Commit f0c00257 authored Feb 03, 2006 by Peter Williams Committed by Linus Torvalds Feb 03, 2006

[PATCH] lib: Fix bug in int_sqrt() for 64 bit longs



The implementation of int_sqrt() assumes that longs have 32 bits.  On
systems that have 64 bit longs this will result in gross errors when the
argument to the function is greater than 2^32 - 1 on such systems.  I doubt
whether any such use is currently made of int_sqrt() but the attached patch
fixes the problem anyway.

Signed-off-by: Peter Williams <pwil3058@bigpond.com.au>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent 6bf8d889

lib/int_sqrt.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -15,7 +15,7 @@ unsigned long int_sqrt(unsigned long x)
		op = x;
		res = 0;

		one = 1 << 30;
		one = 1UL << (BITS_PER_LONG - 2);
		while (one > op)
		one >>= 2;

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