container_of: add container_of_const() that preserves const-ness of the pointer

container_of does not preserve the const-ness of a pointer that is
passed into it, which can cause C code that passes in a const pointer to
get a pointer back that is not const and then scribble all over the data
in it.  To prevent this, container_of_const() will preserve the const
status of the pointer passed into it using the newly available _Generic()
method.

Suggested-by: Jason Gunthorpe <[email protected]>
Suggested-by: Sakari Ailus <[email protected]>
Reviewed-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Sakari Ailus <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

0 files changed, 0 insertions, 0 deletions