tree 074ff542cbe3325e7d985924209870b86fd9168b
parent 4d45e75a9955ade5c2f49bd96fc4173b2cec9a72
author Matthew Wilcox (Oracle) <willy@infradead.org> 1602817984 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1602871882 -0700

ramfs: fix nommu mmap with gaps in the page cache

ramfs needs to check that pages are both physically contiguous and
contiguous in the file.  If the page cache happens to have, eg, page A for
index 0 of the file, no page for index 1, and page A+1 for index 2, then
an mmap of the first two pages of the file will succeed when it should
fail.

Fixes: 642fb4d1f1dd ("[PATCH] NOMMU: Provide shared-writable mmap support on ramfs")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Howells <dhowells@redhat.com>
Link: https://lkml.kernel.org/r/20200914122239.GO6583@casper.infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>