1. 27 Aug, 2009 3 commits
    • Josh Boyer's avatar
      powerpc: Fix __flush_icache_range on 44x · 14d75752
      Josh Boyer authored
      The ptrace POKETEXT interface allows a process to modify the text pages of
      a child process being ptraced, usually to insert breakpoints via trap
      instructions.  The kernel eventually calls copy_to_user_page, which in turn
      calls __flush_icache_range to invalidate the icache lines for the child
      process.
      
      However, this function does not work on 44x due to the icache being virtually
      indexed.  This was noticed by a breakpoint being triggered after it had been
      cleared by ltrace on a 440EPx board.  The convenient solution is to do a
      flash invalidate of the icache in the __flush_icache_range function.
      Signed-off-by: default avatarJosh Boyer <jwboyer@linux.vnet.ibm.com>
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      14d75752
    • Benjamin Herrenschmidt's avatar
      powerpc/mm: Cleanup handling of execute permission · ea3cc330
      Benjamin Herrenschmidt authored
      This is an attempt at cleaning up a bit the way we handle execute
      permission on powerpc. _PAGE_HWEXEC is gone, _PAGE_EXEC is now only
      defined by CPUs that can do something with it, and the myriad of
      #ifdef's in the I$/D$ coherency code is reduced to 2 cases that
      hopefully should cover everything.
      
      The logic on BookE is a little bit different than what it was though
      not by much. Since now, _PAGE_EXEC will be set by the generic code
      for executable pages, we need to filter out if they are unclean and
      recover it. However, I don't expect the code to be more bloated than
      it already was in that area due to that change.
      
      I could boast that this brings proper enforcing of per-page execute
      permissions to all BookE and 40x but in fact, we've had that now for
      some time as a side effect of my previous rework in that area (and
      I didn't even know it :-) We would only enable execute permission if
      the page was cache clean and we would only cache clean it if we took
      and exec fault. Since we now enforce that the later only work if
      VM_EXEC is part of the VMA flags, we de-fact already enforce per-page
      execute permissions... Unless I missed something
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      ea3cc330
    • Benjamin Herrenschmidt's avatar
      f480fe39
  2. 26 Aug, 2009 4 commits
  3. 25 Aug, 2009 13 commits
  4. 24 Aug, 2009 20 commits