• Reinette Chatre's avatar
    [PATCH] bitmap: parse input from kernel and user buffers · 01a3ee2b
    Reinette Chatre authored
    
    
    lib/bitmap.c:bitmap_parse() is a library function that received as input a
    user buffer.  This seemed to have originated from the way the write_proc
    function of the /proc filesystem operates.
    
    This has been reworked to not use kmalloc and eliminates a lot of
    get_user() overhead by performing one access_ok before using __get_user().
    
    We need to test if we are in kernel or user space (is_user) and access the
    buffer differently.  We cannot use __get_user() to access kernel addresses
    in all cases, for example in architectures with separate address space for
    kernel and user.
    
    This function will be useful for other uses as well; for example, taking
    input for /sysfs instead of /proc, so it was changed to accept kernel
    buffers.  We have this use for the Linux UWB project, as part as the
    upcoming bandwidth allocator code.
    
    Only a few routines used this function and they were changed too.
    Signed-off-by: default avatarReinette Chatre <reinette.chatre@linux.intel.com>
    Signed-off-by: default avatarInaky Perez-Gonzalez <inaky@linux.intel.com>
    Cc: Paul Jackson <pj@sgi.com>
    Cc: Joe Korty <joe.korty@ccur.com>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    01a3ee2b