lib: Fix generic strnlen_user for 32-bit big-endian machines

The aligned_byte_mask() definition is wrong for 32-bit big-endian machines: the "7-(n)" part of the definition assumes a long is 8 bytes. This fixes it by using BITS_PER_LONG - 8 instead of 8*7. Tested on 32-bit and 64-bit PowerPC. Signed-off-by: Paul Mackerras <[email protected]> Acked-by: David S. Miller <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
niw · May 28, 2012 · 69ea640 · 69ea640
1 parent 1e2aec8
commit 69ea640
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c
@@ -8,7 +8,7 @@
 #ifdef __LITTLE_ENDIAN
 #  define aligned_byte_mask(n) ((1ul << 8*(n))-1)
 #else
-#  define aligned_byte_mask(n) (~0xfful << 8*(7-(n)))
+#  define aligned_byte_mask(n) (~0xfful << (BITS_PER_LONG - 8 - 8*(n)))
 #endif
 
 /*