svn commit: r223893 - head/sys/sys

[Marius Strobl]

Author: marius
Date: Sat Jul  9 18:47:51 2011
New Revision: 223893
URL: http://svn.freebsd.org/changeset/base/223893

Log:
  Fix the definition for PCPU_NAME_LEN, which is intended to fit
  ("CPU %d", cpuid) where cpuid <= MAXCPU.
  
  1. sizeof(__XSTRING(MAXCPU) + 1) is a typo: typeof(__XSTRING(...) + 1)
     is 'char *', so sizeof() will return the size of the pointer, not
     the size of the string contents. The proper expression should be
     'sizeof(__XSTRING(MAXCPU)) + 1'.
  
  2. One should not add one, but substract it: sizeof() accounts for the
     trailing '\0' and we have two sizeof's, so the size of one '\0'
     should be substracted -- this will give the maximal string buffer
     length for CPU with its number, no less, no more.
  
  Submitted by:	rea

Modified:
  head/sys/sys/pcpu.h

Modified: head/sys/sys/pcpu.h
==============================================================================
--- head/sys/sys/pcpu.h	Sat Jul  9 18:09:57 2011	(r223892)
+++ head/sys/sys/pcpu.h	Sat Jul  9 18:47:51 2011	(r223893)
@@ -146,7 +146,7 @@ struct rm_queue {
 	struct rm_queue* volatile rmq_prev;
 };
 
-#define	PCPU_NAME_LEN (sizeof("CPU ") + sizeof(__XSTRING(MAXCPU) + 1))
+#define	PCPU_NAME_LEN (sizeof("CPU ") + sizeof(__XSTRING(MAXCPU)) - 1)
 
 /*
  * This structure maps out the global data that needs to be kept on a