30 Oct, 2011

1 commit


23 May, 2011

1 commit


19 May, 2011

1 commit

  • While debugging I stumbled over two problems in the code that protects module
    pages.

    First issue is that disabling the protection before freeing init or unload of
    a module is not symmetric with the enablement. For instance, if pages are set
    to RO the page range from module_core to module_core + core_ro_size is
    protected. If a module is unloaded the page range from module_core to
    module_core + core_size is set back to RW.
    So pages that were not set to RO are also changed to RW.
    This is not critical but IMHO it should be symmetric.

    Second issue is that while set_memory_rw & set_memory_ro are used for
    RO/RW changes only set_memory_nx is involved for NX/X. One would await that
    the inverse function is called when the NX protection should be removed,
    which is not the case here, unless I'm missing something.

    Signed-off-by: Jan Glauber
    Signed-off-by: Rusty Russell

    Jan Glauber
     

20 Apr, 2011

1 commit


16 Mar, 2011

1 commit

  • Implement write protection for kernel modules text and read-only
    data sections by implementing set_memory_[ro|rw] on s390.
    Since s390 has no execute bit in the pte's NX is not supported.

    set_memory_[ro|rw] will only work on normal pages and not on
    large pages, so in case a large page should be modified bail
    out with a warning.

    Signed-off-by: Jan Glauber
    Signed-off-by: Martin Schwidefsky

    Jan Glauber