lib/libvassert/vassert.c

   1 #include <string.h>
   2 #include <stdarg.h>
   3 #include <signal.h>
   4 #include <setjmp.h>
   5 #include <minix/config.h>
   6 #include <minix/const.h>
   7 #include <minix/ipc.h>
   8 #include <minix/com.h>
   9 #include <minix/syslib.h>
  10 #include "vassert.h"
  11
  12 VAssert_StateWrapper vassert_state ALIGNED(VASSERT_PAGE_SIZE);
  13
  14 #define TRUE 1
  15 #define FALSE 0
  16
  17 #define MAGIC_CMD  0x564d5868
  18 #define MAGIC_PORT 0x5658
  19 #define HIGH_BAND_PORT 0x5659
  20
  21 #define BACKDOOR_PORT           51
  22 #define BACKDOOR_HB_PORT        1
  23 #define CMD_SET_ADDRESS         BACKDOOR_PORT|(1<<16)
  24 #define CMD_RETURN_REPLAY       BACKDOOR_PORT|(2<<16)
  25 #define CMD_GO_LIVE             BACKDOOR_PORT|(3<<16)
  26 #define CMD_LOG                 BACKDOOR_HB_PORT|(4<<16)
  27 #define CMD_SET_RECORD          47
  28
  29 #define LOG_MAX 512
  30
  31 typedef char Bool;
  32 typedef unsigned int uint32;
  33 typedef unsigned long long uint64;
  34
  35 #ifdef VM_X86_64
  36 typedef uint64 VA;
  37 #else
  38 typedef uint32 VA;
  39 #endif
  40
  41 static sigjmp_buf segv_jmp;
  42
  43 void libvassert_process_backdoor(uint32, uint32, uint32, reg_t *, reg_t *,
  44                                  reg_t *, reg_t *);
  45
  46 /*
  47  *---------------------------------------------------------------------
  48  *
  49  * sig_segv --
  50  *
  51  *    Customed SEGV signal handler for VAssert_IsInVM.
  52  *
  53  * Results:
  54  *
  55  *    None.
  56  *
  57  * Side effects:
  58  *    None.
  59  *
  60  *---------------------------------------------------------------------
  61  */
  62
  63 static void
  64 sig_segv(int sig_no)
  65 {
  66    /* jumping to error handling in VAssert_IsInVM. */
  67    siglongjmp(segv_jmp, 1);
  68 }
  69
  70
  71 /*
  72  *---------------------------------------------------------------------
  73  *
  74  * VAssert_IsInVM --
  75  *
  76  *    Check if we are in virtual world.
  77  *
  78  * Results:
  79  *
  80  *    Return TRUE on success, or FALSE on failure.
  81  *
  82  * Side effects:
  83  *    None.
  84  *
  85  *---------------------------------------------------------------------
  86  */
  87
  88 static Bool
  89 VAssert_IsInVM(void)
  90 {
  91    uint32 eax, ebx, ecx, edx;
  92    static Bool inVM = FALSE;
  93    static Bool tested = FALSE;
  94    if (!tested) {
  95       /* Error handling. */
  96       if (sigsetjmp(segv_jmp, 0) != 0) {
  97          signal(SIGSEGV, SIG_DFL);
  98          inVM = FALSE;
  99          return inVM;
 100       }
 101       tested = TRUE;
 102       /* Install custom handler. */
 103       signal(SIGSEGV, sig_segv);
 104       /* Test if we are in a VM. */
 105       libvassert_process_backdoor(0x0a, 0, MAGIC_PORT, &eax, &ebx, &ecx, &edx);
 106       signal(SIGSEGV, SIG_DFL);
 107       inVM = TRUE;
 108    }
 109    return inVM;
 110 }
 111
 112
 113 /*
 114  *---------------------------------------------------------------------
 115  *
 116  * VAssert_Init --
 117  *
 118  *    Tell vmx that vassert is inited.
 119  *
 120  * Results:
 121  *
 122  *    Return 0 on success, or -1 on failure.
 123  *
 124  * Side effects:
 125  *    None
 126  *
 127  *---------------------------------------------------------------------
 128  */
 129
 130 char
 131 VAssert_Init(void)
 132 {
 133    uint32 eax, ebx, ecx, edx;
 134    VA page_address = (VA) &vassert_state.inReplay;
 135    if (!VAssert_IsInVM()) {
 136       return -1;
 137    }
 138    bzero((char*) &vassert_state, sizeof vassert_state);
 139 #ifndef __minix
 140    /* Lock the page. */
 141    if (mlock(&vassert_state, sizeof vassert_state)) {
 142       return -1;
 143    }
 144 #endif
 145
 146    libvassert_process_backdoor(CMD_SET_ADDRESS, page_address,
 147         MAGIC_PORT|(1<<16), &eax, &ebx, &ecx, &edx);
 148
 149    return (eax != -1) ? 0 : -1;
 150 }
 151
 152
 153 /*
 154  *---------------------------------------------------------------------
 155  *
 156  * VAssert_Uninit --
 157  *
 158  *    Tell vmx that vassert is finalized.
 159  *
 160  * Results:
 161  *
 162  *    Return 0 on success, or -1 on failure.
 163  *
 164  * Side effects:
 165  *    None
 166  *
 167  *---------------------------------------------------------------------
 168  */
 169
 170 char
 171 VAssert_Uninit(void)
 172 {
 173    unsigned int eax, ebx, ecx, edx;
 174    if (!VAssert_IsInVM()) {
 175       return -1;
 176    }
 177    libvassert_process_backdoor(CMD_SET_ADDRESS, 0, MAGIC_PORT|(0<<16), &eax, &ebx, &ecx, &edx);
 178    return (eax != -1) ? 0 : 1;
 179 }
 180
 181
 182 /*
 183  *---------------------------------------------------------------------
 184  *
 185  * VAssert_LogMain --
 186  *
 187  *    Print message to a text file on host side.
 188  *
 189  * Results:
 190  *    None
 191  *
 192  * Side effects:
 193  *    Write to a text file with fixed name.
 194  *    If the file exists, host UI will ask for append/replace/ignore
 195  *
 196  *---------------------------------------------------------------------
 197  */
 198
 199 void
 200 VAssert_LogMain(const char *format, ...)
 201 {
 202    unsigned int eax, ebx, ecx, edx;
 203    char buf[LOG_MAX];
 204    unsigned int len = 0;
 205    va_list ap;
 206    va_start(ap, format);
 207    len = vsnprintf(buf, LOG_MAX, format, ap);
 208    va_end(ap);
 209    __asm__ __volatile__("cld; rep outsb;"
 210                         : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx)
 211                         : "0"(MAGIC_CMD), "1"(CMD_LOG), "2"(len), "d"(HIGH_BAND_PORT), "S"(buf)
 212                         : "memory"
 213                        );
 214 }
 215
 216
 217 /*
 218  *---------------------------------------------------------------------
 219  *
 220  * VAssert_GoLiveMain --
 221  *
 222  *    Make the vm which is in replay exit replay.
 223  *
 224  * Results:
 225  *    None
 226  *
 227  * Side effects:
 228  *    Replay is stopped.
 229  *
 230  *---------------------------------------------------------------------
 231  */
 232
 233 void
 234 VAssert_GoLiveMain()
 235 {
 236    unsigned int eax, ebx, ecx, edx;
 237    vassert_state.inReplay = 0;
 238    libvassert_process_backdoor(CMD_GO_LIVE, 0, MAGIC_PORT, &eax, &ebx, &ecx, &edx);
 239 }
 240
 241
 242 /*
 243  *---------------------------------------------------------------------
 244  *
 245  * VAssert_ReturnToReplayMain --
 246  *
 247  *    Called after the custom work is done, and replay is to continue.
 248  *
 249  * Results:
 250  *    None
 251  *
 252  * Side effects:
 253  *    Replay is continued from pause.
 254  *
 255  *---------------------------------------------------------------------
 256  */
 257
 258 void
 259 VAssert_ReturnToReplayMain()
 260 {
 261    unsigned int eax, ebx, ecx, edx;
 262    libvassert_process_backdoor(CMD_RETURN_REPLAY, 0, MAGIC_PORT, &eax, &ebx, &ecx, &edx);
 263 }
 264
 265
 266 /*
 267  *---------------------------------------------------------------------
 268  *
 269  * VAssert_SetRecordingMain --
 270  *
 271  *    Ask vmx for starting or stopping recording.
 272  *
 273  * Results:
 274  *
 275  *    Return TRUE on success, or FALSE on failure.
 276  *
 277  * Side effects:
 278  *    Recording is started or stopped.
 279  *
 280  *---------------------------------------------------------------------
 281  */
 282
 283 char
 284 VAssert_SetRecordingMain(char start)
 285 {
 286    uint32 eax, ebx, ecx, edx;
 287    if (!VAssert_IsInVM()) {
 288       return FALSE;
 289    }
 290    libvassert_process_backdoor(CMD_SET_RECORD, start ? 1 : 2, MAGIC_PORT, &eax, &ebx, &ecx, &edx);
 291    return (eax == 1) ? TRUE : FALSE;
 292 }
 293