target-i386/mpx_helper.c

   1 /*
   2  *  x86 MPX helpers
   3  *
   4  *  Copyright (c) 2015 Red Hat, Inc.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "cpu.h"
  21 #include "exec/helper-proto.h"
  22 #include "exec/cpu_ldst.h"
  23
  24
  25 void cpu_sync_bndcs_hflags(CPUX86State *env)
  26 {
  27     uint32_t hflags = env->hflags;
  28     uint32_t hflags2 = env->hflags2;
  29     uint32_t bndcsr;
  30
  31     if ((hflags & HF_CPL_MASK) == 3) {
  32         bndcsr = env->bndcs_regs.cfgu;
  33     } else {
  34         bndcsr = env->msr_bndcfgs;
  35     }
  36
  37     if ((env->cr[4] & CR4_OSXSAVE_MASK)
  38         && (env->xcr0 & XSTATE_BNDCSR_MASK)
  39         && (bndcsr & BNDCFG_ENABLE)) {
  40         hflags |= HF_MPX_EN_MASK;
  41     } else {
  42         hflags &= ~HF_MPX_EN_MASK;
  43     }
  44
  45     if (bndcsr & BNDCFG_BNDPRESERVE) {
  46         hflags2 |= HF2_MPX_PR_MASK;
  47     } else {
  48         hflags2 &= ~HF2_MPX_PR_MASK;
  49     }
  50
  51     env->hflags = hflags;
  52     env->hflags2 = hflags2;
  53 }
  54
  55 void helper_bndck(CPUX86State *env, uint32_t fail)
  56 {
  57     if (unlikely(fail)) {
  58         env->bndcs_regs.sts = 1;
  59         raise_exception_ra(env, EXCP05_BOUND, GETPC());
  60     }
  61 }
  62
  63 static uint64_t lookup_bte64(CPUX86State *env, uint64_t base, uintptr_t ra)
  64 {
  65     uint64_t bndcsr, bde, bt;
  66
  67     if ((env->hflags & HF_CPL_MASK) == 3) {
  68         bndcsr = env->bndcs_regs.cfgu;
  69     } else {
  70         bndcsr = env->msr_bndcfgs;
  71     }
  72
  73     bde = (extract64(base, 20, 28) << 3) + (extract64(bndcsr, 20, 44) << 12);
  74     bt = cpu_ldq_data_ra(env, bde, ra);
  75     if ((bt & 1) == 0) {
  76         env->bndcs_regs.sts = bde | 2;
  77         raise_exception_ra(env, EXCP05_BOUND, ra);
  78     }
  79
  80     return (extract64(base, 3, 17) << 5) + (bt & ~7);
  81 }
  82
  83 static uint32_t lookup_bte32(CPUX86State *env, uint32_t base, uintptr_t ra)
  84 {
  85     uint32_t bndcsr, bde, bt;
  86
  87     if ((env->hflags & HF_CPL_MASK) == 3) {
  88         bndcsr = env->bndcs_regs.cfgu;
  89     } else {
  90         bndcsr = env->msr_bndcfgs;
  91     }
  92
  93     bde = (extract32(base, 12, 20) << 2) + (bndcsr & TARGET_PAGE_MASK);
  94     bt = cpu_ldl_data_ra(env, bde, ra);
  95     if ((bt & 1) == 0) {
  96         env->bndcs_regs.sts = bde | 2;
  97         raise_exception_ra(env, EXCP05_BOUND, ra);
  98     }
  99
 100     return (extract32(base, 2, 10) << 4) + (bt & ~3);
 101 }
 102
 103 uint64_t helper_bndldx64(CPUX86State *env, target_ulong base, target_ulong ptr)
 104 {
 105     uintptr_t ra = GETPC();
 106     uint64_t bte, lb, ub, pt;
 107
 108     bte = lookup_bte64(env, base, ra);
 109     lb = cpu_ldq_data_ra(env, bte, ra);
 110     ub = cpu_ldq_data_ra(env, bte + 8, ra);
 111     pt = cpu_ldq_data_ra(env, bte + 16, ra);
 112
 113     if (pt != ptr) {
 114         lb = ub = 0;
 115     }
 116     env->mmx_t0.MMX_Q(0) = ub;
 117     return lb;
 118 }
 119
 120 uint64_t helper_bndldx32(CPUX86State *env, target_ulong base, target_ulong ptr)
 121 {
 122     uintptr_t ra = GETPC();
 123     uint32_t bte, lb, ub, pt;
 124
 125     bte = lookup_bte32(env, base, ra);
 126     lb = cpu_ldl_data_ra(env, bte, ra);
 127     ub = cpu_ldl_data_ra(env, bte + 4, ra);
 128     pt = cpu_ldl_data_ra(env, bte + 8, ra);
 129
 130     if (pt != ptr) {
 131         lb = ub = 0;
 132     }
 133     return ((uint64_t)ub << 32) | lb;
 134 }
 135
 136 void helper_bndstx64(CPUX86State *env, target_ulong base, target_ulong ptr,
 137                      uint64_t lb, uint64_t ub)
 138 {
 139     uintptr_t ra = GETPC();
 140     uint64_t bte;
 141
 142     bte = lookup_bte64(env, base, ra);
 143     cpu_stq_data_ra(env, bte, lb, ra);
 144     cpu_stq_data_ra(env, bte + 8, ub, ra);
 145     cpu_stq_data_ra(env, bte + 16, ptr, ra);
 146 }
 147
 148 void helper_bndstx32(CPUX86State *env, target_ulong base, target_ulong ptr,
 149                      uint64_t lb, uint64_t ub)
 150 {
 151     uintptr_t ra = GETPC();
 152     uint32_t bte;
 153
 154     bte = lookup_bte32(env, base, ra);
 155     cpu_stl_data_ra(env, bte, lb, ra);
 156     cpu_stl_data_ra(env, bte + 4, ub, ra);
 157     cpu_stl_data_ra(env, bte + 8, ptr, ra);
 158 }
 159
 160 void helper_bnd_jmp(CPUX86State *env)
 161 {
 162     if (!(env->hflags2 & HF2_MPX_PR_MASK)) {
 163         memset(env->bnd_regs, 0, sizeof(env->bnd_regs));
 164         env->hflags &= ~HF_MPX_IU_MASK;
 165     }
 166 }