x86: ptrace: Add function argument access API
Add regs_get_argument() which returns N th argument of the
function call.
Note that this chooses most probably assignment, in some case
it can be incorrect (e.g. passing data structure or floating
point etc.)
This is expected to be called from kprobes or ftrace with regs
where the top of stack is the return address.
Link: http://lkml.kernel.org/r/152465885737.26224.2822487520472783854.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
diff --git a/arch/Kconfig b/arch/Kconfig
index 6801123..facace0 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -290,6 +290,13 @@
This symbol should be selected by an architecture if it
supports an implementation of restartable sequences.
+config HAVE_FUNCTION_ARG_ACCESS_API
+ bool
+ help
+ This symbol should be selected by an architecure if it supports
+ the API needed to access function arguments from pt_regs,
+ declared in asm/ptrace.h
+
config HAVE_CLK
bool
help