devlib2 bugfix (rare string corruption)

[Till Straumann <Till.Straumann@alumni.tu-berlin.de>]

vallocPrintf()

first calls vsnprintf() with a length argument of zero to determine
the necessary buffer size, allocates a buffer and then calls

size2 = vsprintf(buf,format,args)

It then goes on and complains if size2 is different from what the
initial vsnprintf() returned.

If, however, this really happens (and I have observed this under 64-bit 
ubuntu-12.10)
then it is well possible that vsprintf() writes beyond the length of the 
buffer.
Hence, I suggest to replace vsprintf() by

size2 = vsnprintf(buf, size+1, format, args)

just to make sure. (Note that the 'size' argument to snprintf() includes 
space for
the terminating NUL whereas the return value does not.)

- Till

A patch is attached for sake of convenience.

diff -r ed471db5e741 pciApp/os/Linux/devLibPCIOSD.c
--- a/pciApp/os/Linux/devLibPCIOSD.c	Wed Dec 19 11:52:40 2012 -0600
+++ b/pciApp/os/Linux/devLibPCIOSD.c	Wed Dec 19 11:53:34 2012 -0600
@@ -187,7 +187,7 @@
         errlogPrintf("vaprintf: Failed to allocate memory for format '%s'\n",format);
         goto fail;
     }
-    size2=vsprintf(ret,format,args);
+    size2=vsnprintf(ret,size+1,format,args);
     if (size!=size2) {
         errlogPrintf("vaprintf: Format yielded different size %d %d : %s\n",size,size2,format);
         goto fail;