1. 30 Sep, 2010 2 commits
  2. 13 Aug, 2010 1 commit
    • Linus Torvalds's avatar
      mm: keep a guard page below a grow-down stack segment · 320b2b8d
      Linus Torvalds authored
      This is a rather minimally invasive patch to solve the problem of the
      user stack growing into a memory mapped area below it.  Whenever we fill
      the first page of the stack segment, expand the segment down by one
      page.
      
      Now, admittedly some odd application might _want_ the stack to grow down
      into the preceding memory mapping, and so we may at some point need to
      make this a process tunable (some people might also want to have more
      than a single page of guarding), but let's try the minimal approach
      first.
      
      Tested with trivial application that maps a single page just below the
      stack, and then starts recursing.  Without this, we will get a SIGSEGV
      _after_ the stack has smashed the mapping.  With this patch, we'll get a
      nice SIGBUS just as the stack touches the page just above the mapping.
      Requested-by: default avatarKeith Packard <keithp@keithp.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      320b2b8d
  3. 12 Aug, 2010 37 commits