linux-imx

tracing/uprobes: Add support for full argument access methods

Enable to fetch other types of argument for the uprobes.  IOW, we can
access stack, memory, deref, bitfield and retval from uprobes now.

The format for the argument types are same as kprobes (but @SYMBOL
type is not supported for uprobes), i.e:

  @ADDR   : Fetch memory at ADDR
  $stackN : Fetch Nth entry of stack (N >= 0)
  $stack  : Fetch stack address
  $retval : Fetch return value
  +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address

Note that the retval only can be used with uretprobes.

Original-patch-by: Hyeoncheol Lee <cheol.lee@lge.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Hyeoncheol Lee <cheol.lee@lge.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>