arm64: Add trampoline code for kretprobes

The trampoline code is used by kretprobes to capture a return from a probed
function.  This is done by saving the registers, calling the handler, and
restoring the registers. The code then returns to the original saved caller
return address. It is necessary to do this directly instead of using a
software breakpoint because the code used in processing that breakpoint
could itself be kprobe'd and cause a problematic reentry into the debug
exception handler.

Signed-off-by: William Cohen <[email protected]>
Signed-off-by: David A. Long <[email protected]>
Acked-by: Masami Hiramatsu <[email protected]>
[[email protected]: removed unnecessary masking of the PSTATE bits]
Signed-off-by: Catalin Marinas <[email protected]>

0 files changed, 0 insertions, 0 deletions