/*++
Function:
CONTEXT_GetRegisters
Abstract
retrieve the machine registers value of the indicated process.
Parameter
processId: process ID
registers: reg structure in which the machine registers value will be returned.
Return
returns TRUE if it succeeds, FALSE otherwise
--*/
BOOL CONTEXT_GetRegisters(DWORD processId, ucontext_t *registers)
{
#if HAVE_BSD_REGS_T
int regFd = -1;
#endif // HAVE_BSD_REGS_T
BOOL bRet = FALSE;
if (processId == GetCurrentProcessId())
{
#if HAVE_GETCONTEXT
if (getcontext(registers) != 0)
{
ASSERT("getcontext() failed %d (%s)\n", errno, strerror(errno));
return FALSE;
}
#elif HAVE_BSD_REGS_T
char buf[MAX_PATH];
struct reg bsd_registers;
sprintf_s(buf, sizeof(buf), "/proc/%d/regs", processId);
if ((regFd = PAL__open(buf, O_RDONLY)) == -1)
{
ASSERT("PAL__open() failed %d (%s) \n", errno, strerror(errno));
return FALSE;
}
if (lseek(regFd, 0, 0) == -1)
{
ASSERT("lseek() failed %d (%s)\n", errno, strerror(errno));
goto EXIT;
}
if (read(regFd, &bsd_registers, sizeof(bsd_registers)) != sizeof(bsd_registers))
{
ASSERT("read() failed %d (%s)\n", errno, strerror(errno));
goto EXIT;
}
#define ASSIGN_REG(reg) MCREG_##reg(registers->uc_mcontext) = BSDREG_##reg(bsd_registers);
ASSIGN_ALL_REGS
#undef ASSIGN_REG
#else
#error "Don't know how to get current context on this platform!"
#endif
}
else
{
BOOL
PALAPI
PAL_Random(
IN BOOL bStrong,
IN OUT LPVOID lpBuffer,
IN DWORD dwLength)
{
int rand_des = -1;
BOOL bRet = FALSE;
DWORD i;
char buf;
long num = 0;
static BOOL sMissingDevRandom;
static BOOL sMissingDevURandom;
static BOOL sInitializedMRand;
PERF_ENTRY(PAL_Random);
ENTRY("PAL_Random(bStrong=%d, lpBuffer=%p, dwLength=%d)\n",
bStrong, lpBuffer, dwLength);
i = 0;
if (bStrong == TRUE && i < dwLength && !sMissingDevRandom)
{
// request non-blocking access to avoid hangs if the /dev/random is exhausted
// or just simply broken
if ((rand_des = PAL__open(RANDOM_DEVICE_NAME, O_RDONLY | O_NONBLOCK)) == -1)
{
if (errno == ENOENT)
{
sMissingDevRandom = TRUE;
}
else
{
ASSERT("PAL__open() failed, errno:%d (%s)\n", errno, strerror(errno));
}
// Back off and try /dev/urandom.
}
else
{
for( ; i < dwLength; i++)
{
if (read(rand_des, &buf, 1) < 1)
{
// the /dev/random pool has been exhausted. Fall back
// to /dev/urandom for the remainder of the buffer.
break;
}
*(((BYTE*)lpBuffer) + i) ^= buf;
}
close(rand_des);
}
}
if (i < dwLength && !sMissingDevURandom)
{
if ((rand_des = PAL__open(URANDOM_DEVICE_NAME, O_RDONLY)) == -1)
{
if (errno == ENOENT)
{
sMissingDevURandom = TRUE;
}
else
{
ASSERT("PAL__open() failed, errno:%d (%s)\n", errno, strerror(errno));
}
// Back off and try mrand48.
}
else
{
for( ; i < dwLength; i++)
{
if (read(rand_des, &buf, 1) < 1)
{
// Fall back to srand48 for the remainder of the buffer.
break;
}
*(((BYTE*)lpBuffer) + i) ^= buf;
}
close(rand_des);
}
}
if (!sInitializedMRand)
{
srand48(time(NULL));
sInitializedMRand = TRUE;
}
// always xor srand48 over the whole buffer to get some randomness
// in case /dev/random is not really random
for(i = 0; i < dwLength; i++)
{
if (i % sizeof(long) == 0) {
num = mrand48();
}
*(((BYTE*)lpBuffer) + i) ^= num;
num >>= 8;
}
bRet = TRUE;
LOGEXIT("PAL_Random returns %d\n", bRet);
PERF_EXIT(PAL_Random);
return bRet;
}
