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

quoted

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 :-)

You have to consider those possible values before you see it cannot
overflow.  So no, it's a lot _less_ readable IMHO.

It's also a dangerous habit to get into.  Just say no :-)


Segher