1 files changed, 61 insertions, 49 deletions

diff --git a/sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c b/sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c
index ddaff303c5..6d2e766aa4 100644
--- a/sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c
+++ b/sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c
@@ -22,14 +22,15 @@
 #include <string.h>
 #include <unistd.h>
 #include <libc-internal.h>
-
+#include <sysdep.h>
+#include <bits/libc-vdso.h>
 
 hp_timing_t
 __get_clockfreq (void)
 {
   /* We read the information from the /proc filesystem.  /proc/cpuinfo
      contains at least one line like:
-        timebase        : 33333333
+     timebase        : 33333333
      We search for this line and convert the number into an integer.  */
   static hp_timing_t timebase_freq;
   hp_timing_t result = 0L;
@@ -38,67 +39,78 @@ __get_clockfreq (void)
   if (timebase_freq != 0)
     return timebase_freq;
 
-  int fd = open ("/proc/cpuinfo", O_RDONLY);
-  if (__builtin_expect (fd != -1, 1))
+  /* If we can use the vDSO to obtain the timebase even better.  */
+#ifdef SHARED
+  INTERNAL_SYSCALL_DECL (err);
+  timebase_freq = INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK (get_tbfreq, err, 0);
+  if (INTERNAL_SYSCALL_ERROR_P (timebase_freq, err)
+      && INTERNAL_SYSCALL_ERRNO (timebase_freq, err) == ENOSYS)
+#endif
     {
-      /* The timebase will be in the 1st 1024 bytes for systems with up
-         to 8 processors.  If the first read returns less then 1024
-	 bytes read,  we have the whole cpuinfo and can start the scan.
-	 Otherwise we will have to read more to insure we have the
-	 timebase value in the scan.  */
-      char buf[1024];
-      ssize_t n;
+      int fd = open ("/proc/cpuinfo", O_RDONLY);
 
-      n = read (fd, buf, sizeof (buf));
-      if (n == sizeof (buf))
+      if (__builtin_expect (fd != -1, 1))
 	{
-	  /* We are here because the 1st read returned exactly sizeof
-	     (buf) bytes.  This implies that we are not at EOF and may
-	     not have read the timebase value yet.  So we need to read
-	     more bytes until we know we have EOF.  We copy the lower
-	     half of buf to the upper half and read sizeof (buf)/2
-	     bytes into the lower half of buf and repeat until we
-	     reach EOF.  We can assume that the timebase will be in
-	     the last 512 bytes of cpuinfo, so two 512 byte half_bufs
-	     will be sufficient to contain the timebase and will
-	     handle the case where the timebase spans the half_buf
-	     boundry.  */
-	  const ssize_t half_buf = sizeof (buf) / 2;
-	  while (n >= half_buf)
+	  /* The timebase will be in the 1st 1024 bytes for systems with up
+	     to 8 processors.  If the first read returns less then 1024
+	     bytes read,  we have the whole cpuinfo and can start the scan.
+	     Otherwise we will have to read more to insure we have the
+	     timebase value in the scan.  */
+	  char buf[1024];
+	  ssize_t n;
+
+	  n = read (fd, buf, sizeof (buf));
+	  if (n == sizeof (buf))
 	    {
-	      memcpy (buf, buf + half_buf, half_buf);
-	      n = read (fd, buf + half_buf, half_buf);
+	      /* We are here because the 1st read returned exactly sizeof
+	         (buf) bytes.  This implies that we are not at EOF and may
+	         not have read the timebase value yet.  So we need to read
+	         more bytes until we know we have EOF.  We copy the lower
+	         half of buf to the upper half and read sizeof (buf)/2
+	         bytes into the lower half of buf and repeat until we
+	         reach EOF.  We can assume that the timebase will be in
+	         the last 512 bytes of cpuinfo, so two 512 byte half_bufs
+	         will be sufficient to contain the timebase and will
+	         handle the case where the timebase spans the half_buf
+	         boundry.  */
+	      const ssize_t half_buf = sizeof (buf) / 2;
+	      while (n >= half_buf)
+		{
+		  memcpy (buf, buf + half_buf, half_buf);
+		  n = read (fd, buf + half_buf, half_buf);
+		}
+	      if (n >= 0)
+		n += half_buf;
 	    }
-	  if (n >= 0)
-	    n += half_buf;
-	}
-
-      if (__builtin_expect (n, 1) > 0)
-	{
-	  char *mhz = memmem (buf, n, "timebase", 7);
 
-	  if (__builtin_expect (mhz != NULL, 1))
+	  if (__builtin_expect (n, 1) > 0)
 	    {
-	      char *endp = buf + n;
-
-	      /* Search for the beginning of the string.  */
-	      while (mhz < endp && (*mhz < '0' || *mhz > '9') && *mhz != '\n')
-		++mhz;
+	      char *mhz = memmem (buf, n, "timebase", 7);
 
-	      while (mhz < endp && *mhz != '\n')
+	      if (__builtin_expect (mhz != NULL, 1))
 		{
-		  if (*mhz >= '0' && *mhz <= '9')
+		  char *endp = buf + n;
+
+		  /* Search for the beginning of the string.  */
+		  while (mhz < endp && (*mhz < '0' || *mhz > '9')
+			 && *mhz != '\n')
+		    ++mhz;
+
+		  while (mhz < endp && *mhz != '\n')
 		    {
-		      result *= 10;
-		      result += *mhz - '0';
-		    }
+		      if (*mhz >= '0' && *mhz <= '9')
+			{
+			  result *= 10;
+			  result += *mhz - '0';
+			}
 
-		  ++mhz;
+		      ++mhz;
+		    }
 		}
+	      timebase_freq = result;
 	    }
-	  timebase_freq = result;
+	  close (fd);
 	}
-      close (fd);
     }
 
   return timebase_freq;