Re: [PATCH 1/1] Punch a hole in /dev/mem for librtas

On Sat, 2011-12-03 at 04:22 +0100, Segher Boessenkool wrote:

quoted

+static inline int page_is_rtas_user_buf(unsigned long pfn)
+{
+	unsigned long paddr = (pfn << PAGE_SHIFT);
+	if (paddr >= rtas_rmo_buf && paddr < (rtas_rmo_buf +  
RTAS_RMOBUF_MAX))

It probably cannot overflow with actual values of rtas_rmo_buf
and RTAS_RMOBUF_MAX, but otherwise it is an incorrect test;
please write

	if (paddr >= rtas_rmo_buf && paddr - rtas_rmo_buf < RTAS_RMOBUF_MAX)

(and, _MAX?  Shouldn't it be the actual size here?  Or is _MAX
just a confusing name :-) )

The original code is a lot more readable and perfectly correct for all
possible values of rtas_rmo_buf :-)

Cheers,
Ben.