usr/src/uts/intel/os/arch_kdi.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  *
  25  * Copyright 2018 Joyent, Inc.
  26  */
  27
  28 /*
  29  * Kernel/Debugger Interface (KDI) routines.  Called during debugger under
  30  * various system states (boot, while running, while the debugger has control).
  31  * Functions intended for use while the debugger has control may not grab any
  32  * locks or perform any functions that assume the availability of other system
  33  * services.
  34  */
  35
  36 #include <sys/systm.h>
  37 #include <sys/x86_archext.h>
  38 #include <sys/kdi_impl.h>
  39 #include <sys/smp_impldefs.h>
  40 #include <sys/psm_types.h>
  41 #include <sys/segments.h>
  42 #include <sys/archsystm.h>
  43 #include <sys/controlregs.h>
  44 #include <sys/trap.h>
  45 #include <sys/kobj.h>
  46 #include <sys/kobj_impl.h>
  47 #include <sys/clock_impl.h>
  48
  49 static void
  50 kdi_system_claim(void)
  51 {
  52         lbolt_debug_entry();
  53
  54         psm_notifyf(PSM_DEBUG_ENTER);
  55 }
  56
  57 static void
  58 kdi_system_release(void)
  59 {
  60         psm_notifyf(PSM_DEBUG_EXIT);
  61
  62         lbolt_debug_return();
  63 }
  64
  65 static cpu_t *
  66 kdi_gdt2cpu(uintptr_t gdtbase)
  67 {
  68         cpu_t *cp = cpu_list;
  69
  70         if (cp == NULL)
  71                 return (NULL);
  72
  73         do {
  74                 if (gdtbase == (uintptr_t)cp->cpu_gdt)
  75                         return (cp);
  76         } while ((cp = cp->cpu_next) != cpu_list);
  77
  78         return (NULL);
  79 }
  80
  81 #if defined(__amd64)
  82 uintptr_t
  83 kdi_gdt2gsbase(uintptr_t gdtbase)
  84 {
  85         return ((uintptr_t)kdi_gdt2cpu(gdtbase));
  86 }
  87 #endif
  88
  89 static uintptr_t
  90 kdi_get_userlimit(void)
  91 {
  92         return (_userlimit);
  93 }
  94
  95 static int
  96 kdi_get_cpuinfo(uint_t *vendorp, uint_t *familyp, uint_t *modelp)
  97 {
  98         desctbr_t gdtr;
  99         cpu_t *cpu;
 100
 101         /*
 102          * CPU doesn't work until the GDT and gs/GSBASE have been set up.
 103          * Boot-loaded kmdb will call us well before then, so we have to
 104          * find the current cpu_t the hard way.
 105          */
 106         rd_gdtr(&gdtr);
 107         if ((cpu = kdi_gdt2cpu(gdtr.dtr_base)) == NULL ||
 108             !cpuid_checkpass(cpu, 1))
 109                 return (EAGAIN); /* cpuid isn't done yet */
 110
 111         *vendorp = cpuid_getvendor(cpu);
 112         *familyp = cpuid_getfamily(cpu);
 113         *modelp = cpuid_getmodel(cpu);
 114
 115         return (0);
 116 }
 117
 118 void
 119 kdi_idtr_set(gate_desc_t *idt, size_t limit)
 120 {
 121         desctbr_t idtr;
 122
 123         /*
 124          * This rare case could happen if we entered kmdb whilst still on the
 125          * fake CPU set up by boot_kdi_tmpinit().  We're trying to restore the
 126          * kernel's IDT that we saved on entry, but it was from the fake cpu_t
 127          * rather than the real IDT (which is still boot's).  It's unpleasant,
 128          * but we just encode knowledge that it's idt0 we want to restore.
 129          */
 130         if (idt == NULL)
 131                 idt = idt0;
 132
 133         CPU->cpu_m.mcpu_idt = idt;
 134         idtr.dtr_base = (uintptr_t)idt;
 135         idtr.dtr_limit = limit;
 136         kdi_idtr_write(&idtr);
 137 }
 138
 139 static void
 140 kdi_plat_call(void (*platfn)(void))
 141 {
 142         if (platfn != NULL)
 143                 platfn();
 144 }
 145
 146 /*
 147  * On Intel, most of these are shared between i86*, so this is really an
 148  * arch_kdi_init().
 149  */
 150 void
 151 mach_kdi_init(kdi_t *kdi)
 152 {
 153         kdi->kdi_plat_call = kdi_plat_call;
 154         kdi->kdi_kmdb_enter = kmdb_enter;
 155         kdi->mkdi_activate = kdi_activate;
 156         kdi->mkdi_deactivate = kdi_deactivate;
 157         kdi->mkdi_idt_switch = kdi_idt_switch;
 158         kdi->mkdi_update_drreg = kdi_update_drreg;
 159         kdi->mkdi_get_userlimit = kdi_get_userlimit;
 160         kdi->mkdi_get_cpuinfo = kdi_get_cpuinfo;
 161         kdi->mkdi_stop_slaves = kdi_stop_slaves;
 162         kdi->mkdi_start_slaves = kdi_start_slaves;
 163         kdi->mkdi_slave_wait = kdi_slave_wait;
 164         kdi->mkdi_memrange_add = kdi_memrange_add;
 165         kdi->mkdi_reboot = kdi_reboot;
 166 }
 167
 168 void
 169 plat_kdi_init(kdi_t *kdi)
 170 {
 171         kdi->pkdi_system_claim = kdi_system_claim;
 172         kdi->pkdi_system_release = kdi_system_release;
 173 }