__improbable(cdp->cpu_nested_istack)) {
+               cdp->cpu_nested_istack_events++;
        }
        else  {
-               uint64_t int_latency = mach_absolute_time() - cpu_data_ptr[cnum]->cpu_int_event_time;
-               if (ilat_assert && (int_latency > interrupt_latency_cap) && !machine_timeout_suspended()) {
-                       panic("Interrupt vector 0x%x exceeded interrupt latency threshold, 0x%llx absolute time delta, prior signals: 0x%x, current signals: 0x%x", interrupt_num, int_latency, cpu_data_ptr[cnum]->cpu_prior_signals, cpu_data_ptr[cnum]->cpu_signals);
+               uint64_t ctime = mach_absolute_time();
+               uint64_t int_latency = ctime - cdp->cpu_int_event_time;
+               uint64_t esdeadline, ehdeadline;
+               /* Attempt to process deferred timers in the context of
+                * this interrupt, unless interrupt time has already exceeded
+                * TCOAL_ILAT_THRESHOLD.
+                */
+#define TCOAL_ILAT_THRESHOLD (30000ULL)
+
+               if ((int_latency < TCOAL_ILAT_THRESHOLD) &&
+                   interrupt_timer_coalescing_enabled) {
+                       esdeadline = cdp->rtclock_timer.queue.earliest_soft_deadline;
+                       ehdeadline = cdp->rtclock_timer.deadline;
+                       if ((ctime >= esdeadline) && (ctime < ehdeadline)) {
+                               interrupt_coalesced_timers++;
+                               TCOAL_DEBUG(0x88880000 | DBG_FUNC_START, ctime, esdeadline, ehdeadline, interrupt_coalesced_timers, 0);
+                               rtclock_intr(state);
+                               TCOAL_DEBUG(0x88880000 | DBG_FUNC_END, ctime, esdeadline, interrupt_coalesced_timers, 0, 0);
+                       } else {
+                               TCOAL_DEBUG(0x77770000, ctime, cdp->rtclock_timer.queue.earliest_soft_deadline, cdp->rtclock_timer.deadline, interrupt_coalesced_timers, 0);
+                       }
                }
-               if (int_latency > cpu_data_ptr[cnum]->cpu_max_observed_int_latency) {
-                       cpu_data_ptr[cnum]->cpu_max_observed_int_latency = int_latency;
-                       cpu_data_ptr[cnum]->cpu_max_observed_int_latency_vector = interrupt_num;
+
+               if (__improbable(ilat_assert && (int_latency > interrupt_latency_cap) && !machine_timeout_suspended())) {
+                       panic("Interrupt vector 0x%x exceeded interrupt latency threshold, 0x%llx absolute time delta, prior signals: 0x%x, current signals: 0x%x", interrupt_num, int_latency, cdp->cpu_prior_signals, cdp->cpu_signals);
+               }
+
+               if (__improbable(int_latency > cdp->cpu_max_observed_int_latency)) {
+                       cdp->cpu_max_observed_int_latency = int_latency;
+                       cdp->cpu_max_observed_int_latency_vector = interrupt_num;
                }
        }
 
@@ -504,17 +457,22 @@ interrupt(x86_saved_state_t *state)
         * Having serviced the interrupt first, look at the interrupted stack depth.
         */
        if (!user_mode) {
-               uint64_t depth = cpu_data_ptr[cnum]->cpu_kernel_stack
+               uint64_t depth = cdp->cpu_kernel_stack
                                 + sizeof(struct x86_kernel_state)
                                 + sizeof(struct i386_exception_link *)
                                 - rsp;
-               if (depth > kernel_stack_depth_max) {
+               if (__improbable(depth > kernel_stack_depth_max)) {
                        kernel_stack_depth_max = (vm_offset_t)depth;
                        KERNEL_DEBUG_CONSTANT(
                                MACHDBG_CODE(DBG_MACH_SCHED, MACH_STACK_DEPTH),
-                               (long) depth, (long) rip, 0, 0, 0);
+                               (long) depth, (long) VM_KERNEL_UNSLIDE(rip), 0, 0, 0);
                }
        }
+       
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, 
+               MACHDBG_CODE(DBG_MACH_EXCP_INTR, 0) | DBG_FUNC_END,
+               interrupt_num, 0, 0, 0, 0);
+
 }
 
 static inline void
@@ -540,11 +498,7 @@ kernel_trap(
        x86_saved_state_t       *state,
        uintptr_t *lo_spp)
 {
-#ifdef __i386__
-       x86_saved_state32_t     *saved_state;
-#else
        x86_saved_state64_t     *saved_state;
-#endif
        int                     code;
        user_addr_t             vaddr;
        int                     type;
@@ -560,28 +514,9 @@ kernel_trap(
        int                     fault_in_copy_window = -1;
 #endif
        int                     is_user = 0;
-#if MACH_KDB
-       pt_entry_t              *pte;
-#endif /* MACH_KDB */
        
        thread = current_thread();
 
-#ifdef __i386__
-       if (__improbable(is_saved_state64(state))) {
-               panic_64(state, 0, "Kernel trap with 64-bit state", FALSE);
-       }
-
-       saved_state = saved_state32(state);
-
-       /* Record cpu where state was captured (trampolines don't set this) */
-       saved_state->cpu = cpu_number();
-
-       vaddr = (user_addr_t)saved_state->cr2;
-       type  = saved_state->trapno;
-       code  = saved_state->err & 0xffff;
-       intr  = (saved_state->efl & EFL_IF) != 0;       /* state of ints at trap */
-       kern_ip = (vm_offset_t)saved_state->eip;
-#else
        if (__improbable(is_saved_state32(state)))
                panic("kernel_trap(%p) with 32-bit state", state);
        saved_state = saved_state64(state);
@@ -594,7 +529,6 @@ kernel_trap(
        code  = (int)(saved_state->isf.err & 0xffff);
        intr  = (saved_state->isf.rflags & EFL_IF) != 0;        /* state of ints at trap */
        kern_ip = (vm_offset_t)saved_state->isf.rip;
-#endif
 
        myast = ast_pending();
 
@@ -637,8 +571,9 @@ kernel_trap(
        if (__improbable(T_PREEMPT == type)) {
                ast_taken(AST_PREEMPTION, FALSE);
 
-               KERNEL_DEBUG_CONSTANT((MACHDBG_CODE(DBG_MACH_EXCP_KTRAP_x86, type)) | DBG_FUNC_NONE,
-                                     0, 0, 0, kern_ip, 0);
+               KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, 
+                       (MACHDBG_CODE(DBG_MACH_EXCP_KTRAP_x86, type)) | DBG_FUNC_NONE,
+                       0, 0, 0, VM_KERNEL_UNSLIDE(kern_ip), 0);
                return;
        }
        
@@ -679,10 +614,22 @@ kernel_trap(
                                is_user = -1;
                        }
 #else
-                       if (vaddr < VM_MAX_USER_PAGE_ADDRESS) {
+                       if (__probable(vaddr < VM_MAX_USER_PAGE_ADDRESS)) {
                                /* fault occurred in userspace */
                                map = thread->map;
                                is_user = -1;
+
+                               /* Intercept a potential Supervisor Mode Execute
+                                * Protection fault. These criteria identify
+                                * both NX faults and SMEP faults, but both
+                                * are fatal. We avoid checking PTEs (racy).
+                                * (The VM could just redrive a SMEP fault, hence
+                                * the intercept).
+                                */
+                               if (__improbable((code == (T_PF_PROT | T_PF_EXECUTE)) && (pmap_smep_enabled) && (saved_state->isf.rip == vaddr))) {
+                                       goto debugger_entry;
+                               }
+
                                /*
                                 * If we're not sharing cr3 with the user
                                 * and we faulted in copyio,
@@ -699,9 +646,11 @@ kernel_trap(
 #endif
                }
        }
-       KERNEL_DEBUG_CONSTANT(
+       user_addr_t     kd_vaddr = is_user ? vaddr : VM_KERNEL_UNSLIDE(vaddr);  
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, 
                (MACHDBG_CODE(DBG_MACH_EXCP_KTRAP_x86, type)) | DBG_FUNC_NONE,
-               (unsigned)(vaddr >> 32), (unsigned)vaddr, is_user, kern_ip, 0);
+               (unsigned)(kd_vaddr >> 32), (unsigned)kd_vaddr, is_user,
+               VM_KERNEL_UNSLIDE(kern_ip), 0);
 
 
        (void) ml_set_interrupts_enabled(intr);
@@ -724,11 +673,7 @@ kernel_trap(
                fpSSEexterrflt();
                return;
            case T_DEBUG:
-#ifdef __i386__
-                   if ((saved_state->efl & EFL_TF) == 0 && NO_WATCHPOINTS)
-#else
                    if ((saved_state->isf.rflags & EFL_TF) == 0 && NO_WATCHPOINTS)
-#endif
                    {
                            /* We've somehow encountered a debug
                             * register match that does not belong
@@ -744,40 +689,6 @@ kernel_trap(
              goto debugger_entry;
 #endif
            case T_PAGE_FAULT:
-               /*
-                * If the current map is a submap of the kernel map,
-                * and the address is within that map, fault on that
-                * map.  If the same check is done in vm_fault
-                * (vm_map_lookup), we may deadlock on the kernel map
-                * lock.
-                */
-
-               prot = VM_PROT_READ;
-
-               if (code & T_PF_WRITE)
-                       prot |= VM_PROT_WRITE;
-#if     PAE
-               if (code & T_PF_EXECUTE)
-                       prot |= VM_PROT_EXECUTE;
-#endif
-
-#if    MACH_KDB
-               /*
-                * Check for watchpoint on kernel static data.
-                * vm_fault would fail in this case 
-                */
-               if (map == kernel_map && db_watchpoint_list && db_watchpoints_inserted &&
-                   (code & T_PF_WRITE) && vaddr < vm_map_max(map) &&
-                   ((*(pte = pmap_pte(kernel_pmap, (vm_map_offset_t)vaddr))) & INTEL_PTE_WRITE) == 0) {
-                       pmap_store_pte(
-                               pte,
-                               *pte | INTEL_PTE_VALID | INTEL_PTE_WRITE);
-                       /* XXX need invltlb here? */
-
-                       result = KERN_SUCCESS;
-                       goto look_for_watchpoints;
-               }
-#endif /* MACH_KDB */
 
 #if CONFIG_DTRACE
                if (thread != THREAD_NULL && thread->options & TH_OPT_DTRACE) { /* Executing under dtrace_probe? */
@@ -791,25 +702,23 @@ kernel_trap(
                        }
                }
 #endif /* CONFIG_DTRACE */
+               
+               prot = VM_PROT_READ;
+
+               if (code & T_PF_WRITE)
+                       prot |= VM_PROT_WRITE;
+#if     PAE
+               if (code & T_PF_EXECUTE)
+                       prot |= VM_PROT_EXECUTE;
+#endif
 
                result = vm_fault(map,
-                                 vm_map_trunc_page(vaddr),
+                                 vm_map_trunc_page(vaddr,
+                                                   PAGE_MASK),
                                  prot,
                                  FALSE, 
                                  THREAD_UNINT, NULL, 0);
 
-#if    MACH_KDB
-               if (result == KERN_SUCCESS) {
-                       /*
-                        * Look for watchpoints
-                        */
-look_for_watchpoints:
-                       if (map == kernel_map && db_watchpoint_list && db_watchpoints_inserted && (code & T_PF_WRITE) &&
-                           db_find_watchpoint(map, vaddr, saved_state))
-                               kdb_trap(T_WATCHPOINT, 0, saved_state);
-               }
-#endif /* MACH_KDB */
-
                if (result == KERN_SUCCESS) {
 #if NCOPY_WINDOWS > 0
                        if (fault_in_copy_window != -1) {
@@ -863,9 +772,6 @@ FALL_THROUGH:
                        kprintf("kernel_trap() ignoring spurious trap 15\n"); 
                        return;
                }
-#if defined(__x86_64__) && DEBUG
-               kprint_state(saved_state);
-#endif
 debugger_entry:
                /* Ensure that the i386_kernel_state at the base of the
                 * current thread's stack (if any) is synchronized with the
@@ -873,30 +779,14 @@ debugger_entry:
                 * access through the debugger.
                 */
                sync_iss_to_iks(state);
-#if MACH_KDB
-restart_debugger:
-#endif /* MACH_KDB */          
 #if  MACH_KDP
-                if (current_debugger != KDB_CUR_DB) {
+               if (current_debugger != KDB_CUR_DB) {
                        if (kdp_i386_trap(type, saved_state, result, (vm_offset_t)vaddr))
                                return;
-               } else {
-#endif /* MACH_KDP */
-#if MACH_KDB
-                       if (kdb_trap(type, code, saved_state)) {
-                               if (switch_debugger) {
-                                       current_debugger = KDP_CUR_DB;
-                                       switch_debugger = 0;
-                                       goto restart_debugger;
-                               }
-                               return;
-                       }
-#endif /* MACH_KDB */
-#if MACH_KDP
                }
 #endif
        }
-       __asm__ volatile("cli":::"cc");
+       pal_cli();
        panic_trap(saved_state);
        /*
         * NO RETURN
@@ -904,66 +794,21 @@ restart_debugger:
 }
 
 
-#ifdef __i386__
-static void
-set_recovery_ip(x86_saved_state32_t  *saved_state, vm_offset_t ip)
-{
-        saved_state->eip = ip;
-}
-#else
 static void
 set_recovery_ip(x86_saved_state64_t  *saved_state, vm_offset_t ip)
 {
         saved_state->isf.rip = ip;
 }
-#endif
 
 
-#ifdef __i386__
-static void
-panic_trap(x86_saved_state32_t *regs)
-{
-       const char *trapname = "Unknown";
-       pal_cr_t        cr0, cr2, cr3, cr4;
-
-       pal_get_control_registers( &cr0, &cr2, &cr3, &cr4 );
-
-       /*
-        * Issue an I/O port read if one has been requested - this is an
-        * event logic analyzers can use as a trigger point.
-        */
-       panic_io_port_read();
 
-       kprintf("panic trap number 0x%x, eip 0x%x\n", regs->trapno, regs->eip);
-       kprintf("cr0 0x%08x cr2 0x%08x cr3 0x%08x cr4 0x%08x\n",
-               cr0, cr2, cr3, cr4);
 
-       if (regs->trapno < TRAP_TYPES)
-               trapname = trap_type[regs->trapno];
-#undef panic
-       panic("Kernel trap at 0x%08x, type %d=%s, registers:\n"
-             "CR0: 0x%08x, CR2: 0x%08x, CR3: 0x%08x, CR4: 0x%08x\n"
-             "EAX: 0x%08x, EBX: 0x%08x, ECX: 0x%08x, EDX: 0x%08x\n"
-             "CR2: 0x%08x, EBP: 0x%08x, ESI: 0x%08x, EDI: 0x%08x\n"
-             "EFL: 0x%08x, EIP: 0x%08x, CS:  0x%08x, DS:  0x%08x\n"
-             "Error code: 0x%08x\n",
-             regs->eip, regs->trapno, trapname, cr0, cr2, cr3, cr4,
-             regs->eax,regs->ebx,regs->ecx,regs->edx,
-             regs->cr2,regs->ebp,regs->esi,regs->edi,
-             regs->efl,regs->eip,regs->cs & 0xFFFF, regs->ds & 0xFFFF, regs->err);
-       /*
-        * This next statement is not executed,
-        * but it's needed to stop the compiler using tail call optimization
-        * for the panic call - which confuses the subsequent backtrace.
-        */
-       cr0 = 0;
-}
-#else
 static void
 panic_trap(x86_saved_state64_t *regs)
 {
        const char      *trapname = "Unknown";
        pal_cr_t        cr0, cr2, cr3, cr4;
+       boolean_t       potential_smep_fault = FALSE, potential_kernel_NX_fault = FALSE;
 
        pal_get_control_registers( &cr0, &cr2, &cr3, &cr4 );
        assert(ml_get_interrupts_enabled() == FALSE);
@@ -981,6 +826,15 @@ panic_trap(x86_saved_state64_t *regs)
 
        if (regs->isf.trapno < TRAP_TYPES)
                trapname = trap_type[regs->isf.trapno];
+
+       if ((regs->isf.trapno == T_PAGE_FAULT) && (regs->isf.err == (T_PF_PROT | T_PF_EXECUTE)) && (regs->isf.rip == regs->cr2)) {
+               if (pmap_smep_enabled && (regs->isf.rip < VM_MAX_USER_PAGE_ADDRESS)) {
+                       potential_smep_fault = TRUE;
+               } else if (regs->isf.rip >= VM_MIN_KERNEL_AND_KEXT_ADDRESS) {
+                       potential_kernel_NX_fault = TRUE;
+               }
+       }
+
 #undef panic
        panic("Kernel trap at 0x%016llx, type %d=%s, registers:\n"
              "CR0: 0x%016llx, CR2: 0x%016llx, CR3: 0x%016llx, CR4: 0x%016llx\n"
@@ -989,7 +843,7 @@ panic_trap(x86_saved_state64_t *regs)
              "R8:  0x%016llx, R9:  0x%016llx, R10: 0x%016llx, R11: 0x%016llx\n"
              "R12: 0x%016llx, R13: 0x%016llx, R14: 0x%016llx, R15: 0x%016llx\n"
              "RFL: 0x%016llx, RIP: 0x%016llx, CS:  0x%016llx, SS:  0x%016llx\n"
-             "CR2: 0x%016llx, Error code: 0x%016llx, Faulting CPU: 0x%x\n",
+             "Fault CR2: 0x%016llx, Error code: 0x%016llx, Fault CPU: 0x%x%s%s%s\n",
              regs->isf.rip, regs->isf.trapno, trapname,
              cr0, cr2, cr3, cr4,
              regs->rax, regs->rbx, regs->rcx, regs->rdx,
@@ -997,7 +851,10 @@ panic_trap(x86_saved_state64_t *regs)
              regs->r8,  regs->r9,  regs->r10, regs->r11,
              regs->r12, regs->r13, regs->r14, regs->r15,
              regs->isf.rflags, regs->isf.rip, regs->isf.cs & 0xFFFF,
-             regs->isf.ss & 0xFFFF,regs->cr2, regs->isf.err, regs->isf.cpu);
+             regs->isf.ss & 0xFFFF,regs->cr2, regs->isf.err, regs->isf.cpu,
+             virtualized ? " VMM" : "",
+             potential_kernel_NX_fault ? " Kernel NX fault" : "",
+             potential_smep_fault ? " SMEP/User NX fault" : "");
        /*
         * This next statement is not executed,
         * but it's needed to stop the compiler using tail call optimization
@@ -1005,7 +862,6 @@ panic_trap(x86_saved_state64_t *regs)
         */
        cr0 = 0;
 }
-#endif
 
 #if CONFIG_DTRACE
 extern kern_return_t dtrace_user_probe(x86_saved_state_t *);
@@ -1071,7 +927,7 @@ user_trap(
 
        pal_sti();
 
-       KERNEL_DEBUG_CONSTANT(
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, 
                (MACHDBG_CODE(DBG_MACH_EXCP_UTRAP_x86, type)) | DBG_FUNC_NONE,
                (unsigned)(vaddr>>32), (unsigned)vaddr,
                (unsigned)(rip>>32), (unsigned)rip, 0);
@@ -1214,7 +1070,8 @@ user_trap(
                break;
 
            case T_PAGE_FAULT:
-               prot = VM_PROT_READ;
+           {
+                   prot = VM_PROT_READ;
 
                if (err & T_PF_WRITE)
                        prot |= VM_PROT_WRITE;
@@ -1222,13 +1079,19 @@ user_trap(
                if (__improbable(err & T_PF_EXECUTE))
                        prot |= VM_PROT_EXECUTE;
 #endif
-               kret = vm_fault(thread->map, vm_map_trunc_page(vaddr),
-                                prot, FALSE,
-                                THREAD_ABORTSAFE, NULL, 0);
+               kret = vm_fault(thread->map,
+                               vm_map_trunc_page(vaddr,
+                                                 PAGE_MASK),
+                               prot, FALSE,
+                               THREAD_ABORTSAFE, NULL, 0);
+
+               if (__probable((kret == KERN_SUCCESS) || (kret == KERN_ABORTED))) {
+                       thread_exception_return();
+                       /*NOTREACHED*/
+               }
 
                user_page_fault_continue(kret);
-       
-               /* NOTREACHED */
+           }   /* NOTREACHED */
                break;
 
            case T_SSE_FLOAT_ERROR:
@@ -1254,14 +1117,6 @@ user_trap(
                break;
 
            default:
-#if     MACH_KGDB
-               Debugger("Unanticipated user trap");
-               return;
-#endif  /* MACH_KGDB */
-#if    MACH_KDB
-               if (kdb_trap(type, err, saved_state32(saved_state)))
-                   return;
-#endif /* MACH_KDB */
                panic("Unexpected user trap, type %d", type);
                return;
        }
@@ -1322,39 +1177,6 @@ i386_exception(
 }
 
 
-#if    MACH_KDB
-
-extern void    db_i386_state(x86_saved_state32_t *regs);
-
-#include <ddb/db_output.h>
-
-void 
-db_i386_state(
-       x86_saved_state32_t *regs)
-{
-       db_printf("eip  %8x\n", regs->eip);
-       db_printf("trap %8x\n", regs->trapno);
-       db_printf("err  %8x\n", regs->err);
-       db_printf("efl  %8x\n", regs->efl);
-       db_printf("ebp  %8x\n", regs->ebp);
-       db_printf("esp  %8x\n", regs->cr2);
-       db_printf("uesp %8x\n", regs->uesp);
-       db_printf("cs   %8x\n", regs->cs & 0xff);
-       db_printf("ds   %8x\n", regs->ds & 0xff);
-       db_printf("es   %8x\n", regs->es & 0xff);
-       db_printf("fs   %8x\n", regs->fs & 0xff);
-       db_printf("gs   %8x\n", regs->gs & 0xff);
-       db_printf("ss   %8x\n", regs->ss & 0xff);
-       db_printf("eax  %8x\n", regs->eax);
-       db_printf("ebx  %8x\n", regs->ebx);
-       db_printf("ecx  %8x\n", regs->ecx);
-       db_printf("edx  %8x\n", regs->edx);
-       db_printf("esi  %8x\n", regs->esi);
-       db_printf("edi  %8x\n", regs->edi);
-}
-
-#endif /* MACH_KDB */
-
 /* Synchronize a thread's i386_kernel_state (if any) with the given
  * i386_saved_state_t obtained from the trap/IPI handler; called in
  * kernel_trap() prior to entering the debugger, and when receiving
@@ -1373,27 +1195,11 @@ sync_iss_to_iks(x86_saved_state_t *saved_state)
                pal_get_kern_regs( saved_state );
 
        if ((kstack = current_thread()->kernel_stack) != 0) {
-#ifdef __i386__
-               x86_saved_state32_t     *regs = saved_state32(saved_state);
-#else
                x86_saved_state64_t     *regs = saved_state64(saved_state);
-#endif
 
                iks = STACK_IKS(kstack);
 
                /* Did we take the trap/interrupt in kernel mode? */
-#ifdef __i386__
-               if (regs == USER_REGS32(current_thread()))
-                       record_active_regs = TRUE;
-               else {
-                       iks->k_ebx = regs->ebx;
-                       iks->k_esp = (int)regs;
-                       iks->k_ebp = regs->ebp;
-                       iks->k_edi = regs->edi;
-                       iks->k_esi = regs->esi;
-                       iks->k_eip = regs->eip;
-               }
-#else
                if (regs == USER_REGS64(current_thread()))
                        record_active_regs = TRUE;
                else {
@@ -1406,20 +1212,9 @@ sync_iss_to_iks(x86_saved_state_t *saved_state)
                        iks->k_r15 = regs->r15;
                        iks->k_rip = regs->isf.rip;
                }
-#endif
        }
 
        if (record_active_regs == TRUE) {
-#ifdef __i386__
-               /* Show the trap handler path */
-               __asm__ volatile("movl %%ebx, %0" : "=m" (iks->k_ebx));
-               __asm__ volatile("movl %%esp, %0" : "=m" (iks->k_esp));
-               __asm__ volatile("movl %%ebp, %0" : "=m" (iks->k_ebp));
-               __asm__ volatile("movl %%edi, %0" : "=m" (iks->k_edi));
-               __asm__ volatile("movl %%esi, %0" : "=m" (iks->k_esi));
-               /* "Current" instruction pointer */
-               __asm__ volatile("movl $1f, %0\n1:" : "=m" (iks->k_eip));
-#else
                /* Show the trap handler path */
                __asm__ volatile("movq %%rbx, %0" : "=m" (iks->k_rbx));
                __asm__ volatile("movq %%rsp, %0" : "=m" (iks->k_rsp));
@@ -1433,7 +1228,6 @@ sync_iss_to_iks(x86_saved_state_t *saved_state)
                                 : "=m" (iks->k_rip)
                                 :
                                 : "rax");
-#endif
        }
 }
 
@@ -1450,16 +1244,6 @@ sync_iss_to_iks_unconditionally(__unused x86_saved_state_t *saved_state) {
 
        if ((kstack = current_thread()->kernel_stack) != 0) {
                iks = STACK_IKS(kstack);
-#ifdef __i386__
-               /* Display the trap handler path */
-               __asm__ volatile("movl %%ebx, %0" : "=m" (iks->k_ebx));
-               __asm__ volatile("movl %%esp, %0" : "=m" (iks->k_esp));
-               __asm__ volatile("movl %%ebp, %0" : "=m" (iks->k_ebp));
-               __asm__ volatile("movl %%edi, %0" : "=m" (iks->k_edi));
-               __asm__ volatile("movl %%esi, %0" : "=m" (iks->k_esi));
-               /* "Current" instruction pointer */
-               __asm__ volatile("movl $1f, %0\n1:" : "=m" (iks->k_eip));
-#else
                /* Display the trap handler path */
                __asm__ volatile("movq %%rbx, %0" : "=m" (iks->k_rbx));
                __asm__ volatile("movq %%rsp, %0" : "=m" (iks->k_rsp));
@@ -1470,6 +1254,5 @@ sync_iss_to_iks_unconditionally(__unused x86_saved_state_t *saved_state) {
                __asm__ volatile("movq %%r15, %0" : "=m" (iks->k_r15));
                /* "Current" instruction pointer */
                __asm__ volatile("leaq 1f(%%rip), %%rax; mov %%rax, %0\n1:" : "=m" (iks->k_rip)::"rax");
-#endif
        }
 }