Dear Memory Management Maintainer,

I am Po-Hao Su, a graduate student from the Operating Systems and Embedded Systems Lab at National Cheng Kung University in Taiwan.

I am writing in reference to report a bug in do_mmap(...) function.
Recently, I found that there seems a bug after get_unmapped_area(...) function is return.
do_mmap(...) function will check the addr parameter is aligned on a page boundary or not after get_unmapped_area(...) function is return.
But it will return addr parameter, not an error(probably to -EINVAL) while address not aligned on a page boundary.
Therefore, I think address not aligned on a page boundary should be an error(-EINVAL).

I also discussed this issue with others when the meeting of my lab, others views are consistent with me.
In view of this, I report the issue. Attached is the patch for this.

If this is a wrong report, I am sorry, and please show me why kernel do it, if convenient. Thank you.
I look forward to hearing from you.