From: Joseph Myers <joseph@codesourcery.com>
Date: Tue, 20 Aug 2013 16:43:59 +0000 (+0000)
Subject: Use __getpagesize and __ffs in MMAP2_PAGE_SHIFT == -1 case of mmap64.
X-Git-Tag: glibc-2.19~893
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=42c8fdd8f1d3245a0abf957fc9f0a6eb35145643;p=thirdparty%2Fglibc.git

Use __getpagesize and __ffs in MMAP2_PAGE_SHIFT == -1 case of mmap64.
---

diff --git a/ChangeLog b/ChangeLog
index 0880ef74ecf..d6eb8dcd452 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2013-08-20  Joseph Myers  <joseph@codesourcery.com>
+
+	* sysdeps/unix/sysv/linux/mmap64.c (__mmap64)
+	[MMAP2_PAGE_SHIFT == -1]: Use __getpagesize to determine page
+	size.  Use __ffs to determine corresponding shift.
+
 2013-08-20  Joseph Myers  <joseph@codesourcery.com>
 	    Roland McGrath  <roland@hack.frob.com>
 
diff --git a/sysdeps/unix/sysv/linux/mmap64.c b/sysdeps/unix/sysv/linux/mmap64.c
index e2dcdc4d9ab..4ba686c8fbf 100644
--- a/sysdeps/unix/sysv/linux/mmap64.c
+++ b/sysdeps/unix/sysv/linux/mmap64.c
@@ -42,9 +42,8 @@ __mmap64 (void *addr, size_t len, int prot, int flags, int fd, off64_t offset)
 #if MMAP2_PAGE_SHIFT == -1
   if (page_shift == 0)
     {
-      int page_size = getpagesize ();
-      while ((1 << ++page_shift) != page_size)
-	;
+      int page_size = __getpagesize ();
+      page_shift = __ffs (page_size) - 1;
     }
 #endif
   if (offset & ((1 << page_shift) - 1))