Messages in this thread | | | Date | Thu, 9 Aug 2007 14:31:35 +0800 | From | "jidong xiao" <> | Subject | Re: Question on IS_ERR |
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On 8/9/07, H. Peter Anvin <hpa@zytor.com> wrote: > > No. There is no requirement that the pointer is page-aligned. The last > page of the address space is (in the Linux kernel) invalid by > definition, so there are in effect three kinds of pointers in the Linux > kernel: valid pointers, NULL, and ERR_PTR()s. > > -hpa >
Regarding "The last page of the address space is invalid by definition", I am wondering why do we define the last page as invalid. The reason for defining this is just because we want to take use of the error number handling?
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